Tabanus chrysurus is a potential biological vector of Trypanosoma (Megatrypanum) theileri in Japan.

Several species of horse flies (Diptera: Tabanidae) are known as vectors of Trypanosoma (Megatrypanum) theileri and T. theileri-like trypanosomes; these host-parasite relationships were established based on the developmental stages of these parasites discovered in the hindgut of horse flies. T. theileri and T. theileri-like trypanosomes have been detected in cattle and wild deer in Japan; however, the vector horse fly species remains unidentified. Therefore, in this study, we aimed to identify the potential horse fly species serving as vectors of T. theileri in Japan. A total of 176 horse flies were collected between June to September 2020 and 2021 in Tokachi, Hokkaido, Japan. The T. theileri infection in the captured horse flies was determined by PCR and microscopic analyses of their midgut and hindgut. Additionally, the trypanosome, microscopically detected in a horse fly, was molecularly characterized and phylogenetically analyzed using 18S rRNA and partial cathepsin L-like protein gene (CATL) sequence of the trypanosome. The microscopy and PCR analyses revealed 0.57% and 35.8% prevalence of T. theileri in horse flies, respectively. Epimastigote stages of T. theileri, adhered to the hindgut epithelial cells of Tabanus chrysurus via flagella or actively moving in the lumen of the gut, were detected. Phylogenetic analysis revealed the connection of isolated trypanosomes with T. theileri in the TthI clade. These results suggest that Ta. chrysurus is a potential vector of T. theileri.

Molecular Detection of Animal Trypanosomes in Different Animal Species in the Visayas Region of the Philippines.

PURPOSE: Animal trypanosomosis is one of the most important parasitic diseases significantly affecting the Philippine economy. It is considered by the government to be the second most important disease of livestock after fasciolosis. A PCR-based molecular survey for trypanosomes in different animals in Bohol, Philippines, was performed to assess the prevalence of trypanosomosis in the area during the rainy and dry season. METHODS: A total of 269 blood samples were collected in two batches in rainy and dry season from different animal species in Ubay Stock Farm in Ubay, Bohol, the Philippines, including 151 samples from water buffaloes, 76 samples from cattle, 35 samples from goats, and 7 samples from horses. DNA was subsequently extracted from these blood samples, and two different PCR assays were employed to detect and identify trypanosomes DNA including ITS1 PCR and CatL PCR. RESULTS: Animal trypanosomes, Trypanosoma evansi and Trypanosoma theileri, were detected in water buffalo (37.7%) [95%CI: 30.4 - 45.7], cattle (44.7%) [95%CI: 34.1 - 55.9], and goats (34.3%) [95%CI: 20.8 - 50.8]. Only T. evansi was detected in horses (28.6%) [95% CI: 8.2 - 64.1]. No clinical signs were observed in all positive animals. CONCLUSION: This highlights the importance of domestic animals that can be infected with no signs but may act as reservoir animals and transmit trypanosomosis to susceptible animals. This study supports the importance of regular surveillance to estimate the prevalence of the disease, emphasizing its various dynamics in the affected areas and supporting efficient intervention measures.

Therapeutic Efficacy of Orally Administered Nitrofurantoin against Animal African Trypanosomosis Caused by Trypanosoma congolense Infection.

Animal African trypanosomosis (AAT) leads to emaciation and low productivity in infected animals. Only six drugs are commercially available against AAT; they have severe side effects and face parasite resistance. Thus, the development of novel trypanocidal drugs is urgently needed. Nitrofurantoin, an antimicrobial, is used for treating bacterial urinary tract infections. Recently, we reported the trypanocidal effects of nitrofurantoin and its analogs in vitro. Furthermore, a nitrofurantoin analog, nifurtimox, is currently used to treat Chagas disease and chronic human African trypanosomiasis. Thus, this study was aimed at evaluating the in vivo efficacy of nitrofurantoin in treating AAT caused by Trypanosoma congolense. Nitrofurantoin was orally administered for 7 consecutive days from 4 days post-infection in T. congolense-infected mice, and the animals were observed for 28 days. Compared to the control group, the treatment group showed significantly suppressed parasitemia at 6 days post-infection. Furthermore, survival was significantly prolonged in the group treated with at least 10 mg/kg nitrofurantoin. Moreover, 100% survival and cure was achieved with a dose of nitrofurantoin higher than 30 mg/kg. Thus, oral nitrofurantoin administration has potential trypanocidal efficacy against T. congolense-induced AAT. This preliminary data will serve as a benchmark when comparing future nitrofurantoin-related compounds, which can overcome the significant shortcomings of nitrofurantoin that preclude its viable use in livestock.

