Trypanosome Species Research Articles

Molecular characterization of pathogenic African trypanosomes in biting flies and camels in surra-endemic areas outside the tsetse fly belt in Kenya

African animal trypanosomosis (nagana) is becoming prevalent beyond its traditionally defined geographical boundaries in African tsetse belts. However, knowledge of clinically important trypanosomes and infection rate in non-tsetse hematophagous flies and domestic animals are limited. This study characterized the potential mechanical vectors, their host feeding patterns, and trypanosome infection in them and domestic animals outside the tsetse belt in northern Kenya. Field-trapped flies and blood from camels, cattle, donkeys, goats, and sheep were screened for trypanosome infection by microscopy and polymerase chain reaction (PCR) of the internal transcribed spacer 1 region. Blood-fed specimens were analysed using PCR-HRM and/or sequencing of 16S rRNA gene to identify vertebrate blood-meal host sources. Hippobosca camelina, Stomoxys calcitrans, Tabanus spp., and Pangonia rueppellii were identified as potential vectors of trypanosomes outside the tsetse belt in Marsabit County. The trypanosome species, Trypanosoma vivax, T. evansi, T. brucei, and T. congolense were recovered in biting flies as well as in camels (Camelus dromedarius). The diversity of parasites in the biting flies was similar to that detected in the tsetse fly Glossina pallidipes collected from the tsetse-infested Shimba Hills, in coastal Kenya, suggesting a wide geographic distribution of the trypanosomes in Kenya. The biting flies fed on camels, cattle, goats, and sheep. Furthermore, we identified diverse clinical outcomes based on PCV (anemia), heamorrhagia) associated with infection with disparate Trypanosoma species. Thus, infection of flies and camels by diverse Trypanosoma species could contribute to the complex epidemiology of observed trypanosomosis in camels.

Glossina pallidipes Density and Trypanosome Infection Rate in Arba Minch Zuria District of Gamo Zone, Southern Ethiopia.

Background African trypanosomosis is a disease of both animals and humans resulting from infection with parasitaemic protozoa of the genus Trypanosoma transmitted mainly by the tsetse flies (Glossina species). The disease has been reported in different parts of the country. However, information on the apparent density and trypanosome infection rates of the vectors is very limited in the Southern part of Ethiopia. Therefore, this study was conducted to estimate the apparent density, infection rate of trypanosomes in Glossina pallidipes, and the trypanosome species involved in Arba Minch Zuria district of Southern Ethiopia. Methods A cross-sectional study was conducted from January to June 2018 in two purposely selected kebeles of Arbaminch Zuria district and in the escarpments of Nech Sar National Park of Southern Ethiopia. For entomological survey, a total of 40 standard NGU traps were deployed around the watering and grazing areas. A total of 300 fresh Glossina pallidipes were examined for trypanosome infection using a dissection procedure as described by the FAO Training manual for tsetse control personnel. Results The study revealed the presence of only one Glossina species, known as Glossina pallidipes, and biting flies including Stomoxys and Tabanus. A total of 2176 flies were caught of which 1803 (82.86%) belong to Glossina pallidipes and the remaining 373 (17.14%) were biting flies. The overall apparent density of Glossina pallidipes and biting flies in the study area were 15.03 fly/trap/day (F/T/D) and 3.11 F/T/D, respectively. Relatively higher Glossina pallidipes and biting flies, respectively, were caught in a wood-grass land (15.87 F/T/D and 3.69 F/T/D) and riverine forest (15.13 F/T/D and 3.42 F/T/D) than bush land vegetation types (13.87 F/T/D and 1.76 F/T/D). The overall trypanosome infection rate of Glossina pallidipes was 17.67% (53/300). Two trypanosome species, namely, Trypanosoma congolense (66.04%) and Trypanosoma vivax (33.96%), were responsible for Glossina pallidipes infection in the study area. Trypanosome infection rate was significantly higher in female G. pallidipes than in male (OR = 3.39, 95%CI = 1.53‐7.52). Significantly, higher trypanosome infection rate was observed in flies older than 20 days (OR = 2.5, 95%CI = 1.12‐5.56) and in hunger stage 1 flies (OR = 14.24, 95%CI = 4.01‐50.59). Glossina pallidipes infection was significantly higher in and around park grazing areas (OR = 3.41, 95%CI = 1.76‐6.6) and wood-grass land vegetation type (OR = 2.7, 95%CI = 1.2‐6.5). Conclusion The current study revealed high apparent density and trypanosome infection in Glossina pallidipes in Arba Minch Zuria district of Southern Ethiopia. So, this study warrants the need for strengthening both vector and parasite control strategies in the study area.

