Marrama L, Jambou R, Rakotoarivony I, Leong Pock Tsi J M, Duchemin J B, Laventure S, Mouchet J, Roux J
Unité d' Epidémiologie de l'Institut Pasteur de Dakar, 36 Avenue Pasteur, BP 220, Dakar, Senegal.
Acta Trop. 2004 Jan;89(2):193-203. doi: 10.1016/j.actatropica.2003.09.014.
A 4-year entomological study was carried out in Southern Madagascar to identify malaria vectors, evaluate the transmission and compare the influence of irrigation in the sub-arid and adjacent humid regions. Three villages were involved in this entomological survey: Androvasoa (located in the natural sub-arid ecosystem), Pépiniére (sited at the centre of an irrigated rice scheme in the sub-arid region) and Esana (bordered with rice fields in the humid region). Mosquitoes were collected inside and outside dwellings when landing on human beings, with light traps and with knockdown indoor sprays. Anopheles arabiensis, Anopheles merus and Anopheles funestus were found in every village while Anopheles gambiae s.s. was only found in the village bordering the rice-fields (Pépiniére) and Anopheles mascarensis, a mosquito native to Madagascar, was only found in the humid region (Esana). In Pépiniére, the annual entomological inoculation rate (EIR) was low (EIR=0.4 infective bites/man/year (IBM)). In the irrigated scheme of the sub-arid region, malaria transmission was 150 times higher (mean EIR=63 IBM) than in the natural ecosystem and A. funestus was the main vector, responsible for 90% of infective bites. In Esana, the level of malaria transmission was high (EIR=41 IBM) and 2/3 of the infective bites were due to A. mascarensis, despite the presence of A. gambiae s.s. and A. funestus. These results are discussed with reference to the impact of irrigation on malaria in Africa ("the paddies paradox").
在马达加斯加南部开展了一项为期4年的昆虫学研究，以确定疟疾传播媒介，评估传播情况，并比较灌溉对亚干旱地区及相邻湿润地区的影响。三个村庄参与了这项昆虫学调查：安德罗瓦索阿（位于天然亚干旱生态系统中）、佩皮尼埃（位于亚干旱地区一个灌溉水稻田中心）和埃萨纳（与湿润地区的稻田接壤）。采用人饵诱捕法、光诱捕法和室内击倒喷雾法，在住宅内外收集蚊子。在每个村庄都发现了阿拉伯按蚊、梅氏按蚊和富氏按蚊，而冈比亚按蚊只在与稻田接壤的村庄（佩皮尼埃）被发现，马达加斯加本土蚊子马斯卡林按蚊只在湿润地区（埃萨纳）被发现。在佩皮尼埃，年度昆虫学接种率（EIR）较低（EIR = 0.4感染性叮咬/人/年（IBM））。在亚干旱地区的灌溉区，疟疾传播率比天然生态系统高150倍（平均EIR = 63 IBM），富氏按蚊是主要传播媒介，占感染性叮咬的90%。在埃萨纳，疟疾传播水平较高（EIR = 41 IBM），尽管存在冈比亚按蚊和富氏按蚊，但2/3的感染性叮咬是由马斯卡林按蚊造成的。本文结合灌溉对非洲疟疾的影响（“稻田悖论”）对这些结果进行了讨论。
