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Urban rats are significant reservoirs of zoonotic endoparasites, posing serious health risks to humans. This study aimed to detect common endoparasites in wild brown rats (Rattus norvegicus) in Budapest, addressing the current lack of endoparasite surveys in Hungary. Carcasses of 131 rats collected following extermination were examined. Three zoonotic helminths were identified: Hymenolepis nana and Hymenolepis diminuta in the jejunum, and Calodium hepaticum in the liver. Additionally, non-zoonotic parasites were detected, including Eimeria spp., Entamoeba muris, Heterakis spumosa, Nippostrongylus brasiliensis, Eucoleus gastricus, Aonchotheca annulosa, Syphacia muris (intestine), and Trichosomoides crassicauda (urinary bladder). Helminth infection prevalence was 83.9 %, with no noticeable differences in prevalence or infection intensity between sexes. These findings highlight the potential public health risk posed by zoonotic parasites in urban rat populations, emphasising the importance of surveillance to mitigate possible human infection. This study demonstrates a practical and economical approach to monitoring urban rat populations. Further large-scale studies are recommended to better understand the parasitic landscape in Hungary's rat populations, leveraging data from rat control programs., Competing Interests: Declaration of competing interest The authors declare there are no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Humans and animals who have an acute case of diarrhea can be infected with Cryptosporidium spp. Within the category of water-borne disease, it is a zoonotic disease. The zoonotic disease Cryptosporidium is among the several pathogens carried by wild rats ( Rattus spp.). The risk of spreading this disease is rather significant in urban environments because rats are often close to people., Aim: This study aims to detect Cryptosporidium spp. infection in wild rats in Surabaya, East Java, Indonesia., Methods: Through necropsy, a total of 100 wild rats' intestines were sampled for feces. Microscopic observation of the presence of Cryptosporidium was carried out using the float test with a combination of Ziehl Neelsen (ZN) staining. Molecular detection of Cryptosporidium spp. positive results used the Cryptosporidium oocyst wall protein (COWP) gene with polimerase chain reaction method., Results: The results showed that 69 samples were positive for containing Cryptosporidium spp. oocysts and with ZN staining to confirm the diagnosis, the staining results showed Cryptosporidium spp. oocysts dark pink with a clear cavity inside with a percentage of 95.65% in Rattus norvegicus and 61.03% in Rattus tanezumi . In residential and densely populated environments the percentage of Cryptosporidium spp. amounted to 66.66% and in the market environment amounted to 74.19%. The percentage of Cryptosporidium spp. in the North Surabaya region was 42.85%, South Surabaya 100%, West Surabaya 37.5%, East Surabaya 81.39%, and Central Surabaya 65.38%. Molecular detection of Cryptosporidium spp. positive results were obtained using the COWP gene 550 bp., Conclusion: This study aims to detect Cryptosporidium spp. infection in wild rats in Surabaya, East Java, Indonesia. The high number of cases of cryptosporidiosis in wild rats has the potential to be a reservoir for the spread of the disease. The Cryptosporidium spp can detected with COWP in 550 bp in wild rats in Surabaya, East Java, Indonesia., Competing Interests: There is no conflict of interest, according to the authors.

Background: The common cat tapeworm, Hydatigera taeniaeformis, is widely distributed across many regions of the world but its global genetic diversity, ecology, and other biological features are not fully understood. The predator-prey relationship of felids and rodents sustains the transmission in both sylvatic and synanthropic or urban settings. This study was carried out in three urban market centres in Tamale, Ghana to determine the prevalence of H. taeniaeformis infection in urban rats and characterise the local population genetics using the mitochondrial nad1 gene sequences., Methods: From January to May 2023, rats were captured and euthanized to identity and isolate the H. taeniaeformis metacestodes. The full mitochondrial nad1 gene was amplified, sequenced and used to characterise the cestode population., Results: In total 64/80 rats from the three market centres were found naturally infected with metacestodes of H. taeniaeformis. Averagely, infected rats harboured two cysts with one exceptional case of 25 cysts in one liver. Each cyst harboured one metacestode. The DNA sequences revealed four haplotypes in a star-like distribution network across the three market centres. All four haplotypes were found to be unique, clustered with H. taeniaeformis sensu stricto (s.s.) global isolates and had only marginal variation among themselves., Conclusion: This is the first account of the genetic variability within H. taeniaeformis in Ghana and would contribute to ongoing and future studies on African regional biogeographic distribution of the common cat tapeworm., (© 2024. The Author(s).)

Background: Extensive attention has been devoted to studies of Trypanosoma lewisi in rodents ever since it became recognised as a zoonotic pathogen known as atypical human trypanosomiasis. Regrettably, although T. lewisi infections of small mammals remain significant public health concerns for humans, there is a lack of comprehensive study in Indonesia., Aim: The aim of the study was to detect T. lewisi from rodents residing in the densely populated residential regions along the coastal areas of Banyuwangi Sub District., Methods: A total of 169 rodents were captured across three villages of Kampung Mandar, Lateng and Kepatihan, using rat single live traps. After being euthanized and identified, the blood samples were collected from each rodent via cardiac puncture. Subsequently, the samples were subjected to native (direct blood microscopic examination), microscopic blood smear examination, and molecular analyses utilizing TRYP1S-TRYP1R (623 bp) and LEW1S-LEW1R (220 bp)., Results: The results demonstrated that two species of rodents were successfully captured: Rattus norvegicus (65.68%) and Rattus tanezumi (34.32%). Based on the native and microscopic blood smear examinations, the prevalence of T. lewisi across three villages was 23.08% and 24.26% for molecular analysis employing both primers, respectively. The highest prevalence was found in Kampung Mandar Village (31.18%), followed by Kepatihan (16.67%) and Lateng Villages (15.71%)., Conclusion: Statistical analysis revealed that T. lewisi was more prevalent in R. tanezumi compared to R. norvegicus . In terms of sex, no statistically significant distinction was observed between female and male infected rodents of either species ( p > 0.05), indicating both species can serve as a source of T. lewisi for humans in the surveyed villages., Competing Interests: The authors declare that there is no conflict of interest.

Cryptosporidium infection is a common occurrence in rodents worldwide. In this study, 435 wild brown rats were captured from an animal feedlot in Xinjiang, China, with a fecal sample obtained directly from the rectal contents of each rat. The DNA extracted from these fecal samples was analyzed for Cryptosporidium spp. using PCR targeting the SSU rRNA gene. The prevalence of Cryptosporidium infection in brown rats was found to be 5.5% (24 out of 435). Interestingly, the infection rates varied among different animal enclosures, with rates of 0% in the chicken coop (0/51), cowshed (0/3), and varying rates in other areas including the sheepfold (6.1%, 6/98), the pigsty (7.6%, 10/132), the dovecote (7.0%, 5/71), and outdoor environments (3.8%, 3/80). The study identified three species and one genotype of Cryptosporidium, namely C. occultus (n = 10), C. parvum (n = 4), C. ditrichi (n = 1), and Cryptosporidium rat genotype IV (n = 9). Additionally, two of the C. parvum isolates were successfully subtyped as IIdA19G1 (n = 2) at the gp60 gene. These results offer valuable insights into the prevalence and genetic diversity of Cryptosporidium in brown rats within the region., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

A fecal survey in Tamil Nadu, India, revealed 2 persons passed schistosome eggs, later identified as Schistosoma incognitum, a parasite of pigs, dogs, and rats. We investigated those cases and reviewed autochthonous schistosomiasis cases from India and Nepal. Whether the 2 new cases represent true infection or spurious passage is undetermined.

