Trypanosome Species Research Articles

Trypanosoma (Herpetosoma) diversity in rodents and lagomorphs of New Mexico with a focus on epizootological aspects of infection in Southern Plains woodrats (Neotoma micropus).

Protozoan parasites of the genus Trypanosoma infect a broad diversity of vertebrates and several species cause significant illness in humans. However, understanding of the phylogenetic diversity, host associations, and infection dynamics of Trypanosoma species in naturally infected animals is incomplete. This study investigated the presence of Trypanosoma spp. in wild rodents and lagomorphs in northern New Mexico, United States, as well as phylogenetic relationships among these parasites. A total of 458 samples from 13 rodent and one lagomorph species collected between November 2002 and July 2004 were tested by nested PCR targeting the 18S ribosomal RNA gene (18S rRNA). Trypanosoma DNA was detected in 25.1% of all samples, with the highest rates of 50% in Sylvilagus audubonii, 33.1% in Neotoma micropus, and 32% in Peromyscus leucopus. Phylogenetic analysis of Trypanosoma sequences revealed five haplotypes within the subgenus Herpetosoma (T. lewisi clade). Focused analysis on the large number of samples from N. micropus showed that Trypanosoma infection varied by age class and that the same Trypanosoma haplotype could be detected in recaptured individuals over multiple months. This is the first report of Trypanosoma infections in Dipodomys ordii and Otospermophilus variegatus, and the first detection of a haplotype phylogenetically related to T. nabiasi in North America in S. audubonii. This study lends important new insight into the diversity of Trypanosoma species, their geographic ranges and host associations, and the dynamics of infection in natural populations.

Prevalence of Trypanosoma vivax Infection of Cattle in south-west, Nigeria

In south-west Nigeria, several Trypanosoma species are prevalent. These parasites cause trypanosomosis in livestock and man with cellular changes and tissue damages resulting in great loss in production and sometimes death. Hence, continuous surveillance is very necessary for monitoring and control of trypanosomosis. This study concentrated on the survey of trypanosome infection and its effect on both weight and haematological indices of Nigerian cattle. One hundred and eighty cattle were used in the study. The sex of cattle was noted while the age of cattle was determined using dentition and weight was determined using weigh-band. Blood sample was collected from 180 cattle, DNA was extracted from each cattle blood sample and PCR technique was adopted as a molecular diagnostic tool for prevalence study. Reference primer specific for Trypanosoma vivax (Variant Surface Glycoprotein (VSG) gene) was used as a probe for the detection of the presence of parasite while gene amplification on argarose gel was considered positive for the cattle under consideration. The haematological analysis was also carried out using Auto-haemoanalyser. The prevalence rate of Trypanosoma vivax based on sex, age and breed of cattle was determined. The result revealed a prevalence rate of 87.22%. About 19.44% was due to infection in the males while 67.78% of the infection was recorded in the female cattle. For the prevalence within the age group; 0 -1 year was 21.11%, >1≤ 2 years was 21.11%, >2 ≤ 3 years was 32.22%, >3 years was 12.78%. There was no significant (p>0.05) difference between the weight, haematological parameters determined and the infection status. In the phase of infection, the hosts were able to maintain their red blood cell counts from a perceived compensatory response which was revealed in the erythrocycitc indices an packed cell volume. Though the prevalence rate recorded was high, the hosts were able to maintain the haematimetric indices, it can then be concluded that Muturu cattle has displayed trypanotolerant property

First report and molecular identification of Trypanosoma (Duttonella) vivax outbreak in cattle population from Ecuador.