First molecular survey of animal trypanosomes in Paraguayan horses.

Despite the epidemic situation of animal trypanosomosis caused by Trypanosoma evansi, Trypanosoma equiperdum and Trypanosoma vivax in South American countries, there are no reports for the prevalence of animal trypanosomes in Paraguay. In this study, 408 blood samples were obtained from apparently healthy horses from sixteen departments of Paraguay, for routine medical check-up from August to September 2019, and a polymerase chain reaction (PCR)-based cross-sectional study was carried out to identify trypanosome prevalence. The prevalence of Trypanozoon (T. evansi and T. equiperdum) and T. vivax was 7.11% (29/408) and 26.23% (107/408), respectively. Mixed infections were detected in 4.90% (20/408) of the samples. Some of the selected trypanosome positive samples were confirmed as T. vivax and T. evansi Type A by sequence analysis of the internal transcribe spacer region and RoTat1.2 variant surface glycoprotein gene, respectively. In conclusion, we found higher prevalence of T. vivax than Trypanozoon in Paraguayan horses. However, the genotypic variation should be verified in further studies.

First molecular detection and identification of Trypanosoma evansi in goats from Cebu, Philippines using a PCR-based assay.

The increasing number and severity of surra outbreaks in the Philippines led the government to consider it as the second most important disease of livestock in the country. It is one of the most economically important animal parasitic diseases and has been reported in several animal species, including water buffaloes, cattle, and horses in different regions of the Philippines. However, it has not yet been reported in Cebu, the usual gateway of livestock trade in the area that raises 6% of the 3.75 million goats in the country. In the current study, a PCR-based assay was conducted for the molecular detection and characterization of Trypanosoma evansi in goats in Cebu. A total of 251 goats were randomly sampled from four farms. DNA was extracted and ITS1-PCR was applied to detect different trypanosomes in goats. Eighty-five out of the 251 (33.9%) samples tested positive for T. evansi, two of which were also positive for T. theileri-like trypanosome. The detection rate of T. evansi was slightly higher in male goats (38.3%) than in females (32.5%), and in younger goats (34.5%) than in adults (33.5%). The findings, however, did not differ significantly to suggest any association between sex and age with T. evansi infection in goats. The detection of T. evansi and T. theileri-like trypanosome in goats was confirmed by sequence analysis of ITS1 region. To our knowledge, this is the first report on the molecular detection and identification of caprine T. evansi infection in Cebu, Philippines.

Serological and molecular detection of selected hemoprotozoan parasites in donkeys in West Omdurman, Khartoum State, Sudan.

In Sudan, donkeys are important animals, providing transportation and income possibilities. However, the prevalence of parasites in donkeys in Sudan has not been thoroughly characterized. Accordingly, in this study, we aimed to detect selected hemoprotozoan parasites in donkeys in West Omdurman, Khartoum State, Sudan, wherein people depend mainly on donkeys for their daily life. In total, 198 blood samples collected from donkeys in a local market in West Omdurman, were screened using serological and molecular diagnostic techniques. Serologically, 52 (26.3%), 56 (28.3%), and 19 (9.6%) samples were positive for trypanosomosis using Card Agglutination Test for Trypanosoma evansi, Trypanosoma evansi crude antigen -based enzyme-linked immuno sorbent assay (ELISA) and recombinant Trypanosoma evansi GM6-4r-based ELISA, respectively. ELISA for equine piroplasmosis revealed 156 (78.8%) and 10 (5.1%)Theileria equi- and Babesia caballi-positive samples, respectively. PCR detected Trypanosoma congolense, subgenus Trypanozoon, Theileria equi, and Babesia caballi in 18 (9.1%), 77 (38.9%), 18 (9.1%), and 8 (4%) samples, respectively. Of the 77 Trypanozoon-positive samples, 35 (45.5%) were confirmed as Trypanosoma evansi type A. To our knowledge, this is the first report of detection of Trypanosoma congolense in donkeys outside of tsetse-infested areas in Sudan.