Purpose: Rodents are one of the most abundant and diverse species of mammals and have recently been identified as carriers of numerous human pathogens. The current study was conducted to assess the prevalence, subtype (STs) distribution, and zoonotic potential of Blastocystis spp. in various species of rodents in Shiraz, southwestern Iran., Methods: For this aim, a total of 120 fresh fecal samples were collected from Mus musculus (n = 40), Rattus norvegicus (n = 40), and Rattus rattus (n = 40) in various municipality districts of Shiraz (6 out of 10 districts) between February and November 2020. Upon detecting parasites using light microscopy, a DNA fragment of the Blastocystis SSU rDNA gene was amplified using conventional PCR., Results: By employing direct wet mount examination, 8 out of 120 fecal samples (6.7%; 2 from house mice, 3 from black rats, and 3 from brown rats) tested positive. Similarly, 5% (2/40) of house mice, 7.5% (3/40) of black rats, and 7.5% (3/40) of brown rats tested positive using the molecular method. Phylogenetic analysis revealed that the Blastocystis infecting different rodent species in Shiraz belonged to two potentially zoonotic STs (ST1 and ST4). Accordingly, rodents should not be overlooked as potential reservoirs of zoonotic Blastocystis infections. Different sampled urban districts and their statistical association with reported prevalence rates were analyzed separately., Conclusion:  Overall, the issue of the frequency and ST distribution of Blastocystis in urban rodents of Iran is still open to question and for a proper understanding, wider and more comprehensive studies are needed., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Wild rodents serve as reservoirs for Cryptosporidium and are overpopulated globally. However, genetic data regarding Cryptosporidium in these animals from China are limited. Here, we have determined the prevalence and genetic characteristics of Cryptosporidium among 370 wild rodents captured from three distinct locations in the southern region of Zhejiang Province, China. Fresh feces were collected from the rectum of each rodent, and DNA was extracted from them. The rodent species was identified by PCR amplifying the vertebrate cytochrome b gene. Cryptosporidium was detected by PCR amplification and amplicon sequencing the small subunit of ribosomal RNA gene. Positive samples of C. viatorum and C. parvum were further subtyped by analyzing the 60-kDa glycoprotein gene. A positive Cryptosporidium result was found in 7% (26/370) of samples, involving five rodent species: Apodemus agrarius (36), Niviventer niviventer (75), Rattus losea (18), R. norvegicus (155), and R. tanezumi (86). Their respective Cryptosporidium positive rates were 8.3%, 5.3%, 11.1%, 7.1%, and 7.0%. Sequence analysis confirmed the presence of three Cryptosporidium species: C. parvum (4), C. viatorum (1), and C. muris (1), and two genotypes: Cryptosporidium rat genotype IV (16) and C. mortiferum-like (4). Additionally, two subtypes of C. parvum (IIdA15G1 and IIpA19) and one subtype of C. viatorum (XVdA3) were detected. These results demonstrate that various wild rodent species in Zhejiang were concurrently infected with rodent-adapted and zoonotic species/genotypes of Cryptosporidium, indicating that these rodents can play a role in maintaining and dispersing this parasite into the environment and other hosts, including humans., (© Y. Jiang et al., published by EDP Sciences, 2024.)

Trypanosoma lewisi is a worldwide nonpathogenic parasite that is exclusively found in rats. In general, T. lewisi infection in humans is an opportunistic infection from rats to humans through fleas. However, recently, infection with T. lewisi in humans, including a fatal case, has been reported. Notably, rats living close to a human settlement showed a higher prevalence of infection with T. lewisi than those living in other places. It is possible that the urbanization is associated with the prevalence of T. lewisi in rats and enhances the risk of T. lewisi transmission to humans through fleas. In this study, a total of 88 rats were captured from hospitals, markets, and a cargo station, of which 81 were identified as Rattus norvegicus and 7 as Rattus rattus in Hanoi, the urbanizing city of Vietnam. Of these, 55 rats (62.5%) harbored T. lewisi , of which 52 were R. norvegicus and 3 were R. rattus .

Wild rodents are considered as potential carriers of several zoonotic vector-borne bacteria but their epidemiology is poorly understood in Tunisia. A total of 305 biological samples (100 spleens, 100 livers, 100 kidneys, and 5 pooled ectoparasites (Xenopsylla cheopis, Laelaps echidninus, Ornithonyssus sp., Hoplopleura sp. and eggs of the rat fleas)) were collected from 100 wild rodents from three Tunisian governorates. Molecular screening was performed to reveal infections with main vector-borne bacteria. Captured rodents belonged to three rodent genera and species including Rattus rattus (n = 51, 51%), Meriones shawi (n = 24, 24%) and Mus musculus (n = 25, 25%). Examined rodents were found to be heavily infested by the rat flea X. cheopis (n = 32, 47%) and the rat mite L. echidninus (n = 22, 32.3%). However, the rat mite Ornithonyssus sp. (n = 13, 19.1%) and the rat lice Hoplopleura sp. (n = 1, 1.5%) were rarely identified. Based on 16S rRNA and msp4 genes, infection with Anaplasmataceae bacteria was detected in six specimens of R. rattus and one M. shawi. Pathogenic A. phagocytophilum (n = 1), A. phagocytophilum-like 1 (Anaplasma sp. Japan) (n = 1), and A. ovis (n = 5) were identified. On the basis of ompB, ompA and gltA genes, infection with Rickettsia spp. was identified in three specimens of R. rattus and one of M. shawi. Five Rickettsia species of the spotted fever group, corresponding to R. monacensis, R. helvetica, R. massiliae, R. africae, and R. aeschlimannii, were detected in mixed infections. Bartonella henselae DNA was also found in two R. rattus, based on rpoB partial sequences. All revealed Anaplasma, Rickettsia and Bartonella bacteria were detected in spleen samples. Ehrlichia, Coxiella and Borrelia spp. were not identified in any of the tested samples. In Tunisia, this is the first report indicating infections with Anaplasma, Rickettsia and Bartonella spp. in wild rodents, particularly present alongside domestic livestock and human. This represents a serious risk of potential bacterial transmission. Thus, controlling rodent population in animal herds, residential areas and sensitizing local people to this risk seem absolutely necessary., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The nematode Angiostrongylus cantonensis is the most common cause of neuroangiostrongyliasis (manifested as eosinophilic meningitis) in humans. Gastropod molluscs are used as intermediate hosts and rats of various species are definitive hosts of this parasite. In this study, we identified several environmental factors associated with the presence and abundance of terrestrial gastropods in an impoverished urban region in Brazil. We also found that body condition, age and presence of co-infection with other parasite species in urban Rattus norvegicus, as well as environmental factors were associated with the probability and intensity of A. cantonensis infection. The study area was also found to have a moderate prevalence of the nematode in rodents (33% of 168 individuals). Eight species of molluscs (577 individuals) were identified, four of which were positive for A. cantonensis. Our study indicates that the environmental conditions of poor urban areas (presence of running and standing water, sewage, humidity and accumulated rain and accumulation of construction materials) influenced both the distribution and abundance of terrestrial gastropods, as well as infected rats, contributing to the maintenance of the A. cantonensis transmission cycle in the area. Besides neuroangiostrongyliasis, the presence of these hosts may also contribute to susceptibility to other zoonoses.

Chigger mites is a group of arthropods and some of them are vectors of scrub typhus. As a common synanthropic rodent species, the Brown rat (Rattus norvegicus) often harbors lots of ectoparasites including chigger mites. According to some "data mining" strategies, the present study took the advantage of the abundant original data from a long-term field ecological investigation between 2001 and 2015 to make a detailed analysis of chigger mites on R. norvegicus in Yunnan Province, Southwest of China. From 18 of 33 investigated counties, only 1414 chigger mites were collected from 1113 Brown rats with relatively low infestations. The 1414 individual chigger mites were identified as comprising 61 species, 11 genera and 2 subfamilies of the family Trombiculidae with a high species diversity (S=61, H'=3.13). Of 61 mite species, there were four main species, Walchia ewingi, Ascoschoengastia indica, W. koi and A. rattinorvegici, which accounted for 44.41% of the total mites. All the chigger mites were of aggregated distribution among different individuals of R. norvegicus. The Brown rats in the outdoor habitats harbored much more individuals and species of chigger mites with a higher mean abundance (MA=1.46) and mean intensity (MI=12.53) than in the indoor habitats (P<0.05). The overall infestation of the rats was significantly higher in the mountainous landscapes than in the flatland landscapes (P<0.001). The species similarity (C ss ) of the mites on the male and female rats reached 64.44% with sex biased infestations. The male rats harbored more species and individuals of the mites than the female rats. The adult rats harbored more species and individuals of the mites than the juvenile rats. The species abundance distribution of the mites was successfully fitted by Preston's lognormal model with ŝ(R)=15e -[0.31(R-1)]2 (α=0.31, R 2 =0.95). On the basis of fitting the theoretical curve by Preston's model, the total mite species on R. norvegicus was estimated to be 86 species, and 25 rare mite species were missed in the sampling field investigation. The curve tendency of the species-plot relationship indicates that R. norvegicus have a great potential to harbor many species of chigger mites, and more species of the mites would be collected if more rats are sampled.