The bovine trypanosomosis is responsible for economic losses from tropical and subtropical areas of Africa and Latin America. This disease is characterized by fever, anaemia, loss of production and even death. Few studies have been carried out in Ecuador regarding Trypanosoma spp. presence but the species has not been determined in cattle and those have only determined the presence of genus, but not the species. The aim of this study was to identify and characterize the trypanosome species involved in the suspected bovine trypanosomosis outbreak reported in Convento Village in Manabí Province located in the coastal region of Ecuador. Twenty cattle from three farms were sampled. Three samples were positive for T.vivax, using an end-point polymerase chain reaction (PCR) to amplify a fragment of the cathepsin L-like cysteine protease (CatL-like) gene. A phylogenetic tree analysis of these three Ecuadorian isolates showed a close relationship with isolates from South America (Colombia, Brazil and Venezuela) and West Africa (Nigeria). This is the first report of T.vivax in Ecuadorian cattle.

A pilot study demonstrating the identification of Trypanosoma brucei gambiense and T. b. rhodesiense in vectors using a multiplexed high-resolution melt qPCR.

Human African Trypanosomiasis (HAT) is a potentially fatal parasitic infection caused by the trypanosome sub-species Trypanosoma brucei gambiense and T. b. rhodesiense transmitted by tsetse flies. Currently, global HAT case numbers are reaching less than 1 case per 10,000 people in many disease foci. As such, there is a need for simple screening tools and strategies to replace active screening of the human population which can be maintained post-elimination for Gambian HAT and long-term for Rhodesian HAT. Here, we describe the proof of principle application of a novel high-resolution melt assay for the xenomonitoring of Trypanosoma brucei gambiense and T. b. rhodesiense in tsetse. Both novel and previously described primers which target species-specific single copy genes were used as part of a multiplex qPCR. An additional primer set was included in the multiplex to determine if samples had sufficient genomic material for detecting genes present in low copy number. The assay was evaluated on 96 wild-caught tsetse previously identified to be positive for T. brucei s. l. of which two were known to be positive for T. b. rhodesiense. The assay was found to be highly specific with no cross-reactivity with non-target trypanosome species and the assay limit of detection was 104 tryps/mL. The qPCR successfully identified three T. b. rhodesiense positive flies, in agreement with the reference species-specific PCRs. This assay provides an alternative to running multiple PCRs when screening for pathogenic sub-species of T. brucei s. l. and produces results in less than 2 hours, avoiding gel electrophoresis and subjective analysis. This method could provide a component of a simple and efficient method of screening large numbers of tsetse flies in known HAT foci or in areas at risk of recrudescence or threatened by the changing distribution of both forms of HAT.

Species-level identification of trypanosomes infecting Australian wildlife by High-Resolution Melting - Real Time Quantitative Polymerase Chain Reaction (HRM-qPCR)

Conventional nested PCR and Sanger sequencing methods are currently the gold standards for detecting trypanosomes in wildlife. However, these techniques are time-consuming and can often overlook mixed infections. True trypanosome prevalence can thus be underrepresented. Here, we designed an 18S rDNA-based real-time quantitative PCR (qPCR) assay coupled with High-Resolution Melting Analysis (HRMA) to detect and discriminate three Trypanosoma species (T. copemani, T. noyesi, and T. vegrandis) commonly infecting Australian marsupials. A total of 68 genetically characterised samples from blood and tissue were used to validate the High-Resolution Melting - Real Time Quantitative Polymerase Chain Reaction (HRM-qPCR) assay. A further 87 marsupial samples consisting of blood, tissue and in vitro cultures derived from wildlife blood samples, were screened for the first time using this assay, and species identity confirmed using conventional PCR and Sanger sequencing. All three Trypanosoma species were successfully detected in pure cultures using the HRM-qPCR assay, and in samples containing mixed trypanosome infections. Of the 87 marsupial samples screened using the HRM-qPCR assay, 93.1% were positive for trypanosomes, and 8.0% contained more than one trypanosome species. In addition to the three targeted Trypanosoma species, this assay was also able to detect and identify other native and exotic trypanosomes. The turnaround time for this assay, from sample preparation to obtaining results, was less than 2 h, with a detection limit of 10 copies of the amplicon in a reaction for each of the targeted trypanosome species. This more rapid and sensitive diagnostic tool provides a high throughput platform for the detection, identification and quantification of trypanosome infections. It will also improve understanding of host diversity and parasite relationships and facilitate conservation management decisions.