The Broad-Spectrum Antitrypanosomal Inhibitory Efficiency of the Antimetabolite/Anticancer Drug Raltitrexed

Raltitrexed is a classical antifolate drug with antimetabolite and anticancer properties. In this research, we provide its detailed antitrypanosomal inhibition against six Trypanosoma species and investigate its potential mode of action. Molecular dynamics (MD) simulations and in silico analyses were used to track the binding strength and stability. Raltitrexed showed broad-spectrum trypanocidal actions against Trypanosoma brucei brucei GUTat3.1, T. b. rhodesiense IL1501, T. b. gambiense IL1922, T. evansi Tansui, T. equiperdum IVM-t1 and T. congolense IL3000. The estimated IC50 was found to be in the range of 5.18–24.13 µg/mL, indicating inhibition of Trypanosoma in the low micromolar range. Although the co-crystallized ligand had robust hydrogen bonding and lipophilic characteristics, its docking score was only −4.6 compared to raltitrexed’s −7.78, indicating strong binding with T. brucei dihydrofolate reductase-thymidylate synthase (TbDHFR-TS). MD simulations support the strong binding of raltitrexed with TbDHFR-TS evidenced by low root mean square deviation (RMSD), low residues fluctuations, a tight radius of gyration (ROG) and an average of 3.38 ± 1.3 hydrogen bonds during 50 ns MD simulation. The prospective extended spectrum of raltitrexed against Trypanosoma species grants further research for the synthesis of raltitrexed derivatives and repurposing against other protozoa.

African trypanosome infection patterns in cattle in a farm setting in Southern Ghana

African Trypanosomiasis is a debilitating disease in both humans and animals that occurs in sub-Saharan Africa and has a severe negative impact on the livelihood of people in the affected areas. The disease is caused by protozoan parasites of the genus Trypanosoma, which is often described simply as blood-borne; however, a number of studies have shown the parasite inhabits many different environments within the host. Control of the disease involves measures that include the use of trypanocidal drugs to which there are growing number of reported cases of resistance. Here, the patterns of trypanosome DNA presence during a diminazene aceturate treatment round on a cohort of cattle in Adidome, Ghana were assessed. A group of 24 cows were selected irrespective of age and sex and the infecting trypanosome species followed for 18 days before and after treatment with diminazene aceturate in the blood and skin of the animals using a diagnostic nested PCR that targeted the alpha-beta tubulin gene array. Persistence of trypanosome DNA was observed over the period and parasite DNA was readily detected in both the skin and blood, with parasite DNA disappearing and reappearing in both across the study. Moreover, there was limited correlation between the parasite DNA detected in the skin and blood. Overall, the data show the patterns of a natural trypanosome infection during drug treatment. In addition, the diagnostic potential of sampling the skin for African trypanosomiasis is highlighted.

Sodalis glossinidius and Wolbachia infections in wild population of Glossina morsitans submorsitans caught in the area of Lake Iro in the south of Chad

Investigations on the bacterial fauna and their association with trypanosome infections in tsetse fly have revealed contrasting results. This study aimed to detect Wolbachia and S. glossinidius in wild populations of G. m. submorsistans and subsequently, understand the influence that these bacteria may have on the vectorial competence of this tsetse species. Tsetse flies were captured in the area of Lake Iro in the south of Chad using biconical traps. After DNA extraction from each tsetse fly, Sodalis glossinidius and Wolbachia were detected using specific primers. Sodalis glossinidius and Wolbachia infection rates were compared and association studies involving trypanosome infections and S. glossinidius or Wolbachia were performed. From 345 G. m. submorsitans analyzed, 9.0% and 14.5% were respectively infected with S. glossinidius and Wolbachia. Only 2.31% of all tsetse flies were co-infected by the 2 bacteria. Of all trypanosome-infected flies, 7.1% and 9.8% harbored, respectively, S. glossinidius and Wolbachia. No association was observed between Wolbachia and trypanosome infections while a significant association (r = 4.992; P = 0.025) was found between S. glossinidius and the presence of trypanosomes. A significant association (r = 3.147; P = 0.043) was also observed between S. glossinidius and T. simiae; and none with T. congolense or T. godfreyi. This study revealed S. glossinidius and Wolbachia in G. m. submorsitans of the area of lake Iro. It showed that co-infections between Wolbachia and S. glossinidius are rare in wild populations of G. m. submorsitans and that the tripartite associations vary according to trypanosome species as well as symbiotic mricroorganisms.