Murine typhus is a flea-borne zoonotic disease that has been recently reported on Reunion Island, an oceanic volcanic island located in the Indian Ocean. Five years of survey implemented by the regional public health services have highlighted a strong temporal and spatial structure of the disease in humans, with cases mainly reported during the humid season and restricted to the dry southern and western portions of the island. We explored the environmental component of this zoonosis in an attempt to decipher the drivers of disease transmission. To do so, we used data from a previously published study (599 small mammals and 175 Xenopsylla fleas from 29 sampling sites) in order to model the spatial distribution of rat fleas throughout the island. In addition, we carried out a longitudinal sampling of rats and their ectoparasites over a 12 months period in six study sites (564 rats and 496 Xenopsylla fleas) in order to model the temporal dynamics of flea infestation of rats. Generalized Linear Models and Support Vector Machine classifiers were developed to model the Xenopsylla Genus Flea Index (GFI) from climatic and environmental variables. Results showed that the spatial distribution and the temporal dynamics of fleas, estimated through the GFI variations, are both strongly controlled by abiotic factors: rainfall, temperature and land cover. The models allowed linking flea abundance trends with murine typhus incidence rates. Flea infestation in rats peaked at the end of the dry season, corresponding to hot and dry conditions, before dropping sharply. This peak of maximal flea abundance preceded the annual peak of human murine typhus cases by a few weeks. Altogether, presented data raise novel questions regarding the ecology of rat fleas while developed models contribute to the design of control measures adapted to each micro region of the island with the aim of lowering the incidence of flea-borne diseases., Competing Interests: The authors have declared that no competing interests exist.

The diversity and biology of Cryptosporidium that is specific for rats (Rattus spp.) are not well studied. We examined the occurrence and genetic diversity of Cryptosporidium spp. in wild brown rats (Rattus norvegicus) by microscopy and polymerase chain reaction (PCR)/sequencing targeting the small subunit rDNA (SSU), actin and HSP70 genes. Out of 343 faecal samples tested, none were positive by microscopy and 55 were positive by PCR. Sequence analysis of SSU gene revealed the presence of Cryptosporidium muris (n = 4), C. andersoni (n = 3), C. ryanae (n = 1), C. occultus (n = 3), Cryptosporidium rat genotype I (n = 23), Cryptosporidium rat genotype IV (n = 16) and novel Cryptosporidium rat genotype V (n = 5). Spherical oocysts of Cryptosporidium rat genotype I obtained from naturally-infected rats, measuring 4.4-5.4 μm × 4.3-5.1 μm, were infectious to the laboratory rats, but not to the BALB/c mice (Mus musculus) nor Mongolian gerbils (Meriones unguiculatus). The prepatent period was 3 days post infection and the patent period was longer than 30 days. Naturally- and experimentally-infected rats showed no clinical signs of disease. Percentage of nucleotide similarities at the SSU, actin, HSP70 loci between C. ratti n. sp. and the rat derived C. occultus and Cryptosporidium rat genotype II, III, IV, and V ranged from 91.0 to 98.1%. These genetic variations were similar or greater than that observed between closely related species, i.e. C. parvum and C. erinacei (93.2-99.5%). Our morphological, genetic and biological data support the establishment of Cryptosporidium rat genotype I as a new species, Cryptosporidium ratti n. sp.

Because isolated ecosystems contribute to species variability, especially oceanic island ecosystems, the present work focused on the study of the Bartonella species and haplotypes in Lanzarote and El Hierro, two Canary islands with evident bioclimatic differences between them. A total of 123 rodents and 110 fleas from two islands were screened for the presence of Bartonella by PCR analysis of the gltA and nuoG genes. The overall prevalence was 5.7% in rodents and 20.4% in fleas. A total of seven gltA-haplotypes was found in both rodents and fleas, belonging to the species Bartonella mastomydis and Bartonella tribocorum in Lanzarote, and to Bartonella rochalimae and Bartonella elizabethae in El Hierro, as well as recently described species Bartonella kosoyi in both islands. Besides, potential co-infections were detected based on the nuoG analysis. Further, Xenopsylla cheopis was the only flea species identified. Our study shows that isolated ecosystems such as the Canary Islands lead to the appearance of new Bartonella haplotypes along different biotopes, with diverse flea species involved in the spreading of the pathogen being of great relevance due to the zoonotic potential of the species found., (© 2020 The Society for Vector Ecology.)

A rodent survey was conducted in different landscape units of the city of Buenos Aires (Argentina) to determine the prevalence of Cryptosporidium and Giardia in Rattus norvegicus and to, ultimately, assess the biotic, environmental and meteorological factors that explain the variations of the likelihood of infection for both parasites in an urban environment. The results of this study revealed a ubiquitous presence of Cryptosporidium and Giardia in R. norvegicus within an urban environment with the likelihood of infection depending on environmental and meteorological conditions for both parasites. The overall prevalence was greater for Cryptosporidium (p = 50.4%) than for Giardia (20.3%). The prevalence for both parasites separately was higher in parks compared to shantytowns and scrap metal yards. Generalized Linear Mixed Models revealed that the occurrence of these parasites separately, at an individual level, was positively related with rainfall variables and that the effect of temperature depended on the landscape unit. The similarities in the transmission modes, which are affected by common extrinsic factors, may facilitate the co-occurrence of Cryptosporidium and Giardia in urban rats. Rattus norvegicus is recognized as a good model for epidemiological studies and the results of this work suggest that, from an epidemiological point of view, the probability of contact with infectious oocysts and cysts of these parasites can be modulated through environmental management and healthy behaviour towards risk factors. The information presented here will be useful to improve the understanding of the dynamics of zoonotic diseases within urban environments and to contribute to the decision-making of new and effective prophylactic measures., (© 2020 Wiley-VCH GmbH.)

The aim of this study was to develop a simple method to purify Strongyloides eggs from rat faeces using a sucrose gradient centrifugal-flotation technique. This procedure is simple, rapid and possesses a high efficiency in recovering Strongyloides eggs without faecal detritus in less than one hour, thus eliminating the use of complex apparatus and different chemical substances. The possibility of working with pure and live Strongyloides eggs opens up a wide range of future studies on the biology of this parasite. This study constitutes the first report in the scientific literature on purifying Strongyloides eggs using a sucrose density gradient.

In the present study, sarcocysts of Sarcocystis cymruensis were found in four of 42 (9.5%) Norway rats and those of S. ratti were observed in six of 60 (10%) black rats in China. With light microscopy, the sarcocysts of the two parasites were microscopic, and had smooth, thin cyst walls (≤ 1 μm). Ultrastructurally, the sarcocysts of S. cymruensis had small, osmiophilic, bleb-like protrusions, similar to type 1c; those of S. ratti had a cyst wall with regular, short, conical protrusions, similar to type 1 g. Three loci, i.e., 18S rDNA, the mitochondrial cox1 gene (Cox1), and the mitochondrial Cytb gene (Cytb), of the two parasites were sequenced and analyzed, and the Cytb sequences of the two parasites constituted the first records of this marker in GenBank. A comparison of the newly obtained sequences of the three loci between the two parasites revealed that the interspecific similarities of 18S rDNA, Cox1, and Cytb were 96.4-97.2%, 96.5%, and 93.7%, respectively. Therefore, the two species could be better discriminated with Cytb than with 18S rDNA and Cox1. Phylogenetic analysis based on 18S rDNA sequences and Cox1 sequences indicated that the two parasites had a close relationship with Sarcocystis in nonruminant animals, especially birds and canids.

Tsutsugamushi disease (TD) is an acute infectious disease caused by Orientia tsutsugamushi. This study aimed to analyze the epidemiological features of TD, investigate chigger mites and their hosts, and investigate the meteorological factors affecting TD incidence and the host of O. tsutsugamushi in Xiamen city, China. Data on reported TD cases were collected from 2006 to 2018. Spearman's correlation test were used for identifying the relationship between meteorological factors and TD incidence and whether meteorological factors affect the host of O. tsutsugamushi. The incidence of reported TD increased gradually from 2006, reached a peak of 4.59 per 100,000 persons in 2014, and then decreased gradually. The TD incidence was seasonal, with epidemic periods occurred mainly in summer and autumn. Patients aged 40-60 years had the highest proportion of cases, accounting for 44.44% of the total cases. Farmers had the largest number of cases among all occupational groups. Rattus Norvegicus was the most common host, accounting for the largest proportion of rats (73.00%), and the highest rat density was observed in March and October every year. There were significant positive correlations between the number of reported cases and average temperature, sunshine duration, and rainfall as well as between rat density and average temperature. On phylogenetic analysis, 7 sequences of hosts and human TD cases obtained from health records demonstrated the highest similarities to the Kato, Karp, and Gilliam strains. No correlations were observed between rat density, and sunshine duration and rainfall. The transmission of TD in Xiamen city, China, was seasonal, and its incidence was affected by several meteorological factors including average temperature, sunshine duration, and rainfall. However, the host of O. tsutsugamushi was only affected by average temperature., Competing Interests: The authors have declared that no competing interests exist.