Study on Bovine Trypanosomosis and Associated Risk Factors in Chora District of Oromia Region, Ethiopia

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

Assessing different thiazolidine and thiazole based compounds as antileishmanial scaffolds

The compounds from eight different thiazolidine and thiazole series were assessed as potential antileishmanial scaffolds. They were tested for antileishmanial activity against promastigotes of Leishmania major using in vitro primary screen and dose response assays. The compounds from six thiazolidine and thiazole series were identified as the hits with antileishmanial activity against L. major. However, the analyses of structure-activity relations (SARs) showed that the interpretable SARs were obtained only for phenyl-indole hybrids (compounds C1, C2, C3 and C5) as the most effective compounds against L. major promastigotes (IC50 < 10 µM) with low toxicity to human fibroblasts. For the scaffold of these compounds, the most significant SAR patterns were: free N3 position of thiazolidinone core, absence of big fragments at the C5 position of thiazolidinone core and presence of halogen atoms or nitro group in the phenyl ring of phenyl-indole fragment. As previous studies showed that these compounds also have activity against the two Trypanosoma species, Trypanosoma brucei and Trypanosoma gambiense, their scaffold could be associated with a broader antiparasitic activity.

Modelling the impact of climate change on the distribution and abundance of tsetse in Northern Zimbabwe

BackgroundClimate change is predicted to impact the transmission dynamics of vector-borne diseases. Tsetse flies (Glossina) transmit species of Trypanosoma that cause human and animal African trypanosomiasis. A previous modelling study showed that temperature increases between 1990 and 2017 can explain the observed decline in abundance of tsetse at a single site in the Mana Pools National Park of Zimbabwe. Here, we apply a mechanistic model of tsetse population dynamics to predict how increases in temperature may have changed the distribution and relative abundance of Glossina pallidipes across northern Zimbabwe.MethodsLocal weather station temperature measurements were previously used to fit the mechanistic model to longitudinal G. pallidipes catch data. To extend the use of the model, we converted MODIS land surface temperature to air temperature, compared the converted temperatures with available weather station data to confirm they aligned, and then re-fitted the mechanistic model using G. pallidipes catch data and air temperature estimates. We projected this fitted model across northern Zimbabwe, using simulations at a 1 km × 1 km spatial resolution, between 2000 to 2016.ResultsWe produced estimates of relative changes in G. pallidipes mortality, larviposition, emergence rates and abundance, for northern Zimbabwe. Our model predicts decreasing tsetse populations within low elevation areas in response to increasing temperature trends during 2000–2016. Conversely, we show that high elevation areas (> 1000 m above sea level), previously considered too cold to sustain tsetse, may now be climatically suitable.ConclusionsTo our knowledge, the results of this research represent the first regional-scale assessment of temperature related tsetse population dynamics, and the first high spatial-resolution estimates of this metric for northern Zimbabwe. Our results suggest that tsetse abundance may have declined across much of the Zambezi Valley in response to changing climatic conditions during the study period. Future research including empirical studies is planned to improve model accuracy and validate predictions for other field sites in Zimbabwe.

‘Hook, line, and sinker’: Fluorescence in situ hybridisation (FISH) uncovers Trypanosoma noyesi in Australian questing ticks

