Clinical and Parasitological Effects of Aspilia africana (Pers.) C.D. Adams in Fifteen Patients with Uncomplicated Malaria

This paper reports the findings of a clinical study of a herbal preparation of Aspilia africana (Pers.) C.D. Adams against malaria, corroborated by in vitro antiplasmodial and cytotoxicity tests. In a non-controlled prospective design, 15 patients with uncomplicated malaria were administered with the herbal preparation and assessed for clinical manifestations of malaria, parasitaemia and global quality of life using the Kanorfsky Performance Scale. Antiplasmodial activity of extracts against the chloroquine-resistant strain of Plasmodium falciparum Dd2 was determined using the [3H]-hypoxanthine radioactive method while cytotoxicity against human urinary bladder carcinoma (ECV-304) and human hepatocellular carcinoma (HepG2) cell lines was determined using the MTT assay. Remarkable clinical improvements occurred 3 to 21 days after initiation of treatment. Forty nine days after starting treatment, all 15 patients had complete resolution of malaria symptoms and were cleared of parasitaemia and attained a Karnofsky Performance score of 100. The petroleum ether/ethyl acetate extract possessed in vitro antiplasmodial activity (IC50 30μg/ml) but no remarkable cytotoxicity. The A. africana preparation shows potential as an alternative for the management of uncomplicated malaria.East and Central African Journal of Pharmaceutical Sciences Vol. 12 (2009) 37-4

Human African Trypanosomiasis and challenges to its control in Urambo, Kasulu and Kibondo Districts, western Tanzania

A study was carried out to determine the prevalence and management of Human African Trypanosomiasis (HAT) in Urambo, Kasulu and Kibondo districts of western Tanzania. Parasitological surveys for trypanosome and other blood parasites were conducted in selected villages. Interviews with health workers were conducted to explore facility capacity to diagnose and manage HAT. Community knowledge on tsetse and availability of trypanocidal drugs was explored. Results showed that, although health facility records showed HAT is an important public health problem in the three districts, typanosomes were found in 0.6% of the examined individuals in Urambo district only. Malaria parasites with a prevalence of 12.1%, 19.7% and 9.7%, in Urambo, Kibondo and Kasulu, respectively were detected in blood samples from the same individuals examined for trypanosomes. There was poor capacity for most of the health facilities in the diagnosis, treatment and control of HAT. In both districts, communities were knowledgeable of the tsetse identity (82.4%) and had experienced tsetse bites (94%). The majority (91.4%) of the community members knew that they were at risk of acquiring HAT. However, only 29% of the respondents knew that anti-trypanocidal drugs were readily available free of charge from health care facilities. Late treatment seeking behaviour was common in Kasulu and Urambo districts. In conclusion, health facilities in western Tanzania are faced with problems of poor capacity to diagnose and manage HAT and that treatment seeking behaviour among the communities at risk is poor. Efforts should be made to strengthen the capacity of the health facility to handle HAT cases and health education to the population at risk. Keywords: Human African Trypanosomiasis, diagnosis, control, TanzaniaTanzania Health Research Bulletin Vol. 8 (2) 2006: pp. 80-8

Multiple Trypanosoma infections are common amongst Glossina species in the new farming areas of Rufiji district, Tanzania

<p>Abstract</p> <p>Background</p> <p>Tsetse flies and trypanosomiasis are among several factors that constrain livestock development in Tanzania. Over the years Rufiji District was excluded from livestock production owing to tsetse fly infestation, however, a few years ago there was an influx of livestock following evictions aimed at conserving the Usangu wetlands.</p> <p>Methods</p> <p>A study was conducted to determine the efficiency of available traps for catching tsetse flies, <it>Glossina </it>species infesting the area, their infection rates and <it>Trypanosoma </it>species circulating in the area. Trapping was conducted during the semi dry season for a total of 30 days (ten days each month) during the onset of the dry season of May - July 2009. Harvested flies after every 24 hours were dissected and examined under a light microscope for trypanosome infections and whole fly DNA was extracted from 82 flies and analyzed for trypanosomes by polymerase chain reaction (PCR) using different sets of primers.</p> <p>Results</p> <p>The proportions of total tsetse catches per trap were in the following decreasing order S3 (33%), H-Trap (27%), Pyramidal (19%), sticky panel (11%) and biconical trap (10%). Of the 1200 trapped flies, 75.6% were identified as <it>Glossina pallidipes</it>, 11.7% <it>as G. brevipalpis</it>, 9.6% as <it>G. austeni </it>and 3.0% <it>G. morsitans morsitans</it>. Dissections revealed the overall infection rate of 6.6% (13/197). Whole DNA was extracted from 82 tsetse flies and the prevalence of trypanosomes circulating in the area in descending order was 92.7% (76/82) for <it>T. simiae</it>; 70.7% (58/82) for <it>T. brucei </it>types; 48.8% (40/82) for the <it>T. vivax </it>types and 32.9% (27/82) for the <it>T. congolense </it>types as determined by PCR. All trypanosome types were found in all tsetse species analysed except for the <it>T. congolense </it>types, which were absent in <it>G. m. morsitans</it>. None of the <it>T. brucei </it>positive samples contained human infective trypanosomes by SRA - PCR test</p> <p>Conclusion</p> <p>All tsetse species found in Rufiji are biologically important in the transmission of animal trypanosomiasis and the absence of <it>T. congolense </it>in <it>G. m. morsitans </it>could be a matter of chance only. Therefore, plans for control should consider all tsetse species.</p

