Trypanosome Species Research Articles

Trypanosomes infection, endosymbionts, and host preferences in tsetse flies (Glossina spp.) collected from Akagera park region, Rwanda: A correlational xenomonitoring study

Akagera National Park and its surroundings are home to tsetse flies and a number of their mammalian hosts in Rwanda. A One-health approach is being used in the control and surveillance of both animal and human trypanosomosis in Rwanda. Determination of the infection level in tsetse flies, species of trypanosomes circulating in vectors, the source of tsetse blood meal and endosymbionts is crucial in understanding the epidemiology of the disease in animals and humans in the region.Tsetse flies (n = 1101), comprising Glossina pallidipes (n = 771) and Glossina morsitans centralis (n = 330) were collected from Akagera park and surrounding areas between May 2018 and June 2019. The flies were screened for trypanosomes, vertebrate host DNA to identify sources of blood meal, and endosymbionts by PCR - High Resolution Melting analysis and amplicon sequencing. The feeding frequency and the feeding indices (selection index - W) were calculated to identify the preferred hosts. An overall trypanosome infection rate of 13.9% in the fly's Head and Proboscis (HP) and 24.3% in the Thorax and Abdomen (TA) were found. Eight trypanosome species were identified in the tsetse fly HP and TA, namely: Trypanosoma (T.) brucei brucei, T. congolense Kilifi, T. congolense savannah, T. vivax, T. simiae, T. evansi, T. godfreyi, T. grayi and T. theileri. We found no evidence of human-infective T. brucei rhodesiense. We also identified eighteen species of vertebrate hosts that tsetse flies fed on, and the most frequent one was the buffalo (Syncerus caffer) (36.5%). The frequently detected host by selection index was the rhinoceros (Diceros bicornis) (W = 16.2). Most trypanosome infections in tsetse flies were associated with the buffalo blood meal. The prevalence of tsetse endosymbionts Sodalis and Wolbachia was 2.8% and 4.8%, respectively. No Spiroplasma and Salivary Gland Hypertrophy Virus were detected. These findings implicate the buffaloes as the important reservoirs of tsetse-transmitted trypanosomes in the area. This contributes to predicting the main cryptic reservoirs and therefore guiding the effective control of the disease. The study findings provide the key scientific information that supports the current One Health collaboration in the control and surveillance of tsetse-transmitted trypanosomosis in Rwanda.

Spatial-Temporal Variations in Parasitological Prevalence and Host-Related Risk Factors of Camel Trypanosomiasis and Its Vectors in North Eastern Kenya: A Repeated Cross-Sectional Study.

Camel trypanosomiasis (Surra) is endemic in the Horn of Africa. Understanding the spatiotemporal variations in Surra prevalence, vector dynamics, and host-related risk factors is important in developing effective control strategies. A repeated cross-sectional study was conducted to determine the Surra parasitological prevalence, livestock reservoirs, vector density/diversity, and host-related risk factors in Kenya. Random samples of 847, 1079, and 824 camels were screened at the start of the dry season, peak dry season, and during the rainy season, respectively. Blood samples were examined using the dark ground/phase contrast buffy-coat technique, and Trypanosoma species were identified based on their movement and morphology in wet and stained thin smears. Reservoir status for Trypanosoma evansi was assessed in 406 cattle and 372 goats. A rainy and dry seasons entomological surveys were conducted to determine the Surra vector abundance/diversity and spatiotemporal density changes. Surra prevalence was 7.1%, 3.4%, and 4.1% at the start of the dry season, peak dry season, and rainy season, respectively. Camel co-infections by Trypanozoon (T. evansi or Trypanosoma brucei brucei) and Trypanosoma vivax were recorded. Spatial variations in Surra prevalence were recorded at the beginning of dry (X (7, N = 846) 2 = 110.9, p ≤ 0.001), peak dry (X (7, N = 1079) 2 = 42.2, p ≤ 0.001), and rainy (X (7, N = 824) 2 = 29.1, p ≤ 0.001) seasons. The screened cattle and goats tested negative for Trypanozoon (T. evansi or T. b. brucei), while two cattle tested positive for Trypanosoma congolense. Biting fly catches were composed of a single species from Tabanus, Atylotus, Philoliche, Chrysops, and Stomoxys genera. The total catches for Philoliche, Chrysops, and Stomoxys were higher in the rainy than dry season consistent with the prevalence results. Surra remains an important camel disease in the region with its prevalence varying in space and time. Camel co-infections by Trypanozoon (T. evansi or T. b. brucei) and T. vivax necessitate proper diagnosis of suspected cases and targeted therapy.