Trypanosomes are blood-borne parasites infecting a range of mammalian hosts worldwide. In Australia, an increasing number of novel Trypanosoma species have been identified from various wildlife hosts, some of which are critically endangered. Trypanosoma noyesi is a recently described species of biosecurity concern, due to a close relationship to the South American human pathogen, Trypanosoma cruzi. This genetic similarity increases the risk for introduction of T. cruzi via a local vector. Unfortunately, there is a lack of knowledge concerning the vectorial capacity of Australian invertebrates for native Trypanosoma species. Australian ixodid ticks (Ixodidae), which are widespread ectoparasites of mammalian wildlife, have received the most attention as likely candidates for trypanosome transmission and have been previously implicated as vectors. However, as all studies to date have focused on blood-fed ticks collected directly from infected mammalian hosts, the question of whether ticks maintain a trypanosome infection between blood meals is unknown. In this study, we investigated the presence of Trypanosoma within 148 Australian adult and nymph questing ticks of the species Amblyomma triguttatum, Ixodes australiensis, Ixodes myrmecobii and larvae Ixodes spp., collected from an endemic region of south-west Australia. Using a novel HRM-qPCR detection method that can discriminate between species of Trypanosoma based on primer melting temperature (Tm), we report the first molecular detection of Trypanosoma DNA in Australian questing ticks, with 6 ticks DNA positive for T. noyesi. Additionally, the presence of intact T. noyesi parasites within all (n = 3) smeared gut and gland contents of questing ticks was confirmed using a fluorescence in situ hybridisation (FISH) assay. Whilst this study was unable to determine the in situ tissue location of trypanosomes for the purpose of discerning a potential route of transmission, these combined molecular and FISH smear data indicate that trypanosomes can persist in ticks between blood meals and that ticks are possibly vectors in the transmission of T. noyesi between native wildlife. Transmission experiments are still required to evaluate the competency of Australian ticks as vectors for T. noyesi. Nevertheless, these novel findings warrant further investigation concerning potential life stages and the development of trypanosomes in both Australian, and other, tick species.

Phylogenomics from transcriptomic "bycatch" clarify the origins and diversity of avian trypanosomes in North America.

The eukaryotic blood parasite genus Trypanosoma includes several important pathogens of humans and livestock, but has been understudied in wildlife broadly. The trypanosomes that infect birds are in particular need of increased attention, as these parasites are abundant and globally distributed, yet few studies have addressed their evolutionary origins and diversity using modern molecular and analytical approaches. Of specific interest are the deep evolutionary relationships of the avian trypanosomes relative to the trypanosome species that are pathogenic in humans, as well as their species level diversity in regions where they have been understudied such as North America. Here, we address these unresolved areas of study using phylogenomic data for two species of avian trypanosomes that were isolated as "bycatch" from host transcriptome assemblies, as well as a large 18S DNA barcode sequence dataset that includes 143 novel avian Trypanosoma 18S sequences from North America. Using a phylogenomic approach, we find that the avian trypanosomes are nested within a clade of primarily mammalian trypanosomes that includes the human pathogen Trypanosoma cruzi, and are paraphyletic with respect to the ruminant trypanosome Trypanosoma theileri. DNA barcode sequences showed that T. avium and an unidentified small, non-striated trypanosome that was morphologically similar to T. everetti are each represented by highly abundant and divergent 18S haplotypes in North America. Community-level sampling revealed that additional species-level Trypanosoma lineages exist in this region. We compared the newly sequenced DNA barcodes from North America to a global database, and found that avian Trypanosoma 18S haplotypes generally exhibited a marked lack of host specificity with at least one T. avium haplotype having an intercontinental distribution. This highly abundant T. avium haplotype appears to have a remarkably high dispersal ability and cosmopolitan capacity to evade avian host immune defenses, which warrant further study.

Trypanocidal Essential Oils: A Review.

Trypanosomiases are diseases caused by parasitic protozoan trypanosomes of the genus Trypanosoma. In humans, this includes Chagas disease and African trypanosomiasis. There are few therapeutic options, and there is low efficacy to clinical treatment. Therefore, the search for new drugs for the trypanosomiasis is urgent. This review describes studies of the trypanocidal properties of essential oils, an important group of natural products widely found in several tropical countries. Seventy-seven plants were selected from literature for the trypanocidal activity of their essential oils. The main chemical constituents and mechanisms of action are also discussed. In vitro and in vivo experimental data show the therapeutic potential of these natural products for the treatment of infections caused by species of Trypanosoma.