Reproductive health services for populations at high risk of HIV: Performance of a night clinic in Tete province, Mozambique

<p>Abstract</p> <p>Background</p> <p>Different models exist to provide HIV/STI services for most-at-risk populations (MARP). Along the Tete traffic corridor in Mozambique, linking Malawi and Zimbabwe, a night clinic opening between 4 and 10 PM was established targeting female sex workers (FSW) and long-distance truck drivers (LDD). The clinic offers free individual education and counselling, condoms, STI care, HIV testing, contraceptive services and outreach peer education. To evaluate this clinic model, we assessed relevance, service utilisation, efficiency and sustainability.</p> <p>Methods</p> <p>In 2007-2009, mapping and enumeration of FSW and LDD was conducted; 28 key informants were interviewed; 6 focus group discussions (FGD) were held with FSW from Mozambique and Zimbabwe, and LDD from Mozambique and Malawi. Clinic outputs and costs were analysed.</p> <p>Results</p> <p>An estimated 4,415 FSW work in the area, or 9% of women aged 15-49, and on average 66 trucks stay overnight near the clinic. Currently on average, 475 clients/month visit the clinic (43% for contraception, 24% for counselling and testing and 23% for STI care). The average clinic running cost is US$ 1408/month, mostly for human resources. All informants endorsed this clinic concept and the need to expand the services. FGD participants reported high satisfaction with the services and mentioned good reception by the health staff, short waiting times, proximity and free services as most important. Participants were in favour of expanding the range of services, the geographical coverage and the opening times.</p> <p>Conclusions</p> <p>Size of the target population, satisfaction of clients and endorsement by health policy makers justify maintaining a separate clinic for MARP. Cost-effectiveness may be enhanced by broadening the range of SRHR-HIV/AIDS services, adapting opening times, expanding geographical coverage and targeting additional MARP. Long-term sustainability remains challenging and requires private-public partnerships or continued project-based funding.</p

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

A Multi-Host Agent-Based Model for a Zoonotic, Vector-Borne Disease. A Case Study on Trypanosomiasis in Eastern Province, Zambia

Background: This paper presents a new agent-based model (ABM) for investigating T. b. rhodesiense human African trypanosomiasis (rHAT) disease dynamics, produced to aid a greater understanding of disease transmission, and essential for development of appropriate mitigation strategies. Methods: The ABM was developed to model rHAT incidence at a fine spatial scale along a 75 km transect in the Luangwa Valley, Zambia. The method offers a complementary approach to traditional compartmentalised modelling techniques, permitting incorporation of fine scale demographic data such as ethnicity, age and gender into the simulation. Results: Through identification of possible spatial, demographic and behavioural characteristics which may have differing implications for rHAT risk in the region, the ABM produced output that could not be readily generated by other techniques. On average there were 1.99 (S.E. 0.245) human infections and 1.83 (S.E. 0.183) cattle infections per 6 month period. The model output identified that the approximate incidence rate (per 1000 person-years) was lower amongst cattle owning households (0.079, S.E. 0.017), than those without cattle (0.134, S.E. 0.017). Immigrant tribes (e.g. Bemba I.R. = 0.353, S.E.0.155) and school-age children (e.g. 5–10 year old I.R. = 0.239, S.E. 0.041) were the most at-risk for acquiring infection. These findings have the potential to aid the targeting of future mitigation strategies. Conclusion: ABMs provide an alternative way of thinking about HAT and NTDs more generally, offering a solution to the investigation of local-scale questions, and which generate results that can be easily disseminated to those affected. The ABM can be used as a tool for scenario testing at an appropriate spatial scale to allow the design of logistically feasible mitigation strategies suggested by model output. This is of particular importance where resources are limited and management strategies are often pushed to the local scale. © 2016 Alderton et al

Genome sequence of the tsetse fly (Glossina morsitans):Vector of African trypanosomiasis

