A review on the diagnosis of animal trypanosomoses

Ticks as vectors of Trypanosomatidae with medical or veterinary interest: Insights and implications from a comprehensive systematic review and meta-analysis

Since the 20th century, numerous studies have detected or isolated parasites from the Trypanosomatidae family in various tick species. However, the status of ticks as vectors for medically or veterinary significant Trypanosoma and Leishmania remains unclear. We conducted a systematic review and meta-analysis to provide new insights into the potential vector status of these pathogens, which have significant medical and veterinary implications. We searched three databases (PubMed, Google Scholar, and Web of Science) from 1912 to June 30, 2023, resulting in 94 papers included in the qualitative analysis and 86 papers in the quantitative analysis. All identified field studies were conducted in endemic areas and investigated the presence of Trypanosoma and Leishmania parasites, DNA, or antigens in ticks. We recorded a pooled prevalence of Trypanosomatidae detection in ticks at 15.48 % [7.99-24.61 %], with significant variations depending on the year, detection method, and geographical area. Most of the infected tick species belonged to the genera Amblyomma, Hyalomma, Ixodes, and Rhipicephalus. Experimental laboratory work on transmission routes demonstrated potential vector competence in both the Argasidae and Ixodidae tick families. Although our systematic review and meta-analysis provide compelling evidence of the natural infection of ticks by Trypanosomatidae parasites, along with some evidence of non-traditional transmission routes, they do not offer conclusive evidence regarding the role of ticks as biological or mechanical vectors for Trypanosomatidae species of veterinary and medical interest. This highlights the urgent need for additional investigations to address this point.

Comparative evaluation of rapid diagnostic test and PCR-based diagnostic assay for identification of trypanosomes in cattle of Apac and Kiryandongo districts, Uganda: A cross sectional study

BACKGROUND

Diagnostic tests and knowledge of their diagnostic accuracies are important for animal trypanosomosis surveillance and treatment.

METHODOLOGY

A cross-sectional study was conducted in November 2021 to compare the performance of rapid diagnostic test (RDT) and PCR-based assay for the detection of trypanosome infections. Random sampling and probability proportional to size sampling were used to sample study households and animals from the sampled household respectively. Animals were screened for the presence of trypanosomes using both tests. A total of 100 cattle (52 from Apac and 48 from Kiryandongo districts) were included in the study. The percentage of positive tests, sensitivity, and specificity of the tests using mini PCR as a reference were computed. Cohen's kappa statistics was computed to assess how well the rapid diagnostic test agrees with the mini PCR. McNemar's statistic assessed if the proportion of positive tests identified by mini PCR significantly differed from that identified by the rapid diagnostic test.

RESULTS

The mini PCR test detected 31.2% Trypanosome spp positive samples in Kiryandongo while it detected only 5.7% positive samples in Apac district. The rapid diagnostic test (RDT) analysis detected 91.6% Trypanosome spp positive samples in Kiryandongo district and only 46.1% in Apac district. T. congolense was the most common Trypanosoma species identified in Apac (36.5%) and Kiryandongo (47.9%) by the RDT. The percentage of each of the Trypanosome species (T.vivax, T.congolense, and mixed infection of T.vivax and T. congolense) detected by RDT differed significantly (p < 0.001) between the two districts. The RDT had a high sensitivity of 94.4% (95% Confidence Interval (CI): 72.7-99.9) but a very low specificity of 36.6% (95% CI: 26.2-48.0). The kappa test showed evidence of only a slight agreement (kappa = 0.1547, Accuracy = 0.48 (95% Confidence Interval (CI): 0.379,0.5822) between the two tests. The observed agreement between the tests was 47% while the expected agreement was 37.84%.

CONCLUSION

This study found high sensitivity but low specificity of RDT using mini PCR as a reference.

Discovery and Development of an Advanced Lead for the Treatment of African Trypanosomiasis

African trypanosomiasis is a widespread disease of human and veterinary importance caused by various Trypanosoma spp. with a globally devastating impact and a need for novel treatment options. We here provide a comprehensive preclinical evaluation of nucleoside analogues, 6-thioether-modified tubercidins, with curative activity against African trypanosomiasis. Promising hits were identified following in vitro screening against the most relevant trypanosome species. Selected hit compounds were extensively tested for in vitro metabolic stability, potency in in vivo mouse models for the various species, genotoxicity in an in vitro testing battery, and mode of action studies (i.e., genome-wide RNA interference library screening and metabolomics). Among the nucleoside analogues, analogue 3 was curative in mouse models with no indication of genotoxicity and a low ecotoxicological footprint. Mode-of-action studies revealed that P1-type nucleoside transporters and adenosine kinase are involved in the uptake and activation, respectively. Analogue 3 represents a potent, advanced lead fitting the preferred target product profile for a broad-spectrum trypanocide regardless of the causative species.

Hemoparasitism in grazing cattle and risk factors associated with husbandry management in an endemic area of Eastern Colombia

Vector-borne pathogens induce hemoparasitism in cattle causing substantial economic losses in tropical and subtropical areas. Infectious cattle actively contribute to maintaining the transmission cycle, and the presence of these animals must be associated with husbandry management and environmental changes. In the present study, we conducted a cross-sectional study sampling 1,000 bovines to identify infectious cattle diagnosed by a direct technique and employed a dichotomic questionnaire for association analyses, hierarchical clustering, and Principal Component Analysis (PCA). Overall prevalence with infectious cattle was 34.99%, where 97% of the farms had at least one infectious animal per genera, and the prevalence in properties ranged between 16.39 and 53.85%. Of these animals, 26.20% tested positive for Anaplasma sp., 8.40% for Babesia spp., and 1.30% for Trypanosome spp. The main co-infection showed 5% Anaplasma sp. - Trypanosome spp., followed by 4% Babesia spp. - Trypanosome spp. These bovines showed association with the use of the Jersey breed (OR = 2.016 C.I:1.188-3.419), selling animals for replacement (OR = 1.417 CI:1.022-1.965), participation in livestock exhibitions (OR = 2.009 CI:1.262-3.199), premises with burials (OR = 2,064 CR: 1.414-3.011), use of palm kernel (OR = 1.935 C.I:1.198-3.124), and the use of ivermectin (OR = 1.548 CI: 1.085-2.210) as a susceptibility. The hierarchical clustering revealed clusters among properties with different hemoparasite prevalence, with notable co-infections observed. The subsequent PCA identified that significant risk factors contributed to hemoparasitism positivity. We conclude that infectious cattle in the endemic area showed an association with husbandry management that permits the success of vector and maintenance of the enzootic or epizootic cycle in the herds.

Biophysical analysis of the membrane-proximal Venus Flytrap domain of ESAG4 receptor-like adenylate cyclase from Trypanosoma brucei

The protozoan parasite Trypanosoma brucei possesses a large family of transmembrane receptor-like adenylate cyclases (RACs), primarily located to the flagellar surface and involved in sensing of the extracellular environment. RACs exhibit a conserved topology characterized by a large N-terminal extracellular moiety harbouring two Venus Flytrap (VFT) bilobate structures separated from an intracellular catalytic domain by a single transmembrane helix. RAC activation, which typically occurs under mild acid stress, requires the dimerization of the intracellular catalytic domain. The occurrence of VFT domains in the RAC's extracellular moiety suggests their potential responsiveness to extracellular ligands in the absence of stress, although no such ligands have been identified so far. Herein we report the biophysical characterization of the membrane-proximal VFT2 domain of a bloodstream form-specific RAC called ESAG4, whose ectodomain 3D structure is completely unknown. The paper describes an AlphaFold2-based optimisation of the expression construct, enabling facile and high-yield recombinant production and purification of the target protein. Through an interdisciplinary approach combining various biophysical methods, we demonstrate that the optimised VFT2 domain obtained by recombination is properly folded and behaves as a monomer in solution. The latter suggests a ligand-binding capacity independent of dimerization, unlike typical mammalian VFT receptors, as guanylate cyclase. In silico VFT2 genomic analyses shows divergence among cyclase isoforms, hinting at ligand specificity. Taken together this improved procedure enabling facile and high-yield recombinant production and purification of the target protein could benefit researchers studying trypanosomal RAC VFT domains but also any trypanosome domain with poorly defined boundaries. Additionally, our findings support the stable monomeric VFT2 domain as a useful tool for future structural investigations and ligand screening.

Redefining infections with trypanosomatids in Neotropical primates: Case study of the white-footed tamarin (Oedipomidas leucopus)

Trypanosomes are blood parasites capable of infecting nearly any vertebrate. Many Neotropical primates frequently host trypanosomes and are considered potential reservoirs for Trypanosoma cruzi and other human-pathogenic trypanosomatids. However, diagnostic methods originally developed for detecting these trypanosomatids in humans and domestic species must be validated to reliably diagnose infections in non-human primates. Without such validation, taxonomic biases and incorrect assignments of wildlife reservoirs can occur. The white-footed tamarin (Oedipomidas leucopus), a primate endemic to northwestern Colombia, is classified by the World Health Organization as a reservoir of T. cruzi. However, this classification is based on studies with small sample sizes, ambiguous diagnostic methods, and questionable geographic records. In this study, the 18S ribosomal RNA gene was amplified via PCR and sequenced to estimate trypanosome infection rates and identify species in natural populations of O. leucopus across a wide geographic range, as well as in (ex situ) specimens. This molecular approach was also compared with traditional microscopy diagnosis using blood smears. The molecular diagnosis revealed that over 60% of the tested specimens were infected, whereas traditional microscopy resulted in 58% false negatives compared to the molecular method. A Bayesian phylogeny of the 18S gene identified T. minasense as the sole trypanosomatid species present in O. leucopus, with no detections of T. cruzi or other trypanosomatids of concern to human or domestic animal health. This study highlights the risk of overestimating the presence of human-infecting trypanosomes, such as T. cruzi, in tamarins and other vertebrates, and underscores the importance of validating diagnostic methods to accurately assess the zoonotic potential of wild species. Accurate identification of wildlife reservoirs is essential for understanding parasite life cycles and implementing effective management and conservation strategies for primates and other potential reservoirs.