Study on Bovine Trypanosomosis and Tsetse Identification in South Ari Woreda of Southern Nation, Nationalities and People Regional State (SNNPRS)

The study was conducted from December 2009 to March 2010 in South Ari Woreda of SNNP Regional State to determine the prevalence of bovine trypanosomosis and to assess the apparent densities and distributions of tsetse flies. Blood samples were taken from a total of 384 indigenous cattle managed under small holder mixed crop livestock production. Blood Buffy coat dark ground phase contrast Microscopic technique was used for detection of the trypanosome parasites in the blood samples, NGU traps were used for tsetse fly survey and Packed cell volume (PCV) to determine the degree of anemia caused by trypanosomosis. The overall prevalence of 13.54% bovine trypanosomosis was recorded in the study area . The predominant species of trypanosome encountered during the study period were T. congolonce with relative prevalence of (63.5%) followed by T. vivax (36.5%) but there was no mixed infection observed. PCV evaluation showed that the mean PCV of parasitemic animals (25.5%) was significantly lower than that of (30.5%) aparasitemic animals indicating the importance of bovine trypanosomosis in causing anemia. Assessment of tsetse flies indicated that Glossina pallidipes is the major biological vector for bovine trypanosomosis in the study area with apparent density of 27.5 fly/trap/day. Other biting flies (tabanids and stmoxys) were also collected indicating the possibility of mechanical transmission. Keywords : Bovine, Trypanosomosis, Prevalence, Tsetse fly, apparent density, South Ari/S DOI: 10.7176/JBAH/10-20-04 Publication date: October 31 st 2020

Prevalence and hematological parameters of bovine Trypanosomosis in Nsukka municipal abattoir, Southeastern Nigeria

The prevalence and hematological parameters of trypanosomosis in slaughter cattle in Nsukka, Southeastern Nigeria, were investigated. Blood samples from 200 randomly selected cattle were collected following slaughter into labeled sample bottles with anticoagulant. The sex and breed of the sampled cattle were properly noted. Standard trypanosome detection techniques involving wet blood film examination, buffy coat technique, examination of Giemsa-stained blood smears, and mice inoculation were used to detect and identify the trypanosome species present. The hematological parameters—packed cell volume (PCV), hemoglobin concentration (HbC), total erythrocyte count (TEC), total leucocyte count (TLC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC)—were determined following standard procedures. A prevalence rate of 1.5% (95% CI = 0.005–0.043) was obtained for bovine trypanosomosis in Nsukka with 1% (95% CI = 0.003–0.036) and 0.5% (95% CI = 0.001–0.028) prevalence rates in female and male cattle, respectively. Whereas a prevalence rate of 1.5% (95% CI = 0.005–0.043) was recorded in the White Fulani breed, the Sokoto Gudali had 0% prevalence rate. The prevalence recorded in this study was not associated (P ˃ 0.05) with sex or breed. The mean PCV, HbC, TEC, MCV, MCH, MCHC, and TLC values of the infected cattle differed (P < 0.05) from that of the uninfected cattle. In conclusion, trypanosomosis is prevalent in cattle slaughtered in Nsukka, Southeastern Nigeria, with associated hematological changes. Hence, the need for the adoption and implementation of national trypanosomosis integrated control strategies.

First report of Trypanosoma dionisii (Trypanosomatidae) identified in Australia.

