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In this study, an evaluation was made of three treatments against feline leishmaniosis (FeL) and their impacts on the transmission of Leishmania infantum to its vector, Lutzomyia longipalpis. A cat with clinical signs of FeL was examined and L. infantum diagnosed. Subsequently, the cat was subjected to xenodiagnosis and L. infantum detected in the vectors. The cat was then treated with three different drugs and the clinical improvement and parasite transmissibility to the vector were evaluated. Promastigotes were observed in 21/52 female sandflies (40.38%) in a xenodiagnosis prior to the treatments. Clinical signs persisted after the first treatment with marbofloxacin, and the cat remained positive in serological, molecular, and parasitological tests. Therefore, the cat was treated with miltefosine but remained sick and tested positive. A second xenodiagnosis was performed a month after treatment with miltefosine, and promastigotes were observed in 5/9 females (55.55%). Lastly, the cat was treated with allopurinol, which led to good clinical improvement, but it remained positive, and a final xenodiagnosis revealed Leishmania in 2/29 (6.89%) females. The results showed that only treatment with allopurinol produced a good clinical response, but none of the treatments succeeded in eliminating L. infantum infection or preventing transmission to the vector.

The effectiveness of a visceral leishmaniasis (VL) control strategy based on the application of 4 % deltamethrin impregnated collars (DIC) exclusively in seropositive dogs was assessed between 2018 and 2019, through a prospective study. The effectiveness of DIC-collaring was evaluated by comparing the incidence rate of anti-leishmanial antibodies among dogs from two endemic districts in Brazil. In one of the areas, the conventional control measure which is based on the non-compulsory euthanasia of LV seropositive dogs, was practiced by the official healthy service as a regular procedure, whereas strategic collaring, conceived in this study, was carried out in the other. Results of serological tests applied to serum samples collected from all domiciled dogs were evaluated in three consecutive times, spaced by around 200 days. Incidence rates of VL seroreactivity were compared between districts in the same period of time as well as within the same district, in consecutive periods. Based on the results, the risk of infection in the population under conventional control measure was up to four times higher than the risk of infection where DIC-collaring was used. The strategic use of collar proposed here emerged as a promising measure for VL control in dogs from endemic areas. Strategic collaring does not rely on the euthanasia of infected animals, an extremely controversial procedure, and instead of being used in all dogs, as collaring is normally recommended; only seropositive dogs are intervened. Strategic use of DIC has the potential to drastically reduce costs, if compared to mass collaring canine population., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Visceral leishmaniasis (VL) is a neglected disease considered a serious public health problem, especially in endemic countries. Several studies have discovered monoxenous trypanosomatids ( Leptomonas and Crithidia ) in patients with VL. In different situations of leishmaniasis, investigations have examined cases of co-infection between Leishmania spp. and Crithidia spp. These coinfections have been observed in a wide range of vertebrate hosts, indicating that they are not rare. Diagnostic techniques require improvements and more robust tools to accurately detect the causative agent of VL. This study aimed to develop a real-time quantitative dye-based PCR (qPCR) assay capable of distinguishing Leishmania infantum from Crithidia -related species and to estimate the parasite load in samples of VL from humans and animals. The primer LinJ31_2420 targets an exclusive phosphatase of L. infantum ; the primer Catalase_LVH60-12060_1F targets the catalase gene of Crithidia . Therefore, primers were designed to detect L. infantum and Crithidia sp. LVH60A (a novel trypanosomatid isolated from VL patients in Brazil), in samples related to VL. These primers were considered species-specific, based on sequence analysis using genome data retrieved from the TriTryp database and the genome assembling of Crithidia sp. LVH60A strain, in addition to experimental and clinical data presented herein. This novel qPCR assay was highly accurate in identifying and quantifying L. infantum and Crithidia sp. LVH60A in samples obtained experimentally (in vitro and in vivo) or collected from hosts (humans, dogs, cats, and vectors). Importantly, the screening of 62 cultured isolates from VL patients using these primers surprisingly revealed that 51 parasite cultures were PCR+ for Crithidia sp. In addition, qPCR assays identified the co-infection of L. infantum with Crithidia sp. LVH60A in two new VL cases in Brazil, confirming the suspicion of co-infection in a previously reported case of fatal VL. We believe that the species-specific genes targeted in this study can be helpful for the molecular diagnosis of VL, as well as for elucidating suspected co-infections with monoxenous-like trypanosomatids, which is a neglected fact of a neglected disease.