Drugs for Vector-Borne Protozoal Diseases in a One Health Scenario. A European Perspective

Vector-borne protozoal diseases (VBPD) represent an enormous health and economic burden, particularly in low- and middle-income countries. Their control requires integrated approaches that consider not only therapeutic interventions for affected human and animal populations but also preventive tools. Environmental contamination can lead to therapeutic ineffectiveness. Effective intervention must consider in-depth knowledge of the environmental factors that regulate the exposure, transmission and pathogenicity of VBPD within a One Health approach. In recent decades, the incidence and prevalence of VBPD have been substantially reduced in many regions of the world, although there are still hot spots and emerging epidemiological cycles. Except for a partially protective vaccine against malaria, vaccination is not available for any other human VBPD, and therefore epidemiological control and chemotherapy are the main control tools. Current therapeutics have several drawbacks, including reduced efficacy, toxicity and high price of safer formulations. In addition, the industrial pipeline is limited, and no therapeutic breakthroughs are expected. Integrated control of VBPD requires multitarget control systems adapted to the disease and region. In this scenario, harmonized surveillance systems, accurate reporting and increased public and private investment will ensure more rational use of the few available and new drugs.

Molecular and serological diagnosis of the circulating Trypanosoma evansi in Egyptian livestock with risk factors assessment

This study aimed to characterize and determine the prevalence and the associated risk factors of trypanosomiasis in different Egyptian livestock from various governorates using molecular and serological techniques, adding to an assessment of some biochemical alterations in serum samples. A total 1019 blood samples were collected from nine governorates in the period from January 2020 to September 2021 from cattle (n = 752), buffaloes (n = 42), sheep (n = 65), goats (n = 60), donkeys (n = 54), and horses (n = 46). Molecular investigation followed by sequencing confirmed the presence of only Trypanosoma evansi (T. evansi) infection with a prevalence rate of 3.73 % (38/1019). Serologically, T. evansi was detected by indirect ELISA in 11 samples out of 519 negative PCR ones, with an overall prevalence 2.1 %. Furthermore, statistical difference was found between investigated governorates in both molecular and seroprevalence. Surprisingly, the risk of T. evansi infection was significantly (P < 0.05) higher in winter (9.83 %) than in autumn (1.4 %), while no infection was recorded in the spring and summer seasons. No significant difference regarding animal hosts, age, and sex as risk factors was recorded. Serum biochemical analysis showed a non-significant decrease of total proteins, albumin, A/G ratio, and HDL-cholesterol in cattle, equine, and goats with a non-significant increase in total globulins level. In sheep, a significant increase was determined in all tested parameters except a significant decrease in the level of albumin and A/G ratio. To the best of our knowledge, this is the first large-scale epidemiological study determining the endemicity of the neglected T. evansi infection in different animal species in multiple governorates of Egypt. It is recommended to use both molecular and serological techniques for efficient diagnosis of trypanosomiasis as a preliminary approach to control the disease.

First Report of Trypanosoma vivax (Duttonella), Babesia bovis and Babesia bigemina DNA in Cattle from the Galapagos Islands, Ecuador, and Its Relationship with Anaplasma marginale

Bovine trypanosomoses, caused by Trypanosoma vivax, is a disease present in African and South American countries. This haemoflagellate protozoan parasite, as well as Anaplasma marginale and Babesia spp., are microorganisms that have a blood tropism, mainly causing fever and anaemia, which reduces the productive capacity of dairy or meat farms. This study aimed to detect T. vivax and other blood parasites in bovine herds in the Galapagos Islands. A total of 170 blood samples from bovines in 19 farms on Santa Cruz Island (the most populated) were collected and analyzed using different PCR techniques: Da-PCR and CatL-PCR to detect Trypanosoma vivax, CatL-PCR to detect Trypanosoma theileri, ESAG-PCR to detect Trypanosoma evansi, 18S rRNA-PCR to detect Babesia spp., rap-1-PCR to detect Babesia bovis, hyp-PCR to detect Babesia bigemina, and msp5-PCR to detect A. marginale. The prevalence of T. vivax, B. bovis, B. bigemina, and A. marginale was estimated as 14.7%, 11.2%, 14.7%, and 67.1%, respectively. In this study, the presence of four haemotropic agents was evidenced in 26.3% (5/19) of the farms. Coinfected cattle (A. marginale, B. bovis and B. bigemina) had significantly higher body temperatures compared to others (two-sample Wilcoxon rank-sum test; p-value = 0.047). The molecular techniques used in this study demonstrated the presence of T. vivax and B. bovis in cattle from Santa Cruz Island in the Galapagos for the first time. The study also investigates the relationship between T. vivax, A. marginale and Babesia spp., making a significant contribution to the field of veterinary medicine.

Trypanosomiasis in Introduced Southern White Rhinoceros (Ceratotherium simum simum) Gifts to Ex Situ Habitat in Aitong, Kenya

During the opening of diplomatic relations in the 1990s, South Africa gifted 20 southern white rhinoceros (Ceratotherium simum simum) to Kenya. The species is not indigenous to Kenya, and management of the introduction was not clearly addressed in the legislation. Responsibility was left to the private sector and local authorities. Ten of the animals were introduced to land contiguous with the Maasai Mara National Reserve, an area with tsetse-trypanosomiasis challenges, and with rare cases of human sleeping sickness. Mortalities had been previously documented when indigenous naïve black rhinoceros were introduced to areas with tsetse; hence there was no consensus on the management of this introduction. Feasibility was only explored once before with the introduction of two animals in a monitored and managed translocation from Lewa Downs, Laikipia in 1992-1994. Ultimately, Kenyan experts were co-opted to address risk after trypanosomiasis occurred in many animals. Unfortunately, this finding was followed by gradual mortalities of most rhinoceros with only a few being saved by removal to highland private sanctuaries. This event was complicated by many factors. Samples were only sporadically collected, and mainly from sick animals. With no clear responsibility by government agencies, a collaboration between veterinarians and researchers resulted in characterization of the disease challenge, and when invited, assessment of health status. Laboratory diagnostics revealed common and sometimes severe infections with Trypanosoma brucei, a normally infrequent trypanosome. Infection was associated with disturbances in erythropoiesis, especially anemia. Symptoms varied from sudden death associated with intestinal atony, to a semiparalyzed animal that was partially responsive to treatment for trypanosomes. This event should be used as a caution to future movements of this species that are planned or ongoing in Africa, for conservation or other purposes.

First record of a possible trypanotolerant cattle breed in Latin America: Parasitological, serological, and clinical aspects

Trypanosoma vivax infections are endemic in Africa, where they provoke trypanosomosis against which some local taurine breeds are tolerant and are thus named trypanotolerant. In Latin America, T. vivax was imported in 1919, since when it has been responsible for periodic outbreaks of the disease. This study assessed whether a South American taurine breed resilient to several parasitic and infectious diseases (Curraleiro Pé-Duro-CPD) can meet trypanotolerant criteria (control parasite proliferation, prevent anemia, survive without treatment, and maintain productivity). Three groups were established, each consisting of six animals (Group 1: CPD-infected; Group 2: Holstein/Gyr-infected; Group 3: Holstein/Gyr-uninfected, negative control). Groups 1 and 2 were infected with T. vivax on Day 0 and evaluated until day 532. Throughout the experimental period, parasitological (Woo and Brener), molecular (cPCR), serological (enzyme-linked immunosorbent assay - ELISA, indirect fluorescent antibody test - IFAT, immunochromatographic assay - IA), and clinical (hemogram, fever, weight loss) aspects were evaluated. During the acute phase of the disease, T. vivax was initially detected in Holstein/Gyr. Notably, the CPD animals restored their packed cell volume (PCV) values to the normal range 74 days after inoculations. In the chronic phase, two of the six CPD animals were positive by cPCR until D + 522 following immunosuppression with dexamethasone. Regarding serological aspects, the two CPD animals had positive tests until D + 532. The absence of T. vivax in blood during the chronic phase did not correspond to "self-cure". Holstein/Gyr animals exhibited fever on more evaluation days than CPD animals. Both breeds experienced weight loss, with Holstein/Gyr animals losing significantly more weight. On D + 25, the Holstein/Gyr group required treatment. During the 532 days, none of the CPD animals required treatment, even after being sensitized with dexamethasone. Animals from Group 3 tested negative for T. vivax throughout the experiment. This study demonstrated that CPD cattle fulfill the mentioned trypanotolerant criteria.