Molecular survey of Babesia, Theileria, Trypanosoma, and Anaplasma infections in camels (Camelus dromedaries) in Egypt.

The one-humped camel (Camelus dromedarius) or dromedary is an economically important domestic animal. However, infectious diseases, including those caused by vector-borne hemopathogens, frequently compromise the health and production of camels. In this study, we examined infections caused by Babesia, Theileria, Trypanosoma, and Anaplasma species in camels in Egypt. We analyzed blood DNA samples from 148 camels reared in six Egyptian governorates (Giza, Asyut, Sohag, Qena, Luxor, and the Red Sea) using pathogen-specific Polymerase Chain Reaction (PCR) assays. Our results indicated that 29 (19.6%), 22 (14.9%), 1 (0.7%), 2 (1.4%), 1 (0.7%), 2 (1.4%), and 28 (18.9%) of the surveyed animals were infected with Babesia bovis, B. bigemina, Babesia sp. Mymensingh, Theileria sp. Yokoyama, Theileria equi, Trypanosoma evansi, and Anaplasma marginale, respectively. We found that a total of 68 (45.9%) animals were infected with at least one of the detected hemopathogens. Sequencing analyses of PCR amplicons confirmed our diagnostic results. This study is the first to report Theileria sp. Yokoyama and Babesia sp. Mymensingh in Egypt. This is also the first report of infection with these two species in one-humped camel. In conclusion, this study found that camels in Egypt are infected with several vector-borne hemopathogens, including novel parasite species.

Structure-based design, synthesis and evaluation of a novel family of PEX5-PEX14 interaction inhibitors against Trypanosoma

Trypanosomiases are neglected tropical diseases caused by Trypanosoma (sub)species. Available treatments are limited and have considerable adverse effects and questionable efficacy in the chronic stage of the disease, urgently calling for the identification of new targets and drug candidates.Recently, we have shown that impairment of glycosomal protein import by the inhibition of the PEX5-PEX14 protein-protein interaction (PPI) is lethal to Trypanosoma. Here, we report the development of a novel dibenzo[b,f][1,4]oxazepin-11(10H)-one scaffold for small molecule inhibitors of PEX5-PEX14 PPI. The initial hit was identified by a high throughput screening (HTS) of a library of compounds. A bioisosteric replacement approach allowed to replace the metabolically unstable sulphur atom from the initial dibenzo[b,f][1,4]thiazepin-11(10H)-one HTS hit with oxygen. A crystal structure of the hit compound bound to PEX14 surface facilitated the rational design of the compound series accessible by a straightforward chemistry for the initial structure-activity relationship (SAR) analysis. This guided the design of compounds with trypanocidal activity in cell-based assays providing a promising starting point for the development of new drug candidates to tackle trypanosomiases.

In silico analysis of the HSP90 chaperone system from the African trypanosome, Trypanosoma brucei.

African trypanosomiasis is a neglected tropical disease caused by Trypanosoma brucei (T. brucei) and spread by the tsetse fly in sub-Saharan Africa. The trypanosome relies on heat shock proteins for survival in the insect vector and mammalian host. Heat shock protein 90 (HSP90) plays a crucial role in the stress response at the cellular level. Inhibition of its interactions with chaperones and co-chaperones is being explored as a potential therapeutic target for numerous diseases. This study provides an in silico overview of HSP90 and its co-chaperones in both T. brucei brucei and T. brucei gambiense in relation to human and other trypanosomal species, including non-parasitic Bodo saltans and the insect infecting Crithidia fasciculata. A structural analysis of T. brucei HSP90 revealed differences in the orientation of the linker and C-terminal domain in comparison to human HSP90. Phylogenetic analysis displayed the T. brucei HSP90 proteins clustering into three distinct groups based on subcellular localizations, namely, cytosol, mitochondria, and endoplasmic reticulum. Syntenic analysis of cytosolic HSP90 genes revealed that T. b. brucei encoded for 10 tandem copies, while T. b. gambiense encoded for three tandem copies; Leishmania major (L. major) had the highest gene copy number with 17 tandem copies. The updated information on HSP90 from recently published proteomics on T. brucei was examined for different life cycle stages and subcellular localizations. The results show a difference between T. b. brucei and T. b. gambiense with T. b. brucei encoding a total of twelve putative HSP90 genes, while T. b. gambiense encodes five HSP90 genes. Eighteen putative co-chaperones were identified with one notable absence being cell division cycle 37 (Cdc37). These results provide an updated framework on approaching HSP90 and its interactions as drug targets in the African trypanosome.