One hundred and sixty-six cats from two animal shelters were subjected to enzyme-linked immunosorbent assay (ELISA), indirect immunofluorescence antibody test (IFAT), conventional polymerase chain reaction (cPCR), quantitative PCR (qPCR) and parasitological tests (PA) for the diagnosis of Leishmania spp. Among them, 15% (25/166), 53.6% (89/166), 3.6% (06/166) and 1.8% (03/166) were positive by ELISA, IFAT, both PCRs and PA, respectively. The sequencing of ITS-1 PCR amplicons revealed a 100% match with Leishmania infantum. After the Leishmania spp. survey, 12 cats were selected and divided into two groups for clinical, hematological, and biochemical analysis: six L. infantum positive cats (G1) and six Leishmania spp. negative cats (G2). All the cats were negative for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV). A statistical analysis indicated significantly low platelet counts and significant hyperproteinemia associated with hypoalbuminemia in positive cats (p<0.05). Our results suggest that in endemic areas, cats with clinical signs of feline leishmaniosis (such as skin lesions, weight loss and/or enlarged lymph nodes) and that exhibit hematological and biochemical changes, such as low platelet counts and hyperproteinemia with hypoalbuminemia, should be tested for Leishmania spp. infection.

This study evaluated the humoral and cellular response in 100 cats living in an endemic area of visceral leishmaniosis (VL) using the Montenegro Skin Test (MST) and serological diagnosis and compared the MST with other diagnostic techniques. Sixty 60%, (60/100) cats were positive for MST and the diameter of positive skin reactions ranged from 5 to 9 mm. By serological methods, 74% (74/100) and 34% (34/100) had antibodies against Leishmania spp. by Immunofluorescence Antibody Test (IFAT) and Indirect Enzyme-Linked Immunosorbent Assay (ELISA), respectively. Comparing tests, the observed profiles were (1) IFAT (+)/MST (-) = 27 cats, (2) IFAT(-)/MST(+) = 13 cats, (3) IFAT(+)/MST(+) = 47 cats, (4) ELISA(+)/MST(-) = 12 cats, (5) ELISA(-)/MST(+) = 38 cats and (6) ELISA(+)/MST(+) = 22 cats. Through the combination of serological diagnosis and MST, a positivity frequency of 87% (87/100) by IFAT + MST and 72% (72/100) by ELISA + MST was identified in this cat population. Five cats (5%) were positive for Leishmania donovani complex DNA by molecular analysis, and two cats (2%) had Leishmania spp. amastigotes in lymph node smears. Therefore, the agreement between tests was classified as poor for all tests by Kappa index. The IFAT (+)/MST (+) response was the most frequent considering all cats (47%; 47/100); nonetheless, the most frequent immune expression in Polymerase Chain Reaction (PCR)-positive cats was the IFAT (+)/MST (-) profile (80%; 4/5). Five sick and PCR-positive cats, negative for Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV), that PCR sequencing matched 100% with L. donovani complex, all but one were MST negative. These results suggest that cats develop a significant cellular response against infection by parasites of the L. donovani complex, and most PCR and parasitological positive cats may be unable to develop a significant cellular response., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Leishmaniasis is a neglected tropical disease that continues to pose a serious public health problem. Albeit dogs have long been held as the major reservoirs of Leishmania infantum, the involvement of domestic cats in the zoonotic cycle of visceral leishmaniasis has gained prominence. Here, 240 cats were evaluated by clinical signs and haematological/biochemical changes compatible with leishmaniasis and were diagnosed by serological, molecular, and parasitological techniques. Thus, four cats naturally infected by L. infantum were submitted to xenodiagnosis. A total of 203 females of Lutzomyia longipalpis were subjected to feeding on four cats, with all females completing the blood meal. Parasitological and molecular assays were carried out to evaluate the presence of L. infantum in the sand flies' midgut. Promastigotes were observed in 10 females (6.5%) that fed on one cat, and L. infantum DNA was detected in 17 (8.4%) females that fed on two cats. Our results strengthen the evidence that naturally infected cats are capable of transmitting L. infantum to sand flies., (© 2021 Wiley-VCH GmbH.)

Visceral leishmaniasis (VL) is a neglected tropical disease caused by the Leishmania infantum parasite. The protozoan is able to infect several domestic and wild mammals. Since the first report on Leishmania spp. infection in horses in South America, leishmaniasis in equids has been highlighted in Brazil. A molecular epidemiological survey was carried out to verify the occurrence of Leishmania spp. DNA in horses and donkeys, in leishmaniases endemic areas in Sao Paulo State, Brazil. To this end, blood samples were obtained from 107 horses and 36 donkeys and subjected to DNA extraction followed by PCR targeting the ITS-1 region. Among the horses and donkeys, 1.87% (2/107) and 8.33% (3/36) were positive by PCR, respectively. The DNA sequencing of the ITS-1 amplification products confirmed L. infantum DNA in these animals. Our results suggest that horses and donkeys from non-VL and VL endemic areas of São Paulo State may be infected by the parasite.

Phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae) are a group of small insects of great concern for Public Health. These dipterous are intensely studied worldwide due to their involvement in the transmission of several pathogens, mainly Leishmania spp. parasites. Nowadays, the molecular tools have been included in Phlebotomine sand flies studies and has shown to be powerful tools in bioecology studies of these dipterous. Thereby, when molecular approaches are employed, there is a great concern regarding the amount and quality of the DNA obtained for analysis. Here, seven methods of DNA extraction, between commercial kits and in house extraction protocols were evaluated. We considered measure of DNA concentration and purity ratios using a spectrophotometer to check the performance of each protocol. In addition, the quality evaluation of the DNA extracted was performed by endogenous gene PCR on samples. The results of the seven evaluated DNA extraction protocols and their implications are discussed., (Copyright © 2020 Elsevier Inc. All rights reserved.)

An epidemiological Leishmania spp. and entomological Phlebotomine sandflies survey was performed in cat shelters at leishmaniasis endemic area of Brazil. Blood and conjunctival swab (CS) samples were collected from 94 cats in two animal protection shelters. These samples were subjected to serological tests using the indirect immunofluorescence antibody test (IFAT) and indirect enzyme-linked immunosorbent assay (ELISA) and to molecular test by polymerase chain reaction (PCR). In addition, a Phlebotomine sandflies survey was performed in the same shelters. The analyses revealed a positivity of 31.91% (30/94) through ELISA and 29.79% (28/94) through IFAT. The two serological tests showed a positive association with perfect agreement (k = 0.925). None of the cats were positive by Leishmania spp. DNA. One Lutzomyia (Lutzomyia) longipalpis male was found in one of the cat shelters. The results and the implications of our findings are discussed below., (© 2020 Blackwell Verlag GmbH.)

Leishmania spp. are important agents of human and animal leishmaniases that have an important impact on public health. In this study, we aimed to detect the circulation of Leishmania spp. in cattle from a visceral leishmaniasis non-endemic area of the state of São Paulo, Brazil. DNA was extracted from blood samples from 100 heifers in the municipality of Pirassununga and was amplified using primers specific for the first internal transcriber spacer (ITS1), to assess the presence of trypanosomatids. The assays revealed that one sample presented bands of between 300 and 350 base pairs. In GenBank, this sample matched 100% with Leishmania infantum (314 base pairs). The results suggest that cattle can be infected by Leishmania infantum in Brazil.

The feeding of diets with greater energy content than that needed for body maintenance following mating is believed to reduce embryonic survival in pigs. In swine operations, therefore, feed intake is often restricted during the first and second week of pregnancy to reduce embryo mortality. There is thought to be a relationship between feeding diets that result in energy intake that is greater than that needed for body maintenance and embryonic death. This relationship is associated with lesser than typical progesterone (P4) concentrations when feeding diets with greater energy content due to increased hepatic clearance. There is no consensus, however, as to whether feeding should be restricted during early pregnancy to avert this possible detrimental effect. Thus, the aim of this systematic review is to assess the effect in sows and gilts of feeding diets with different energy contents post-mating on embryonic survival, evaluating when possible, the relationship of a greater energy intake and P4 concentrations on embryonic survival. An electronic search was conducted of the PubMed, Science Direct, Scopus, Web of science, and Scielo databases during June 2018. A total of 109 articles were retrieved, and of these, only 16 articles were selected after applying the selection criteria. There was no negative effect of a greater feed intake than that needed for body maintenance after breeding in 75% of the experiments. Results from 35% of the experiments indicated feeding early pregnant sows a diet with greater energy content than that needed for body maintenance resulted in augmented embryonic death. In 66.7% of the experiments, in which there was assessment of P4 concentration, there was no negative effect of feeding after farrowing a diet with greater energy than that needed for body maintenance. In conclusion, it appears that restricted feed intake in early pregnancy is no longer relevant when there are modern prolific dam lines utilized in swine production enterprises because dietary energy of as great as 54 MJ ME/day had no detrimental effect on embryo survival., (Copyright © 2019 Elsevier B.V. All rights reserved.)