Faye O, Diallo M, Dia I, Ba Y, Faye O, Mondo M, Sylla R, Faye P C, Sall A A
Institut Pasteur de Dakar, 36 avenue Pasteur, BP 220, Dakar, Sénégal.
Bull Soc Pathol Exot. 2007 Aug;100(3):187-92.
The aim was to undertake a pilot study of integrated surveillance of yellow fever (YF) in Senegal, based on i) a human surveillance involving healthcare centers in the 11 administrative regions of the country ii) an entomological surveillance including domestic and sylvatic environment and iii) screening mosquitoes for YF virus using RT-PCR method. The integrated approach of human and entomological surveillance was conducted for 2 years (2003-2004). Surveillance in human population was based on screening samples of YF suspected cases (i.e. patients with acute (< or = 15 days) febrile illness with jaundice) for YF specific IgM antibodies. The entomological surveillance was carried out by collecting mosquitoes using human landing catch method and attempt to detect YF virus on them by RT-PCR. Forty five percent of the healthcare centres notified at least one suspected YF case during 2003-2004 periods. Among the 342 sera collected over 2 years, 2 revealed anti-YF IgM antibodies leading to investigations which allowed identification of the source and place of infection and implementation of a reactive focused YF immunization campaign. In addition, YFV was detected by RT-PCR from 49 out of 1762 mosquitoes tested and distributed as follows: in the sylvatic environment, 29 from Aedes furcifer and 1 from Aedes aegypti while in the domestic area, 15 Aedes aegypti and 4 Aedes furcifer. RT-PCR was found more sensitive and rapid than viral isolation for YF virus detection in mosquitoes. The pilot study in Senegal for YF surveillance integrating human and entomological parameters in domestic and sylvatic areas showed that this approach is very efficient in detecting yellow fever virus circulation due to the complementarity of the two systems. Therefore, in the light of the encouraging results presented herein, similar studies in different context and areas are needed to further validate and allow the extension of its application to other endemic regions of Africa.
目的是在塞内加尔开展一项黄热病综合监测试点研究，该研究基于：i）涉及该国11个行政区医疗中心的人类监测；ii）包括家庭和丛林环境的昆虫学监测；iii）使用逆转录聚合酶链反应（RT-PCR）方法对蚊子进行黄热病病毒筛查。人类和昆虫学监测的综合方法持续了2年（2003 - 2004年）。人群监测基于对黄热病疑似病例（即患有急性（≤15天）发热性疾病并伴有黄疸的患者）样本进行黄热病特异性IgM抗体筛查。昆虫学监测通过人饵诱捕法收集蚊子，并尝试通过RT-PCR检测其上的黄热病病毒。在2003 - 2004年期间，45%的医疗中心报告了至少1例黄热病疑似病例。在两年内收集的342份血清中，有2份检测出抗黄热病IgM抗体，从而开展了调查，得以确定感染源和感染地点，并实施了针对性的黄热病应急免疫接种活动。此外，在1762只检测蚊子中，有49只通过RT-PCR检测出黄热病病毒，分布如下：在丛林环境中，29只来自叉尾伊蚊，1只来自埃及伊蚊；在家庭区域，15只来自埃及伊蚊，4只来自叉尾伊蚊。发现RT-PCR在检测蚊子中的黄热病病毒方面比病毒分离更灵敏、快速。在塞内加尔开展的将人类和昆虫学参数纳入家庭和丛林区域的黄热病监测试点研究表明，由于这两个系统的互补性，该方法在检测黄热病病毒传播方面非常有效。因此，鉴于本文呈现的令人鼓舞的结果，需要在不同背景和地区开展类似研究，以进一步验证并将其应用扩展到非洲其他流行地区。