Trypanosomes are blood-borne parasites that can infect a variety of different vertebrates, including animals and humans. This study aims to broaden scientific knowledge about the presence and biodiversity of trypanosomes in Australian bats. Molecular and morphological analysis was performed on 86 blood samples collected from seven different species of microbats in Western Australia. Phylogenetic analysis on 18S rDNA and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) sequences identified Trypanosoma dionisii in five different Australian native species of microbats; Chalinolobus gouldii, Chalinolobus morio, Nyctophilus geoffroyi, Nyctophilus major and Scotorepens balstoni. In addition, two novels, genetically distinct T. dionisii genotypes were detected and named T. dionisii genotype Aus 1 and T. dionisii genotype Aus 2. Genotype Aus 2 was the most prevalent and infected 20.9% (18/86) of bats in the present study, while genotype Aus 1 was less prevalent and was identified in 5.8% (5/86) of Australian bats. Morphological analysis was conducted on trypomastigotes identified in blood films, with morphological parameters consistent with trypanosome species in the subgenus Schizotrypanum. This is the first report of T. dionisii in Australia and in Australian native bats, which further contributes to the global distribution of this cosmopolitan bat trypanosome.

Molecular surveillance reveals bats from eastern Colombia infected with Trypanosoma theileri and Trypanosoma wauwau-like parasites

Several species of trypanosomes can infect bats (Chiroptera), but current information about bat trypanosomes in Colombia is scarce. The objectives of this study were to estimate the infection rate and to characterize the trypanosome species infecting bats from three rural regions near the municipality of Cumaribo in Vichada, Colombia. Blood samples were collected from 39 bats. DNA was extracted from the blood samples and analyzed using nuclear genetic markers (SSU rDNA, ITS rDNA, and cathepsin genes) to discriminate among trypanosome species. Trypanosomes were detected in 66.7 % (26/39) of blood samples using PCR; 61.5 % (24/39) of infections were identified as Trypanosoma theileri and 5.1 % (2/39) as T. wauwau-like parasites. The phylogeographic analysis revealed that our T. theileri sequences were associated with the TthIIB genotype from cattle in Brazil and Venezuela. The T. wauwau-like parasites represent a new genotype of the species and were found in Molossus molossus and Platyrrhinus helleri bats. These data represent the first evidence of this trypanosome in both Colombia, and in these species of bats. Bat infections with T. theileri suggest an important role of these hosts in maintaining this genotype, probably acquired by ingesting insect vectors. The T. wauwau-like genotype in new mammalian host species supports the 'bat seeding' hypothesis of the T. cruzi clade. The epidemiological and evolutionary implications of these findings are discussed.

A Trypanosoma species detected in Rhipicephalus (Boophilus) microplus ticks from Argentina

Specimens of a Trypanosoma sp. were found in a haemolymph sample of Rhipicephalus microplus from Argentina. Polymerase chain reaction (PCR) was done targeting the SSU rRNA gene of Trypanosoma spp. and a fragment of 2300 base pairs (bp) was amplified, subsequently a phylogenetic analysis was conducted, based on an alignment of 905 bp, containing the sequence of the Argentina isolate and sequences of different Trypanosoma species retrieved from GenBank. Phylogenetic analysis revealed that this trypanosome is not related to Trypanosoma theileri as was previously thought, instead the strain of Trypanosoma detected in this study can be provisionally determined as belonging to the recently described organism Trypanosoma rhipicephalis. Furthermore, phylogenetic analysis performed in this work revealed that T. rhipicephalis belongs to a novel clade of tick-related trypanosomes, most with limited genetic data, for which essential aspects of both the vertebrate and invertebrate life cycles are lacking. The lack of basic information restricts the inferences that can be done from the present finding and, in addition, points out a clear knowledge gap in the biology of this group of trypanosomes.

Parasitological and molecular detection of Trypanosoma spp. in cattle, goats and sheep in Somalia.