Epidemiology and Economic Cost of Trypanosomosis Among SmallHolder Cattle Herders in Arba Minch and Zuria Districts, Gamo Zone, Ethiopia

A significant limitation to cattle production is animal trypanosomosis, which threatens household food security and livelihoods. In addition to stalling livestock productivity, the disease has a devastating impact on animal health. Besides, halting livestock productivity, the disease has a devastating effect on health. Thus, the objectives this study was to assess the epidemiology, and financial impacts of bovine trypanosomosis on livestock producers' in Arba Minch and Zuria districts of Gamo zone, Ethiopia, from December 2021 to January 2023. Both repeated survey and cross-sectional study were carried out to assess the economic losses, estimate the prevalence and assess the determinants of bovine trypanosomosis. Direct microscopy was applied using buffy coat method to detect trypanosome parasite. The study included 182 households and 384 bovine species. Bovine trypanosomosis caused substantial economic losses through cattle mortality, drug purchases, and the oxen's loss of draft power. Also, farmers spent a significantly (P < .05) higher amount of money treating trypanosomosis than all other diseases combined. The annual losses per household were estimated to be 9528 ± 1754 Ethiopian Birr (ETB) (95% CI: 6065-12 992) (US$ 176.4) which were spent on purchasing trypanocidal drugs per year per household. The overall mortality from bovine trypanosomiasis was 8.8%. Many farmers prioritized draft power losses as the most significant impact of the disease. Analysis of blood samples also showed a 7.8% overall prevalence of bovine trypanosomosis. The disease burden was significantly (P < .05) higher in the black body coat animals compared to white ones. This study showed that trypanosomosis is an important animal health problem and a potential threat to health and productivity of cattle in Arba Minch and zuria districts of Gamo, Southern Ethiopia. The common trypanocidal drugs were administered by the farmers themselves. Hence, policymakers and professionals should prevent irrational drug use and regularly monitor local trypanocide usage.

Cholesterol Efflux Decreases TLR4-Target Gene Expression in Cultured Macrophages Exposed to T. brucei Ghosts

Trypanosoma brucei causes African trypanosomiasis in humans. Infection with T. brucei elicits a potent pro-inflammatory immune response within infected human hosts, and this response is thought to at least be partially due to Toll-like receptor (TLR) activation. In response to stimulation by lipopolysaccharide and other pathogen antigens, TLR4 translocates to lipid rafts, which induces the expression of pro-inflammatory genes. However, cholesterol efflux is acknowledged as anti-inflammatory due to promoting lipid raft disruption. In this study, we wanted to assess the impact of T. brucei "ghosts", which are non-viable T. brucei essentially devoid of intracellular contents, in stimulating macrophage TLR4 translocation to lipid rafts, and whether promoting cholesterol efflux in macrophages incubated with T. brucei ghosts attenuates TLR4-target gene expression. When cultured macrophages were exposed to T. brucei ghosts, we observed an increase in lipid raft TLR4 protein content, which suggests certain surface molecules of T. brucei serve as ligands for TLR4. However, pretreating macrophages with cholesterol acceptors before T. brucei ghost exposure decreased lipid raft TLR4 protein content and the expression of pro-inflammatory TLR4-target genes. Taken together, these results imply that macrophage cholesterol efflux weakens pro-inflammatory responses which occur from T. brucei infection via increasing macrophage lipid raft disruption.

Reproductive, productive and financial consequences of chronic Trypanosoma vivax infection in a dairy cattle herd in a region without a cyclic vector

This study evaluated the reproductive, productive and financial consequences of chronic Trypanosoma vivax infection in a dairy cattle herd located in a region without the cyclic vector during two years. Animals were categorized as either positive (chronically infected) or negative for T. vivax antibodies using a commercial rapid test. Additionally, serum samples from cows were analyzed for the presence of anti-Neospora caninum antibodies. Pregnancy diagnoses were performed through rectal palpation and ultrasonography after 30, 60 and every 21 days until the 144th day of pregnancy. If an abortion occurred in the final trimester, serology and cPCR were performed on calves for T. vivax and N. caninum. The breeding period, calving interval and pregnancy losses were recorded. The milk production of each animal during the 305 days of lactation was measured, and the annual financial impact of milk production was calculated using a revenue minus feed cost (RMFC) indicator. Out of 177 cows, 71.75 % were chronically infected, and 13.50 % were T. vivax-negative. No correlation (p = 0.8854) of co-infection between T. vivax and N. caninum was observed. Negative cows required fewer (p≤0.05) artificial inseminations than chronically infected ones. T. vivax was not significantly associated (p = 0.7893) with pregnancy loss up to 81 days of pregnancy. Cows chronically infected by T. vivax had 4-fold greater chance (p = 0.0280) of experiencing pregnancy loss between 82 and 144 days of gestation. Eighteen cows aborted, two were positive for T. vivax antibodies, and one for N. caninum antibodies. The calves were negative for T. vivax and N. caninum. Chronically infected cows and negative cows for T. vivax that experienced pregnancy loss (82-144 days of pregnancy) had a longer (p≤0.05) breeding period to become pregnant, and consequently a longer calving interval compared to cows that maintained pregnancy. The difference (p≤0.05) in milk production was evident when pregnancy loss occurred between 82 and 144 days of gestation in cows chronically infected by T. vivax. The RMFC indicated a negative impact of 38.2 % on the farm's annual milk revenue due to the presence of chronically infected cows.

Drug resistance in animal trypanosomiases: Epidemiology, mechanisms and control strategies

Animal trypanosomiasis (AT) is a complex of veterinary diseases known under various names such as nagana, surra, dourine and mal de caderas, depending on the country, the infecting trypanosome species and the host. AT is caused by parasites of the genus Trypanosoma, and the main species infecting domesticated animals are T. brucei brucei, T. b. rhodesiense, T. congolense, T. simiae, T. vivax, T. evansi and T. equiperdum. AT transmission, again depending on species, is through tsetse flies or common Stomoxys and tabanid flies or through copulation. Therefore, the geographical spread of all forms of AT together is not restricted to the habitat of a single vector like the tsetse fly and currently includes almost all of Africa, and most of South America and Asia. The disease is a threat to millions of companion and farm animals in these regions, creating a financial burden in the billions of dollars to developing economies as well as serious impacts on livestock rearing and food production. Despite the scale of these impacts, control of AT is neglected and under-resourced, with diagnosis and treatments being woefully inadequate and not improving for decades. As a result, neither the incidence of the disease, nor the effectiveness of treatment is documented in most endemic countries, although it is clear that there are serious issues of resistance to the few old drugs that are available. In this review we particularly look at the drugs, their application to the various forms of AT, and their mechanisms of action and resistance. We also discuss the spread of veterinary trypanocide resistance and its drivers, and highlight current and future strategies to combat it.

Bartonella, Blechomonas and Trypanosoma in fleas from the long-tailed ground squirrel (Spermophilus undulatus) in northwestern China

Fleas are known to be vectors for a variety of pathogens in veterinary medicine. However, no information is available on the presence of Bartonella and Trypanosomatidae in fleas of the long-tailed ground squirrel (LTGR, Spermophilus undulatus). The present study shows detection of these pathogens in LTGR fleas. During 2022-2023, a total of 396 fleas were collected from 91 LTGRs in 4 alpine regions of Xinjiang Uygur Autonomous Region (northwestern China) and grouped into 54 flea pools. Flea species were identified according to morphological characteristics and molecular data. In addition, all flea samples were analyzed for Bartonella with amplification and sequencing of a 380-bp part of the gltA gene and Trypanosomatidae with targeting the 18S rRNA (850-bp) and gGAPDH (820-bp) genes. The flea species included Frontopsylla elatoides elatoides (203), Neopsylla mana (49), and Citellophilus tesquorum dzetysuensis (144). Of 54 flea pools, seven (12.96%) tested positive for Bartonella, and three (5.56%) were positive for Trypanosomatidae. Based on BLASTn and phylogenetic analyses, i) Bartonella washoensis in F. elatoides elatoides and C. tesquorum dzetysuensis, and Bartonella rochalimae in F. elatoides elatoides were identified. Interestingly, a new haplotype within the species Ba. washoensis was discovered in C. tesquorum dzetysuensis; and ii) Blechomonas luni was confirmed in C. tesquorum dzetysuensis and Trypanosoma otospermophili in F. elatoides elatoides. Two Bartonella species and two Trypanosomatidae members were discovered for the first time in fleas from LTGRs. This study broadens our understanding of the geographic distribution and potential vectors for Bartonella and Trypanosomatidae.

In vitro trypanocidal activities and structure-activity relationships of ciprofloxacin analogs

Tropical diseases, such as African trypanosomiasis, by their nature and prevalence lack the necessary urgency regarding drug development, despite the increasing need for novel, structurally diverse antitrypanosomal drugs, using different mechanisms of action that would improve drug efficacy and safety. Traditionally antibacterial agents, the fluoroquinolones, reportedly possess in vitro trypanocidal activities against Trypanosoma brucei organisms. During our research, the fluroquinolone, ciprofloxacin (1), and its analogs (2-24) were tested against bloodstream forms of T. brucei brucei, T. b. gambiense, T. b. rhodesiense, T. evansi, T. equiperdum, and T. congolense and Madin-Darby bovine kidney cells (cytotoxicity). Ciprofloxacin [CPX (1)] demonstrated selective trypanocidal activity against T. congolense (IC50 7.79 µM; SI 39.6), whereas the CPX derivatives (2-10) showed weak selective activity (25 < IC50 < 65 µM; 2 < SI < 4). Selectivity and activity of the CPX and 1,2,3-triazole (TZ) hybrids (11-24) were governed by their chemical functionality at C-3 (carboxylic acid, or 4-methylpiperazinyl amide) and their electronic effect (electron-donating or electron-withdrawing para-benzyl substituent), respectively. Trypanocidal hits in the micromolar range were identified against bloodstream forms of T. congolense [CPX (1); CPX amide derivatives 18: IC50 8.95 µM; SI 16.84; 22: IC50 5.42 µM; SI 25.2] and against T. brucei rhodesiense (CPX acid derivative 13: IC50 4.51 µM; SI 10.2), demonstrating more selectivity toward trypanosomes than mammalian cells. Hence, the trypanocidal hit compound 22 may be optimized by retaining the 4-methylpiperazine amide functional group (C-3) and the TZ moiety at position N-15 and introducing other electron-withdrawing ortho-, meta-, and/or para-substituents on the aryl ring in an effort to improve the pharmacokinetic properties and increase the trypanocidal activity.