Diversity of tsetse flies and trypanosome species circulating in the highly infested cattle rearing area of the Faro and Deo subdivision, Adamawa region, Cameroon

Animal African Trypanosomiasis (AAT) remains an animal health problem in sub-Saharan Africa and in Cameroon in particular. Despite more than 40 years of fighting against AAT in some tsetse infested areas, the disease prevalence is still a concern. Improving the control strategies in different settings requires to understand the current epidemiological situation of AAT. The aim of the present study was to update our knowledge on the diversity of tsetse fauna and trypanosome species in the tsetse infested area of Faro and Deo division, Adamawa region, Cameroon. Tsetse flies were caught using Vavoua trap in two villages and the apparent density per trap (ADP) were estimated. After morphological identification of tsetse fly species, flies were dissected and their midguts recovered. The presence of blood meal residues was recorded. Trypanosomes species were checked in the flies' midguts by microscopy followed by PCR method. The vertebrate taxa on which tsetse flies have taken blood meal were determined using the heteroduplex-PCR method. A total of 338 tsetse flies including 11 teneral flies (10 Glossina palpalis palpalis and 01 G. morsitans submorsitans) and 327 non-teneral were trapped in Mayo Lainde and Tchabal Mbabo. Amongst the caught tsetse flies, of the 327 non-teneral flies, 315 (96.3%) were G. p. palpalis, 8 (2.4%) were G. morsitans submorsitans and 4 (1.2%) G. fuscipes fuscipes. Trypanosome infections including Trypanosoma congolense forest (19.88%) and savanah (2.53%) “types”, T. brucei s.l. (7.30%) and T. vivax (2.85%) were identified in 45.08% of non-teneral flies (32.38% for single infection and 12.70% for mixed infection). Amongst the 54 blood meals identified in tsetse midguts, 41% were from humans, 33% from cattle and 26% from other vertebrate hosts. About 51.9% of blood meals were found with various trypanosome species including 42.6% with T. congolense and 24% with T. brucei s.l. This study revealed the presence of three tsetse taxa and the circulation of four trypanosome taxa in villages of the Faro and Deo division. About 45% of captured tsetse fly are infected with trypanosome species causing AAT. Tsetse flies feed on humans, cattle and many other vertebrates. Strategies to eliminate the vectors must be improved to reduce the pathological impacts of trypanosome infections in this area.

Investigation on Prevalence of Canine Trypanosomiasis in the Conservation Areas of Bwindi-Mgahinga and Queen Elizabeth in Western Uganda.

Nowadays, despite the instauration of several control strategies, animal trypanosomiasis continues to be reported all over Uganda. Few canine African trypanosomiasis (CAT) studies have been carried out, yet dogs are known Trypanosoma reservoirs that share identical home ranges with livestock and serve as parasite link between livestock and humans. This study evaluates the prevalence of CAT in dogs in the Bwindi-Mgahinga and Queen Elizabeth conservation areas. This information will be useful to evaluate the possible role of dogs in the transmission cycle of Trypanosoma species in livestock and wild animals. Trypanosome tests using microhematocrit centrifugation/dark ground microscopy technique (MHCT) followed by conventional polymerase chain reaction (cPCR) were performed in blood samples collected from identified indigenous dogs (n = 124). Four (3.23%) out of 124 dogs were positive for CAT. One dog was positive with Trypanosoma congolense and three with T. vivax. There was no significant statistical difference in CAT prevalence rate in relation to dog's age, sex, and site (P > 0.05). This study reports what we believe is the first time detection of T. congolense and T. vivax in the indigenous dogs found in the Bwindi-Mgahinga and Queen Elizabeth conservation areas in western Uganda. The noticed T. congolense and T. vivax could be responsible for both canine and animal trypanosomiasis and represent a serious threat to the livestock industry. Therefore, there is a need for continuous trypanosomiasis surveillance and integrated management in contiguity to wildlife reserves.

