Gingrich J B, Nisalak A, Latendresse J R, Sattabongkot J, Hoke C H, Pomsdhit J, Chantalakana C, Satayaphanta C, Uechiewcharnkit K, Innis B L
U.S. Army Medical Component, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
J Med Entomol. 1992 May;29(3):436-44. doi: 10.1093/jmedent/29.3.436.
An unexpected outbreak of Japanese encephalitis (JE) in Bangkok in 1985 led us to investigate the vector ecology of urban JE from January 1986 to June 1987 at three suburban sites that displayed a wide range of factors imputed to influence JE transmission. Culex tritaeniorhynchus Giles and Cx. gelidus Theobald, suspected vectors, comprised 71-96% of all mosquitoes collected by CO2-baited CDC traps at the three sites. Mean of mosquito abundance per two trap-nights per month ranged from 28 to 5,728 mosquitoes at the sites of lowest and highest abundance, respectively. Cx. tritaeniorhynchus yielded more JE isolates (n = 16) than Cx. gelidus (n = 7), but the minimum infection rates of the two species (number of JE isolates per 1,000 mosquitoes tested; MIR, 0.17 and 0.47, respectively) were comparable and covaried with vector abundance. Moreover, the proportion of sentinel pigs that had JE antibodies generally increased proportionately with vector abundance at the sites. Vector abundance was high in monsoon (May-October), moderate in transition (March-April and November-December), and low in dry (January-February) seasons. Mosquitoes collected in monsoon seasons yielded 96% of the JE isolates, whereas 4 and 0% of the isolates were obtained from transition and dry season collections, respectively. More pigs seroconverted in monsoon and transition seasons than in dry seasons. Indices of JE transmission activity (vector abundance, pig seroconversions, and MIRs) increased proportionately with rainfall. Despite higher indices at the site of greatest vector abundance than elsewhere, the risk of human infection appeared greatest at the site with moderate vector abundance because of its greatest human population density.
1985年曼谷意外爆发日本脑炎（JE），促使我们于1986年1月至1987年6月在三个郊区地点调查城市JE的病媒生态学，这些地点展现出一系列被认为会影响JE传播的因素。三带喙库蚊（Culex tritaeniorhynchus Giles）和杰氏库蚊（Cx. gelidus Theobald）这两种疑似病媒，占三个地点用二氧化碳诱捕的疾控中心诱捕器捕获的所有蚊子的71%-96%。在蚊子数量最少和最多的地点，每月每两个诱捕夜的蚊子平均丰度分别为28只至5728只。三带喙库蚊分离出的JE毒株（n = 16）比杰氏库蚊（n = 7）多，但这两种蚊子的最低感染率（每1000只检测蚊子中的JE分离株数量；MIR分别为0.17和0.47）相当，且与病媒丰度共同变化。此外，有JE抗体的哨兵猪的比例通常在各地点随病媒丰度成比例增加。病媒丰度在季风季节（5月至10月）较高，过渡季节（3月至4月和11月至12月）适中，旱季（1月至2月）较低。在季风季节捕获的蚊子分离出了96%的JE毒株，而分别有4%和0%的毒株是从过渡季节和旱季的捕获物中获得的。在季风和过渡季节血清转化的猪比旱季更多。JE传播活动指数（病媒丰度、猪血清转化和MIR）随降雨量成比例增加。尽管病媒丰度最高的地点的指数高于其他地方，但由于人口密度最大，人类感染风险似乎在病媒丰度适中的地点最大。