Iatrogenic transmission of Trypanosoma evansi infection in camels and its consequences

Trypanosoma evansi infection has started to become a wide spread phenomena around the camel-rearing areas of North Africa and the Middle East. The disease caused by trypanosomes is locally known as "Surra" and it can seriously impact not only the health of domestic animals but the local economy as well. After taking over the management of a farm containing approximately 700 camels, it was found that a large number were suffering from trypanosome infection and it was of the utmost importance to find the source of this infection. An extensive dive into the records and observations were initially made to identify the infected population. Under closer inspection it was found that the infection was limited mostly to female individuals that had undergone extended reproductive analysis or treatment. Blood samples were taken from each of the individuals for buffy coat test and blood smears. Among the total number of tested camels (n = 590), almost 40% were infected with trypanosomes. The number and percentage of infection correlate with the number of fertility and pregnancy treatments that the camels had undergone. The most severely infected group, underwent between 17 and 20 instances of treatment or tests, had an infection rate of almost 90%. The devastating effect of trypanosomiasis on camel pregnancy and birth were also verified with 61% of all abortions and 82% of all neonatal deaths coming from trypanosome infected individuals. These results clearly demonstrate how damaging iatrogenic infections of T. evansi can be and how simply they could have been prevented.

Trypanosoma vivax in and outside cattle blood: Parasitological, molecular, and serological detection, reservoir tissues, histopathological lesions, and vertical transmission evaluation

This study reports assessment of the sensitivity of diagnostic techniques to detect T. vivax in experimentally infected cattle. Additionally, it describes T. vivax extravascular parasitism during the acute and chronic phases of trypanosomosis and congenital transmission. The T. vivax diagnosis was compared using blood samples collected from the jugular, coccygeal and ear tip veins. For this study, 13 males and two females were infected with ≈ 1 × 106 viable T. vivax trypomastigotes (D0). One animal was kept as a negative control during the entire study. The 13 infected males were euthanized between 14 and 749 days post-infection (DPI). After confirming the cyclicity of both females (9 months of age), they were naturally mated with a bull. One female was euthanized at 840 DPI, and the other at 924 DPI. The two calves, one from each female, were euthanized at six months of age (924 DPI), and the negative control at 924 DPI. During this period, T. vivax in blood was assessed using direct methods (Woo test, cPCR, microscopic examination of fresh wet blood films and parasite quantification - Brener method), and serological methods (IFAT, ELISA, and IA). Tissue samples were collected from the liver, spleen, brain, cerebellum, heart, testicles, epididymis, kidneys, eyeballs, pre-scapular lymph nodes, ear tips, mammary glands, uterus, and ovaries. The protozoan DNA was examined using LAMP. There was no difference in the detection of T. vivax using the Woo test and Brener method among the jugular, coccygeal, and ear tip veins. The sensitivity of the detection methods varied depending on the disease phase. Direct methods (Woo test, Brener method, and cPCR) demonstrated higher sensitivity during the acute phase, while serological methods (IFAT, ELISA, and IA) were more sensitive during the chronic phase. Anti-T. vivax antibodies were detected up to 924 DPI. Tissue evaluation using LAMP demonstrated the presence of T. vivax DNA and associated histopathological changes up to 840 or 924 DPI. Only in mammary glands and ovaries was no DNA detected. The most frequently observed histopathological alteration was lymphohistioplasmocytic inflammatory infiltrate. No transplacental transmission of T. vivax was observed.

Improved serodiagnosis of Trypanosoma vivax infections in cattle reveals high infection rates in the livestock regions of Argentina

Bovine trypanosomosis, caused by Trypanosoma vivax, currently affects cattle and has a significant economic impact in sub-Saharan Africa and South America. The development of new diagnostic antigens is essential to improve and refine existing methods. Our study evaluated the efficacy of two recombinant antigens in detecting specific antibodies in cattle. These antigens are derivatives of an invariant surface glycoprotein (ISG) from T. vivax. A fraction of a previously described antigen (TvY486_0045500), designated TvISGAf, from an African strain was evaluated, and a new ISG antigen from an American isolate, TvISGAm, was identified. The two antigens were expressed as fusion proteins in Escherichia coli: TvISGAf was fused to the MBP-His-tag, and TvISGAm was obtained as a His-tag fused protein. An ELISA evaluation was conducted using these antigens on 149 positive and 63 negative bovine samples. The diagnostic performance was enhanced by the use of a combination of both antigens (referred to as TvISG-based ELISA), achieving a sensitivity of 89.6% and specificity of 93.8%. Following the validation of the TvISG-based ELISA, the seroprevalence of T. vivax infection in 892 field samples from cattle in the central region of Argentina was determined. The mean seroprevalence of T. vivax was 53%, with variation ranging from 21% to 69% among the six departments studied. These results support the use of the TvISG ELISA as a valuable serological tool for the detection and monitoring of T. vivax infection in cattle. Furthermore, we report for the first time the seroprevalence of T. vivax in Argentina, which highlights the widespread endemic nature of the disease in the region. In order to effectively manage the increasing spread of T. vivax in the vast livestock production areas of South America, it is essential to implement consistent surveillance programs and to adopt preventive strategies.

Tractable Quinolone Hydrazides Exhibiting Sub-Micromolar and Broad Spectrum Antitrypanosomal Activities

Nagana and Human African Trypanosomiasis (HAT), caused by (sub)species of Trypanosoma, are diseases that impede human and animal health, and economic growth in Africa. The few drugs available have drawbacks including suboptimal efficacy, adverse effects, drug resistance, and difficult routes of administration. New drugs are needed. A series of 20 novel quinolone compounds with affordable synthetic routes was made and evaluated in vitro against Trypanosoma brucei and HEK293 cells. Of the 20 compounds, 12 had sub-micromolar potencies against the parasite (EC50 values=0.051-0.57 μM), and most were non-toxic to HEK293 cells (CC50 values>5 μM). Two of the most potent compounds presented sub-micromolar activities against other trypanosome (sub)species (T. cruzi and T. b. rhodesiense). Although aqueous solubility is poor, both compounds possess good logD values (2-3), and either robust or poor microsomal stability profiles. These varying attributes will be addressed in future reports.

Enhancing Trypanosomatid Identification and Genotyping with Oxford Nanopore Sequencing: Development and Validation of an 18S rRNA Amplicon-Based Method

Trypanosomatids, including Trypanosoma and Leishmania species, present significant medical and veterinary challenges, causing substantial economic losses, health complications, and even fatalities. Diagnosing and genotyping these species and their genotypes is often complex, involving multiple steps. This study aimed to develop an amplicon-based sequencing (ABS) method using Oxford Nanopore long-read sequencing to enhance Trypanosomatid detection and genotyping. The 18S rDNA gene was targeted for its inter-species conservation. The Trypanosomatid-ABS method effectively distinguished between 11 Trypanosoma species (including Trypanosoma evansi, Trypanosoma theileri, Trypanosoma vivax, and Trypanosoma rangeli) and 6 Trypanosoma cruzi discrete typing units (TcI to TcVI and TcBat), showing strong concordance with conventional methods (κ index of 0.729, P < 0.001). It detected co-infections between Trypanosomatid genera and T. cruzi, with a limit of detection of one parasite per mL. The method was successfully applied to human, animal, and triatomine samples. Notably, TcI predominated in chronic Chagas samples, whereas TcII and TcIV were found in the acute stage. Triatomine vectors exhibited diverse Trypanosomatid infections, with Triatoma dimidiata mainly infected with TcI and occasional TcBat co-infections, and Rhodnius prolixus showing TcI and TcII infections, along with T. rangeli co-infections and mixed TcII infections. Animals were infected with T. vivax, T. theileri, and T. evansi. The ABS method's high resolution, sensitivity, and accuracy make it a valuable tool for understanding Trypanosomatid dynamics, enhancing disease control strategies, and enabling targeted interventions.

In vitro antitrypanosomal activity of synthesized nitrofurantoin-triazole hybrids against Trypanosoma species causing animal African trypanosomosis

Animal African trypanosomosis (AAT) is a disease caused by Trypanosoma brucei brucei, T. vivax, T. evansi and T. congolense which are mainly transmitted by tsetse flies (maybe the family/genus scientific name for the tsetse flies here?). Synthetic trypanocidal drugs are used to control AAT but have reduced efficacy due to emergence of drug resistant trypanosomes. Therefore, there is a need for the continued development of new safe and effective drugs. The aim of this study was to evaluate the in vitro anti-trypanosomal activity of novel nitrofurantoin compounds against trypanosomes (Trypanosoma brucei brucei, T. evansi and T. congolense) causing AAT. This study assessed previously synthesized nineteen nitrofurantoin-triazole (NFT-TZ) hybrids against animal trypanosomes and evaluated their cytotoxicity using Madin-Darby bovine kidney cells. The n-alkyl sub-series hybrids, 8 (IC50 0.09 ± 0.02 μM; SI 686.45) and 9 (IC50 0.07 ± 0.04 μM; SI 849.31) had the highest anti-trypanosomal activity against T. b. brucei. On the contrary, the nonyl 6 (IC50 0.12 ± 0.06 μM; SI 504.57) and nitrobenzyl 18 (IC50 0.11 ± 0.03 μM; SI 211.07) displayed the highest trypanocidal activity against T. evansi. The nonyl hybrid 6 (IC50 0.02 ± 0.01 μM; SI 6328.76) was also detected alongside the undecyl 8 (IC50 0.02 ± 0.01 μM; SI 3454.36) and 3-bromobenzyl 19 (IC50 0.02 ± 0.01 μM; SI 2360.41) as the most potent hybrids against T. congolense. These hybrids had weak toxicity effects on the mammalian cells and highly selective submicromolar antiparasitic action efficacy directed towards the trypanosomes, hence they can be regarded as potential trypanocidal leads for further in vivo investigation.