Prevalence and Associated Risk Factors of Bovine Trypanosomosis in Nono District, West Shewa Zone, Ethiopia

Trypanosomosis is a major constraint to livestock production due to the challenge of vector control activities and drug resistance development in Sub-Saharan Africa particularly Ethiopia. The most common trypanosome species that affects cattle in Ethiopia are T. congolense. T. vivax and T. brucei. Therefore, A cross sectional study was conducted from November 2019 to December 2020 to determine the prevalence of bovine trypanosomosis Nono district of Western Shewa zone, Ethiopia. The study district was purposively selected and PAs were randomly selected to take sample for the study. For the prevalence study, dark phase contrast buffy coat examination and Giemsa stained thin blood smears were used and Chi- Square test was used to analysis the results. Out of a total of 384 randomly selected and examined cattle, an overall prevalence of 5.5% was recorded. Highest prevalence was recorded in Nano Halo 8(6.7%) followed by Biftu Jalala 6(5.5%) and Halo Dinki 7(4.5%) peasant associations. This study showed no significant difference (P>0.05) in trypanosomiasis infection rate among peasant associations and there was significant association between risk factors like age(X2= 6.97, P= 0.008), sex (X2= 5.38, P= 0.02), body condition (X2 = 6.09, P= 0.048) and PCV values (X2= 18.47, P= 0.000) of examined cattle. Out of species of trypanosome identified highest was T. Congolense was 13(61.91%), followed by T. Vivax was 7(33.33%) and 1(4.76%) were mixed. The present work evidenced that tsetse and trypanosomosis has continued to pose a considerable threat to cattle of the study area warranting an integrated control to safeguard cattle production and productivity.

Trypanosome infections in animals from tsetse infected areas of Cameroon and their sensitivity and resistance molecular profiles for diminazene aceturate and isometamidium chloride

Monitoring and assessment of control strategies for African trypanosomoses' elimination require not only updating data on trypanosome infections, but also to have an overview on the molecular profiles of trypanocides resistance in different epidemiological settings. This study was designed to determine, in animals from six tsetse-infested areas of Cameroon, the prevalence of trypanosome infections as well as the diminazene aceturate (DA) and isometamidium chloride (ISM) sensitivity/resistance molecular profiles of these trypanosomes. From 2016 to 2019, blood was collected in pigs, dogs, sheep, goats and cattle from six tsetse infested areas of Cameroon. DNA was extracted from blood and trypanosome species were identified by PCR. The sensitivity/resistance molecular profiles of trypanosomes to DA and ISM were investigated using PCR-RFLP. From 1343 blood samples collected, Trypanosoma vivax, Trypanosoma congolense forest and savannah, Trypanosoma theileri and trypanosomes of the sub-genus Trypanozoon were identified. The overall prevalence of trypanosome infections was 18.7%. These prevalence vary between trypanosome species, animal taxa, within and between sampling sites. Trypanosoma theileri was the predominant species with an infection rate of 12.1%. Trypanosomes showing resistant molecular profiles for ISM and DA were identified in animals from Tibati (2.7% for ISM and 65.6% for DA) and Kontcha (0.3% for ISM and 6.2% for DA). No trypanosome carrying resistant molecular profile for any of the two trypanocides was detected in animals from Fontem, Campo, Bipindi and Touboro. Mixed molecular profiles of sensitive/resistant trypanosomes were detected in animals from Tibati and Kontcha. Results of this study highlighted the presence of various trypanosome species as well as parasites carrying sensitive/resistant molecular profiles for DA and ISM in animals of tsetse infested areas of Cameroon. They indicate that the control strategies must be adapted according to epidemiological settings. The diversity of trypanosomes indicates that AAT remains a serious threat for animal breeding and animal health in these tsetse infested areas.