Background: The family Hoplopleuridae contains at least 183 species of blood-sucking lice, which widely parasitize both mice and rats. Fragmented mitochondrial (mt) genomes have been reported in two rat lice (Hoplopleura kitti and H. akanezumi) from this family, but some minichromosomes were unidentified in their mt genomes., Methods: We sequenced the mt genome of the rat louse Hoplopleura sp. with an Illumina platform and compared its mt genome organization with H. kitti and H. akanezumi., Results: Fragmented mt genome of the rat louse Hoplopleura sp. contains 37 genes which are on 12 circular mt minichromosomes. Each mt minichromosome is 1.8-2.7 kb long and contains 1-5 genes and one large non-coding region. The gene content and arrangement of mt minichromosomes of Hoplopleura sp. (n = 3) and H. kitti (n = 3) are different from those in H. akanezumi (n = 3). Phylogenetic analyses based on the deduced amino acid sequences of the eight protein-coding genes showed that the Hoplopleura sp. was more closely related to H. akanezumi than to H. kitti, and then they formed a monophyletic group., Conclusions: Comparison among the three rat lice revealed variation in the composition of mt minichromosomes within the genus Hoplopleura. Hoplopleura sp. is the first species from the family Hoplopleuridae for which a complete fragmented mt genome has been sequenced. The new data provide useful genetic markers for studying the population genetics, molecular systematics and phylogenetics of blood-sucking lice.

Background: Rodents, globally overpopulated, are an important source for zoonotic disease transmission to humans, including Enterocytozoon bieneusi (one of the most prevalent zoonotic pathogens). Here, we studied the prevalence and performed genetic analyses of E. bieneusi in rodents from the Hainan Province of China., Methods: A total of 603 fresh fecal samples were gathered from 369 wild rats, 117 bamboo rats, 93 Asiatic brush-tailed porcupine and 24 red-bellied squirrels. The wild rats were identified to the species level by amplification of a 421-bp region of the cytb gene from fecal DNA using PCR. Genotype analysis was performed by amplification of the internal transcribed spacer (ITS) region of rDNA of E. bieneusi using PCR., Results: Seven wild rat species were identified. The average rate of infection with E. bieneusi was 15.8% (95/603) with 18.7% (69/369) in wild rats, 11.9% (25/210) in farmed rodents and 4.2% (1/24) in red-bellied squirrels. Sixteen E. bieneusi genotypes were identified, including 9 known genotypes (D, Type IV, PigEBITS7, Peru8, Peru11, ESH02, S7, EbpA and CHG5), and 7 novel genotypes (HNR-I to HNR-VII). Genotype D (44.2%, 42/95) predominated, followed by PigEBITS7 (20.0%, 19/95), HNR-VII (15.8%, 15/95), Type IV (5.3%, 5/95), HNR-III (2.1%, 2/95), HNR-VI (2.1%, 2/95) and each of the remaining 10 genotypes (1.1%, 1/95). The phylogenetic analysis of the ITS region of E. bieneusi divided the identified genotypes into the following four groups: Group 1 (n = 13), Group 2 (n = 1), Group 12 (n = 1), and the novel Group 13 (n = 1)., Conclusions: To our knowledge, this is the first report on the identification of E. bieneusi in rodents from Hainan, China. The zoonotic potential of the identified E. bieneusi genotypes suggested that the rodents poses a serious threat to the local inhabitants. Thus, measures need to be taken to control the population of wild rats in the areas investigated in this study, along with identification of safe methods for disposal of farmed rodent feces. Additionally, the local people should be made aware of the risk of disease transmission from rodents to humans.

Rodents are reservoirs and hosts of several pathogens around the world, including zoonotic parasite species. This study aimed to determine the occurrence of zoonotic gastrointestinal helminths in rodents captured inside households in a rural community from southern Guatemala. Sixty-nine rodents were captured in 33% (49/148) of the surveyed households, including Rattus rattus, Rattus norvegicus, Mus musculus, and Sigmodon hispidus. Thirty-six percent (25/69) of these rodents (3 Rattus and 22 Mus musculus), from 45% (22/49) of the households, were parasitized with at least 1 gastrointestinal helminth species. Helminths from 6 species were identified: Hymenolepis diminuta, Moniliformis moniliformis, Heterakis spumosa, Nippostrongylus sp., Strongyloides sp., and Syphacia sp. Two zoonotic species were found in Rattus, H. diminuta in R. rattus (1/6), and M. moniliformis in R. norvegicus (1/1). Coinfection with other non-zoonotic helminth parasites, such as He. spumosa and Strongyloides sp., also was observed in the Rattus genus. Mus musculus had only non-zoonotic helminths: He. spumosa, Nippostrongylus sp., and Syphacia sp. being the most common, and He. spumosa (96%) followed by Nippostrongylus sp. (48%), with a higher presence in males than females, with a similar proportion in adult and young individuals. This is the first report of zoonotic and non-zoonotic helminths parasites in rodents from Guatemala., (© American Society of Parasitologists 2020.)

The objective of the present study was to determine the characterization of Toxoplasma gondii in cats, rats, and chickens in the border areas of Yunnan Province. A total of 259 samples was collected from 10 border areas in Yunnan Province including 94 cats, 58 rats, and 107 chickens. Samples were screened by a nested polymerase chain reaction (PCR) assay and the positive products were analyzed by multilocus PCR-restriction fragment length polymorphism (RFLP) to determine the genotypes. Toxoplasma gondii deoxyribonucleic acid (DNA) was detected from 15.96% of 94 cats, 15.52% of 58 rats, and 6.54% of 107 chickens, respectively, and the average infection rate is 11.97%. Using the multilocus PCR-RFLP, we found that the genotype of T. gondii in cats and rats was ToxoDB#9. Because of low DNA concentration, no genotype was determined from chickens. These results fill the gaps of knowledge in the prevalence and genotype of T. gondii in the border areas of Yunnan Province and have implications for the better control of T. gondii infection in humans and animals., (© American Society of Parasitologists 2020.)

Haematophagous ectoparasites are worldwide vectors of many zoonotic bacterial diseases, both emerging and re-emerging, whose incidences are rising. Livestock development alters different environmental characteristics such as the microclimate of a site, changing the availability, density and susceptibility of the hosts to pathogens and vectors, indirectly influencing the spread and persistence of a disease within an ecosystem. The Norway rat (Rattus norvegicus), the most abundant vertebrate pest species found on livestock farms from Argentina, is a reservoir for several important zoonotic bacteria and may harbor ectoparasite species, which act as their vectors. Even though the Norway rat is widely known for its role as an ectoparasite host, the ecological characteristics of their ectoparasite communities and the related factors with parasitism on livestock farms have never been described. In the present study, we describe the ectoparasite community in Norway rats from central Argentina livestock farms, while also depicting the influencing factors on both ectoparasite occurrence and abundance. Ectoparasites were collected from rats captured in 20 sites from Buenos Aires province, between the winter of 2016 and the summer of 2018. A total of 1441 ectoparasite individuals were collected from 159 Norway rat individuals [Total ectoparasite prevalence = 69.2%; Mean ectoparasite specimen abundance (± CI) = 9.06 ± 2.32 ectoparasite individuals per rat; Mean ectoparasite specimen intensity (±CI) = 13.10 ± 3.08 ectoparasite individuals per infested rat found]. Ectoparasite assemblage consisted of four cosmopolitan species, recognized for their sanitary relevance: mites (Laelapidae: Laelaps nuttalli and Laelaps echidninus), lice (Polyplacidae: Polyplax spinulosa) and fleas (Pulicidae: Xenopsylla cheopis). We observed higher Norway rat abundance in sites related to higher ectoparasite occurrence and abundance frequencies on the rats. Additionally, ectoparasites were more abundant on rats in warm seasons and on male individuals, over female rats. Moreover, the geographical location of the studied sites influenced the ectoparasite assemblage structure observed on the rats. This study broadens the knowledge on the role of Norway rats as zoonotic ectoparasites hosts and analyzes the drivers influencing ectoparasite occurrence and abundance on the most populated region of Argentina, which is also the region with the most intensive livestock farming. Therefore, this survey may assist in evaluating potential risks for humans and generate effective sanitary control strategies for ectoparasite-borne infectious diseases., Competing Interests: Declaration of Competing Interest None., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Historical European exploration and colonization resulted in the introduction of four species of rodents to the Australian continent from Eurasia: the brown rat, Rattus norvegicus, the black rat, R. rattus, the Pacific rat, R. exulans, and the house mouse, Mus musculus. The spread of these rodents created opportunities for their co-introduced sucking lice to parasitize and adapt to endemic rodents in Australia., Methods: We collected sucking lice from rodent specimens in seven museums across Australia. We identified the spiny rat louse, Polyplax spinulosa, based on morphology. We sequenced the mitochondrial cox1 and rrnL genes of P. spinulosa specimens and constructed a phylogenetic tree with rrnL sequences., Results: We examined 989 rodent specimens of 54 species and collected 2111 adult sucking lice and 1064 nymphal sucking lice. We found that P. spinulosa had nearly doubled its host range by parasitizing at least six endemic rodent species in Australia. The other two introduced lice, P. serrata and Hoplopleura pacifica, however, have apparently failed to expand to any endemic rodents in Australia. Our analysis of mitochondrial rrnL gene sequences divided P. spinulosa into two genotypes (European vs Southeast Asian), which differ by 7.5%; both genotypes were introduced into Australia and then expanded their host ranges to include endemic rodents., Conclusions: The earliest record of a European ship landing in Australia was in 1606, followed by British settlement in 1788. The expansion of P. spinulosa to at least six endemic rodent species in Australia has therefore occurred in the time frame of 200 to 400 years, which is extremely rapid relative to its host expansion to eight native rat species in Eurasia in ~ 16 million years since it diverged from P. serrata. The host expansion of P. spinulosa is remarkable for a blood-sucking louse and is in stark contrast to the absence of host expansion by P. serrata and H. pacifica. Comparison among these three introduced sucking lice indicated that both louse-specific factors and host-specific factors can contribute to the success or failure of host expansion.

