Paying attention to uncertainty: A stochastic multimodal transformers for post-traumatic stress disorder detection using video.

BACKGROUND AND OBJECTIVES: Post-traumatic stress disorder is a debilitating psychological condition that can manifest following exposure to traumatic events. It affects individuals from diverse backgrounds and is associated with various symptoms, including intrusive thoughts, nightmares, hyperarousal, and avoidance behaviors. METHODS: To address this challenge this study proposes a decision support system powered by a novel multimodal deep learning approach, based on a stochastic Transformer and video data. This Transformer has the ability to take advantage of its stochastic activation function and layers that allow it to learn sparse representations of the inputs. The method leverages a combination of low-level features extracted using three modalities, including Mel-frequency cepstral coefficients extracted from audio recordings, Facial Action Units captured from facial expressions, and textual data obtained from the audio transcription. By considering these modalities, our proposed model captures a comprehensive range of information related to post-traumatic stress disorder symptoms, including vocal cues, facial expressions, and linguistic content. RESULTS: The deep learning model was trained and evaluated on the eDAIC dataset, which consists of clinical interviews with individuals with and without post-traumatic disorder. The model achieved state-of-the-art results, demonstrating its effectiveness in accurately detecting PTSD, showing an impressive Root Mean Square Error of 1.98, and a Concordance Correlation Coefficient of 0.722, signifying the model's superior performance compared to existing approaches. CONCLUSION: This work introduces a new method for post-traumatic stress disorder detection from videos by utilizing a multimodal stochastic Transformer model. The model makes use of a variety of modalities, such as text, audio, and visual data, to gather comprehensive and varied information in order to make the detection.

A Survey on Trypanosoma evansi (Kinetoplastida, Trypanosomatidae) Infection in Domestic Animals in a Surra Endemic Area of Southern Algeria.

Background: Trypanosoma (T.) evansi infection is endemic in dromedary camels (Camelus dromedaries) of southern Algeria. Materials and Methods: In order to assess the presence of T. evansi in other domestic animals living together with dromedary camels, a study was conducted in the wilayate of Béchar, El Bayadh, Ouargla and Tamanrasset, between 2015 and 2017. Authorisation to conduct the survey was obtained from the Direction des Services Vétérinaires (DSV, Ministry of Agriculture, Rural Development and Fisheries). A total of 190 animals were sampled, including 42 cattle (Bos taurus), 11 dogs (Canis familiaris), 44 horses (Equus caballus), 3 donkeys (Equus asinus) and 1 mule, 49 goats (Capra hircus) and 40 sheep (Ovis aries). These animals were examined by parasitological (Giemsa stained thin smear, GST), serological (card agglutination test for trypanosomosis (CATT/T. evansi), enzyme-linked immunosorbent assay/Variant Surface Glycoprotein/Rode Trypanozoon antigen type 1.2 [ELISA/VSG RoTat 1.2], immune trypanolysis [TL]) and molecular tests (T. evansi type A specific RoTat 1.2 PCR). Results and Conclusions: The CATT/T. evansi was positive in 10/42 cattle, 0/11 dogs, 2/48 equids, 27/49 goats and 15/40 sheep. On the other hand, 20/38 cattle, 1/9 dogs, 21/42 equids, 17/44 goats and 31/39 sheep were positive in ELISA/VSG RoTat 1.2. However, no single animal was positive in TL. In addition, the T. evansi parasite could not be demonstrated by either GST or RoTat 1.2 PCR in any of the examined animals. This may suggest cross-reactions of CATT/T. evansi and ELISA/VSG RoTat 1.2 with other pathogenic or commensal trypanosome species such as T. vivax or other parasites. Based on these data, in particular taking into account the high specificity of the TL for T. evansi type A, this study does not support the hypothesis that T. evansi circulates in the studied domestic animal species and that they would act as reservoirs for the parasite that causes trypanosomosis in dromedary camels.

Development of a control strategy towards elimination of Trypanosoma evansi infection (surra) in camels in Africa.

