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Outbreaks of fish trypanosomiasis are regularly reported in cultured groupers (Epinephelus spp.), largemouth bass (Micropterus salmoides), and many other species of Cyprinidae, but only rarely reported in ornamental fish. This study reports a trypanosomiasis outbreak in farmed blood parrot cichlids (Vieja melanura ♀ × Amphilophus citrinellus ♂) in the Nansha district, Guangzhou, Guangdong province. From May 2021 to January 2022, up to 100 fish died daily with an estimated overall mortality of 20%. Blood samples were collected from 21 sick fish, characterized by reduced feeding, slow movement and swimming close to the surface of the water, and 5 asymptomatic fish for parasite examination. Wet blood mounts and Giemsa-stained smears showed that trypanosomes were found in 20 of 21 sick fish (95.2%) and 4 of 5 (80%) asymptomatic fish. Parasitemias were recorded at levels of up to approximately 108 trypanosomes /ml of blood. Morphological and genetic analysis showed that the trypanosome infecting blood parrot cichlids was Trypanosoma carassii danilewskyi. In addition, histopathological analysis showed a severe steatosis in liver and an aggregation of pigments in the spleen and kidneys, which are likely to be melanomacrophages. To our knowledge, this is the first report of an outbreak of trypanosomiasis found in farmed blood parrot cichlids. • The first outbreak of trypanosomiasis caused high mortality in farmed ornamental fish. • Trypanosoma carassii danilewskyi is highly prevalent in both sick fish and asymptomatic fish. • Trypanosomiasis is linked with severe steatosis and melanomacrophage aggregation. [ABSTRACT FROM AUTHOR]

[Display omitted] • The trypanosomes isolated from a freshwater leech, Hirudinaria manillensis , belong to a new species. • This trypanosome is a new TthIII phylogenetic lineage in the Trypanosoma (Megatrypanum) clade. • Water buffalo is most likely the mammalian host of this trypanosome. • Results highlight the potential role of freshwater leeches in the transmission of mammalian trypanosomes. Leeches have long been considered potential vectors for the aquatic lineage of trypanosomes, while bloodsucking insects are generally considered as the vectors for the terrestrial lineage of trypanosomes. The freshwater leech, Hirudinaria manillensis , is a widely distributed species in southern China and could potentially act as the vector for trypanosomes. Prior to this study, no trypanosomes had been reported from this leech. However, in this study, leeches were collected from three different places in Guangdong province, China, and a large number of flagellates were isolated and successfully cultured in vitro. Based on morphology, these flagellates looked like a typical trypanosome species. Analysis was carried out on the molecular sequences of the 18S rRNA gene and the glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) gene. To our surprise, these flagellates were identified as likely to be a mammalian trypanosome belonging to the clade containing Trypanosoma (Megatrypanum) theileri but they are significantly different from the typical TthI and TthII stocks. Analyses of blood composition indicated that the source of the blood meal in these leeches was from the water buffalo (Bubalus bubalis). To further test if this flagellate from the freshwater leech was indeed a mammalian trypanosome, we transferred the trypanosomes cultured at 27–37 °C and they were able to successfully adapt to this mammalian body temperature, providing further supporting evidence. Due to the significant genetic differences from other related trypanosomes in the subgenus Megatrypanum , we propose that this flagellate, isolated from H. manillensis , is a new species and have named it Trypanosoma bubalisi. Our results indicate that freshwater leeches may be a potential vector of this new mammalian trypanosome. [ABSTRACT FROM AUTHOR]