Enterocytozoon bieneusi, an obligate intracellular microsporidian parasite, can infect humans and a wide variety of animals worldwide. However, information on the prevalence and molecular characterization of E. bieneusi in pet rats and guinea pigs is lacking. In this study, 325 fecal samples were collected from 152 pet fancy rats and 173 pet guinea pigs purchased from pet shops in Henan and Shandong provinces. The prevalence of E. bieneusi was 11.2% (17/152) in pet fancy rats and 20.2% (35/173) in pet guinea pigs. Genotypes D (n = 12), Peru11 (n = 3), S7 (n = 1) and SCC-2 (n = 1) were identified in pet fancy rats, and genotype S7 (n = 30) and a novel genotype PGP (n = 5) were identified in pet guinea pigs. The ITS sequence and its phylogenetic analysis showed that the novel genotype PGP was distinctly different; it exhibited less than 50% similarity to the reference sequences, and did not cluster with any of the known E. bieneusi genotype groups, forming a unique branch between groups 6 and 7. These data suggest that this is a new E. bieneusi genotype group. This is the first report of E. bieneusi infection in pet fancy rats and pet guinea pigs worldwide. The identification of zoonotic genotypes D, Peru11, and S7 suggests that pet fancy rats and guinea pigs can be potential sources of human microsporidiosis., (© J. Wang et al., published by EDP Sciences, 2020.)

The role of rodents as reservoirs of helminths of public health importance is not well known. The zoonotic potential of Syphacia spp. has been confirmed; therefore, the study aimed to estimate the occurrence of oxyurid nematodes in small rodents from pet shops and breeding clubs in Slovakia. Fecal samples of 586 pet rodents kept in 133 cages were collected between 2016 and 2018 and examined by Faust´s flotation method. Four species of oxyurid nematodes, Syphacia muris, S. obvelata, Aspiculuris tetraptera and Paraspidodera uncinata were detected. A. tetraptera was found in the faecal samples of all rodent species included in this survey. The number of positive boxes varied from 5.4% in hamsters to 70.0% with mice. The prevalence of Syphacia muris was highest in Mongolian gerbils where up to 75.0% boxes were positive; S. obvelata was found in 26.7% of boxes with mice, 25.0% of boxes with Mongolian gerbils and 3.2% of boxes with rats. The high prevalence of Syphacia spp. in all animal species points out the infection risk for humans. Animals offered for sale are often in close contact with human beings; therefore they should be regularly tested for parasites and then effectively dewormed.

The cestode Hymenolepis diminuta is highly prevalent in wild rat populations and has also been observed rarely in humans, generally causing no apparent harm. The organism has been studied for decades in the laboratory, and its colonization of laboratory rats has recently been shown as protective against some inflammation-associated disorders. Recently, H. diminuta has become a leading candidate for helminth therapy, an emerging method of "biota enrichment" used to treat or prevent inflammatory diseases of humans in Western society. While most of the experimental isolates of H. diminuta are identified based on typical morphological features, hymenolepidid tapeworms may represent complexes of cryptic species as detected by molecular sequence data. In the present study, we explored the diversity of laboratory-kept strains using partial sequences of two genes (lsrDNA and cox1) and determined that H. diminuta isolates currently considered for therapeutic purposes in the US and Europe belong to a single, genetically nearly uniform lineage, showing only little genetic deviation from wild-caught isolates., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Introduction: Trypanosoma cruzi is the causal agent of the American trypanosomiasis, an endemic disease in México. The commensal rodents Mus musculus and Rattus rattus are reservoirs of this parasite, which invades cardiac fibers and develops parasite nests causing various lesions. Histopathological studies in naturally infected rodents are scarce. Objective: To describe the types and frequencies of microscopic lesions in cardiac tissue of M. musculus and R. rattus infected with T. cruzi captured in Mérida, México. Materials and methods: The rodents were captured in suburban environments of Mérida. Cardiac tissue was extracted and processed by the paraffin inclusion technique and hematoxylin and eosin stained. The observation was made with a conventional microscope and all the lesions, as well as their degree, were identified. Results: Eight tissue samples of M. musculus and seven of R. rattus were studied. Parasite nests were found in 7/15, specifically 3/8 in M. musculus and 4/7 in R. rattus. The inflammatory infiltrate was the most frequent lesion. Other lesions were: Degeneration of cardiac fibers (8/15), congestion of blood vessels (6/15), and necrosis (5/15). Discussion: The lesions we observed have been described in experimental animal models and in humans with American trypanosomiasis. The inflammatory infiltrate has been identified as the most significant lesion in humans and reservoirs in the chronic stage of the disease. Conclusion: The lesions we described are associated with T. cruzi infection, which confirms that the rodents studied are reservoirs of this parasite.

Introduction: Angiostrongylus cantonensis is a serious public health problem and is widely distributed in the country. When the parasite infects the snails, it becomes deeply embedded in their interior and accidentally, it can infect people and other mammals. Objective: To establish the geographical distribution of A. cantonensis intermediate hosts (Achatina fulica) and definitive hosts (Rattus spp.) in Ecuador from 2014 to 2017. Materials and methods: We collected 2,908 A. fulica specimens in 16 provinces using the capture method per unit of effort for 30 minutes. We captured 211 hosts of which 20 were Rattus rattus and 191 R. norvegicus. The specimens were transported to the Instituto Nacional de Salud Pública e Investigación in Guayaquil where the larvae L3 were identified and counted in the tissues of the snail, which were then inoculated in laboratory rats to reproduce the life cycle. In the rodents, the brains, hearts, lung arteries and lungs were dissected, and the parasites were identified by taxonomic morphology. Results: Of the snails harvested, 441 were positive for A. cantonensis (15.2%) and a total of 6,166 L3 larvae were found; 77 (36.5%) specimens of Rattus spp., were infected with A. cantonensis and a total of 220 parasites (L4-L5 larvae and adult worms) were collected. Conclusions: We confirmed the presence of A. cantonensis in several provinces, which ratifies the endemic nature of this zoonosis in the national territory. Rattus spp. specimens constitute the definitive hosts of the parasite, which together with the presence of intermediate hosts, indicates the zoonotic potential of this parasitic infection.

The black rat Rattus rattus has a distribution that includes much of Earth's terrestrial surface, and has adapted to exploit both habitats extensively modified by humans and rural habitats. Despite the fact that R. rattus are nearly ubiquitous, few studies have investigated urban or peri-urban R. rattus as potential hosts for ticks. In this study, we identified the species of ticks that parasitize R. rattus in a remnant bush area within Sydney, Australia. We then examined the relationship between ticks and R. rattus by testing several rat body characteristics as predictors of tick abundance. We show that larva and nymphs of five species of native Australian tick parasitize R. rattus in urban Australia. The most abundance species was Ixodes holocyclus, a tick of veterinary and human health concern. We found that ticks were more abundant on R. rattus in better condition, for larva and nymphs of I. holocyclus and I. tasmani. Rattus rattus supports a rich assembly of ticks in a remnant forest in urban Australia, and as the R. rattus in best condition have the most ticks, tick parasitism at the levels observed does not appear to negatively impact R. rattus. Our findings illustrate that R. rattus, and other human commensal species, may be important hosts for ticks in human modified environments., (Copyright © 2019 Elsevier GmbH. All rights reserved.)