With an increasing worldwide population that presently exceeds 38 million, camels are important source of meat, milk, and transportation of goods, in many regions of the world. Camels are particularly critical in the northern parts of Africa, above the tsetse belt. However, camel breeding areas are expanding into southern areas, under the pressures of global warming, leading to increasing risk of acquiring parasitic infections in these non-traditional ecotypes. Common biting flies (tabanids, stomoxyine flies, and Hippobosca camelina) act as mechanical vectors, resulting in exposure to trypanosomosis (Trypanosoma evansi; Surra) and high camel morbidity and mortality. In these regions, complicating infections with other Trypanosoma may also occur, particularly Trypanosoma vivax. In many modern camel-breeding areas, human populations are living under political upheaval (terrorism, riots), poverty, and precarity (drought, climate modification). Hence, control and/or elimination of Surra in camels would be beneficial to the economies of these populations. Due to the relatively straightforward epidemiology (single parasite with seasonal transmission in a single host species), control of Surra in Africa is affordable and should be based on implementing: (1) national veterinary services capabilities; (2) efficient diagnosis and control methods; (3) joint integrated control of Surra, gastrointestinal helminthoses (mainly haemonchosis), and sarcoptic mange. We propose that methods to control two economically-critical disease problems, gastrointestinal parasitosis and sarcoptic mange, will support improved Surra control in camels. Aided by decision-makers and donors, elimination of Surra could improve camel health and productivity, and stabilize camel-rearing in regions of the world that suffer from political instability and global warming pressures.

Three mitochondrial lineages and no Atlantic-Mediterranean barrier for the bogue Boops boops across its widespread distribution.

Marine species exhibiting wide distributional ranges are frequently subdivided into discrete genetic units over limited spatial scales. This is often due to specific life-history traits or oceanographic barriers that prevent gene flow. Fine-scale sampling studies revealed distinct phylogeographic patterns in the northeastern Atlantic and the Mediterranean, ranging from panmixia to noticeable population genetic structure. Here, we used mitochondrial sequence data to analyse connectivity in the bogue Boops boops throughout most of its widespread distribution. Our results identified the existence of three clades, one comprising specimens from the Azores and eastern Atlantic/Mediterranean, another with individuals from the Canary Islands, Madeira and Cape Verde archipelagos, and the third with samples from Mauritania only. One of the branches of the northern subtropical gyre (Azores Current) that drifts towards the Gulf of Cádiz promotes a closer connection between the Azores, southern Portugal and the Mediterranean B. boops populations. The Almería-Oran Front, widely recognised as an oceanographic barrier for many organisms to cross the Atlantic-Mediterranean divide, does not seem to affect the dispersal of this benthopelagic species. The southward movement of the Cape Verde Frontal Zone during the winter, combined with the relatively short duration of the pelagic larval stage of B. boops, may be potential factors for preventing the connectivity between the Atlantic oceanic archipelagos and Mauritania shaping the genetic signature of this species.

Unexpected Rift Valley fever outbreak, northern Mauritania.

During September-October 2010, an unprecedented outbreak of Rift Valley fever was reported in the northern Sahelian region of Mauritania after exceptionally heavy rainfall. Camels probably played a central role in the local amplification of the virus. We describe the main clinical signs (hemorrhagic fever, icterus, and nervous symptoms) observed during the outbreak.

Molecular characterization of Fasciola gigantica from Mauritania based on mitochondrial and nuclear ribosomal DNA sequences.

Fasciolosis caused by Fasciola hepatica and Fasciola gigantica (Platyhelminthes: Trematoda: Digenea) is considered the most important helminth infection of ruminants in tropical countries, causing considerable socioeconomic problems. From Africa, F. gigantica has been previously characterized from Burkina Faso, Senegal, Kenya, Zambia and Mali, while F. hepatica has been reported from Morocco and Tunisia, and both species have been observed from Ethiopia and Egypt on the basis of morphometric differences, while the use of molecular markers is necessary to distinguish exactly between species. Samples identified morphologically as F. gigantica (n=60) from sheep and cattle from different geographical localities of Mauritania were genetically characterized by sequences of the first (ITS-1), the 5.8S, and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA) genes and the mitochondrial Cytochrome c Oxidase I (COI) gene. Comparison of the sequences of the Mauritanian samples with sequences of Fasciola spp. from GenBank confirmed that all samples belong to the species F. gigantica. The nucleotide sequencing of ITS rDNA of F. gigantica showed no nucleotide variation in the ITS-1, 5.8S, and ITS-2 rDNA sequences among all samples examined and those from Burkina Faso, Kenya, Egypt and Iran. The phylogenetic trees based on the ITS-1 and ITS-2 sequences showed a close relationship of the Mauritanian samples with isolates of F. gigantica from different localities of Africa and Asia. The COI genotypes of the Mauritanian specimens of F. gigantica had a high level of diversity, and they belonged to the F. gigantica phylogenically distinguishable clade. The present study is the first molecular characterization of F. gigantica in sheep and cattle from Mauritania, allowing a reliable approach for the genetic differentiation of Fasciola spp. and providing basis for further studies on liver flukes in the African countries.

