Guedes D R D, Cordeiro M T, Melo-Santos M A V, Magalhaes T, Marques E, Regis L, Furtado A F, Ayres C F J
Departamento de Entomologia, Centro de Pesquisas Aggeu Magalhães/Fundação Oswaldo Cruz (CPqAM/FIOCRUZ), Av. Professor Moraes Rego s/n, Cidade Universitária, Recife PE, Brazil.
J Vector Borne Dis. 2010 Jun;47(2):67-75.
BACKGROUND & OBJECTIVES: Dengue is currently one of the most important arthropod-borne diseases and may be caused by four different dengue virus serotypes (DENV-1 to DENV-4), transmitted mainly by Aedes aegypti (Diptera: Culicidae) mosquitoes. With the lack of a dengue vaccine, vector control strategies constitute a crucial mode to prevent or reduce disease transmission. In this context, DENV detection in natural Ae. aegypti populations may serve as a potential additional tool for early prediction systems of dengue outbreaks, leading to an intensification of vector control measures, aimed at reducing disease transmission. In Brazil, this type of surveillance has been performed sporadically by a few groups and has not been incorporated as a routine activity in control programs. This study aimed at detecting DENV in natural Ae. aegypti from Recife, Pernambuco, to check the circulating serotypes and the occurrence of transovarial transmission in local mosquito populations.
From January 2005 to June 2006, mosquitoes (adults and eggs) were collected in houses where people with clinical suspicion of dengue infection lived at. RNA was extracted from pooled mosquitoes and RT-PCR was performed in these samples for detection of the four DENV serotypes.
RESULTS & CONCLUSION: Out of 83 pools of adult mosquitoes collected in the field, nine were positive for DENV: five for DENV-1, two for DENV-2 and two for DENV-3. From 139 pools of adult mosquitoes reared from collected eggs, there were 17 positive pools: three for DENV-1, 10 for DENV-2, and four for DENV-3. These results are discussed in the paper in regard to the local dengue epidemiological data. The conclusions clearly point to the informative power and sensitivity of DENV entomological surveillance and to the importance of including mosquito immature forms in this strategy.
登革热是目前最重要的节肢动物传播疾病之一，可由四种不同的登革病毒血清型（DENV-1至DENV-4）引起，主要通过埃及伊蚊（双翅目：蚊科）传播。由于缺乏登革热疫苗，病媒控制策略是预防或减少疾病传播的关键方式。在此背景下，在自然环境中的埃及伊蚊种群中检测登革病毒可作为登革热疫情早期预测系统的潜在附加工具，从而加强病媒控制措施，以减少疾病传播。在巴西，此类监测由少数研究团队偶尔开展，尚未纳入控制项目的常规活动。本研究旨在检测累西腓市（伯南布哥州）自然环境中的埃及伊蚊体内的登革病毒，以检查当地蚊群中传播的血清型以及经卵传递的情况。
2005年1月至2006年6月，在临床怀疑有登革热感染的人员居住的房屋中收集蚊子（成蚊和蚊卵）。从合并的蚊子样本中提取RNA，并对这些样本进行逆转录聚合酶链反应，以检测四种登革病毒血清型。
在野外采集的83组成蚊样本中，有9组登革病毒呈阳性：5组为DENV-1，2组为DENV-2，2组为DENV-3。从收集的蚊卵孵化饲养的139组成蚊样本中，有17组呈阳性：3组为DENV-1，10组为DENV-2，4组为DENV-3。本文结合当地登革热流行病学数据对这些结果进行了讨论。结论明确指出了登革病毒昆虫学监测的信息价值和敏感性，以及在该策略中纳入蚊幼体的重要性。