Evaluation of antibody responses to tsetse fly saliva in domestic animals in the sleeping sickness endemic foci of Bonon and Sinfra, Côte d'Ivoire.

After intensive control efforts, human African trypanosomiasis (HAT) was declared eliminated in Côte d'Ivoire as a public health problem in December 2020 and the current objective is to achieve the interruption of the transmission (zero cases). Reaching this objective could be hindered by the existence of an animal reservoir of Trypanosoma (T.) brucei (b.) gambiense. In the framework of a study led in 2013 to assess the role of domestic animals in the epidemiology of HAT in the two last active foci from Côte d'Ivoire (Bonon and Sinfra), plasmas were sampled from four species of domestic animals for parasitological (microscopic examination by the buffy coat technique (BCT)), serological (immune trypanolysis (TL)) and molecular (specific PCR: TBR for T. brucei s.l., TCF for T. congolense forest type, TVW for T. vivax and PCR for T. b. gambiense) testing. In order to improve the understanding of the involvement/role of these animals in the transmission of T. b. gambiense, we have quantified in this study the IgG response to whole saliva extracts of Glossina palpalis gambiensis in order to perform an association analysis between anti-saliva responses and the positivity of diagnostic tests. Cattle and pigs had significantly higher rates of anti-tsetse saliva responses compared to goats and sheep (p<0.01). In addition, the anti-tsetse saliva responses were strongly associated with the parasitology (BCT+), serology (TL+) and PCR (TBR+ and TCF+) results (p<0.001). These associations indicate a high level of contacts between the positive/infected animals and tsetse flies. Our findings suggest that protecting cattle and pigs against tsetse bites could have a significant impact in reducing transmission of both animal and human trypanosome species, and advocates for a "One health" approach to better control African trypanosomosis in Côte d'Ivoire.

Incidence of Bovine Trypanosomosis and the Distribution of Vector in Chora District of Buno Bedele Zone, Oromia Region, Ethiopia

Bovine Trypanosomosis is one of the most parsimoniously problematic diseases in influencing mammals like cattle and it is a grave haemoprotozoan disease triggered by different species of unicellular eurykaryotic parasite of the genus trypanosome. This study was conducted to assess the incidence of Bovine Trypanosomosis, and density of vector distribution as well as the influence of its associated risk factors on cattle reared in Chora district of Buno Bedele Zone. A Blood sample was collected from a total of 401 cattle of age ranges from 1 to 6 years. The presence of parasites from sampled blood was examined using a method of Buffy Coat Technique and a technique of Giemsa-stained thin blood films was used to identify the existing trypanosome species in the study area. The Packed Cell Volume (PCV) of collected blood samples was determined using haematocrit. A total of 50 traps were deployed to study the entomological survey. In general, 2.99 % of the studied cattle were infected with Trypanosomosis and the T.Vivax (58.33%) was the dominant species of trypanosomosis and followed by T. congulense (41.67%) in the study area. Statistically significant differences (P&lt;0.05) were observed due to associated risk factors viz. Body Condition and age of cattle, whereas sampling sites and sex were not significantly affect the prevalence of Bovine Trypanosomosis. The mean PCV value of Parasitaemic and Aparasitaemic animals were 21.37 ± 0.19 and 27.89 ± 0.16, respectively and they were statistically different at (P&lt; 0.05). Overall of 0.80 flies per trap per day was recorded from the study area and among the caught flies of Glossina species, 10%, 54% and 36% of them were, G.tachinoides, G.pallidipes and G.fuscipes, respectively. Therefore, the veterinarian’s has to continue providing the appropriate medication/treatment for the infected animals per appropriate recommendation and Bedele NTTICC has to take more focus to control the density and distribution of tsetse flies as well as biting flies for the transmission of high incidence of T. Vivax through mechanical ways of transmission of the disease. Keywords: Cattle, Incidence, Prevalence, T. Vivax, T. Congulense DOI: 10.7176/JBAH/12-17-03 Publication date: September 30 th 2022