Against all odds: a tale of marine range expansion with maintenance of extremely high genetic diversity.

The displacement of species from equatorial latitudes to temperate locations following the increase in sea surface temperatures is among the significant reported consequences of climate change. Shifts in the distributional ranges of species result in fish communities tropicalisation, i.e., high latitude colonisations by typically low latitude distribution species. These movements create new interactions between species and new trophic assemblages. The Senegal seabream, Diplodus bellottii, may be used as a model to understand the population genetics of these invasions. In the last decades, this species has undergone an outstanding range expansion from its African area of origin to the Atlantic coast of the Iberian Peninsula, where now occurs abundantly. Mitochondrial and nuclear markers revealed a striking high haplotypic nucleotide and genetic diversity values, along with significant population differentiation throughout the present-day geographical range of the Senegal seabream. These results are not consistent with the central-marginal hypothesis, nor with the expectations of a leptokurtic distribution of individuals, as D. bellottii seems to be able to retain exceptional levels of diversity in marginal and recently colonised areas. We discuss possible causes for hyperdiversity and lack of geographical structure and subsequent implications for fisheries.

Epidemiological and Mycological Aspects of Onychomycosis in Dakar (Senegal).

Onychomycosis is a fungal nails infection often caused by yeasts, dermatophytes and molds. It is an important public health concern due to its high prevalence, the problem of diagnostics, and the poor response to treatments. The objective of this study was to evaluate the epidemiological and microbiological profile of onychomycosis diagnosed at the Laboratory of Parasitology-Mycology of the National University Hospital of Fann in Dakar, Senegal, from 2012 to 2016. A retrospective and descriptive study was performed from January 2012 to December 2016 in a patient attending the laboratory of Parasitology-Mycology at the Fann teaching hospital. Socio-demographic, clinical and biological data were collected from the bench registers. Samples from the lesions were tested using direct microscopy and cultured on a Sabouraud-Chloramphenicol and Sabouraud-Chloramphenicol-Actidione medium. A descriptive analysis was done using Stata IC 12 software. The significance level of different tests was set at 5% two-side. A total of 469 patients were included in this study. The mean age of the study population was 33.2 ± 15.2 years, and the sex ratio was 0.52. The prevalence of onychomycosis was 48.4% (227/469). The main clinical presentations were disto-lateral subungual onychomycosis (37.9%) and onyxis (46.5%). Identified fungal species were Candida albicans (42.7%), Candida spp (39.5%), Trichophyton soudanense (10.1%), Fusarium spp (5.3%), and Candida tropicalis (2.6%). Candida albicans was more frequent in subjects over 15 years of age (43.6%) and women (45%). However, Trichophyton soudanense was higher in patients under 15 years old (17.4%) as well as in male subjects (18.8%). In conclusion, onychomycosis is a common cause of consultation in health facilities. Candida albicans and Trichophyton Soudanense are the main fungal species causing onychomycosis. A better understanding of the epidemiology of onychomycosis as well as the spectrum of the pathogen could contribute to improve the management of the infection.

Epidemiological investigations on Trypanosoma evansi infection in dromedary camels in the South of Algeria.

An epidemiological study of Trypanosoma evansi (T. evansi) infection in dromedaries was conducted in four wilayate (localities) of Southern Algeria: Béchar, El Bayadh, Ouargla, Tamanrasset. Between February 2014 and April 2016, 1056 camels of different ages and both sexes from 84 herds were sampled. The prevalence was determined through parasitological examination (Giemsa stained thin smear, GST), serological tests (CATT/T. evansi, ELISA/VSG RoTat 1.2, immune trypanolysis), and molecular tests (T. evansi type A specific RoTat 1.2 PCR and T. evansi type B specific EVAB PCR). The overall prevalence was 2.4 % with GST, 32.4% with CATT/T. evansi, 23.1% with ELISA/VSG RoTat 1.2, 21.0% with immune trypanolysis (TL), 11.2 % with RoTat 1.2 PCR and 0% with EVAB PCR. El Bayadh was the most affected wilaya with 11.8% positives in GST, 74.9% in CATT/T. evansi, 70.1% in ELISA/VSG RoTat 1.2 and 62.2% in immune trypanolysis. Only in Béchar, a non-significantly higher prevalence (13.6%) was observed with RoTat1.2 PCR than in El Bayadh (13.0%). We didn't find any evidence of the presence of T. evansi type B in the study area.