African animal trypanosomiasis (AAT) affects the livestock of 12.3 million Somalis and constrains their development and wellbeing. There is missing data on AAT in the country after the civil war of the 1990s. Therefore, this study has aimed to assess the prevalence of Trypanosoma spp. in 614 blood samples from cattle (n = 202), goats (n = 206) and sheep (n = 206) in Afgoye and Jowhar districts, Somalia using parasitological and molecular methods. Twenty-one out of 614 (3.4%; 95% CI: 2.1-5.2%) and 101/614 (16.4%; 95% CI: 13.6-19.6%) ruminants were positive for Trypanosoma spp. by buffy coat technique (BCT) and internal transcribed spacer 1 (ITS1)-polymerase chain reaction (PCR), respectively. Using ITS1-PCR, the highest prevalence was observed in cattle (23.8%; 95% CI: 18.4-30.1%) followed by goats (17.5%; 95% CI: 12.9-23.3%) and sheep (8.3%; 95% CI: 5.1-12.9%). A total of 74/101 (73.3%; 95% CI: 63.5-81.6%) ruminants were shown coinfection with at least two Trypanosome species. The four T. brucei-positive samples have tested negative for T. b. rhodesiense, by the human-serum-resistance-associated-PCR. Trypanosoma evansi, T. godfreyi, T. vivax, T. brucei, T. simiae and T. congolense were the Trypanosoma species found in this study. This is the first study on the molecular detection of Trypanosoma sp. in ruminants in Somalia. Further investigations and control measures are needed to manage Trypanosomiasis spreading in the country. Studies should also focus on the detection of T. b. rhodesiense in the country.

Prevalence of Cattle Trypanosomosis and Apparent Density of Its Fly Vectors in Bambasi District of Benishangul-Gumuz Regional State, Western Ethiopia.

Trypanosomosis is the most serious disease of cattle, which causes great socioeconomic losses in the country. Its socioeconomic impact is reflected on direct losses due to mortality, morbidity, and reduction in milk and meat production, abortion and stillbirth, and also costs associated with combat of the disease are direct losses. A cross-sectional study was carried out to assess the prevalence of cattle trypanosomosis, and the apparent density and distribution of its fly vectors in selected study areas. The methods employed during the study were buffy coat technique for parasitological study and deploying trap for the collection of tsetse flies. A total of 1512 flies were trapped, and among them, 1162 were tsetse flies while 350 were biting flies. Higher apparent density for tsetse fly (7.7 F/T/D) followed by Stomoxys (0.9 F/T/D), Tabanus (0.8 F/T/D), and Hematopota (0.6 F/T/D) was recorded. Out of 638 examined cattle, the overall prevalence of trypanosomosis in the study area was 9.1% (58/638). Out of positive cases, Trypanosoma congolense (7.7%) was the dominant trypanosome species followed by Trypanosoma vivax (0.9%), Trypanosoma brucei (0.2%), and mixed infection of Trypanosoma brucei and Trypanosoma vivax (0.3%). There was no a significant difference (p > 0.05) in trypanosome infection between age, sex, and trypanosome species. The prevalence of trypanosomosis on the bases of body condition was 2.8% for poor, 5.5% for medium, and 0.8% for good body condition. The overall prevalence of anemia was (36.8%), and presence of anemia was higher in trypanosome positive animals (62.5%) than in negative animals (34.3%) which is statistically significant (p < 0.05, CI = 1.794–5.471). The overall mean packed cell volume (PCV) value for examined animals was 25.84 ± 0.252SE. Mean (PCV) of parasitaemic cattle (9.1%) was significantly (p < 0.05) lower than that of aparasitaemic cattle (90%). This survey showed that trypanosomosis is still a core problem for livestock production of the study area. Therefore, more attention should be given to the control of both the disease and its vectors.

Sporogonic cycle of Plasmodium falciparum in a human blood sample.