Current Status of Trypanosoma grosi and Babesia microti in Small Mammals in the Republic of Korea

Small mammals, such as rodents and shrews, are natural reservoir hosts of zoonotic diseases, including parasitic protozoa. To assess the risk of rodent-borne parasitic protozoa in the Republic of Korea (ROK), this study investigated the status of parasitic protozoa, namely Trypanosoma, Babesia, and Theileria, in small mammals. In total, 331 blood samples from small mammals were analyzed for parasites using PCR and sequenced. Samples were positive for Trypanosoma grosi (23.9%; n = 79) and Babesia microti (10%; n = 33) but not Theileria. Small mammals from Seogwipo-si showed the highest infection rate of T. grosi (48.4%), while the highest B. microti infection rate was observed in those from Gangneung-si (25.6%). Sequence data revealed T. grosi to be of the AKHA strain. Phylogenetic analysis of B. microti revealed the US and Kobe genotypes. B. microti US-type-infected small mammals were detected throughout the country, but the Kobe type was only detected in Seogwipo-si. To our knowledge, this is the first nationwide survey that confirmed T. grosi and B. microti infections at the species level in small mammals in the ROK and identified the Kobe type of B. microti. These results provide valuable information for further molecular epidemiological studies on these parasites.

Molecular, immunological, and physiological evidences of a sphingosine-activated plasma membrane Ca2+-channel in Trypanosoma equiperdum

The hemoparasite Trypanosoma equiperdum belongs to the Trypanozoon subgenus and includes several species that are pathogenic to animals and humans in tropical and subtropical areas across the world. As with all eukaryotic organisms, Ca2+ is essential for these parasites to perform cellular processes thus ensuring their survival across their life cycle. Despite the established paradigm to study proteins related to Ca2+ homeostasis as potential drug targets, so far little is known about Ca2+ entry into trypanosomes. Therefore, in the present study, the presence of a plasma membrane Ca2+-channel in T. equiperdum (TeCC), activated by sphingosine and inhibited by verapamil, is described. The TeCC was cloned and analyzed using bioinformatic resources, which confirmed the presence of several domains, motifs, and a topology similar to the Ca2+ channels found in higher eukaryotes. Biochemical and confocal microscopy assays using antibodies raised against an internal region of human L-type Ca2+ channels indicate the presence of a protein with similar predicted molar mass to the sequence analyzed, located at the plasma membrane of T. equiperdum. Physiological assays based on Fura-2 signals and Mn2+ quenching performed on whole parasites showed a unidirectional Ca2+ entry, which is activated by sphingosine and blocked by verapamil, with the distinctive feature of insensitivity to nifedipine and Bay K 8644. This suggests a second Ca2+ entry for T. equiperdum, different from the store-operated Ca2+ entry (SOCE) previously described. Moreover, the evidence presented here for the TeCC indicates molecular and pharmacological differences with their mammal counterparts, which deserve further studies to evaluate the potential of this channel as a drug target.

Wildlife parasitology: sample collection and processing, diagnostic constraints, and methodological challenges in terrestrial carnivores

Wild terrestrial carnivores play a crucial role as reservoir, maintenance, and spillover hosts for a wide parasite variety. They may harbor, shed, and transmit zoonotic parasites and parasites of veterinary importance for domestic hosts. Although wild carnivores are globally distributed and comprise many different species, some living in close proximity to human settlements, only a few studies have investigated parasites of wild terrestrial carnivores using non-specific techniques. Access to samples of wild carnivores may be challenging as some species are protected, and others are secretive, possibly explaining the data paucity. Considering the importance of wild carnivores' health and ecological role, combined with the lack of specific diagnostic methodologies, this review aims to offer an overview of the diagnostic methods for parasite investigation in wild terrestrial carnivores, providing the precise techniques for collection and analysis of fecal, blood, and tissue samples, the environmental impact on said samples, and the limitations researchers currently face in analyzing samples of wild terrestrial carnivores. In addition, this paper offers some crucial information on how different environmental factors affect parasite detection postmortem and how insects can be used to estimate the time of death with a specific highlight on insect larvae. The paper contains a literature review of available procedures and emphasizes the need for diagnostic method standardization in wild terrestrial carnivores.

Risk of a vector-borne endemic zoonosis for wildlife: Hosts, large-scale geography, and diversity of vector-host interactions for Trypanosoma cruzi

Drivers for wildlife infection are multiple and complex, particularly for vector-borne diseases. Here, we studied the role of host competence, geographic area provenance, and diversity of vector-host interactions as drivers of wild mammal infection risk to Trypanosoma cruzi, the aetiological agent of Chagas disease. We performed a systematic sampling of wild mammals in 11 states of Mexico, from 2017 to 2018. We tested the positivity of T. cruzi with the Tc24 marker in tissues samples for 61 wild mammal species (524 specimens sampled). 26 mammal species were positive for T. cruzi, of which 11 are new hosts recorded in Mexico 75 specimens were positive and 449 were negative for T. cruzi infection, yielding an overall prevalence of 14.3%. The standardized infection risk of T. cruzi of our examined specimens was similar, no matter the host species or their geographic origins. Additionally, we used published data of mammal positives for T. cruzi to complement records of T. cruzi infection in wild mammals and inferred a trophic network of Triatoma spp. (vectors) and wild mammal species in Mexico, using spatial data-mining modelling. Infection with T. cruzi was not homogeneously distributed in the inferred trophic network. This information allowed us to develop a predictive model for T. cruzi infection risk for wild mammals in Mexico, considering risk as a function of the diversity of vector-host spatial associations in a large-scale geographic context, finding that the addition of competent vectors to a multi-host parasite system amplifies host infection risk. The diversity of vector-host interactions per se constitutes a relevant driver of infection risk because hosts and vectors are not isolated from each other.

An Atlas of Surra in Spain: A Tool to Support Epidemiological Investigations and Disease Control

Trypanosomosis is a global animal issue, causing significant economic losses, particularly in Africa. In Spain, only one pathogenic species, Trypanosoma evansi, has been identified so far. It was first detected in a dromedary camel in the Canary Islands in 1997. Since then, numerous cases of the disease, known as Surra, have been diagnosed, prompting various studies and efforts in control and surveillance. Given the lack of a comprehensive database that consolidates the most relevant data in this area, the development of a national atlas, with a focus on the Canary Islands, to incorporate all available information on T. evansi in Spain became a necessity. For the development of the atlas, a repository was constructed, encompassing a range of datasets and documents spanning from 1997 to 2022. Information from each source, and in particular georeferenced locations and results of blood tests on animals, were extracted and integrated into a comprehensive database. A total of 31 sources were analysed, providing a total of 99 georeferenced locations and 12,433 animal samples. Out of these samples, 601 (mostly from dromedaries) were found to be positive for T. evansi. The Card Agglutination Test for T. evansi (CATT/T. evansi), a serological test, was the most commonly used diagnostic method, and it showed a higher prevalence for all tested animal species. Positive cases were mainly concentrated in the Canary Islands, specifically in the eastern islands, with isolated cases found in the province of Alicante (Iberian Peninsula). This atlas provides an overview of the history and occurrence of Surra in Spain, and it represents a valuable tool for future control initiatives and for research. Still, the need for more studies remains, especially for further testing of potential hosts other than camelids and for the examination of their potential transmission vectors.

In vitro trypanocidal potency and in vivo treatment efficacy of oligomeric ethylene glycol-tethered nitrofurantoin derivatives

African trypanosomiasis is a significant vector-borne disease of humans and animals in the tsetse fly belt of Africa, particularly affecting production animals such as cattle, and thus, hindering food security. Trypanosoma congolense (T. congolense), the causative agent of nagana, is livestock's most virulent trypanosome species. There is currently no vaccine against trypanosomiasis; its treatment relies solely on chemotherapy. However, pathogenic resistance has been established against trypanocidal agents in clinical use. This underscores the need to develop new therapeutics to curb trypanosomiasis. Many nitroheterocyclic drugs or compounds, including nitrofurantoin, possess antiparasitic activities in addition to their clinical use as antibiotics. The current study evaluated the in vitro trypanocidal potency and in vivo treatment efficacy of previously synthesized antileishmanial active oligomeric ethylene glycol derivatives of nitrofurantoin. The trypanocidal potency of analogues 2a-o varied among the trypanosome species; however, T. congolense strain IL3000 was more susceptible to these drug candidates than the other human and animal trypanosomes. The arylated analogues 2k (IC50 0.04 µM; SI >6365) and 2l (IC50 0.06 µM; SI 4133) featuring 4-chlorophenoxy and 4-nitrophenoxy moieties, respectively, were revealed as the most promising antitrypanosomal agents of all analogues against T. congolense strain IL3000 trypomastigotes with nanomolar activities. In a preliminary in vivo study involving T. congolense strain IL3000 infected BALB/c mice, the oral administration of 100 mg/kg/day of 2k caused prolonged survival up to 18 days post-infection relative to the infected but untreated control mice which survived 9 days post-infection. However, no cure was achieved due to its poor solubility in the in vivo testing medium, assumably leading to low oral bioavailability. These results confirm the importance of the physicochemical properties lipophilicity and water solubility in attaining not only in vitro trypanocidal potency but also in vivo treatment efficacy. Future work will focus on the chemical optimization of 2k through the investigation of analogues containing solubilizing groups at certain positions on the core structure to improve solubility in the in vivo testing medium which, in the current investigation, is the biggest stumbling block in successfully treating either animal or human Trypanosoma infections.