Urinary tract infection with Corynebacterium aurimucosum after urethroplasty stricture of the urethra: a case report.

INTRODUCTION: Corynebacteria have an important place among the commensal flora of the skin and mucous membranes. Except for Corynebacterium diphtheriae, they were once considered contaminants of mucosa. Recent publications in medical bacteriology have highlighted the importance of several species, such as C. aurimucosum. To the best of our knowledge, we report the first isolation of this strain from urine. CASE PRESENTATION: We report a case of a patient with a urinary tract infection with C. aurimucosum. We isolated this bacterium from a 52-year-old man of Wolof ethniticity (an ethnic group in Senegal, West Africa) at the regional hospital of Saint Louis, Senegal. Microscopic examination of his total urine sample showed coryneform Gram-positive bacilli associated with a high leukocyte reaction. After repeated isolation of the corynebacteria in three samples from the patient's urine, it was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The strain was susceptible to antibiotics, except for penicillin and co-trimoxazole. The potential infectious role of these commensal species in several infections should be taken into consideration. CONCLUSIONS: This case highlights the significant proportion of species in the genus Corynebacterium other than dyphteriae in the infectious process. The use of mass spectrometry for identification highlights the originality of this work and the importance of these new diagnostic tools that are unavailable in most health facilities of countries with limited resources. We share the results of our method of identification of the isolated bacteria. This case should prompt attention to these rare bacteria, which can cause severe infections.

Mechanical transmission of Trypanosoma vivax in cattle by the African tabanid Atylotus fuscipes.

An experiment was carried out in Burkina Faso to evaluate the potential for mechanical transmission of Trypanosoma vivax by the African tabanid Atylotus fuscipes. The experiment was carried out in a corral (10 m x 10 m) completely covered by a mosquito net (12 m x 12 m and 2.5m high). Eight heifers (cross-bred Zebu X Baoulé), free of trypanosome infection, were kept together with two heifers experimentally infected with a local stock of T. vivax. An average of 539 A. fuscipes per day, freshly captured with two Nzi traps, were introduced into the mosquito net from Day 1 to 20, to allow mechanical transmission of the parasites among cattle. Daily parasitological examinations (BCM) of cattle blood samples indicated that six of the eight receiver heifers were positive from days 9, 10, 15, 16, 19 and 29. Mechanical transmission of T. vivax by A. fuscipes was demonstrated unequivocally in close to natural conditions, at a high rate (75% incidence over a 20-day period) under a mean challenge of 54 insects per heifer per day. These results, in addition to previous demonstration of mechanical transmission of T. vivax by Atylotus agrestis, confirm that mechanical transmission can be a significant route of infection.

Development of a mathematical model for mechanical transmission of trypanosomes and other pathogens of cattle transmitted by tabanids.

Mechanical transmission of pathogens by biting insects is a non-specific phenomenon in which pathogens are transmitted from the blood of an infected host to another host during interrupted feeding of the insects. A large range of pathogens can be mechanically transmitted, e.g. hemoparasites, bacteria and viruses. Some pathogens are almost exclusively mechanically transmitted, while others are also cyclically transmitted. For agents transmitted both cyclically and mechanically (mixed transmission), such as certain African pathogenic trypanosomes, the relative impact of mechanical versus cyclical transmission is essentially unknown. We have developed a mathematical model of pathogen transmission by a defined insect population to evaluate the importance of mechanical transmission. Based on a series of experiments aimed at demonstrating mechanical transmission of African trypanosomes by tabanids, the main parameters of the model were either quantified (host parasitaemia, mean individual insect burden, initial prevalence of infection) or estimated (unknown parameters). This model allows us to simulate the evolution of pathogen prevalence under various predictive circumstances, including control measures and could be used to assess the risk of mechanical transmission under field conditions. If adjustments of parameters are provided, this model could be generalized to other pathogenic agents present in the blood of their hosts (Bovine Leukemia virus, Anaplasma, etc.) or other biting insects such as biting muscids (stomoxyines) and hippoboscids.

