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Biomedical subjects

S M Mpofu

Publications and source records attributed to S M Mpofu.

7 recordsLinked to original sources
PubMed1993

Laboratory colonization of Anopheles quadriannulatus from sympatry with other sibling species of the Anopheles gambiae complex in Zimbabwe.

A laboratory colony of the mosquito Anopheles quadriannulatus was established from a wild population occurring sympatrically with An.arabiensis in Zimbabwe. These sibling species are members of the An.gambiae Giles complex and were distinguished primarily by means of their specific polytene chromosome banding patterns. By using an ox-baited trap, we sampled selectively for the more zoophilic An.quadriannulatus. It was confirmed that An.quadriannulatus has the diagnostic slow allozyme of aspartate aminotransferase (AAT95/95). In a mixed population under laboratory conditions, An.arabiensis displaced An.quadriannulatus within eight generations, without introgression. Colonization of An.quadriannulatus was facilitated by pooling the progeny from wild-caught mothers of confirmed identity and by using a specially adapted cage to promote mating.

Animals↗
PubMed1991

Potential use of bendiocarb (Ficam VC) for malaria control in an area of Zimbabwe.

Ficam (bendiocarb) was tested for its residual efficacy and irritation in malaria vector control by using a laboratory bred colony of Anopheles arabiensis. In the study area, the insecticide remained active for up to 8 wk (96% mortality) on thatch. In similar, especially constructed huts, 74% mortality was achieved up to 20 wk on mud compared with up to 100% on thatch. In the special huts, release/capture studies indicated that the lethal effect of Ficam on the insects was more pronounced than its irritant effect. This was shown by the low recapture numbers in exit traps as compared with the hut-floor mortalities. The implications of these findings in relation to studies elsewhere and the potential of Ficam use in malaria control are discussed.

Animals↗
PubMed1988

An evaluation of the residual lifespan of DDT in malaria control.

The insecticide lifespan of DDT was assessed in huts sprayed for malaria control. The age of the spray deposits ranged from 3 up to 22 months. Blood-fed female Anopheles arabiensis were either released into the huts or exposed on sprayed surfaces by a bioassay technique. Mosquitoes released were recovered in exit traps fitted on windows or dead on the floor. Only 50% or less of mosquitoes released in sprayed huts were recovered. Mortality figures for recovered mosquitoes ranged from 94% at 3 months, declining to 19% for huts sprayed 18 months previously. Of the recovered mosquitoes, 60% or more attempted to escape from sprayed huts within two hours postrelease up to 15 months postspray. Bioassays gave average mortalities of 95 and 76% on thatch and mud walls, respectively. Analysis of mud samples from test huts showed that target dose of 2 g AI/m2 of DDT was not being achieved. The results support the need for an annual spraying cycle.

Animals↗
PubMed1985

Seasonal vector density and disease incidence patterns of malaria in an area of Zimbabwe.

Anopheline mosquitoes were studied in an area of Zimbabwe to correlate their population densities with seasonality in malaria incidence. Four trapping methods were employed for adult mosquitoes: pit traps, outdoor and indoor man-baited nets and a sheep-baited net. Anopheles funestus exhibited two population peaks during the year, one in March and the other in September/October. The following over-all proportions of the An. gambiae complex were recorded: An. gambiae Giles (2.5%), An. arabiensis Patton (14.3%) and An. guadriannulatus Theobald (83.2%). Peak populations were observed in March, with most An. gambiae and An. arabiensis preferring outdoor man-baited nets. Approximately equal preference for outdoor nets and pit traps was observed for An. guadriannulatus, which was the only species present throughout the year. The implications of these findings for malaria transmission, which showed a peak in April, and the suitability of the sampling methods employed are discussed.

Animals↗