A Flow Cytometry Study of the Binding and Stimulation Potential of Inactivated Trypanosoma evansi toward Dromedary Camel Leukocytes

Surra, a wasting disease caused by Trypanosoma evansi, is one of the major animal health burdens in camel-rearing countries, imposing significant economic losses due to reduced fertility and high mortality rates. The present study used inactivated T. evansi (from the Card Agglutination Test for Trypanosomes/Trypanosoma evansi; CATT/T. evansi) and flow cytometry to investigate their binding and activation potential toward camel leukocyte subsets. Labeling T. evansi with propidium iodide (PI) enabled their flow cytometric enumeration and identification with forward scatter (FSC; indicative for cell size) and side scatter (SSC; indicative for cell internal complexity) characteristics that are comparable with values reported for Trypanosoma cruzi. The incubation of PI-labeled non-opsonized T. evansi with camel leukocyte populations revealed that camel monocytes have the highest potential to bind T. evansi, followed by granulocytes and lymphocytes. The identification of pattern recognition receptors (PRRs) on camel immune cells and the pathogen-associated molecular patterns (PAMPs) in T. evansi that are responsible for this different binding capacity requires further studies. Stimulation of camel neutrophils with Trypanosoma evansi induced shape change, reactive oxygen species (ROS) production, and neutrophil extracellular traps (NET)-formation. To ensure that T. evansi, in the parasite concentration used in this study, is not apoptotic or necrotic to camel leukocytes, we evaluated cell apoptosis and necrosis after stimulation with T. evansi. The results revealed no impact of T. evansi stimulation for 2 h on the cell viability of camel leukocytes. Subsequent work may focus on the diagnostic employment of labeled T. evansi and flow cytometry for the detection of anti-Trypanosoma antibodies in camel serum. In addition, more efforts should be deployed to investigate the host-pathogen interaction mechanisms and the escape mechanisms of T. evansi in camels. To complete these data, further studies using the living or freshly killed parasites could also be implemented in camels and/or horses.

Detection of anti-Leishmania spp. antibodies in poultry from central region of Rio Grande do Sul, Brazil

Domestic birds such as Gallus gallus, Meleagris gallopavo, Anser anser and Numida meleagris are widely distributed throughout the world and maintain contact with humans and other animal species considered reservoirs of both Visceral Leishmaniasis (VL) and American Tegumentary Leishmaniasis (ATL), including dogs and cats; wild canids, marsupials; and synanthropic animals such as rodents and chiroptera. Therefore, this study aimed to detect the presence of anti-Leishmania spp. antibodies in birds from a rural area of the municipality of Santa Maria, southern Brazil. From May to December 2022, 262 blood samples were collected from 244 chickens, 8 turkeys, 7 guinea fowl and 3 geese, distributed in 27 rural properties in 6 districts. All the sites visited presented positive birds for the presence of Leishmania spp. Thus, it is inferred that, contact with this protozoan can induce the production of antibodies, suggesting that these animals can be used as sentinels for the circulation of this agent. In addition, the blood of these animals is a preferred food source for insects of the subfamily Phlebotominae, which can be used them as bioindicators of the presence of these phlebotomes.

Assessment of genetic diversity of Trypanosoma evansi in the domestic animal populations through ITS-1 gene sequence analysis

Trypanosoma evansi infects domestic animals, causing a debilitating and occasionally fatal disease. The disease leads to significant economic losses to farmers and poses a substantial impediment to the growth of livestock production in developing nations, including India. Considering the challenges associated with managing this infection, there is an urgent need to enhance our understanding of the molecular and genetic diversity of T. evansi. Therefore, this study was planned to analyze the genetic diversity of T. evansi using available internal transcribed spacer-1 (ITS-1) gene sequences from India and compare them with sequences from around the globe. Blood samples used in this study were collected from naturally infected animals including dogs, cattle, and buffaloes in the Indian state of Madhya Pradesh. Using the ITS-1 gene, we amplified a 540 base pairs (bp) segment using polymerase chain reaction (PCR), sequenced it, and identified intra-specific variations. Phylogenetic analysis of 90 sequences, including 27 from India, revealed three distinct clusters with high bootstrap support values. A haplotype network analysis identified 34 haplotypes, with H7 being the most prevalent, indicating a complex evolutionary history involving multiple countries. The genetic analysis of the Indian population revealed distinct characteristics. Despite low nucleotide diversity, there was high haplotype diversity in comparison to other populations. Tajima's D, Fu and Li's D, and Fu and Li's F exhibited non-significant negative values, indicating potential stability. Additionally, the slightly positive values in Fu's Fs, Raggedness (r), and Ramos-Onsins and Rozas (R2) statistics suggested a lack of recent significant selective pressures or population expansions. Furthermore, the presence of genetic differentiation and gene flow among T. evansi populations highlighted ongoing evolutionary processes. These findings collectively depicted a complex genetic landscape, suggesting both stability and ongoing evolutionary dynamics within the Indian population of T. evansi. The findings of this study are important for understanding the evolutionary history and population dynamics of T. evansi, and they may help us develop effective control strategies.

An epidemiological survey of vector-borne pathogens infecting cattle in Kyrgyzstan

Cattle production is a major contributor to the national economy of Kyrgyzstan. Most cattle in Kyrgyzstan are managed via extensive systems and graze in communal pastures. As a result, infestations with ectoparasites are widespread, implying that various vector-borne diseases might be common in cattle. However, methods to control such infectious diseases are not available in Kyrgyzstan because the epidemiology of vector-borne pathogens (VBPs) infecting cattle remains unclear. The present study was therefore designed to survey Kyrgyz cattle for VBPs. We prepared blood DNA samples from 319 cattle in Kyrgyzstan and screened them with specific PCR assays for detecting Babesia bovis, Babesia bigemina, Babesia naoakii, Theileria annulata, Theileria orientalis, Trypanosoma evansi, Trypanosoma theileri, and Anaplasma marginale infections. Our findings indicated that the surveyed cattle were infected with six of the eight pathogens targeted, with the exceptions being B. naoakii and Try. evansi. The most common pathogen was T. orientalis (84.3%), followed by B. bigemina (47.6%), T. annulata (16.6%), A. marginale (11.6%), Try. theileri (7.2%), and B. bovis (2.5%). Additional screening of the B. bovis- and B. bigemina-negative samples with a Babesia genus-specific 18S rRNA PCR identified two positive samples, and sequencing analysis confirmed that each of them was infected with either Babesia major or Babesia occultans. To the best of our knowledge, this is the first report of B. bovis, B. bigemina, B. occultans, Try. theileri, and A. marginale infections in cattle in Kyrgyzstan. Our findings suggest that cattle in Kyrgyzstan are at high risk of infectious diseases caused by VBPs.

Prevalence of African animal trypanosomiasis among livestock and domestic animals in Uganda: a systematic review and meta-regression analysis from 1980 to 2022

African animal trypanosomiasis (AAT) is one of the major constraints to animal health and production in sub-Saharan Africa. To inform AAT control in Uganda and help advance along the progressive control pathway (PCP), we characterized AAT prevalence among eight host species in Uganda and explored factors that influence the prevalence variation between studies. We retrieved AAT prevalence publications (n = 2232) for Uganda (1980-2022) from five life sciences databases, focusing on studies specifying AAT detection methods, sample size, and the number of trypanosome-positive animals. Following PRISMA guidelines, we included 56 publications, and evaluated publication bias by the Luis Furuya-Kanamori (LFK) index. National AAT prevalence under DNA diagnostic methods for cattle, sheep and goats was 22.15%, 8.51% and 13.88%, respectively. Under DNA diagnostic methods, T. vivax was the most common Trypanosoma sp. in cattle (6.15%, 95% CI: 2.91-10.45) while T. brucei was most common among small ruminants (goats: 8.78%, 95% CI: 1.90-19.88, and sheep: 8.23%, 95% CI: 4.74-12.50, respectively). Northern and Eastern regions accounted for the highest AAT prevalence. Despite the limitations of this study (i.e., quality of reviewed studies, underrepresentation of districts/regions), we provide insights that could be used for better control of AAT in Uganda and identify knowledge gaps that need to be addressed to support the progressive control of AAT at country level and other regional endemic countries with similar AAT eco-epidemiology.

In Vitro and In Vivo Trypanocidal Efficacy of Nitrofuryl- and Nitrothienylazines

African trypanosomiasis is a vector-borne disease of animals and humans in the tsetse fly belt of Africa. Trypanosoma congolense ("nagana") is the most pathogenic trypanosome in livestock and causes high morbidity and mortality rates among cattle. In the absence of effective preventative vaccines, the management of trypanosomiasis relies on chemoprophylaxis and/or -therapy. However, the trypanocides in clinical use exhibit poor oral bioavailability and toxicity, and therapeutic failures occur because of resistant strains. Because nitrofurantoin displayed, in addition to its clinical use, promising antiparasitic activity, the current study was conducted to evaluate the in vitro trypanocidal activity and preliminary in vivo treatment efficacy of previously synthesized nitrofuranylazines. The trypanocidal activity of these nitrofuran derivatives varied among the evaluated trypanosome species; however, T. congolense strain IL3000 was more susceptible than other animal and human trypanosomes. The nitrofurylazines 4a (IC50 0.04 μM; SI > 7761) and 7a (IC50 0.03 μM; SI > 9542) as well as the nitrothienylazine 8b (IC50 0.04 μM; SI 232), with nanomolar IC50 values, were revealed as early antitrypanosomal leads. Although these derivatives showed strong trypanocidal activity in vitro, no in vivo treatment efficacy was observed in T. congolense IL3000 infected mice after both oral and intraperitoneal administration in a preliminary study. This was attributed to the poor solubility of the test compounds in the in vivo testing media. Indeed, a challenge in drug discovery is finding a balance between the physicochemical properties of a drug candidate, particularly lipophilicity and water solubility, and maintaining adequate potency to provide an effective dose. Hence, future chemical modifications may be required to generate lead-like to lead-like nitrofuranylazines that possess optimal physicochemical and pharmacokinetic properties while retaining in vitro and, ultimately, in vivo trypanocidal efficacy.