Tsetse flies are the sole vectors of human African trypanosomiasis throughout sub-Saharan Africa. Both sexes of adult tsetse feed exclusively on blood and contribute to disease transmission. Notable differences between tsetse and other disease vectors include obligate microbial symbioses, viviparous reproduction, and lactation. Here, we describe the sequence and annotation of the 366-megabase Glossina morsitans morsitans genome. Analysis of the genome and the 12,308 predicted protein-encoding genes led to multiple discoveries, including chromosomal integrations of bacterial (Wolbachia) genome sequences, a family of lactation-specific proteins, reduced complement of host pathogen recognition proteins, and reduced olfaction/chemosensory associated genes. These genome data provide a foundation for research into trypanosomiasis prevention and yield important insights with broad implications for multiple aspects of tsetse biology.IS

Quantifying Heterogeneity in Host-Vector Contact: Tsetse (Glossina swynnertoni and G. pallidipes) Host Choice in Serengeti National Park, Tanzania

Identifying hosts of blood-feeding insect vectors is crucial in understanding their role in disease transmission. Rhodesian human African trypanosomiasis (r-HAT or ‘sleeping sickness’) caused by Trypanosoma brucei rhodesiense and transmitted by tsetse flies, is commonly associated with wilderness areas of east and southern Africa. Such areas hold a diverse range of species which form communities of hosts for disease maintenance. The relative importance of different wildlife hosts remains unclear. This study quantified tsetse feeding preferences in a wilderness area of great host species richness, Serengeti National Park, Tanzania, assessing tsetse feeding and host density contemporaneously. Glossina swynnertoni and G.pallidipes were collected from six study sites. Bloodmeal sources were identified through matching Cytochrome B sequences amplified from bloodmeals from fed flies to published sequences. Densities of large mammal species in each site were quantified, and feeding indices calculated to assess the relative selection or avoidance of each host species by tsetse. The host species most commonly identified in G. swynnertoni bloodmeals, warthog (94/220), buffalo (48/220) and giraffe (46/220), were found at relatively low densities (3-11/km2) and fed on up to 15 times more frequently than expected by their relative density. Wildebeest, zebra, impala and Thomson’s gazelle, found at the highest densities, were never identified in bloodmeals. Commonly identified hosts for G. pallidipes were buffalo (26/46), giraffe (9/46) and elephant (5/46). This study is the first to quantify tsetse host range by molecular analysis of tsetse diet with simultaneous assessment of host density in a wilderness area. Although G.swynnertoni and G.pallidipes can feed on a range of species, they are highly selective. Many host species are rarely fed on, despite being present in areas where tsetse are abundant. These feeding patterns, along with the ability of key host species to maintain and transmit T.b.rhodesiense, drive the epidemiology of r-HAT in wilderness areas

Bacterial diversity obtained by culturable approaches in the gut of Glossina pallidipes population from a non sleeping sickness focus in Tanzania: preliminary results

Abstract Background Glossina pallidipes is a haematophagous insect that serves as a cyclic transmitter of trypanosomes causing African Trypanosomiasis (AT). To fully assess the role of G. pallidipes in the epidemiology of AT, especially the human form of the disease (HAT), it is essential to know the microbial diversity inhabiting the gut of natural fly populations. This study aimed to examine the diversity of G. pallidipes fly gut bacteria by culture-dependent approaches. Results 113 bacterial isolates were obtained from aerobic and anaerobic microorganisms originating from the gut of G. pallidipes. 16S rDNA of each isolate was PCR amplified and sequenced. The overall majority of identified bacteria belonged in descending order to the Firmicutes (86.6%), Actinobacteria (7.6%), Proteobacteria (5.5%)and Bacteroidetes (0.3%). Diversity of Firmicutes was found higher when enrichments and isolation were performed under anaerobic conditions than aerobic ones. Experiments conducted in the absence of oxygen (anaerobiosis) led to the isolation of bacteria pertaining to four phyla (83% Firmicutes, 15% Actinobacteria, 1% Proteobacteria and 0.5% Bacteroidetes, whereas those conducted in the presence of oxygen (aerobiosis) led to the isolation of bacteria affiliated to two phyla only (90% Firmicutes and 10% Proteobacteria). Phylogenetic analyses placed these isolates into 11 genera namely Bacillus, Acinetobacter, Mesorhizobium, Paracoccus, Microbacterium, Micrococcus, Arthrobacter, Corynobacterium, Curtobacterium, Vagococcus and Dietzia spp.which are known to be either facultative anaerobes, aerobes, or even microaerobes. Conclusion This study shows that G. pallidipes fly gut is an environmental reservoir for a vast number of bacterial species, which are likely to be important for ecological microbial well being of the fly and possibly on differing vectorial competence and refractoriness against AT epidemiology