Mourya D T, Basu A, Barde P V, Sapkal G N, Padbidri V S, Gore M M
National Institute of Virology, Pune, India.
Acta Virol. 2001 Apr;45(2):67-71.
Isofemale lines of Aedes aegypti mosquitoes highly and lowly susceptible to dengue type 2 (DEN-2) virus (DEN(h) and DEN(l), respectively) were established by oral feeding and individual rearing. The susceptibility at F13 generation was found to be 61% and 25% for the DEN(h) and DEN(l) line, respectively. The virus-infected mosquito females were allowed to probe on bovine albumin phosphate saline pH 7.2 (BAPS) through membrane feeders. The presence of virus in the probed BAPS was determined either by ELISA or by intrathoracic (i.t.) inoculation of mosquitoes or by both methods. The rate of oral transmission of virus was found to be 2 times higher in the DEN(h) isofemale line than in the DEN(l) one. Similarly, vertical transmission rate of the virus was found to be 7 times higher in the DEN(h) line. When batches of eggs obtained from infected female mosquitoes were allowed to hatch after two months the vertical transmission rate of the virus was very high. It is possible that, at room temperature, the virus gets an opportunity to multiply and increase its copy number in the quiescent embryos. The progeny obtained from the infected mosquitoes was found to be capable of transmitting the virus horizontally when allowed to probe on BAPS through the membrane feeder. This is the first report demonstrating horizontal transmission of DEN-2 virus by mosquitoes infected through vertical transmission. The higher vertical transmission rate of the virus in the progeny obtained from the eggs dessicated for a longer time and the horizontal transmission of the virus from the progeny is of very high epidemiological significance.
通过口服感染和个体饲养建立了对登革热2型（DEN - 2）病毒高度易感和低度易感的埃及伊蚊同雌系（分别为DEN(h)和DEN(l)）。在F13代时，发现DEN(h)系和DEN(l)系的易感性分别为61%和25%。让感染病毒的雌蚊通过膜饲器在pH 7.2的牛白蛋白磷酸盐缓冲液（BAPS）上刺吸。通过ELISA或对蚊子进行胸腔内（i.t.）接种或两种方法同时使用来确定被刺吸的BAPS中是否存在病毒。发现病毒的经口传播率在DEN(h)同雌系中比在DEN(l)同雌系中高2倍。同样，病毒的垂直传播率在DEN(h)系中高7倍。当从感染雌蚊获得的卵批次在两个月后孵化时，病毒的垂直传播率非常高。有可能在室温下，病毒有机会在静止的胚胎中繁殖并增加其拷贝数。发现从感染蚊子获得的子代在通过膜饲器在BAPS上刺吸时能够水平传播病毒。这是第一份证明通过垂直传播感染的蚊子水平传播DEN - 2病毒的报告。从长时间干燥的卵获得的子代中病毒较高的垂直传播率以及子代的病毒水平传播具有非常高的流行病学意义。
