Year to year and seasonal variations in vector bionomics and malaria transmission in a humid savannah village in west Burkina Faso

Abstract

A longitudinal entomological study was carried out from 1999 to 2001 in Lena, a humid savannah village in the western region of Burkina Faso in order to establish malaria vector bionomics and the dynamics of malaria transmission. In the first year, malaria transmission was mainly due to An. gambiae s.s., but during the two later years was due to An. funestus, which were observed in high frequency towards the end of the rainy season. PCR identification of samples of An. gambiae s.l. showed 93% to be An. gambiae s.s. and 7% An. arabiensis. An. funestus constituting more than 60% of the vectors were identified in PCR as An. funestus s.s. The persistence of intense vectorial activity in this village was probably due to the road building in a swampy area creating a semi-permanent swamp that provided large sites for larval mosquitoes. These swampy sites seemed to be more favorable for An. funestus than for An. gambiae s.s. Thus, land development must be monitored and subjected to planning to minimize vector proliferation. Such a system of planning could lead to the restriction or even elimination of the swamp that is the source of larvae developing in the heart of the village.

The dominant Anopheles vectors of human malaria in Africa, Europe and the Middle East: occurrence data, distribution maps and bionomic précis

“…This late-night biting preference is clearly evident throughout its range, with all studies reviewed reporting a peak biting period occurring after 22:00, and most commonly between midnight and the early hours of the morning [123,124,128,131,145,152-157] (Table 13). Endophilic resting behaviour is also commonly reported [84,86,114,124,125,145,146,149,152,156,158,159], and combined with a relatively high longevity, makes it as good a vector, or better in some areas, as An. gambiae [10,11,18,160].…”

“…water in hoof prints, wheel ruts or areas of rice cultivation) (Tables 11, 12). It is considered to be highly anthropophilic, with 11 of 15 studies that examined biting behaviour (Table 13) reporting a marked preference for human hosts [131,145,149,150,157,159,174-177]. However, there are a number of studies that indicate An.…”

“…funestus that may increase their ability to effectively transmit malaria parasites (see above) [19,123,127,145,153,154,157,175,177,185,187-190] (Table 13). Anopheles gambiae is often described as an endophagic and endophilic species, both biting and resting indoors, however, the majority of studies listed herein (nine of 11), that compared indoor and outdoor human-landing catches reported no difference in the numbers of females collected at either location [123,127,145,149,153,157,175,190,191] and an equal number of studies recorded post-feeding exophilic resting [122,131,154,175] as resting indoors [145,149,159,178]. Bockarie et al [175] linked differences in the exo-or endophilic behaviour of An.…”

Contribution ofAnopheles funestus,An. gambiaeandAn. nili(Diptera: Culicidae) to the perennial malaria transmission in the southern and western forest areas of Côte d’Ivoire

“…Although this species is usually the only member of the An. funestus group represented in entomological surveys conducted elsewhere in West Africa, such as in Senegal (Cohuet et al, 2004), Burkina Faso (Dabiré et al, 2008) and Ghana (Coetzee et al, 2006), the sampling techniques used often preferentially target anthropophilic (human landing catches) and/or endophagic (indoor spray catches) species such as An. funestus s.s.. All of the members of the An.…”

Field efficacy of a new mosaic long-lasting mosquito net (PermaNet® 3.0) against pyrethroid-resistant malaria vectors: a multi centre study in Western and Central Africa

“…Both M & S molecular forms of An. gambiae co-exist in sympatry but the M form is mostly present during the dry season [34]. Anopheles gambiae showed high level of resistance to pyrethroids due to the presence of the Kdr mutation occurring at high allelic frequency among the molecular M and S forms [35].…”