Morphological and molecular diagnosis of two new species of Trypanosoma Gruby, 1843 infecting South African cordylid lizards (Squamata: Cordylidae: Cordylinae), Trypanosoma (Squamatrypanum) ndumoensis n. sp. and Trypanosoma (Trypanosoma) tokoloshi n. sp.

Despite reptile trypanosomes forming a large group, the majority of species descriptions are data deficient, lacking key characteristic data and supporting molecular data. Reptile hosts show potential to facilitate transmission of zoonotic trypanosomiases and offer key information to understanding the genus of Trypanosoma. Several species of squamates from different localities in South Africa were screened molecularly and microscopically for trypanosomes in the present study. Based on the combination of morphological and molecular analyses, two new species of Trypanosoma, Trypanosoma (Squamatrypanum) ndumoensis n. sp. and Trypanosoma (Trypanosoma) tokoloshi n. sp., infecting South African cordylid lizards (Cordylidae: Cordylinae) are described in this study. The first molecular data for a South African reptile trypanosome is provided herewith.

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.

Taxonomic re-evaluation of African anuran trypanosomes with the redescription and molecular diagnosis of Trypanosoma (Trypanosoma) nelspruitense Laveran, 1904 and Trypanosoma (Haematomonas) grandicolor Pienaar, 1962.

The aquatic and terrestrial clades of species of Trypanosoma could provide insight into the evolutionary history of the genus, as well as complementary information for biomedical studies of medically and economically important species of Trypanosoma. The ecological interactions and phylogeny of aquatic trypanosomes are currently not well-understood, mostly due to their complex life cycles and a deficiency of data. The species of Trypanosoma from African anuran hosts are of the least understood taxa in the genus. Trypanosomes were collected from South African frogs and subjected to morphological and phylogenetic analyses. This study redescribes Trypanosoma (Trypanosoma) nelspruitense Laveran, 1904 and Trypanosoma (Haematomonas) grandicolor Pienaar, 1962, with morphological and molecular data. The present study aims to create a platform for further future research on African anuran trypanosomes.

Prevalence of bovine trypanosomiasis in Côte d'Ivoire: Systematic review and meta-analysis.

Bovine trypanosomiasis is a parasitic disease caused by protozoans of the genusTrypanosoma. The disease cause economic losses in livestock production. In order to determine the status of research on this disease in Côte d'Ivoire, we used the systematic review method and meta-analysis. Three electronics databases, namely Google Scholar, PubMed and CrossRef were used to search for publications on trypanosomiasis prevalence that met our inclusion criteria. Twenty five articles were identified, 11 of which met the inclusion criteria. Bovine trypanosomiasis prevalence of 2.99% (95% confidence interval [CI]: 2.96% - 3.01%) to 25.28% (95% CI: 25.17% - 25.38%) were recorded between 1960 and 2021. The analyses showed that the most infected regions were the Bagoue 11.26% (95% CI: 11.25% - 11.27%), Bounkani 14.94% (95% CI: 14.93% - 14.95%), Gbeke 10.34% (95% CI: 10.33% - 10.35%), Marahoue 13.79% (95% CI: 13.78% - 13.80%), Poro 8.50% (95% CI: 8.49% - 8.51%), and Tchologo 11.83% (95% CI: 11.82% - 11.84%).The most sensitive diagnostic method used was the polymerase chain reaction (PCR). The species of trypanosomes diagnosed wereTypanosoma vivax4.99% (95% CI: 4.97% - 5.01%),T. congolense1.51% (95% CI: 1.49% - 1.52%), andT. brucei0.61% (95% CI: 0.59% - 0.62%). Despite some variation, the prevalence of bovine trypanosomiasis in Côte d'Ivoire caused mainly byT. vivaxhas increased in the years between 1977 and 2017. Efforts to control tsetse and other mechanical vectors should also be put in place to minimize its transmission.Contribution:The authors studied the prevalence of bovine trypanosomiasis using the systematic review method and MA in order to determine the status of research on this disease in Côte d'Ivoire.