Retortamonas spp. has been reported as an intestinal parasite among various host organisms, including humans; however, its intra-genus molecular diversity has not yet been elucidated. Haplotypes of the 18S small subunit ribosomal RNA locus (1836-1899 bp) of Retortamonas spp. from humans (n = 8), pigs (n = 6), dogs (n = 1), goats (n = 16), water buffalos (n = 23), cattle (n = 7), rats (n = 3), and chickens (n = 5) were analyzed with references isolated from non-human mammals, amphibians, and insects. Phylogenetic and network analyses revealed a statistically supported three cluster formation among the vertebrate-isolated haplotypes, while insect-isolated haplotypes were independently clustered with Chilomastix. In the clade of vertebrate isolates, assemblage A (amphibian genotype), which included the amphibian references, was addressed as an out-group of the other clusters. Assemblage B (mammalian and chicken genotype) included most haplotypes from various mammals including humans with the haplotypes isolated from a chicken. Human isolates were all classified into this assemblage, thus assemblage B might correspond to R. intestinalis. Assemblage C (bovine genotype), which included specific haplotypes from water buffalos and cattle, was addressed as a sister lineage of assemblage B. Among the diversified haplotypes of assemblage B, a specific haplotype, which was identified from multiple host mammals (humans, dogs, pigs, cattle, water buffalos, elks, goats, and rats), indicates the potential zoonotic transmission of the Retortamonas among them. The genotyping classification of retortamonads could contribute to a better understanding of its molecular epidemiology, especially among humans and related host organisms., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Coiling patterns of heligmonellid nematodes were examined for 520, 208, and 33 individuals of Nippostrongylus brasiliensis, Orientostrongylus tenorai, and Sabanema sp., respectively, collected from murine rodents of Indonesia. Besides typical sinistral coiling, complete dextral coiling was found in 3.3% of N. brasiliensis and 12.1% of Sabanema sp. Mixed coiling with partial sinistral and dextral patterns was also observed in 38.8% of N. brasiliensis, 60.7% of Sabanema sp., and 3.4% of O. tenorai. In dextral coils, the left ventral area with large ridges was located inside as in sinistral coils, keeping the ability to cling to intestinal villi. The cuticular dilatation at left to left dorsal area was located caudally in sinistral coils but rostrally in dextral coils. Presence of mixed coiling indicates that the coiling patterns can change. As the transition of coiling pattern accompanies a change in direction of coil axis, it is surmised that the dextral coiling may be chosen when a worm leaves a villus to move to another villus.

Trypanosoma lewisi (Kinetoplastea: Trypanosomatida: Trypanosomatidae) with a cosmopolitan distribution is the type species of the subgenus Herpetosoma, which includes ca. 50 nominal species isolated mainly from rodents. Since members of Herpetosoma in different host species have an almost identical morphology of bloodstream forms, these trypanosomes are referred to as 'T. lewisi-like', and the molecular genetic characterization of each species is necessary to verify their taxonomy. In the present study, we collected blood samples from 89 murid rodents of 15 species and 11 soricids of four species in Indonesia, Philippines, Vietnam, Taiwan, and mainland China for the detection of hemoprotozoan infection. T. lewisi and T. lewisi-like trypanosomes were found in the blood smears of 10 murid animals, which included Bandicota indica (two rats), Rattus argentiventer (one rat), and Rattus tiomanicus (two rats) in Indonesia; Rattus rattus (one rat) in the Philippines; and Niviventer confucianus (four rats) in mainland China. Furthermore, large- or medium-sized non-T. lewisi-like trypanosomes were detected in two soricids, Crocidura dracula in Vietnam and Anourosorex yamashinai in Taiwan, respectively. Molecular genetic characterization of the small subunit (SSU) ribosomal RNA gene (rDNA) and glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) gene indicated that the trypanosomes from all the murid hosts had identical SSU rDNA or gGAPDH gene nucleotide sequences except for those in N. confucianus in mainland China. These N. confucianus-infecting trypanosomes also showed several unique morphological features such as smaller bodies, anteriorly positioned nuclei, and larger rod-shaped kinetoplasts when compared with T. lewisi trypomastigotes. Trypanosoma (Herpetosoma) niviventerae n. sp. is erected for this new species. Similarly, based on morphological and molecular genetic characterization, Trypanosoma sapaensis n. sp. and Trypanosoma anourosoricis n. sp. are proposed for the trypanosomes in C. dracula in Vietnam and A. yamashinai in Taiwan, respectively. More effort directed toward the morphological and molecular genetic characterization of the trypanosomes of rodents and soricids is required to fully understand the real biodiversity of their hemoflagellates.

Introduction: The highest risk of trichinellosis for human is considered in eating meat products containing live larvae, mostly from wild boars or pigs. Spreading of Trichinella spp. may occur in various ways, one of which is transmission by vectors. The rat is considered to be the most common vector for Trichinella parasite. The population of rats living on pig farms can play an important role in maintaining or spreading the parasite to other animals., Objective: The aim of presented survey was to investigate the occurrence of Trichinella spp. in rats on farms with pigs infected with this parasite., Material and Methods: From pig farms selected for study, the muscles of collected rats were investigated by magnetic stirrer digestion method to assess occurrence of Trichinella in the rat population. Isolated Trichinella parasites were identified under stereomicroscope and multiplex PCR were performed for species identification., Results: Rats infected with Trichinella spp. were discovered on three of five investigated pig farms. The mean extent of invasion in rats from the studied farms was 23.33%. The calculated medium intensity of invasion was 4.09 lpg (larvae per gram) (SD 5.41). All larvae of Trichinella discovered from rats were identified as T.spiralis ., Conclusions: The results obtained indicate that in farms with a high prevalence of Trichinella invasion in pigs there are very likely to be found rats infected by this nematode. This suggests possibility to maintain the invasion in herd and spread into neighborhood farms.

Diagnosis of parasitic diseases that involve tissue-stage larvae is challenging, and serology remains the most effective antemortem test for detecting these infections. Baylisascaris procyonis, the raccoon roundworm, is a zoonotic ascarid. Raccoons are the usual definitive host, and humans may be infected as accidental hosts. More than 150 species of birds and mammals may act as paratenic hosts, and rodents play an important role in the transmission and maintenance of this parasite in nature. Migratory larvae in paratenic host tissues can produce ocular disease and severe to fatal neurologic disease, but not all infected hosts develop signs. A sensitive and specific Western blot (WB) assay based on a recombinant Baylisascaris-specific antigen (rBpRAG-1) has been developed for use in humans. We evaluated the use of this antigen to detect Baylisascaris spp. infections in rodent paratenic hosts. With the use of 4 species of Peromyscus mice ( Peromyscus californicus, Peromyscus leucopus, Peromyscus maniculatus, Peromyscus polionotus) from a previous infection trial, we developed species-adapted WB and ELISA assays and evaluated performance compared to detection of larvae in tissue samples. These assays revealed species-level differences in seroconversion and terminal antibody concentrations, with P. leucopus developing significantly greater antibody concentrations than P. californicus and P. polionotus at all dose levels, and P. maniculatus at the low dose. Some P. californicus and P. polionotus failed to seroconvert despite the recovery of larvae from their tissues. WB and ELISA results were correlated; however, the WB demonstrated higher sensitivity than the ELISA overall (72.2% versus 63.9%, respectively). With the use of experimental samples, specificity was 100% for WB and 94.1% for ELISA. A WB was also used to test Mus and Rattus samples, and although numbers were too limited to evaluate sensitivity and specificity, all animals known to be infected by tissue digestion were WB positive, and all uninfected animals were negative. Finally, the Peromyscus-adapted WB and ELISA were used to test a set of serum samples from wild-trapped P. maniculatus and Rattus rattus. Both assays were generally sensitive, but specificity was equivocal. This emphasizes the challenge of using serology for investigation of wildlife diseases, in which hosts have unknown exposure histories. Nevertheless, serologic methods have utility in the study of Baylisascaris spp. in paratenic hosts, either wild or captive, and have advantageous attributes (non-lethal, high-throughput), but results should be interpreted carefully.

