Institut de Recherche en Sciences de la Santé (IRSS), BP 390, Bobo-Dioulasso, Burkina Faso.
Malar J. 2010 Mar 19;9:78. doi: 10.1186/1475-2875-9-78.
Several cases of malaria are frequently recorded during the dry period in Ouagadougou town (Burkina Faso). This has led to the design of a series of studies focusing on both parasitological and entomological investigations intended to provide relevant health data on the risk of local malaria transmission according to the way of urbanisation.
A cross-sectional entomological survey was carried out in various districts of Ouagadougou in April and October 2006. Adult malaria vectors were collected using CDC traps and indoor insecticide spraying performed in four houses during four consecutive days/nights. Intensive larval sampling was also done in available water ponds throughout the study sites.
In April, the anopheline breeding sites consisted only of semi-permanent or permanent swamps located mainly in the two peripheral districts. Despite the presence of anopheline larvae in these breeding sites, less than five Anopheles gambiae s.l. adults were caught by CDC traps and indoor insecticide spraying. In October, additionally to the permanent breeding sites reported in April, some rainfall swamps were also found positive to anophelines. The number of adults' mosquitoes was higher than that collected in April (2 vs 159 in October). Out of 115 larvae of An. gambiae s.l. analysed by PCR in April, 59.1% (68/115) were identified as Anopheles arabiensis, 39.1% (45/115) as An. gambiae M while the S form represented less than 2%. Overall 120 larvae and 86 females were identified by PCR in October as An. gambiae M form (51%) and An. arabiensis (42.2%). The S form represented only 6.8%. The global sporozoite rate recorded was high (6.8%) and did not differ between the districts except in the central district where no positive mosquito was detected.
Although only few adults' mosquitoes were actively caught during the driest month, malaria vectors persisted all year long that increases the risk of urban malaria transmission. The distribution of breeding sites and especially the occurrence of malaria vectors were more abundant in the periphery, which is more like that of a rural settlement. The evolution of malaria prevalence and the factors sustaining the risk of transmission in Ouagadougou as well in many African cities during the dry season are discussed.
在布基纳法索瓦加杜古镇的旱季，经常记录到几例疟疾病例。这导致了一系列研究的设计，这些研究侧重于寄生虫学和昆虫学调查，旨在根据城市化方式提供有关当地疟疾传播风险的相关健康数据。
2006 年 4 月和 10 月，在瓦加杜古的各个区进行了横断面昆虫学调查。使用 CDC 诱捕器收集成年疟疾媒介，并在四个房屋内连续四天/夜进行室内杀虫剂喷洒。在整个研究地点，还对可用池塘进行了密集的幼虫采样。
4 月，按蚊滋生地仅由主要位于两个边缘区的半永久性或永久性沼泽组成。尽管这些滋生地存在按蚊幼虫，但通过 CDC 诱捕器和室内杀虫剂喷洒捕获的冈比亚按蚊属成虫不到 5 只。10 月，除了 4 月报告的永久性滋生地外，还发现一些降雨沼泽对按蚊呈阳性。成虫蚊子的数量高于 4 月（10 月 2 比 159）。4 月通过 PCR 分析的 115 只冈比亚按蚊属幼虫中，59.1%（68/115）鉴定为阿拉伯按蚊，39.1%（45/115）为冈比亚按蚊 M 型，而 S 型不到 2%。10 月通过 PCR 共鉴定出 120 只幼虫和 86 只雌蚊为冈比亚按蚊 M 型（51%）和阿拉伯按蚊（42.2%）。S 型仅占 6.8%。记录的总孢子率很高（6.8%），除了在中心区没有检测到阳性蚊子外，各区之间没有差异。
尽管在最干旱的月份只捕获了少量活跃的成年蚊子，但疟疾病媒全年都存在，增加了城市疟疾传播的风险。滋生地的分布，特别是疟疾媒介的出现，在外围地区更为丰富，更像是农村定居点。讨论了在旱季期间，瓦加杜古以及许多非洲城市的疟疾流行率演变和维持传播风险的因素。