Comparison of heterologous neutralizing antibody responses of human immunodeficiency virus type 1 (HIV-1)- and HIV-2-infected Senegalese patients: distinct patterns of breadth and magnitude distinguish HIV-1 and HIV-2 infections.

Neutralizing antibody responses against heterologous isolates in human immunodeficiency virus type 1 (HIV-1) and HIV-2 infections were compared, and their relationships with established clinical markers of progression were examined. Neutralizing responses against 7 heterologous primary isolates and 1 laboratory strain were compared between 32 untreated HIV-1-infected subjects and 35 untreated HIV-2-infected subjects using a pseudotyped reporter virus assay. The breadth of the neutralizing response, defined as the proportion of panel viruses positively neutralized by patient plasma, was significantly greater among HIV-2-infected subjects than among HIV-1-infected subjects. Notably, for fully one-third of HIV-2 subjects, all viruses were effectively neutralized in our panel. Magnitudes of responses, defined as reciprocal 50% inhibitory concentration (IC(50)) titers for positive reactions, were significantly greater among HIV-1-infected subjects than among HIV-2-infected subjects. When plasma samples from HIV-1 patients were tested for cross-neutralization of HIV-2 and vice versa, we found that these intertype responses are very rare and their prevalences comparable in both HIV-1 and HIV-2 infection. The significantly higher magnitude of heterologous responses for HIV-1 compared to HIV-2 prompted us to examine associations with viremia, which is known to be significantly higher in HIV-1 infection. Importantly, there was a significant positive correlation between the IC(50) titer and viral load within both the HIV-1 and HIV-2 groups, suggesting heterologous antibodies may be driven by viral replication. We conclude that HIV-2 infection is characterized by a broad, low-magnitude intratype neutralization response, while HIV-1 is characterized by a narrower but higher-magnitude intratype response and that a significant positive association between the IC(50) titer and viremia is common to both HIV-1 and HIV-2 infections.

The absence of anti-Tat antibodies is associated with risk of disease progression in HIV-2 infection.

The Tat protein of human immunodeficiency virus (HIV) is essential for viral replication and has extracellular pathogenic activity. We sought to determine whether the anti-Tat antibody response was predictive of disease progression in 144 HIV type 2 (HIV-2)-infected subjects observed longitudinally between 1985 and 2003. Sixty-eight percent of the subjects tested positive for anti-Tat antibodies, with reactivity notably established early after seroconversion and stably maintained over the course of infection. The risk and rate of progression to advanced HIV-2 AIDS was significantly higher in anti-Tat-negative subjects than in anti-Tat-positive subjects, extending the importance of this prognostic marker for HIV-2 AIDS.

Viral dynamics of primary HIV-1 infection in Senegal, West Africa.

BACKGROUND: Few studies have addressed primary human immunodeficiency virus (HIV) type 1 infection in sub-Saharan Africa, where the epidemic is of a predominantly heterosexual character and is caused by different subtypes. The present study examines the dynamics of viral replication in subjects infected with various HIV-1 subtypes. METHODS: Seven hundred fifty-two HIV-negative Senegalese women at high risk for infection were monitored every 3 months for acute/early HIV infection; 26 infections were identified (23 HIV-1 and 3 HIV-2), with an HIV-1 incidence rate of 3.23 cases/person-years observation. Multiple viral-load measurements were taken for all seroconverters. RESULTS: The mean+/-standard deviation viral load for all subjects during the early stage of infection was 4.13+/-0.66 log10 copies/mL, with an overall decrease of 0.22 log10 copies/mL after the early stage; the viral set point was reached after 12 months of infection. Most subjects had relatively low viral loads during the early stage of infection. HIV-1 CRF02_AG-infected women had a significantly higher mean viral load during the early stage of infection (mean +/- SD, 4.45+/-0.60 log(10) copies/mL) than did non-HIV-1 CRF02_AG-infected women (mean+/-SD, 3.78+/-0.46 log(10) copies/mL) (P=.008). None of the subjects reported symptoms consistent with primary HIV-1 infection. CONCLUSION: Our findings in Senegalese women differ from what have been described for primary HIV-1 infection. Further investigations of primary infections with non-B subtypes are warranted, to better characterize their differences with primary infections with subtype B.