The flea genus Neotyphloceras Rothschild (Siphonaptera: Ctenophthalmidae) includes five species and two subspecies distributed from Venezuela to southern Chile and Argentina. Only Neotyphloceras crassispina hemisus Jordan has been registered in Bolivia. The present study examines species of Neotyphloceras collected in Bolivian localities in the Departments of La Paz, Cochabamba and Tarija, and describes the morphology of the modified abdominal segments in males and females of Neotyphloceras rosenbergi Rothschild on the basis of type material and specimens collected from Tarija. A new species, Neotyphloceras boliviensis n. sp., is described and new host associations are reported for N. rosenbergi, Neotyphloceras crassispina crassispina and N. crassispina hemisus. Neotyphloceras c. crassispina and N. rosenbergi are reported for the first time in Bolivia. The distribution of N. rosenbergi is extended 1600 km to the south. Given the potential medical and veterinary significance of fleas as disease vectors, and considering that in the Departments of La Paz and Tarija several human cases of plague have been reported, and species of flea have been identified as main vectors of these diseases, the new records of fleas in Bolivia reported herein may be useful for epidemiological studies on flea-borne diseases., (© 2018 The Royal Entomological Society.)

Toxoplasmosis is a zoonotic disease of worldwide distribution. The parasite exhibits strong geographical patterns of strain variation with contrasting high levels of diversity across South America and restricted variation across North America. Little is known about the diversity of strains in the transitional area between the two continents. Here we present data on the prevalance and diversity of Toxoplasma gondii in the Yucatan peninsula of Mexico, through a study in commercially reared pigs. A survey of 12 farms found evidence of circulating T. gondii DNA in 125 of 632 blood samples (19.8%, CI: 16.7%-23%). In addition, 46 tongue samples were collected from culled animals and 16 of these were positive for T. gondii DNA and 3 were positive in mouse bioassay. PCR-sequencing was used to generate genotyping data from blood and tissue samples. Four loci (SAG1, 2, 3 and GRA6) were reliably amplified and revealed a high diversity among Yucatan strains with evidence of recombination and novel alleles. Sequencing data from the four loci was achieved in eight samples each of which had a different genotype. The predominant allelic type was atypical, in relation to the dominant strain types (I, II, III), the number of allelic variants being 27 (I, II-III, u-1-25), 20 (I, III, u1-18), 6 (I, III, u1-4) and 11 (I, II, u1-9) for the SAG1, SAG2, SAG3 and GRA6 loci respectively. Phylogenetic analysis showed that T. gondii strains from Yucatan shared alleles with strains originating from both North and South America. Our findings are consistent with data from other regions of Central America and suggest the genetic population structure of the parasite, with significant levels of allelic variation and recombination, constitutes a reservoir from which new strains may emerge. Positive bioassay results (7.5%) indicate that consumption of undercooked pork could be a potential T. gondii infection risk to humans., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In the 1970's and 1980's, an unknown species of the genus Brachylaima (Trematoda: Brachylaimidae) had been recorded from the intestines of Rattus norvegicus and Apodemus speciosus in Hokkaido, Japan. The rodent fluke was characteristic in extending a bilateral vitellarium till the level of posterior margin of anterior testis and in keeping almost the same-sized spherical ovary and testes. In this study, the rodent fluke was rediscovered from A. speciosus, Apodemus argenteus, and Myodes rufocanus in Hokkaido. The resultant parasite collection enabled us to make a mitochondrial DNA (mtDNA) barcode for tracking its intermediate hosts. The metacercaria of the rodent fluke was detected frequently from the kidney of three species of land snails (Discus pauper, Succinea lauta, and Ainohelix editha). However, its sporocyst with cercariae was found only from the hepatopancreas of D. pauper, a fairly small snail. The wide-spectrum of the second intermediate host seems to increase the chance of transmitting the parasite to various mammals and birds. The use of indigenous land snails as the first and second intermediate hosts, the distinctiveness of the mtDNA sequence, and the characteristic morphology of all the developmental stages prompted us to propose Brachylaima asakawai sp. nov. for the rodent intestinal fluke in Hokkaido. The present field survey suggests that the life cycle of the new species is primarily dependent on a predator-prey relationship between rodents and D. pauper., (Copyright © 2018. Published by Elsevier B.V.)

The overall goal of this study was to use the Rattus spp./Hymenolepis diminuta model to assess environmental lead pollution in different landscape units of an urban ecosystem. Rats of the genus Rattus were collected from three shanty towns and three residential neighbourhoods of the city of Buenos Aires. Concentrations of lead in the livers of wild rats and in their parasite H. diminuta were measured using inductively coupled plasma mass spectrometry (ICP-MS). The landscape unit and tissue type had a significant effect on lead concentration, being higher in residential neighbourhoods as well as in H. diminuta tissue. Nevertheless, no significant differences were found for the mean lead concentration in livers between uninfected and infected rats. Since the available information describing heavy-metal pollution within the city of Buenos Aires is scarce, the results of this study allow us to update data about the extent of biologically available lead contamination. Considering that rats and H. diminuta are distributed worldwide, this monitoring system for lead pollution might be applied successfully in other urban ecosystems.

The rat tapeworm Hymenolepis diminuta is a parasite of the small intestine of rodents (mainly mice and rats), and accidentally humans. It is classified as a non-invasive tapeworm due to the lack of hooks on the tapeworm's scolex, which could cause mechanical damage to host tissues. However, many studies have shown that metabolites secreted by H. diminuta interfere with the functioning of the host's gastrointestinal tract, causing an increase in salivary secretion, suppression of gastric acid secretion, and an increase in the trypsin activity in the duodenum chyme. Our work presents the biochemical and molecular mechanisms of a parasite-host interaction, including the influence on ion transport and host intestinal microflora, morphology and biochemical parameters of blood, secretion of antioxidant enzymes, expression of Toll-like receptors, mechanisms of immune response, as well as the expression and activity of cyclooxygenases. We emphasize the interrelations between the parasite and the host at the cellular level resulting from the direct impact of the parasite as well as host defense reactions that lead to changes in the host's tissues and organs.

The brown rat, Rattus norvegicus, with a worldwide distribution, is the most commensal species among synanthropic rodents, since its main habitat, in urban as well as in rural areas, is always linked to humans. Therefore, people living in close proximity to rodent populations can be exposed to infection. Whereas bacteria and viruses are the best known rat-associated zoonoses in urban environments, the role of brown rats as reservoirs for helminth parasites and the associated risk for humans are less well known. Specifically, this role has not been analyzed in Spain to date. A total of 100 R. norvegicus trapped in the sewage system (n = 85), and parks (n = 15) of Barcelona was examined. The overall prevalence of helminth infection was 85%. The helminths found were Hymenolepis nana (17%), H. diminuta (33%) (Cestoda), Calodium hepaticum (17%), Eucoleus gastricus (28%), Aonchotheca annulosa (12%), Trichosomoides crassicauda (7%), Nippostrongylus brasiliensis (46%), Heterakis spumosa (62%), Gongylonema neoplasticum (20%) (Nematoda) and Moniliformis moniliformis (6%) (Acanthocephala). Five of the ten helminth species are considered zoonotic parasites, with rats acting as reservoirs for human infection, i.e. H. nana, H. diminuta, C. hepaticum, G. neoplasticum and M. moniliformis. G. neoplasticum and M. moniliformis are reported for the first time in urban rats in Europe. H. nana, H. diminuta and C. hepaticum are the most widespread species in European cities. For H. nana and C. hepaticum, rats act as effective spreaders of the human infective stage (eggs). For H. diminuta, G. neoplasticum and M. moniliformis, rats act as indirect reservoirs of the zoonoses since the eggs shed by the rats are infective for their insect intermediate hosts only. Medical practitioners need to be made aware of the range of parasites carried by rats, as there is a realistic likelihood that ill health currently caused by rat infestations may be misdiagnosed., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Rickettsia parkeri strain Atlantic rainforest (SAR) is the etiological agent of a spotted fever group rickettsiosis in Brazil, where it is transmitted to humans by the tick Amblyomma ovale. A previous study demonstrated that R. parkeri SAR was successfully maintained in A. ovale ticks by transstadial and transovarial passages; however, because this agent induced lower reproduction rates in A. ovale, the participation of a vertebrate amplifier host, yet to be determined, was speculated. Since the rice rat Euryoryzomys russatus was demonstrated to be the most important host for immature stages of A. ovale in a focus of R. parkeri SAR transmission, the present study evaluated the competence of rice rats to act as amplifying host of R. parkeri SAR for A. ovale ticks. Rice rats were infested with R. parkeri SAR-infected A. ovale nymphs, and four days later with uninfected A. ovale larvae. Rickettsial transmission to rats was confirmed by seroconversion to R. parkeri antigens. Detached engorged larvae were allowed to molt to nymphs, in which rickettsial DNA was detected in up to 60% (mean: 20%) of the specimens. When part of these nymphs was allowed to feed on susceptible rice rats, rickettsial transmission was confirmed by seroconversion, indicating that there was successful horizontal transmission of R. parkeri SAR from infected nymphs to uninfected larvae in the previous acquisition infestations. Because we used naïve, susceptible rats, we infer that this horizontal transmission occurred via a systemic infection (rickettsemia) in the rat. Our results, coupled with previous epidemiological studies, suggest that under natural conditions rice rats could be acting as amplifying hosts of R. parkeri SAR to A. ovale ticks., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