Molecular characterization of a new Trypanosoma (Megatrypanum) theileri isolate supports the two main phylogenetic lineages of this species in Japanese cattle.

Trypanosoma (Megatrypanum) theileri is a cosmopolitan, usually non-pathogenic, trypanosome of cattle transmitted by blood-sucking arthropods, mainly tabanid flies. Several T. theileri strains isolated from domestic and wild ruminants via co-culturing with mammalian feeder cells or blood cells have been characterized morphologically and genetically. Here, we cultured a new trypanosome isolate from a Holstein cow in Hokkaido, Japan, and performed morphological and molecular characterization studies. The new isolate (Obihiro strain) was co-cultivated with Madin-Darby bovine kidney (MDBK) cells in GIT medium supplemented with 10% fetal bovine serum. Trypomastigotes and epimastigotes, but not intracellular parasites, were identified in the culture. Analysis of the V7-V8 region of 18S rRNA sequences showed that the Obihiro strain is positioned within the subgenus Megatrypanum. A dendrogram based on whole internal transcribed spacer rDNA sequence showed that the Obihiro strain clustered in the lineage TthII together with the Japanese isolates of T. theileri, Esashi 9, and Esashi 12, and isolates from Zambia and the USA. T. theileri of the KM strain and a T. theileri-like trypanosome isolated from deer (TSD1 strain) clustered in the lineage TthI, separate from the Obihiro strain. Based on a partial cathepsin L-like protein gene analysis, the Obihiro strain clustered with isolates of the TthIIF genotype, which includes T. theileri from Vietnam, Sri Lanka, and Brazil. Our analyses of the T. theileri Obihiro strain provide relevant insights into its genetic diversity in Japanese cattle and corroborate the host specificity of cattle and deer trypanosomes of the subgenus Megatrypanum.

A nosocomial transmission of crimean-congo hemorrhagic fever to an attending physician in North Kordufan, Sudan.

BACKGROUND: Crimean-Congo hemorrhagic fever (CCHF), a tick-borne disease caused by Crimean-Congo hemorrhagic fever virus (CCHFV), is a member of the genus Nairovirus in the family Bunyaviridae. Recently, CCHFV has been reported as an important emerging infectious viral pathogen in Sudan. Sporadic cases and multiple CCHF outbreaks, associated with nosocomial chain of transmission, have been reported in the Kordufan region of Sudan. AIMS: To confirm CCHF in an index patient and attending physician in North Kordufan region, Sudan, and to provide some information on virus genetic lineages. METHODS: Antibody captured ELISA, reverse transcription PCR, partial S segment sequences of the virus and subsequent phylogenetic analysis were used to confirm the CCHFV infection and to determine the virus genetic lineages. RESULTS: CCHF was confirmed by monitoring specific IgM antibody and by detection of the viral genome using RT-PCR. Treatment with oral ribavirin, replacement with fluid therapy, blood transfusion and administration of platelets concentrate resulted in rapid improvement of the health condition of the female physician. Phylogenetic analysis of the partial S segment sequences of the 2 CCHFV indicates that both strains are identical and belong to Group III virus lineage, which includes viruses from Africa including, Sudan, Mauritania, South Africa and Nigeria. CONCLUSION: Further epidemiologic studies including, CCHFV complete genome analysis and implementation of improved surveillance are urgently needed to better predict and respond to CCHF outbreaks in the Kordufan region, Sudan.