Molecular genotyping reveals mixed bovine and human trypanosomiasis in cattle from West Africa.

Animal trypanosomiasis is a major contributor to agricultural and economic losses, especially in sub-Saharan Africa. We have shown that some animal species expressed genes that are significant players in immune response to bovine trypanosomosis, impeding signs and symptoms of the disease. We hypothesize that such animals are contributors to disease transmission dynamics and severe outcomes. Therefore, this study aims to ascertain trypanosome species diversity in cattle and their potential role as reservoirs for the transmission of human disease. We performed a molecular genotyping of trypanosome internal transcribed spacer 1 (ITS-1) and 18S ribosomal RNA genes on genomic DNA extracts from randomly sampled N'Dama cattle from slaughterhouses in Nigeria. We identified trypanosome species circulating among the animals through polymerase chain reaction and genomic sequencing. We performed multiple sequence alignments as well as conducted a phylogenetic relationship between identified species. In all, 9 of 127 (7.1%) samples were positively amplified (band sizes ranging from 250 bp to 710 bp), including an isolate with two distinct bands (700 and 710 bp), indicating two trypanosome types. Sequence similarity and homology analysis identified four species, namely: Trypanosoma vivax, Trypanosoma congolense forest type, T. congolense savannah type, and Trypanosoma brucei. Interestingly, one of the bands, additionally verified by nucleotide sequencing, was identified as a human trypanosome (Trypanosoma brucei gambiense), confirming our hypothesis that cattle are potential reservoir hosts for human trypanosomes. Overall, we observed different trypanosome species in our study area, with animals on the same farm infected with multiple species, which could complicate treatment and disease control strategies. Finding human trypanosome species strengthens the argument that disease transmission dynamics are modulated by other vertebrates, further complicating control programs.

Prevalence and Association of Trypanosomes and Sodalis glossinidius in Tsetse Flies from the Kafue National Park in Zambia

Tsetse flies are obligate hematophagous vectors of animal and human African trypanosomosis. They cyclically transmit pathogenic Trypanosoma species. The endosymbiont Sodalis glossinidius is suggested to play a role in facilitating the susceptibility of tsetse flies to trypanosome infections. Therefore, this study was aimed at determining the prevalence of S. glossinidius and trypanosomes circulating in tsetse flies and checking whether an association exists between trypanosomes and Sodalis infections in tsetse flies from Kafue National Park in Zambia. A total of 326 tsetse flies were sampled from the Chunga and Ngoma areas of the national park. After DNA extraction was conducted, the presence of S. glossinidius and trypanosome DNA was checked using PCR. The Chi-square test was carried out to determine whether there was an association between the presence of S. glossinidius and trypanosome infections. Out of the total tsetse flies collected, the prevalence of S. glossinidius and trypanosomes was 21.8% and 19.3%, respectively. The prevalence of S. glossinidius was 22.2% in Glossina morsitans and 19.6% in Glossina pallidipes. In relation to sampling sites, the prevalence of S. glossinidius was 26.0% in Chunga and 21.0% in Ngoma. DNA of trypanosomes was detected in 18.9% of G. morsitans and 21.4% of G. pallidipes. The prevalence of trypanosomes was 21.7% and 6.0% for Ngoma and Chunga, respectively. The prevalences of trypanosome species detected in this study were 6.4%, 4.6%, 4.0%, 3.7%, 3.1%, and 2.5% for T. vivax, T. simiae, T. congolense, T. godfreyi, T. simiae Tsavo, and T. b. brucei, respectively. Out of 63 trypanosome infected tsetse flies, 47.6% of the flies also carried S. glossinidius, and the remaining flies were devoid of S. glossinidius. A statistically significant association was found between S. glossinidius and trypanosomes (p < 0.001) infections in tsetse flies. Our findings indicated that presence of S. glossinidius increases the susceptibility of tsetse flies to trypanosome infections and S. glossinidius could be a potential candidate for symbiont-mediated vector control in these tsetse species.