The History of the ABC Proteins in Human Trypanosomiasis Pathogens

Human trypanosomiasis affects nearly eight million people worldwide, causing great economic and social impact, mainly in endemic areas. T. cruzi and T. brucei are protozoan parasites that present efficient mechanisms of immune system evasion, leading to disease chronification. Currently, there is no vaccine, and chemotherapy is effective only in the absence of severe clinical manifestations. Nevertheless, resistant phenotypes to chemotherapy have been described in protozoan parasites, associated with cross-resistance to other chemically unrelated drugs. Multidrug resistance is multifactorial, involving: (i) drug entry, (ii) activation, (iii) metabolism and (iv) efflux pathways. In this context, ABC transporters, initially discovered in resistant tumor cells, have drawn attention in protozoan parasites, owing to their ability to decrease drug accumulation, thus mitigating their toxic effects. The discovery of these transporters in the Trypanosomatidae family started in the 1990s; however, few members were described and functionally characterized. This review contains a brief history of the main ABC transporters involved in resistance that propelled their investigation in Trypanosoma species, the main efflux modulators, as well as ABC genes described in T. cruzi and T. brucei according to the nomenclature HUGO. We hope to convey the importance that ABC transporters play in parasite physiology and chemotherapy resistance.

Molecular Identification of Trypanosome Diversity in Domestic Animals Reveals the Presence of Trypanosoma brucei gambiense in Historical Foci of Human African Trypanosomiasis in Gabon.

Human African Trypanosomiasis (HAT) is an infectious disease caused by protozoan parasites belonging to the Trypanosoma genus. In sub-Saharan Africa, there is a significant threat as many people are at risk of infection. Despite this, HAT is classified as a neglected tropical disease. Over the last few years, several studies have reported the existence of a wide diversity of trypanosome species circulating in African animals. Thus, domestic and wild animals could be reservoirs of potentially dangerous trypanosomes for human populations. However, very little is known about the role of domestic animals in maintaining the transmission cycle of human trypanosomes in central Africa, especially in Gabon, where serious cases of infection are recorded each year, sometimes leading to hospitalization or death of patients. Komo-Mondah, located within Estuaries (Gabonese province), stays the most active HAT disease focus in Gabon, with a mean of 20 cases per year. In this study, we evaluated the diversity and prevalence of trypanosomes circulating in domestic animals using the Polymerase Chain Reaction (PCR) technique. We found that 19.34% (53/274) of the domestic animals we studied were infected with trypanosomes. The infection rates varied among taxa, with 23.21% (13/56) of dogs, 16.10% (19/118) of goats, and 21.00% (21/100) of sheep infected. In addition, we have observed a global mixed rate of infections of 20.75% (11/53) among infected individuals. Molecular analyses revealed that at least six Trypanosome species circulate in domestic animals in Gabon (T. congolense, T. simiae, T. simiae Tsavo, T. theileri, T. vivax, T. brucei (including T. brucei brucei, and T. brucei gambiense)). In conclusion, our study showed that domestic animals constitute important potential reservoirs for trypanosome parasites, including T. brucei gambiense, which is responsible for HAT.

Clinical Diagnosis and Therapeutic Management of Trypanosoma theileri Infection Associated with Peritonitis in Crossbred Cow: A Rare Case Report

The present study reports a very rare case of Trypanosoma theileri like infection in the peritoneal fluid of a 6-year-old female Holstein Friesian (HF) cattle brought to Veterinary Clinical Complex, Lala Lajpat Rai University of Veterinary and Animal Sciences (LUVAS), Hisar. The aim of the clinical study was to report an unusual case of T. theileri-like infection associated with peritonitis and its therapeutic management. For confirmatory diagnosis, peritoneal fluid and blood sample was collected from animal for haemato-biochemical examination, buffy coat examination and detection of Trypanosoma antigen by monoclonal antibody-based latex agglutination test. Animal had history of anorexia, high fever, oedematous swelling on the abdominal area and decrease in milk yield since 1 week. Clinical examination revealed high fever, congested conjunctival mucus membrane and oedematous inflammatory swelling on the abdominal region. Haematological examination on Day 1 revealed relative neutrophilia and eosinophilia, whereas other parameters measured were on the lower side of normal range. Thin blood smear examination did not reveal any parasite on first attempt. However, after confirmation of Trypanosoma species in peritoneal fluid collected by FNAC, buffy coat examination of blood sample was also found positive for Trypanosoma species. On Day 2, haematological examination revealed neutrophilic leucocytosis, eosinophilia and anaemia. Blood sample was also found serologically positive for Trypanosoma antigen by monoclonal antibody based latex agglutination test. Biochemical examination revealed increased blood urea nitrogen (BUN), gamma glutamyl transferase (GGT) levels, hyperglycemia, hyperprotienemia and decreased levels of sodium and chloride ions. Animal was primarily treated with isometamidium chloride (Nyzom®) @ 0.5mg/kg body weight (IM, single dose) along with supportive therapy. Animal showed clinical recovery after 10days of treatment. Post-recovery, blood sample of the animal was re-examined for parasite and other blood parameters and it was found negative for presence of Trypanosoma infection along with restoration of haematological values. Hence, the present study concludes the confirmatory diagnosis and therapeutic use of isometamidium hydrochloride along with anti-inflammatory drugs to Trypanosoma infection.