Background: Visceral leishmaniasis (VL) has been declared as one of the six major tropical diseases by the World Health Organization. This disease has been successfully controlled in China, except for some areas in the western region, such as the Xinjiang Autonomous Region, where both anthroponotic VL (AVL) and desert type zoonotic VL (DT-ZVL) remain endemic with sporadic epidemics. Methodology/Principal findings: Here, an eleven-year survey (2004–2014) of Leishmania species, encompassing both VL types isolated from patients, sand-fly vectors and Tarim hares (Lepus yarkandensis) from the Xinjiang Autonomous Region was conducted, with a special emphasis on the hares as a potential reservoir animal for DT-ZVL. Key diagnostic genes, ITS1, hsp70 and nagt (encoding N-acetylglucosamine-1-phosphate transferase) were used for phylogenetic analyses, placing all Xinjiang isolates into one clade of the L. donovani complex. Unexpectedly, AVL isolates were found to be closely related to L. infantum, while DT-ZVL isolates were closer to L. donovani. Unrooted parsimony networks of haplotypes for these isolates also revealed their relationship. Conclusions/Significance: The above analyses of the DT-ZVL isolates suggested their geographic isolation and independent evolution. The sequence identity of isolates from patients, vectors and the Tarim hares in a single DT-ZVL site provides strong evidence in support of this species as an animal reservoir. Author summary: Black faver, also known as visceral leishmaniasis (VL), is caused by pathogens of Leishmania species, spread by the bites of infected sand flies. This disease has been successfully controlled in China, except for some areas in the western region, such as Xinjiang. However, the knowledge on Leishmania in these areas remains a few important gaps. Particularly, what is the animal reservoir for desert type zoonotic VL (DT-ZVL), as sand flies get infected in areas free of patient or infected dogs? To address this question, an eleven-year survey (2004–2014) in Xinjiang for Leishmania species was carried out. We found that VLs in Xinjiang are contributed to Leishmania donovani complex, and Tarim hares is likely the reservoir animal for DT-ZVL. [ABSTRACT FROM AUTHOR]

Introduction and Aim: Toxoplasma gondii is an intracellular protozoan parasite infecting approximately 30% of the global human population. It has often been suggested that chronic infection with T. gondii is related to personality changes and various mental disorders including depression. It is not known whether this includes post-partum blues or depression. In this study, we test the hypothesis that there is a relationship between T. gondii infection and post-partum blues by measuring the association between infection and postpartum blues.Methods: A total of 475 Chinese women who have just given birth were detected serology for Toxoplasma IgG and IgM antibodies, and evaluated the degree of depression by Hamilton Depression Scale (HAMD) score. Data were analyzed by Chi-square or Fisher's Exact tests using SPSS software.Results: We found an overall Toxoplasma seroprevalence of 5.68% (27/475; 95% CI: 3.59-7.77) which was broken down into a prevalence of 6.60% (7/106; 95% CI: 1.80-11.41) in mothers with post-partum blues and 5.42% (20/369; 95% CI: 3.10-7.74) in non-affected mothers. There was no significant association between infection and post-partum blues (p = 0.64).Conclusion: The results suggest that there is no relationship between T. gondii infection and postpartum blues, at least in this sample of patients from China. [ABSTRACT FROM AUTHOR]

Abstract: Trypanosoma lewisi has widely been considered as a non-pathogenic rat trypanosome. However, more and more cases of humans infected with T. lewisi have been reported around the world, indicating that it can infect humans in some undetermined circumstances. Quick and sensitive diagnosis of infection by T. lewisi is important for both treatment of patients and epidemiological studies of this parasite. In this paper, three methods i.e. wet blood smear (diagnosis by microscopy), PCR and LAMP were used to detect T. lewisi from 238 wild rats (Rattus norvegicus) collected from the field in Huadu, Guangdong province, China. Infection rates of these samples detected by the 3 methods was 6.7% (16/238), 12.6% (30/238), and 18.9% (45/238), respectively. LAMP could detect all samples shown positive by microscopical observation of wet smear and by single PCR indicating good potential for application in the detection of T. lewisi. So far as we know, this is the first report of the LAMP method being used to detect T. lewisi in wild rats. The specific T. lewisi LAMP primers were able to amplify the target fragment from the genomic DNA of 19 T. lewisi strains isolated from Huadu, Guangdong province (n =16), Changchun, Jilin province of China (n =1) and from Thailand (n =2). Based on the analyses of ITS1 (internal transcribed spacer 1) and ITS2 sequences, these 19 strains show a very close genetic relationship with over 96–97% similarity to the other corresponding sequences of T. lewisi published in Genbank. Phylogenetic trees of the species in the subgenus Herpetosoma were constructed, based on the ITS1 and ITS2 sequences, and these results also indicate that they are closely related and in the same clade. [Copyright &y& Elsevier]