Phylogenetic evidence for a clade of tick-associated trypanosomes

BackgroundTrypanosomes are protozoan parasites of vertebrates that are of medical and veterinary concern. A variety of blood-feeding invertebrates have been identified as vectors, but the role of ticks in trypanosome transmission remains unclear.MethodsIn this study, we undertook extensive molecular screening for the presence and genetic diversity of trypanosomes in field ticks.ResultsExamination of 1089 specimens belonging to 28 tick species from Europe and South America led to the identification of two new trypanosome strains. The prevalence may be as high as 4% in tick species such as the castor bean tick Ixodes ricinus, but we found no evidence of transovarial transmission. Further phylogenetic analyses based on 18S rRNA, EF1-α, hsp60 and hsp85 gene sequences revealed that different tick species, originating from different continents, often harbour phylogenetically related trypanosome strains and species. Most tick-associated trypanosomes cluster in a monophyletic clade, the Trypanosoma pestanai clade, distinct from clades of trypanosomes associated with transmission by other blood-feeding invertebrates.ConclusionsThese observations suggest that ticks may be specific arthropod hosts for trypanosomes of the T. pestanai clade. Phylogenetic analyses provide further evidence that ticks may transmit these trypanosomes to a diversity of mammal species (including placental and marsupial species) on most continents.Graphical

Old Methods, New Insights: Reviewing Concepts on the Ecology of Trypanosomatids and Bodo sp. by Improving Conventional Diagnostic Tools.

Mixed infections by different Trypanosoma species or genotypes are a common and puzzling phenomenon. Therefore, it is critical to refine the diagnostic techniques and to understand to what extent these methods detect trypanosomes. We aimed to develop an accessible strategy to enhance the sensitivity of the hemoculture, as well as to understand the limitations of the hemoculture and the blood clot as a source of parasitic DNA. We investigated trypanosomatid infections in 472 bats by molecular characterization (18S rDNA gene) of the DNA obtained from the blood clot and, innovatively, from three hemoculture sample types: the amplified flagellates ("isolate"), the pellet of the culture harvested in its very initial growth stage ("first aliquot"), and the pellet of non-grown cultures with failure of amplification ("sediment"). We compared (a) the characterization of the flagellates obtained by first aliquots and isolates; and (b) the performance of the hemoculture and blood clot for trypanosomatid detection. We observed: (i) a putative new species of Bodo in Artibeus lituratus; (ii) the potential of Trypanosoma cruzi selection in the hemoculture; (iii) that the first aliquots and sediments overcome the selective pressure of the hemoculture; and (iv) that the blood clot technique performs better than the hemoculture. However, combining these methods enhances the detection of single and mixed infections.

Prevalence of bovine trypanosomosis and apparent density of tsetse flies in Hawa Gelan district, West Oromia, Ethiopia

Across sectional study was conducted from October to November 2021 to determine the prevalence of bovine trypanosomosis and the apparent density of tsetse flies in six peasant association of hawa gelan district. For the prevalence study, dark phase contrast buffy coat examination and giemsa stained thin blood smears were used. Whereas for entomological survey to determine apparent density of flies, traps were deployed. The entomological survey indicated that four species of glossina were the fly species caught in the study area. Apparent tsetse flies density of 5.34 flies/trap/day was recorded in the district and the highest FTD was recorded Mender 16 village. For the prevalence study, out of total of 532 cattle examined, 19(3.57%) were found infected with trypanosomes. Out of infected animals highest prevalence was recorded in cattle with poor body condition (52.63%) followed by medium (31.58%) and good (15.79%).The overall mean PCV value of examined cattle is 29.29± 4.813 and the overall mean PCV value of non infected cattle was slightly higher (29.30%) than that of infected animals (28.3%).Among the species of trypanosomes isolated, Trypanosoma vivax was identified to the major causes of trypanosomosis in the study area accounting for 63.16% of total infections observed followed by trpanosoma congolense (36.84%) respectively. Taken as a whole, the present work evidenced that tsetse and trypanosomosis has continued to pose aconsiderable threat to cattle of the study area warranting an integrated control to safeguard cattle production and productivity.