Angiostrongylus mackerrasae is a parasitic nematode of rats found in Australia. When first reported, it was referred to as A. cantonensis. Recent molecular studies, including the mitochondrial genome, indicate that it is highly similar to A. cantonensis. These studies did not include A. malaysiensis, another member of the A. cantonensis species complex, for comparison. The present study examined the genetic distance and phylogenetic relationship between the component taxa (A. cantonensis, A. mackerrasae and A. malaysiensis) of the A. cantonensis species complex, based on the 12 protein-coding genes (PCGs) of their mitochondrial genome. Both the nucleotide and amino acid sequences were analysed. Angiostrongylus mackerrasae and A. cantonensis are members of the same genetic lineage and both are genetically distinct from A. malaysiensis. The genetic distance based on concatenated nucleotide sequences of 12 mt-PCGs between A. mackerrasae and A. cantonensis from Thailand is p = 1.73%, while that between the Thai and Chinese taxa of A. cantonensis is p = 3.52%; the genetic distance between A. mackerrasae and A. cantonensis from China is p = 3.70%. The results indicate that A. mackerrasae and A. cantonensis belong to the same genetic lineage, and that A. mackerrasae may be conspecific with A. cantonensis. It remains to be resolved whether A. mackerrasae is conspecific with A. cantonensis or undergoing incipient speciation.

Forensic entomology is a complementary tool for penal procedures, mainly on estimating postmortem interval. Study of cadaveric fauna in various environments is primary as source of information to support this science. This study collected information about the fauna of Calliphoridae associated to carcasses of Rattus rattus in the Tijuca National Park, RJ. Four collections were conducted, one for each season of 2015, exposing six carcasses at georeferenced points in each collection. The carcasses were placed 550 m from the boarder and equidistant by 100 m. Five decomposition stages were identified, and 10,559 individuals of Calliphoridae belonging to 10 species were collected. The most abundant species were Hemilucilia semidiaphana (Rondani) (Diptera: Calliphoridae) and Lucilia eximia (Wiedemann) (Diptera: Calliphoridae). L. eximia was the most abundant species during the Swelling and Black Putrefaction stages, succeeded in the next stages by two species of the genera Hemilucilia. H. semidiaphana was the dominant species in the last two stages, followed by Hemilucilia segmentaria (Fabricius) (Diptera: Calliphoridae). The genus Mesembrinella (Diptera: Calliphoridae) occurred mainly during the Black putrefaction stage. Mesembrinella bellardiana (Aldrich) was more abundant, with higher occurrence during the Black putrefaction and Dry decay stages. Mesembrinella peregrina (Aldrich) occurred in the two last stages with low abundance. Huascaromusca aeneiventris (Wiedemann) (Diptera: Calliphoridae) occurred during all the observed stages, mainly during the Butyric fermentation stage. Huascaromusca purpurata (Aldrich) (Diptera: Calliphoridae) occurred only during the Dry decay stage and in low abundance. A succession pattern in the carcasses colonization was observed, providing relevant information for the resolution of criminal investigations in this environment.

This study investigated associations between Trypanosoma lewisi and Xenopsylla cheopis, a common cyclical vector of T. lewisi; Polyplax spinulosa, a reported mechanical vector; and Laelaps echidnina and Laelaps lamborni, 2 rodent mites of Rattus norvegicus in Durban, South Africa. In total, 379 R. norvegicus individuals were live-trapped at 48 sites in 4 locality types around Durban during a 1-yr period. Rats were euthanized, cardiac blood was taken to check for hemoparasites, and ectoparasites were removed for identification. Parasite species richness was higher in pups (2.11) and juveniles (1.02) than adults (0.87). Most rats in the study harbored 1 or 2 of the 5 parasites surveyed. Rats with trypanosomes and fleas were more prevalent in the city center and harbor, where juveniles were most affected. Rats with lice were more prevalent in informal settlements and urban/peri-urban areas, where pups had the highest infestations. There was a significant positive association between rats with fleas and trypanosomes and a negative association between rats with lice and trypanosomes. Location and rat age were significant predictors of T. lewisi, X. cheopis, and P. spinulosa. Mites showed no strong association with trypanosomes. Ectoparasite associations are possibly habitat and life-cycle related. We conclude that Durban's city center, which offers rats harborage, an unsanitary environment, and availability of food, is a high-transmission area for fleas and trypanosomes, and consequently a potential public health risk.

Urban slums provide suitable conditions for infestation by rats, which harbour and shed a wide diversity of zoonotic pathogens including helminths. We aimed to identify risk factors associated with the probability and intensity of infection of helminths of the digestive tract in an urban slum population of Rattus norvegicus. Among 299 rats, eleven species/groups of helminths were identified, of which Strongyloides sp., Nippostrongylus brasiliensis and, the human pathogen, Angiostrongylus cantonensis were the most frequent (97, 41 and 39%, respectively). Sex interactions highlighted behavioural differences between males and females, as eg males were more likely to be infected with N. brasiliensis where rat signs were present, and males presented more intense infections of Strongyloides sp. Moreover, rats in poor body condition had higher intensities of N. brasiliensis. We describe a high global richness of parasites in R. norvegicus, including five species known to cause disease in humans. Among these, A. cantonensis was found in high prevalence and it was ubiquitous in the study area - knowledge which is of public health importance. A variety of environmental, demographic and body condition variables were associated with helminth species infection of rats, suggesting a comparable variety of risk factors for humans.

Background: Trypanosoma cruzi is the agent of Chagas disease, a major public health problem in Latin America. Many wild and domestic animals are naturally infected with T. cruzi; rodents are one of the groups which have been consistently detected infected in different countries. The aim of this work was to characterize blood T. cruzi load in naturally infected rodents from a Chagas disease endemic region in Chile., Methods: Baited traps were set in domestic and peridomestic areas of rural dwellings. The rodents were anesthetized and blood sampled; DNA was extracted and the parasite load was quantified by T. cruzi satellite DNA real-time PCR assays., Results: Seventy-one rodents of four species, Rattus rattus, Mus musculus, Phyllotis darwini and Octodon degus, were captured; R. rattus was the most abundant species. Fifty-nine samples (83.1%) were T. cruzi-positive and the median value of the parasite load was 2.99 parasite equivalents (par-eq)/ml. The comparison of frequency of infection or parasite load by species showed no differences. However, one R. rattus presented very elevated parasitemia (1644 par-eq/ml)., Conclusions: The overall levels of parasitemia were similar to those found in humans in Chile. The high infection levels in exotic and endemic rodents very near to rural settlements increases their relevance as T. cruzi hosts.

In Mexico, the role of most species of mammals involved in the transmission cycle of Trypanosoma cruzi Chagas, 1909 is poorly known. It was carried out a study to investigate the importance of rats as reservoir of T. cruzi in western Mexico, an area with important risk of transmission of T. cruzi to human. Thirty-eight human dwellings were searched on two representative towns of western Mexico along twelve months for collection of rats and triatomines. Study rats (Rattus norvegicus) Berkenhout, 1769 and triatomines (Meccus phyllosomus longipennis) (Usinger, 1939) were collected inside and outside human dwellings. Most rats (68.6%, n=312) and triatomines (68.7%, n=217) were collected along months of the hot season. Most rats (59.3%) were collected in peridomiciliary areas. From 312 examined rats, 71 (22.7%) were positive for T. cruzi on examination by Indirect Hemagglutination, which was confirmed by xenodiagnosis. From the 217 examined triatomines, 169 (77.9%) were infected by T. cruzi. The presence of infected rats and triatomines was highly related since on every studied human dwelling where infected triatomines were collected, infected rats were also found. Rats seem to constitute an important domiciliary and peridomiciliary reservoir for T. cruzi, furthering the risk of infection for human beings., (Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.)