Mechanical transmission of Trypanosoma congolense in cattle by the African tabanid Atylotus agrestis.

The trypanosomes pathogenic to livestock in Africa (Trypanosoma congolense, Trypanosoma vivax, and Trypanosoma brucei) are mainly cyclically transmitted by tsetse (Glossina). However, T. vivax, can also be mechanically transmitted by haematophagous insects. Laboratory studies have demonstrated the mechanical transmission of T. congolense, but confirmation of this under natural conditions was necessary. An experiment was therefore carried out in Lahirasso, Burkina Faso, in a corral completely covered by mosquito net, to avoid exposure to tsetse. Eight receiver heifers, free of trypanosome infection, were kept together with two donor heifers, experimentally infected with local stocks of T. congolense. On average, 291 Atylotus agrestis, freshly captured in Nzi traps, were introduced into the mosquito net daily for a period of 20 days to initiate mechanical transmission among cattle. Daily microscopical observation of their blood indicated that two of the eight receiver heifers became infected with T. congolense from days 42 and 53. Mechanical transmission of T. congolense by A. agrestis was demonstrated unequivocally with a 25% incidence over a 20-day period of exposure under a mean challenge of 29 insects/animal/day. These results, in addition to previous reports, demonstrate the ability of A. agrestis to transmit T. vivax and T. congolense to cattle in Africa by mechanical means. Efforts to eliminate cattle trypanosomosis should therefore consider the eventual persistence of disease as a result of mechanical transmission of trypanosomes by tabanids. Index descriptor and abbreviations: Trypanosoma congolense (Trypanosomatidae) is a pathogenic trypanosome found in wild and domestic herbivores, principally in cattle (Bos taurus, Bos indicus, and cross-breds), in Africa. It is cyclically transmitted by tsetse (Glossina, Diptera); however, mechanical transmission by biting insects may also occur. The present study demonstrates unequivocally the mechanical transmission of T. congolense to cattle by one of the most common African tabanids, A. agrestis. The main conclusion is that tabanids are able to transmit T. congolense; however, the incidence of transmission was lower than in studies carried out under the same conditions with T. vivax. Better models of mechanical transmission are required to understand why, on the one hand, epidemiological studies support the mechanical transmission of T. vivax but not T. congolense, and, on the other hand, experimental studies confirm that both species can be mechanically transmitted. Our studies suggest that the epidemiology of trypanosomosis in cattle involves tabanids, and hence, the eradication of tsetse-flies in Africa will not necessarily lead to the eradication of trypanosomosis in domestic livestock. ADT, apparent density of insects per trap per day (mean number of insects caught in one type of trap per 24h of trapping); D, day; NS, not statistically significant

Trypanosoma vivax: mechanical transmission in cattle by one of the most common African tabanids, Atylotus agrestis.

The role of mechanical vectors in the transmission of African livestock trypanosomes has always been controversial relative to tsetse flies, their cyclical vectors. An experiment was carried out in Burkina Faso to demonstrate mechanical transmission of Trypanosoma vivax by one of the most common tabanids in Africa: Atylotus agrestis. Eight heifers (crossbred zebuxBaoulé), free of trypanosome infection, were kept in a corral covered by a mosquito net, together with two heifers infected experimentally with a local stock of T. vivax. On average, 324 A. agrestis, freshly captured with Nzi traps, were introduced daily over 20 days. Parasitological, PCR and serological examinations were carried out regularly to assess infections and levels of parasitaemia. Microscopic examination of buffy-coats indicated that five of the eight receiver-heifers were infected on days 8, 13, 32, 41, and 48. PCR results indicated that these five heifers were already infected by day 13. Mechanical transmission of T. vivax by A. agrestis was demonstrated unequivocally, at a high rate (63% in 13-20 days). Conditions of transmission in this experiment are discussed in terms of natural rates of challenge. The importance of tabanids as mechanical vectors of T. vivax should be re-considered, in light of these results. Creation of tsetse free zones in Africa will generally lead to the disappearance of T. congolense, T. brucei, and most often T. vivax as well; however, in areas where T. vivax can be mechanically transmitted, clearance of tsetse may not be sufficient to eradicate livestock trypanosomosis.