"Lysis and Concentration Technique" improves the parasitological diagnosis of Trypanosoma vivax

The "Lysis and Concentration Technique" (LCTe) involves lysing red blood cells and concentrating parasites to increase the chances of visualization in low parasitemia and in scenarios of evaluators with less knowledge. The lysis of red blood cells reduced the time of diagnosis by 21 s, showing that the effect produced by the treatment is comparable to the effect of the experience in parasitological examination. In addition, the concentration of parasites was 39.18% higher for slides with high parasitemia and 131.03% for slides with low parasitemia in relation to the standard slide. LCTe proved to be inexpensive, with a total cost of approximately US$0.07 per slide made, which allows it to be easily implemented in most laboratories.

Performance of diagnostic tests for Trypanosoma brucei brucei in experimentally infected pigs

Animal African trypanosomosis is an important vector-borne disease of livestock in sub-Saharan Africa. Pigs seem relatively tolerant to trypanosome infection and could act as a reservoir of trypanosomes affecting animals and humans. Our ability to reliably detect trypanosome infection in pigs depends on the performance of diagnostic tools, which is not well known. In pigs experimentally infected with Trypanosoma brucei brucei, we evaluated the performance of parasitological Buffy Coat Technique (BCT), two molecular (TBR and 5.8S PCR) and four serological tests (CATT, HAT Sero-K-Set rapid diagnostic test-RDT, indirect ELISA, immune trypanolysis). Most diagnostic tests showed high specificity, estimated at 100% (95% CI = 74-100%) with the exception of CATT and RDT whose specificity varied between 100% (95% CI = 74-100%) to 50% (95% CI = 7-93%) during the experiment. The sensitivity of each test fluctuated over the course of the infection. The percentage of positive BCT over the infection (30%) was lower than of positive PCR (56% and 62%, depending on primers). Among the serological tests, the percentage of positive tests was 97%, 96%, 86% and 84% for RDT, ELISA, immune trypanolysis and CATT, respectively. Fair agreement was observed between both molecular tests (κ = 0.36). Among the serological tests, the agreement between the ELISA and the RDT was substantial (κ = 0.65). Our results on the T.b. brucei infection model suggest that serological techniques are efficient in detecting the chronic phase of infection, PCR is able to detect positive samples several months after parasites inoculation while BCT becomes negative. BCT examination and RDT are useful to get a quick information in the field, and BCT can be used for treatment decision. ELISA appears most suited for epidemiological studies. The selection of diagnostic tests for trypanosomosis in pigs depends on the context, the objectives and the available resources.

Developmental dynamics of mitochondrial mRNA abundance and editing reveal roles for temperature and the differentiation-repressive kinase RDK1 in cytochrome oxidase subunit II mRNA editing

IMPORTANCE

Trypanosoma brucei is the unicellular parasite that causes African sleeping sickness and nagana disease in livestock. The parasite has a complex life cycle consisting of several developmental forms in the human and tsetse fly insect vector. Both the mammalian and insect hosts provide different nutritional environments, so T. brucei must adapt its metabolism to promote its survival and to complete its life cycle. As T. brucei is transmitted from the human host to the fly, the parasite must regulate its mitochondrial gene expression through a process called uridine insertion/deletion editing to achieve mRNAs capable of being translated into functional respiratory chain proteins required for energy production in the insect host. Therefore, it is essential to understand the mechanisms by which T. brucei regulates mitochondrial gene expression during transmission from the mammalian host to the insect vector.

Tryp: a dataset of microscopy images of unstained thick blood smears for trypanosome detection

Trypanosomiasis, a neglected tropical disease (NTD), challenges communities in sub-Saharan Africa and Latin America. The World Health Organization underscores the need for practical, field-adaptable diagnostics and rapid screening tools to address the negative impact of NTDs. While artificial intelligence has shown promising results in disease screening, the lack of curated datasets impedes progress. In response to this challenge, we developed the Tryp dataset, comprising microscopy images of unstained thick blood smears containing the Trypanosoma brucei brucei parasite. The Tryp dataset provides bounding box annotations for tightly enclosed regions containing the parasite for 3,085 positive images, and 93 images collected from negative blood samples. The Tryp dataset represents the largest of its kind. Furthermore, we provide a benchmark on three leading deep learning-based object detection techniques that demonstrate the feasibility of AI for this task. Overall, the availability of the Tryp dataset is expected to facilitate research advancements in diagnostic screening for this disease, which may lead to improved healthcare outcomes for the communities impacted.

Phospholipases A and Lysophospholipases in protozoan parasites

Phospholipases (PLs) and Lysophospholipases (LysoPLs) are a diverse group of esterases responsible for phospholipid or lysophospholipid hydrolysis. They are involved in several biological processes, including lipid catabolism, modulation of the immune response and membrane maintenance. PLs are classified depending on their site of hydrolysis as PLA1, PLA2, PLC and PLD. In many pathogenic microorganisms, from bacteria to fungi, PLAs and LysoPLs have been described as critical virulence and/or pathogenicity factors. In protozoan parasites, a group containing major human and animal pathogens, growing literature show that PLAs and LysoPLs are also involved in the host infection. Their ubiquitous presence and role in host-pathogen interactions make them particularly interesting to study. In this review, we summarize the literature on PLAs and LysoPLs in several protozoan parasites of medical relevance, and discuss the growing interest for them as potential drug and vaccine targets.

Evolutionary, structural and functional insights in nuclear organisation and nucleocytoplasmic transport in trypanosomes

One of the remarkable features of eukaryotes is the nucleus, delimited by the nuclear envelope (NE), a complex structure and home to the nuclear lamina and nuclear pore complex (NPC). For decades, these structures were believed to be mainly architectural elements and, in the case of the NPC, simply facilitating nucleocytoplasmic trafficking. More recently, the critical roles of the lamina, NPC and other NE constituents in genome organisation, maintaining chromosomal domains and regulating gene expression have been recognised. Importantly, mutations in genes encoding lamina and NPC components lead to pathogenesis in humans, while pathogenic protozoa disrupt the progression of normal development and expression of pathogenesis-related genes. Here, we review features of the lamina and NPC across eukaryotes and discuss how these elements are structured in trypanosomes, protozoa of high medical and veterinary importance, highlighting lineage-specific and conserved aspects of nuclear organisation.

Surveillance and control of Trypanosoma evansi in the canary Islands: A descriptive analysis

This study examines the occurrence of Surra, a disease caused by Trypanosoma evansi, in camels in the Canary Islands. The 1997 detection of T. evansi in camels in the Canary Islands led to the implementation of an initial control program, resulting in a decrease in prevalence. Following an outbreak in 2014, and due to the impossibility of eradicating it using the conventional measures, a lazaret was set up to separate positive and suspicious animals, in addition to the control measures previously implemented. Stomoxys calcitrans was the only vector captured, and no other animals tested were found to be positive for T. evansi. In November 2019, the last camels that tested serologically positive were detected; however, since February 2018, no camels that tested positive for PCR have been found in the farms were the outbreak was detected, suggesting that the sanitary measures implemented are adequate. The duration of the outbreak control and potential eradication for the disease has yet to be established. This study provides evidence to facilitate the control of African Animal Trypanosomosis in endemic areas of the world, which may contribute to revise the World Organization for Animal Health (WOAH) protocol to implement recommendations of surveillance and control strategies for animal Trypanosomosis in camels.

European Inter-Laboratory Proficiency Test for Dourine Antibody Detection Using the Complement Fixation Test

Dourine is a sexually transmitted parasitic disease affecting equids. Its causative agent is referred to as Trypanosoma equiperdum and the prescribed serodiagnosis method is the complement fixation test (CFT). In the context of our European Reference Laboratory mandate for equine diseases (excluding African horse sickness), we organised dourine CFT inter-laboratory proficiency tests (ILPTs) in 2015, 2018 and 2022 to evaluate the performance of the European Union network of National Reference Laboratories (NRLs) for dourine. ILPT panels were composed of horse sera with or without antibodies against Trypanosoma spp. originating from non-infected, immunised or experimentally infected horses. Twenty-two NRLs participated in at least one of the three sessions. In 2015, 2018 and 2022, the percentage of laboratories obtaining 100% of the expected results was 57, 90 and 80, respectively. These dourine CFT ILPTs showed the benefits of standardising the method's detection limit and underlined the constant need to evaluate NRLs to improve the network's performance. These results also argue in favour of the need for a representative bio-bank to improve the representativeness of ILPT samples and to allow the adoption of alternative serological methods for international surveillance of dourine.

Comparative study of three novel ion exchange resins with DEAE-cellulose for the purification of Trypanosoma evansi

Ion exchange chromatography is a method that uses the different surface charges of trypanosomes and blood cells to separate them. This makes it possible to use molecular and immunological methods to diagnose or study these protozoans. DEAE-cellulose resin is commonly used to perform this method. The goal of this study was to compare three novel chromatographic resins designated as PURIFICA™ (Y-C2N®, Y-HONOH®, and Y-CNC3®). The resins were evaluated based on their ability to isolate the parasite, purification time, examination of parasite viability and morphology, and trypanosome recovery potential after passing through the columns. In terms of the evaluated parameters, there was no significant difference between DEAE-cellulose and the three tested resins in most experiments. However, PURIFICA™ (Y-C2N®, Y-HONOH®, and Y-CNC3®) resins are less expensive and easier to prepare than DEAE-Cellulose, making them an alternative for the purification of Trypanosoma evansi.