Prevalence of pathogenic trypanosome species in naturally infected cattle of three sleeping sickness foci of the south of Chad.

Although a diversity of trypanosome species have been detected in various animal taxa from human African trypanosomosis (HAT) foci, cattle trypanosomosis has not been addressed in HAT foci of west and central African countries including Chad. This study aimed to determine the prevalence of pathogenic trypanosome species in cattle from three HAT foci of the south of Chad. Blood samples were collected from 1466 randomly selected cattle from HAT foci of Mandoul, Maro, and Moïssala in the south of Chad. For each animal, the sex, age and body condition were recorded. Rapid diagnostic test (RDT) was used to search Trypanosoma brucei gambiense antibodies while the capillary tube centrifugation (CTC) test and PCR-based methods enabled to detect and identify trypanosome species. From the 1466 cattle, 45 (3.1%) were positive to RDT. The prevalence of trypanosome infections revealed by CTC and PCR-based method were respectively 2.7% and 11.1%. Trypanosomes of the subgenus Trypanozoon were dominant (6.5%) followed by T. congolense savannah (2.9%), T. congolense forest (2.5%) and T. vivax (0.8%). No animal was found with DNA of human infective trypanosome (T. b. gambiense). The overall prevalence of trypanosome infections was significantly higher in animal from the Maro HAT focus (13.8%) than those from Mandoul (11.1%) and Moïssala HAT foci (8.0%). This prevalence was also significantly higher in animal having poor body condition (77.5%) than those with medium (11.2%) and good (0.5%) body condition. The overall prevalence of single and mixed infections were respectively 9.4% and 1.6%. This study revealed natural infections of several pathogenic trypanosome species in cattle from different HAT foci of Chad. It showed similar transmission patterns of these trypanosome species and highlighted the need of developing control strategies for animal African trypanosomosis (AAT) with the overarching goal of improving animal health and the economy of smallholder farmers.

Comparison of Bioluminescent Substrates in Natural Infection Models of Neglected Parasitic Diseases.

The application of in vivo bioluminescent imaging in infectious disease research has significantly increased over the past years. The detection of transgenic parasites expressing wildtype firefly luciferase is however hampered by a relatively low and heterogeneous tissue penetrating capacity of emitted light. Solutions are sought by using codon-optimized red-shifted luciferases that yield higher expression levels and produce relatively more red or near-infrared light, or by using modified bioluminescent substrates with enhanced cell permeability and improved luminogenic or pharmacokinetic properties. In this study, the in vitro and in vivo efficacy of two modified bioluminescent substrates, CycLuc1 and AkaLumine-HCl, were compared with that of D-luciferin as a gold standard. Comparisons were made in experimental and insect-transmitted animal models of leishmaniasis (caused by intracellular Leishmania species) and African trypanosomiasis (caused by extracellular Trypanosoma species), using parasite strains expressing the red-shifted firefly luciferase PpyRE9. Although the luminogenic properties of AkaLumine-HCl and D-luciferin for in vitro parasite detection were comparable at equal substrate concentrations, AkaLumine-HCl proved to be unsuitable for in vivo infection follow-up due to high background signals in the liver. CycLuc1 presented a higher in vitro luminescence compared to the other substrates and proved to be highly efficacious in vivo, even at a 20-fold lower dose than D-luciferin. This efficacy was consistent across infections with the herein included intracellular and extracellular parasitic organisms. It can be concluded that CycLuc1 is an excellent and broadly applicable alternative for D-luciferin, requiring significantly lower doses for in vivo bioluminescent imaging in rodent models of leishmaniasis and African trypanosomiasis.

