Tracking the Feeding Patterns of Tsetse Flies (Glossina Genus) by Analysis of Bloodmeals Using Mitochondrial Cytochromes Genes

Tsetse flies are notoriously difficult to observe in nature, particularly when populations densities are low. It is therefore difficult to observe them on their hosts in nature; hence their vertebrate species can very often only be determined indirectly by analysis of their gut contents. This knowledge is a critical component of the information on which control tactics can be developed. The objective of this study was to determine the sources of tsetse bloodmeals, hence investigate their feeding preferences. We used mitochondrial cytochrome c oxidase 1 (COI) and cytochrome b (cytb) gene sequences for identification of tsetse fly blood meals, in order to provide a foundation for rational decisions to guide control of trypanosomiasis, and their vectors. Glossina swynnertoni were sampled from Serengeti (Tanzania) and G. pallidipes from Kenya (Nguruman and Busia), and Uganda. Sequences were used to query public databases, and the percentage identities obtained used to identify hosts. An initial assay showed that the feeds were from single sources. Hosts identified from blood fed flies collected in Serengeti ecosystem, included buffaloes (25/40), giraffes (8/40), warthogs (3/40), elephants (3/40) and one spotted hyena. In Nguruman, where G. pallidipes flies were analyzed, the feeds were from elephants (6/13) and warthogs (5/13), while buffaloes and baboons accounted for one bloodmeal each. Only cattle blood was detected in flies caught in Busia and Uganda. Out of four flies tested in Mbita Point, Suba District in western Kenya, one had fed on cattle, the other three on the Nile monitor lizard. These results demonstrate that cattle will form an integral part of a control strategy for trypanosomiasis in Busia and Uganda, while different approaches are required for Serengeti and Nguruman ecosystems, where wildlife abound and are the major component of the tsetse fly food source

Late Presentation With HIV in Africa: Phenotypes, Risk, and Risk Stratification in the REALITY Trial.

This article has been accepted for publication in Clinical Infectious Diseases Published by Oxford University PressBackground: Severely immunocompromised human immunodeficiency virus (HIV)-infected individuals have high mortality shortly after starting antiretroviral therapy (ART). We investigated predictors of early mortality and "late presenter" phenotypes. Methods: The Reduction of EArly MortaLITY (REALITY) trial enrolled ART-naive adults and children ≥5 years of age with CD4 counts .1). Results: Among 1711 included participants, 203 (12%) died. Mortality was independently higher with older age; lower CD4 count, albumin, hemoglobin, and grip strength; presence of World Health Organization stage 3/4 weight loss, fever, or vomiting; and problems with mobility or self-care at baseline (all P < .04). Receiving enhanced antimicrobial prophylaxis independently reduced mortality (P = .02). Of five late-presenter phenotypes, Group 1 (n = 355) had highest mortality (25%; median CD4 count, 28 cells/µL), with high symptom burden, weight loss, poor mobility, and low albumin and hemoglobin. Group 2 (n = 394; 11% mortality; 43 cells/µL) also had weight loss, with high white cell, platelet, and neutrophil counts suggesting underlying inflammation/infection. Group 3 (n = 218; 10% mortality) had low CD4 counts (27 cells/µL), but low symptom burden and maintained fat mass. The remaining groups had 4%-6% mortality. Conclusions: Clinical and laboratory features identified groups with highest mortality following ART initiation. A screening tool could identify patients with low CD4 counts for prioritizing same-day ART initiation, enhanced prophylaxis, and intensive follow-up. Clinical Trials Registration: ISRCTN43622374.REALITY was funded by the Joint Global Health Trials Scheme (JGHTS) of the UK Department for International Development, the Wellcome Trust, and Medical Research Council (MRC) (grant number G1100693). Additional funding support was provided by the PENTA Foundation and core support to the MRC Clinical Trials Unit at University College London (grant numbers MC_UU_12023/23 and MC_UU_12023/26). Cipla Ltd, Gilead Sciences, ViiV Healthcare/GlaxoSmithKline, and Merck Sharp & Dohme donated drugs for REALITY, and ready-to-use supplementary food was purchased from Valid International. A. J. P. is funded by the Wellcome Trust (grant number 108065/Z/15/Z). J. A. B. is funded by the JGHTS (grant number MR/M007367/1). The Malawi-Liverpool–Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine (grant number 101113/Z/13/Z) and the Kenya Medical Research Institute (KEMRI)/Wellcome Trust Research Programme, Kilifi (grant number 203077/Z/16/Z) are supported by strategic awards from the Wellcome Trust, United Kingdom. Permission to publish was granted by the Director of KEMRI. This supplement was supported by funds from the Bill & Melinda Gates Foundation

Summary of data for bloodmeal analysis showing species fed on by tsetse flies caught in the different study sites.

<p>The total number of flies analyzed per site is given in parenthesis. These data combine both cytb and COI, and GenBank accession numbers for representative sequences given, and where not determined indicated as ND.</p><p>1. These data include 2 samples from <i>G. pallidipes</i> in northern Uganda.</p

A map showing georeferenced sites where tsetse flies were trapped in Kenya, Tanzania and Uganda.

<p>A Google Earth map is also available (<a href="http://www.icipe.org/images/stories/downloads/muturi_et_al_figure1.zip.zip" target="_blank">http://www.icipe.org/images/stories/downloads/muturi_et_al_figure1.zip.zip</a>).</p

Trypanosome stabilates characterized using PCR, procyclic transmission test, and isoenzyme techniques.

<p><b>Key:</b> +  =  test was performed; -  =  test was not performed; numbers in parentheses  =  total number of stabilates in the cryobank.</p

Drug resistant trypanosome stabilates stored at the Kenya Trypanosomiasis Research Institute cryobank.

<p>Other than KETRI 2538, which is molecularly characterized (not published), molecular characterization of the other isolates is not available. <b>Key</b>: *  =  these isolates were recovered from cases of treatment failure following suramin chemotherapy; a  =  stabilates which were made resistant to melarsoprol in the laboratory; EATRO  =  East African Trypanosomiasis Research Organization; KETRI  =  Kenya Trypanosomiasis Research Institute; DFMO  =  difluoromethylornithine.</p

Number of primary trypanosome stabilates collected, preserved, and stored at the Kenya Trypanosomiasis Research Institute cryobank.

<p>Number of primary trypanosome stabilates collected, preserved, and stored at the Kenya Trypanosomiasis Research Institute cryobank.</p

Animal hosts from which various trypanosomes were isolated and stored at the Kenya Trypanosomiasis Research Institute cryobank.

<p><b>Key:</b> Tbb  =  Trypanosoma brucei brucei; Tb  =  Trypanosoma brucei; Tbr  =  Trypanosoma brucei rhodesiense; UC  =  unclassified; HNI  =  host of isolation not indicated.</p