A 62-year-old woman recently arrived from Angola to start treatment for a papillary adenocarcinoma of the endometrium presented to the emergency room complaining of asthenia and anorexia. Upon admission the patient was afebrile (patient temperature: 35.9°C-37°C). Laboratory data showed: hemoglobin 9.0 g/dL (reference value [RV]: 12.0-15.3 g/dL), leucocytes 5.74 × 109/L (RV: 4-11 × 109/L), platelets 129 × 109/L (RV: 150-450 × 109/L) alanine aminotransferase 39 U/L (RV: 0-33 U/L), aspartate aminotransferase 33 U/L (RV: 0-32 U/L), total bilirubin 1.20 mg/dL (RV: <1.20 mg/dL), γ-glutamyl transferase 47 U/L (RV: 0-40 U/L), lactate dehydrogenase 269 U/L (RV: 100-250 U/L) and c-reative protein 1676 nmol/L (RV: <47.6 nmol/L). A peripheral blood film was performed two to three hours after blood collection (EDTA container) and the following findings were observed: gametocytes (Image 1A), trophozoites (Image 1B,C [appliqué/accolé presentation]), macrogametocytes (sporogonic [Correction added on September 19, 2020, after first online publication: the incorrect word ‘esporogonic’ is changed to ‘sporogonic’ after original publication.] cycle) (Image 1D,E), exflagellated microgametocytes (Image 1F,G), microgamete (Image 1H (microgamete nucleus [arrow]), neutrophil inclusions (Image 1I,J), Döhle bodies (Image 1K,L) and macroplatelets (Image 1M) (May-Grünwald-Giemsa stain, original magnification x1000). A diagnosis of Plasmodium falciparum infection was made, with a parasitemia of 3%. In the natural life cycle of Plasmodium species the presence of the exflagellated microgametocyte, microgamete and macrogametocytes, shown here, occur in the female Anopheles species mosquito.1-3 In the case presented here the presence of these parasite forms could have been induced in vitro due to a decrease in temperature from 35.9°C-37°C (patient temperature) to 17°C-28°C (room temperature), and by a decrease in the dissolved carbon dioxide when the blood comes in contact with the atmospheric environment, and subsequent increase in pH to above 8.0.3, 4 All these environmental changes occurred due to a delay in sample processing, possibly mimicking the changes which occur in the mosquito's gut.1 The presence of microgametes in the peripheral blood film can pose a diagnostic dilemma, leading to a wrong diagnosis of co-infection, because they can mimic Borrelia species or even for an inexperienced observer Trypanosoma species. The distinction can be made since Borrelia species lack nuclei and frequently have a spiral shape, and Trypanosoma species have a kinetoplast and an undulating membrane. Microgametes can be also seen, erroneously, as an artifact. The presence of macroplatelets may pose a problem because they can give false readings on automated cell counters once they can be counted as erythrocytes.5 None. M.P.B.P.: performed the research, analyzed data and wrote the paper. J.M.C.: analyzed data and wrote the paper. Data sharing is not applicable to this article as no new data were created or analyzed in this study. Data sharing is not applicable to this article as no new data were created or analyzed in this study.

Spatial Distribution of Trypanosomes in Cattle From Western Kenya.

African Animal Trypanosomiasis (AAT) is a tsetse-transmitted protozoan disease endemic in “the tsetse belt” of Africa. Past studies investigating the epidemiology of the disease rarely focused on spatial distribution when reporting the prevalence. The challenge of understanding the spatial epidemiology of the disease is further confounded by low-sensitive parasitological techniques used in field investigations. This study aimed to identify trypanosome species in cattle and their spatial distribution in western Kenya. Low-sensitive microscopic analysis and highly-sensitive polymerase chain reaction (PCR) techniques were also compared to better understand the epidemiology of Trypanosoma infections by use of the geographical information system (GIS). Blood samples from 888 cattle, collected between August 2010 and July 2012, were examined for Trypanosoma parasites by light microscopy and PCR. The spatial distribution of Trypanosoma positive cases by species were mapped and overlaid on the map for tsetse distribution. The estimated prevalence was 4.17% by PCR compared to 2.48% by microscopy. Trypanosomes were detected in tsetse free areas. Trypanosoma vivax and Trypanosoma b. brucei were identified, but not the zoonotic Trypanosoma b. rhodesiense. This study demonstrated the importance of geospatial data analysis to understand the epidemiology of the parasite, to inform future research and formulate control strategies.