Trypanosoma cruzi and Trypanosoma rangeli in Acre, Brazilian Amazonia: Coinfection and Notable Genetic Diversity in an Outbreak of Orally Acquired Acute Chagas Disease in a Forest Community, Wild Reservoirs, and Vectors

Acute Chagas disease (ACD) caused by Trypanosoma cruzi has emerged as a major food-borne disease in Brazilian Amazonia. For the first time, we characterized an outbreak of orally acquired ACD in Acre, in the forest community of Seringal Miraflores, affecting 13 individuals who shared the pulp of açai palm berries: 11 adults and two children (one newborn), all diagnosed by thick-drop blood smears. The fluorescent fragment length barcoding method, which simultaneously identifies species/genotypes of trypanosomes in blood samples, uncovered an unprecedented genetic diversity in patients from a single outbreak of ACD: T. cruzi TcI in all patients, mostly concomitantly with the non-pathogenic Trypanosoma rangeli of genotypes TrA or TrB, and TcI, TcIV, and TrB in the child. The patients presented persistent fever, asthenia, myalgia, edema of the face and lower limbs, hepatosplenomegaly and, rarely, cardiac arrhythmia. The clinical symptoms were not correlated to gender, age, or to trypanosome species and genotypes. The inferred SSU rRNA phylogenetic analyses of trypanosomes from humans, triatomines and sylvatic hosts included the first sequences of T. cruzi and T. rangeli from humans in southwestern (Acre and Rondônia) Amazonia, and the first TcI/TcIV sequences from Rhodnius spp. from Acre. The sylvatic transmission cycles of genetically different trypanosomes in landscapes changed by deforestation for human settlements and increasing açai production is a novel scenario favoring trypanosome transmission to humans in Acre.

Molecular Diagnostic Survey of Honey Bee, Apis mellifera L., Pathogens and Parasites from Arkansas, USA

Abstract Managed honey bee populations have fluctuated over the past several decades in the U.S. While a single factor has not been identified for these losses, the interaction between multiple biotic and abiotic stressors have been suggested to be responsible. Of major concern are several invasive parasite and pathogen species as well as colony management. A single honey bee colony often suffers from multiple harmful agents, that may act synergistically and cause greater declines in bee health. We conducted a survey to detect known and lesser-known honey bee parasites and pathogens. While previous research has primarily focused on commercially managed colonies, research is limited to pertaining parasite and pathogen prevalence in hobbyist managed colonies. Molecular diagnostics were used to screen 541 Arkansas (AR) honey bee colonies from 107 hobbyist beekeepers for eight A. mellifera parasite and pathogen species. Colony samples were obtained between 2015–2016 and represented forty-seven of the seventy-five AR counties. Vairimorpha ceranae (11.6% occurrence) and parasite Varroa destructor (49.4% occurrence) were relatively common in AR hobbyist colonies. Interestingly, the lesser-studied pathogenic trypanosome species, Lotmaria passim, was detected in 11.3% of the colonies and widespread in twenty of the forty-seven counties sampled. None of the honey bee pathogens Vairimorpha apis, Spiroplasma apis, S. melliferum, Crithidia mellificae, or the parasitic phorid fly, Apocephalus borealis, were detected in the colonies sampled. This study provides an extensive assessment of the parasite and pathogen species occurring at the AR state-level in hobbyist-managed honey bee colonies.

Seasonal prevalence of bovine trypanosomosis and trypanosome species distribution in Jimma Horo district, Oromia regional state, Western Ethiopia

A study was conducted to determine the prevalence of bovine trypanosomosis in rainy (June 2019) and dry (February 2020) seasons in Jimma Horoo district, Kellem Wollega Zone, Oromia Regional State, Ethiopia. A total of 720 blood samples were examined using buffy coat and thin blood smear techniques. The packed cell volume (PCV) of each animal was determined. The overall bovine trypanosomosis prevalence was 4.3% (χ2 = 1.25, P = 0.26). The prevalence was 5% (95% CI = 4.1–8.3) and 3.3% (95% CI = 2.7–6.3) in the dry and rainy reasons, respectively (P > 0.05). Trypanosoma congolense, T. vivax and T. b. brucei were detected in (60%), (33.3%) and (6.7%) of infected cattle, respectively. The highest trypanosome prevalence was observed in Burka Gudina (7.6%), and the lowest in Melka Nega village (2.1%). There were significant variations between trypanosome prevalence in relation to body condition scores (χ2 = 23.16; P = 0.0.00) of examined cattle. No significant difference (P > 0.05) was observed between seasons, age, and sex categories of cattle. The PCV values of trypanosome infected (22.94%) was significantly lower than non-infected cattle (26.47%) (χ2 = 19.60; (P < 0.05). The prevalence of bovine trypanosomosis in Jimma Horo district was low and it can be controlled by treatment of infected cattle using sanative pairs of trypanocidal drugs with additional application of deltamethrin pour-on in the dry season. Further, in view of poor sensitivity of buffy coat technique used the use of molecular techniques should be encouraged.