Validation of in vitro-produced and freeze-dried whole cell lysate antigens for ELISA Trypanosoma evansi antibody detection in camels

Trypanosoma evansi is a blood parasite responsible for surra in mammals, with a high impact in camels and horses. The WOAH-recommended reference method for detecting immunoglobulin G directed against T. evansi is ELISA, using whole cell lysate antigens (WCLAs). WCLAs are prepared with T. evansi produced in laboratory rodents, separated from blood cells using DE-cellulose anion exchange chromatography. As parasite lysates are fragile, antigens are preserved frozen pending use. For these reasons and others, T. evansi WCLAs are not commercially available. They are produced in small quantities, in a limited number of specialized laboratories, and they require a reliable and expensive cold chain for their shipment. In this study, we assessed and validated in vitro production of T. evansi and lyophilization of WCLAs in comparison with the reference method using frozen WCLAs prepared with parasites produced in rodents. Using a set of 400 samples monthly collected from 12 naturally infected camels followed-up for 1384 days, and two batches of referenced serum samples (infected, n = 12; non-infected, n = 15), statistical studies on qualitative and semi-quantitative results of the ELISAs did not show any significant difference when comparing the four combinations of parasites produced in vivo or in vitro, and frozen or freeze-dried WCLSAs. A repeatability study (28 repeats in 9 serum samples) was fully satisfying (p-value = 0.055). With the more convenient in vitro-produced freeze-dried WCLAs it was possible to: (i) avoid the ethical concern of in vivo production, (ii) improve the standardization of antigen production, (iii) secure antigen preservation during shipment and (iv) save a considerable amount of money (DE52-cellulose and dry-ice cold chain being avoided). Additional studies with other Trypanosoma spp are required for further extending ELISA to regional laboratories in enzootic areas, especially in view of the current progress in the "Progressive Control Pathway" (PCP) for trypanosomes in Africa.

Trypanosoma lewisi in blood of Rattus rattus complex residing in human settlements, Nakhon Si Thammarat, Thailand: Microscopic and molecular investigations

Trypanosomes are blood parasites infected in various mammals, including rats. The presence of rats in human settlements can increase the chance of Trypanosoma transmission to humans. The molecular study of multispacer in Trypanosoma spp. in naturally infected rodents in Thailand is scanty. The objective of this study was to detect Trypanosoma in the blood of the captured rats in Nakhon Si Thammarat, Thailand, using microscopic and molecular techniques. This was a cross-sectional study conducted in human settlement areas. Ninety-nine blood samples were collected using cardiac puncture. A blood sample was smeared on a glass slide and examined using a compound light microscope and a scanning electron microscope. Moreover, polymerase chain reaction was applied to detect Trypanosoma evansi and T. lewisi in the blood. An additional primer set was used to confirm the species of the detected trypanosome. Approximately 18% of the rats had positive Trypanosoma infections. All Trypanosoma-positive blood samples were matched with sequences of T. lewisi. The stumpy form of trypanosome had higher nucleus related parameters than the slender form. Interestingly, the partial sequences of the alpha-tubulin gene of T. lewisi were first reported in the naturally infected RrC in this study. Based on the results obtained, T. lewisi biology, particularly the virulent components and route of transmission, pathogenesis, and in vitro experiments, are strongly recommended for further study.

Molecular identification of Trypanosoma theileri (Laveran, 1902) in cattle from two slaughterhouses in Ecuador and its relation with other haemotropic agents

Trypanosoma theileri is a worldwide distributed haemoparasite that has been reported throughout the American continent in various species, including bovines, buffaloes and bats. In bovines, high incidence of T. theileri can be harmful when associated with other infections or under stress situations. There is little information on this hemoflagellate in Ecuador, which prompted the study and molecular identification of the trypanosomes collected in two slaughtering centers. Between February and April 2021, a total of 218 samples of bovine blood were collected in abattoirs located in the Andean region of Quito (n = 83) and in the coastal region, in Santo Domingo (n = 135). Quito public Slaughterhouse is the biggest in Ecuador, and for that, they receive animals from all country; on the other hand, Santo Domingo's Slaughterhouse is a small one where mainly females from the region are sacrificed and some males. The samples were evaluated using two molecular tests, the PCR cathepsin L-like (CatL) specific for T. theileri and for the positive samples, a Nested PCR that targets the ITS of the 18S gene. The corresponding PCR products were sequenced, analyzed by BLAST/NCBI and the sequences were used to build a concatenated phylogenetic tree, using the MEGA XI software. Overall, 34 out of the 218 samples, (15.6%) were positive to T. theileri by PCR CatL, resulting from 20/83 (24.1%) positives from the Quito abattoir and 14/135 (10.4%) from the Santo Domingo slaughterhouse. These prevalence rates were found to be significantly different (p = 0.006). According to the phylogenetic tree based on the CatL and ITS concatenated sequences (n = 13), the two novel Equatorial T. theileri isolates, ThI (n = 7) and ThII (n = 6) are closely related and associated to the IC, IB and IIB genotypes, present in Brazil, Venezuela and Colombia. Thirty-one out of the thirty-four T. theileri-positive bovines were co-infected with other haemotropic pathogens, Anaplasma marginale Babesia spp and T. vivax. This coinfection could be responsible for additional pathologies and harmful effects on the affected cattle. This study presents the molecular identification and genotypification of T. theileri isolated from cattle in Ecuador through the analysis of CAtL and ITS sequences, and the high frequency of coinfection of this hemoflagellate with other blood haemotropic organisms.

Morphological, serological, molecular detection, and phylogenetic analysis of Trypanosoma evansi in horses of different regions in Iran

Trypanosoma evansi, the causative agent of "surra" is enzootic in Iran. The current study aimed to detect T. evansi in horses from different regions of Iran using morphological, serological, and molecular methods. In 2021, 400 blood samples were collected from horses in eight regions. Eighty horses showed clinical signs such as cachexia (n = 64), fever (n = 36), foot edema (n = 40), and abdominal edema (n = 32), and 320 horses appeared healthy. All samples from the studied regions were evaluated for the presence of trypanosomes using direct analysis of blood smears, mercuric chloride, and PCR-based tests. In total, 12% (95% CI: ± 3.1%), 21% (95% CI: ± 3.9%), and 21% (84) of animals were positive for Trypanosoma in microscopic, serologic, and molecular analyses, respectively. All animals positive for SSU rDNA PCR were from Qom, Semnan, and Golestan regions. Further molecular analyses on 84 PCR-positive horses revealed that 29 horses scored positive in PCR using primers of trypanozoon species and 5 scored positive in PCR using primers of Trypanosoma evansi type A. All samples (n = 5) were from Qom region. The 205-bp fragments of T. evansi RoTat 1.2VSG (accession numbers: ON017789-93) analyzed and compared to other isolates sequence from GenBank BLAST search. It has close similarities with isolates from Pakistan, Egypt, Malaysia, Kenya, and India. Data herein demonstrated that horses from Iran were at high risk of T. evansi infection. Comprehensive control programs, such as those based on the application of repellants and traps, and also, compliance with quarantine standards are recommended for minimizing the risk of the infection.

Molecular Research on Vector-Borne Diseases of Medical Interest: From Bench to Application 2.0

Infectious diseases caused by parasites (malaria, leishmaniasis, trypanosomiasis, filariasis…), viruses (chikungunya, dengue, phlebovirus, etc [...].

Trypanosome Infections and Anemia in Cattle Returning from Transhumance in Tsetse-Infested Areas of Cameroon

The objective of this work was to assess the anemic status and the use of an immunological test and PCR-based methods to determine the infection rates of trypanosomes species. Transhumance aims to provide cattle with greener pastures and greater water resources than in the Djerem region during the dry season. Two criteria were used to assess the health status of the animals, the prevalence of trypanosomiasis and the level of anemia. In addition, we have evaluated the effectiveness, in trypanosomiasis detection, of the Very Diag Kit (CEVA Santé animale), a Rapid diagnosis test (RDT) based on immunological identification of T. congolense s.l. and T. vivax, responsible for AAT. Four trypanosome species (Trypanosoma congolense savannah type (Tcs), T. congolense forest type (Tcf), T. brucei s.l. (Tbr) and T. vivax (Tvx)) were identified in cattle sampled in four villages. The overall infection rate determined by PCR (68.6%) was much higher than those generally reported in cattle from the Adamawa region (35 to 50%). Infections (including mixed infections) by Tc s.l. (Tcs + Tcf) were predominant (45.7%). The infection rates were also determined using the Very Diag Kit allowing us to identify Tc s.l. and Tvx in the field in less than 20 min. This method provided, for the global infection, a higher rate (76.5%) than that determined by PCR (68.6%), although it is supposed to be less sensitive than PCR. Tc s.l. infection rate (37.8%) was similar to that (38.8%) determined by PCR (Tcs + Tcf single infections). In contrast, the prevalence of Tvx single infections measured by RDT (18%) was nearly two-fold higher than that (9.4%) measured by PCR. Thus, further comparative analyses seem to be needed in order to more accurately assess the sensitivity and specificity of the Very Diag test under our conditions of use on blood samples. The mean PCVs in trypanosome-infected as well as in uninfected cattle were below 25%, the threshold below which an animal is considered anemic. Our study shows that cattle return from transhumance in poor health. It raises questions about its real benefit, especially since the herds are themselves likely to become vectors of trypanosomiasis and possibly of other diseases. At least, effective measures have to be undertaken to treat all cattle coming back from transhumance.