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

Comparative performance of traps in catching tsetse flies (Diptera: Glossinidae) in Tanzania

This study was conducted to determine the efficiency of different tsetse traps in 28 sites across Tanzania. The traps used were biconical, H, NGU, NZI, pyramidal, S3, mobile, and sticky panels. Stationary traps were deployed at a distance of 200 m apart and examined 72 h after deployment. The results showed that 117 (52.2%) out of the 224 traps deployed captured at least one Glossina species. A total of five Glossina species were captured, namely Glossina brevipalpis, Glossina pallidipes, Glossina swynnertoni, Glossina morsitans, and Glossina fuscipes martinii. Biconical traps caught tsetse flies in 27 sites, pyramidal in 26, sticky panel in 20, mobile in 19, S3 in 15, NGU in 7, H in 2 and NZI in 1. A total of 21 107 tsetse flies were trapped, with the most abundant species being G. swynnertoni (55.9%), followed by G. pallidipes (31.1%), G. fuscipes martinii (6.9%) and G. morsitans (6.0%). The least caught was G. brevipalpis (0.2%). The highest number of flies were caught by NGU traps (32.5%), followed by sticky panel (16%), mobile (15.4%), pyramidal (13.0%), biconical (11.3%) and S3 (10.2%). NZI traps managed to catch 0.9% of the total flies and H traps 0.7%. From this study, it can be concluded that the most efficient trap was NGU, followed by sticky panel and mobile, in that order. Therefore, for tsetse fly control programmes, NGU traps could be the better choice. Conversely, of the stationary traps, pyramidal and biconical traps captured tsetse flies in the majority of sites, covering all three ecosystems better than any other traps; therefore, they would be suitable for scouting for tsetse infestation in any given area, thus sparing the costs of making traps for each specific Glossina species. Keywords: tseste; traps; densties; Glossina; mobile; stationary; Tanzani

Prevalence Of Brucellosis In Livestock And Incidences In Humans In East Africaprevalence Of Brucellosis In Livestock And Incidences In Humans In East Africa

Research Article published by African Crop Science JournalBrucellosis is an emerging zoonotic disease that poses a threat to both livestock and public health in east Africa. There are several reports of occurrence of the disease in livestock populations especially in Tanzania and Kenya, suggesting chances of increased spread to humans, and the disease being misdiagnosed for malaria. The objective of this study was to determine brucellosis prevalence in livestock and incidence in humans among pastoralists and agro-pastoralists communities in some areas of Kenya and Tanzania. A total of 2349 ruminants were screened using different serological techniques, in the selected areas. Serum samples from the Southern Highlands Zone (SHZ), Northern zone (NZ) and Eastern Zone (EZ) were screened using Rose Bengal Plate Test (RBPT) antigen, and later positive samples were confirmed using competitive enzyme linked immune-sorbent assay (c-ELISA). Results showed prevalence of 11.4% in the SHZ (n=799), 2.4% in the EZ (n=169) and 1% in the NZ (n= 408). Milk ring test was used to test milk samples from Migori, West Pokot and Mwingi, and the prevalences recorded in cattle were 17.9% (n=56) in 2012 and 11.7 (n=77) in 2014. Within the same period, West Pokot recorded prevalence of up to 21.9% (n=96) in cattle and 16.7% (n=6) in goats. Generally, Migori had lower prevalence in Kenya, but being the third lower in Tanzania and Kenya with the prevalence being 4.3% (n=70) in goats and 2.2% (n=45) in goats. Serum from cattle and goats were tested using compliment fixation test (CFT); showing 0.9% (n=212) prevalence in Migori. In West Pokot, the prevalence was 4.0% (n=101) in cattle, 20% (n=100) in goats and 13.8% (=29) in sheep; whereas in Mwingi prevalence was 4.75% (n=43) and 9.5% (n=21) in cattle and goats respectively. A total of 1,140 human cases were followed up in selected study areas where livestock samples were collected, and an overall incidence of 22.7% (n=1140) was confirmed. Selected areas in Tanzania had an incidence of 28.2% (n=578) and in Kenya 17.1% (n=562). Brucellosis is endemic in many areas of Tanzania and Kenya and pose a high risk to human health