Thongrungkiat Supatra, Maneekan Pannamas, Wasinpiyamongkol Ladawan, Prummongkol Samrerng
Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400 Thailand.
J Vector Ecol. 2011 Jun;36(1):147-52. doi: 10.1111/j.1948-7134.2011.00151.x.
A prospective field study was conducted to determine transovarial dengue-virus transmission in two forms of Aedes aegypti mosquitoes in an urban district of Bangkok, Thailand. Immature Aedes mosquitoes were collected monthly for one year and reared continuously until adulthood in the laboratory. Mosquitoes assayed for dengue virus were processed in pools and their dengue virus infection status was determined by one-step RT-PCR and nested-PCR methods. Of a total 15,457 newly emerged adult Ae. aegypti, 98.2% were dark and 1.8% of the pale form. The results showed that the minimum infection rate (MIR) by transovarial transmission (TOT) of dengue virus during the one-year study ranged between 0 to 24.4/1,000 mosquitoes. Dengue virus TOT increased gradually during the hot summer months, reaching a peak in April-June, while dengue cases peaked in September, a rainy month near the end of the rainy season. Therefore, mosquito infections due to TOT were prevalent four months before a high incidence of human infections. TOT dengue virus infections occurred in both forms of Ae. aegypti. All four dengue serotypes were detected, with DEN-4 predominant, followed by DEN-3, DEN-1, and DEN-2, respectively.
在泰国曼谷的一个市区，开展了一项前瞻性现场研究，以确定登革病毒在两种埃及伊蚊中的经卵传播情况。连续一年每月收集未成熟的埃及伊蚊，并在实验室中持续饲养直至成年。对用于检测登革病毒的蚊子进行混合处理，并通过一步法逆转录聚合酶链反应（RT-PCR）和巢式PCR方法确定其登革病毒感染状况。在总共15457只新羽化的成年埃及伊蚊中，98.2%为深色型，1.8%为浅色型。结果表明，在为期一年的研究中，登革病毒经卵传播（TOT）的最低感染率（MIR）在0至24.4/1000只蚊子之间。登革病毒经卵传播在炎热的夏季月份逐渐增加，在4月至6月达到峰值，而登革热病例在9月达到峰值，9月是雨季接近尾声的一个多雨月份。因此，在人类感染高发前四个月，经卵传播导致的蚊子感染很普遍。两种埃及伊蚊均出现了经卵传播的登革病毒感染。检测到了所有四种登革热血清型，其中以DEN-4为主，其次分别为DEN-3、DEN-1和DEN-2。