Unexpectedly high diversity of trypanosomes in small sub-Saharan mammals

The extremely species-rich genus Trypanosoma has recently been divided into 16 subgenera, most of which show fairly high host specificity, including the subgenus Herpetosoma parasitizing mainly rodents. Although most Herpetosoma spp. are highly host-specific, the best-known representative, Trypanosoma lewisi, has a cosmopolitan distribution and low host specificity. The present study investigates the general diversity of small mammal trypanosomes in East and Central Africa and the penetration of invasive T. lewisi into communities of native rodents. An extensive study of blood and tissue samples from Afrotropical micromammals (1528 rodents, 135 shrews, and five sengis belonging to 37 genera and 133 species) captured in the Central African Republic, Ethiopia, Kenya, Malawi, Mozambique, Tanzania, and Zambia revealed 187 (11.2%) trypanosome-positive individuals. The prevalence of trypanosomes in host genera ranged from 2.1% in Aethomys to 37.1% in Lemniscomys. The only previously known trypanosome detected in our dataset was T. lewisi, newly found in Ethiopia, Kenya, and Tanzania in a wide range of native rodent hosts. Besides T. lewisi, 18S rRNA sequencing revealed 48 additional unique Herpetosoma genotypes representing at least 15 putative new species, which doubles the known sequence-based diversity of this subgenus, and approaches the true species richness in the study area. The other two genotypes represent two new species belonging to the subgenera Ornithotrypanum and Squamatrypanum. The trypanosomes of white-toothed shrews (Crocidura spp.) form a new phylogroup of Herpetosoma, unrelated to flagellates previously detected in insectivores. With 13 documented species, Ethiopia was the richest region for trypanosome diversity, which corresponds to the very diverse environments and generally high biodiversity of this country. We conclude that besides T. lewisi, the subgenus Herpetosoma is highly host-specific (e.g., species parasitizing the rodent genera Acomys and Gerbilliscus). Furthermore, several newly detected trypanosome species are specific to their endemic hosts, such as brush-furred mice (Lophuromys), dormice (Graphiurus), and white-toothed shrews (Crocidura).

Molecular detection of Trypanosoma spp. and Hepatocystis parasite infections of bats in Northern Nigeria.

Bats are mammalian hosts to a large diversity of eukaryotic protozoan blood parasites, including different genera of haemosporidians and diverse species of trypanosomes. Phylogenetic studies suggest that bats, particularly in Africa, have played an important role in the evolutionary histories of these parasite groups. However, our understanding of the diversity and distribution of chiropteran haemosporidians and trypanosomes in Africa remains tenuous. We investigated the prevalence and phylogenetic relationships of the blood parasites in different bat species in Northern Nigeria using molecular methods. A low prevalence of Hepatocystis parasites was detected in a potentially rare host species, the African straw-coloured fruit bat (Eidolon helvum) confirming yet another fruit bat species in the diverse range of African bat hosts. Trypanosome infections were identified in 3 different bat species. The trypanosomes of Mops cf. pumilus were recovered as a distinct lineage that is related to Trypanosoma erneyi, a species which is closely related to Trypanosoma dionisii and Trypanosoma cruzi. Nycteris cf. macrotis bats were infected with trypanosomes that are related to the distinct lineage of Trypanosoma cf. livingstonei parasites. Further, 2 different lineages of trypanosomes in E. helvum bats share highest nucleotide identities with Trypanosoma livingstonei and a group of Trypanosoma sp. parasites that are closely related to T. cf. livingstonei and T. livingstonei, respectively. The findings of this study confirm the notion that trypanosomes of African bats are phylogenetically diverse and that African bats might harbour a variety of yet undescribed trypanosome species.