Tsetse Flies Infected with Trypanosomes in Three Active Human African Trypanosomiasis Foci of the Republic of Congo.

Human African trypanosomiasis (HAT) is a neglected tropical disease still endemic in the Republic of Congo. Despite the continuous detection of HAT cases in the country, there is still not enough data on trypanosome infections in tsetse flies, trypanosome species and tsetse flies' species distribution in endemic foci. The present study was intended to fill this gap and improve understanding of trypanosome circulation in three active foci in the centre and south of Congo. Pyramid traps were set in various places in villages to collect tsetse flies both during the rainy and dry seasons. Once collected, tsetse flies were identified using morphological keys. DNA extracted from flies was processed by PCR for species identification and for detection of trypanosome presence. A second PCR was run for different trypanosome species identification. A total of 1291 tsetse flies were collected. The average apparent density of flies per day was 0.043 in Mpouya, 0.73 in Ngabé and 2.79 in Loudima. Glossina fuscipes quazensis was the predominant tsetse fly collected in Ngabé and Mpouya, while Glossina palpalis palpalis was the only tsetse fly found in Loudima. A total of 224 (17.7%) flies were detected infected by trypanosomes; 100 (7.91%) by Trypanosoma congolense savannah, 22 (1.74%) by Trypanosoma congolense forest, 15 (1.19%) by Trypanosoma vivax, 83 (6.56%) by Trypanosoma brucei (s.l.) and 2 (0.16%) undetermined species. No T Trypanosoma brucei gambiense was found. A total of 57 co-infections between T. brucei (s.l.) and T. congolense savannah or T. brucei (s.l.) and T. congolense forest were found only in G. p. palpalis. Loudima recorded the highest number of infected tsetse flies. The study provided updated information on the distribution of tsetse fly populations as well as on Trypanosoma species circulating in tsetse flies in the different active HAT foci in Congo. These data suggested a high risk of potential transmission of animal trypanosomes in these foci, thus stressing the need for active surveillance in this endemic area.

Human Africa Trypanosomiasis in Littoral Region of Cameroon: an Updated With First Evidence on the Circulation of Trypanosoma Brucei Gambiense in Manoka Island

Aims: A survey on Human African Trypanosomiasis (HAT) is essential for prevention and preparedness for epidemics. The objective of this study is to assess the circulation of human trypanosomes and their vectors across quiescent HAT foci of the Littoral Region of Cameroon. &#x0D; Methodology: A descriptive study on the presence of Trypanosoma brucei gambiense and its potential vectors was carried out in Youpwe, Yabassi, Sodiko, Manoka island and Cape-Cameroon Island from February to April 2022.Tsetse flies collected from the five selected locations using pyramidal traps, were first classified by species according to their morphology, then by sub-species with Polymerase Chain Reaction Diagnostic (PCR-Diag). Trypanosoma species and sub-species were subsequently identified and genotyped using a Nested PCR.&#x0D; Results: Glossina palpalis palpalis was the unique tsetse subspecies recorded across the five locations. The tsetse infection rate by Trypanosoma ssp. varied between 5.35% in Cape-island and 35.71% in Manoka island. Three Trypanosoma species were detected: T. brucei s.l. 32/500 (6.4%), T. congolense 15/500 (3.0%), and T. vivax 8/500 (1.6%). The sub-species T. b. gambiense responsible for HAT was detected in tsetse flies from Manoka (2/150: 1.33%), whereas T. congolense consisted of T. congolense “forest” and T. congolense “savannah” types.&#x0D; Conclusion: The presence of T. b. gambiense and T. congolense sub-species in Manoka and nearby suggests residual circulation of human and animal trypanosomes in quiescent HAT foci of the littoral region of Cameroon.