Molecular survey of Trypanosoma congolense “Forest-Type” in Nigerian cattle

African animal trypanosomosis is an important livestock disease in Nigeria which is considered as a threat to the on-going effort on poverty alleviation in the continent. The disease is caused by several Trypanosoma species which are protozoan parasites transmitted by tsetse. Trypanosomosis is characterized by tissue injury including overwhelming activation of Classical Myeloid cells that results in destruction of the liver and uncontrolled parasite growth. Reduction in production and sometimes death are disease sequella. Hence, proper surveillance of the disease using a sensitive tool is very necessary for monitoring and control of trypanosomosis. Therefore this study concentrated on providing knowledge on the true infection rate of Trypanosoma congolense “forest type” and its effect on body weight and haematological parameters. Blood sample was collected from 180 cattle, DNA was extracted and PCR technique was adopted for prevalence study. Haematological analysis was carried out using Auto-haemo-analyser. Data generated were analysed using SAS statistical package. A prevalence rate of 91.67% was recorded. There were significant (p&lt;0.05) differences between Body-weight, Red Blood Cell count, Mean Corpuscular Volume and Monocyte number of infected and un-infected cattle. The haematology reveals that hosts were able to respond to anaemia compensatorily as perceived in the macro-cytic, normo-chromic status of the peripheral blood erythrocytic generation. The study concluded that the true prevalence of trypanosome infection is high and has both epidemiological and economic importance. This study `provides information that could facilitate future monitoring and control of the disease in the study area.

Parasitological and molecular identification of Trypanosoma species circulating in cattle and tsetse flies in Matutuine District, Maputo Province, Mozambique

Tsetse flies (Diptera: Glossinidae) are haematophagous insects of medical and veterinary importance due to their role in the transmission of trypanosomes. Tsetse-transmitted trypanosomosis is one of the major constraints to agriculture and livestock development in sub-Saharan Africa. Thus, the importance of the assessment of the distribution of both disease and vector in areas where cattle are kept, as is the case of Matutuíne district, where the last longitudinal study was conducted in 2000. From March 2009 to December 2012, 2427 bovine blood samples were collected in five administrative areas of Matutine district (Bela Vista, Zitundo, Catuane, Catembe and Machangulo). For each animal, the packed cell volume (PCV) was determined and blood examined for the presence of motile trypanosomes using microscopy. At the same time, tsetse flies were also captured. Additionally, DNA was extracted from both cattle blood and tsetse flies. The samples were further analysed using the 18S PCR–RFLP. Trypanosome infections in bovines were detected in all Matutuíne´s administrative areas. The overall prevalence of trypanosome infections was 15.62% by buffy coat and 47.34% by molecular testing. A total of 1379 tsetse flies (1379 Glossina brevipalpis and 150 G. austeni) were captured. From this, 408 were analysed by 18S PCR for the presence of trypanosomes. The results showed a percentage of infection of 12.74% and 3.19% for G. brevipalpis and G. austeni, respectively. With these results, it is concluded that tsetse-transmitted trypanosomosis is a major threat to cattle in Matutuine and control actions need to be implemented.

Molecular detection and therapeutic study of Trypanosoma brucei evansi from naturally infected horses in Punjab, Pakistan.

Trypanosomiasis is one of the severe pathogenic infections, caused by several Trypanosoma species, affecting both animals and humans, causing substantial economic losses and severe illness. The objective of this study was to determine the molecular diagnosis and the risk factors associated with trypanosomiasis in District Jhang, Punjab, Pakistan. For this purpose, blood samples were randomly collected from 200 horses. A predesigned questionnaire was used to collect data on risk factors before the sample collection. The microscopy examination through Giemsa staining, formol gel test and PCR techniques were used to find the prevalence. The prevalence was recorded as 22.5% with microscopy examination, 21% through formol gel test and 15.5% with PCR based results. Analysis of risk factors associated with Trypanosoma brucei evansi occurrence was carried out using Chi-square test. It showed the prevalence of Trypanosoma brucei evansi was significantly (p⟨0.05) associated with sex, age, rearing purpose and body condition whereas non-significantly (p⟩0.05) with insects control practices. This study supports the idea that PCR is a sensitive, robust and more reliable technique to diagnose trypanosomiasis. It was concluded that Trypanosoma brucei evansi is widely prevalent in Jhang (Pakistan), highlighting a dire need to develop control strategies and education programmes to control this disease in developing countries.