Ahid S M, Vasconcelos P S, Lourenço-de-Oliviera R
Departamento de Patologia, Universidade Estadual do Maranhão, 65054-970 São Luis, MA, Brasil.
Mem Inst Oswaldo Cruz. 2000 Nov-Dec;95(6):769-75. doi: 10.1590/s0074-02762000000600004.
The vector competence of Culex quinquefasciatus from five localities in Brazil to Dirofilaria immitis was evaluated experimentally. Females from each locality were fed on an infected dog ( approximately 6 microfilariae/microl blood). A sample of blood fed mosquitoes were dissected approximately 1 h after blood meal. These results demonstrated that all had ingested microfilariae (mean, 4.8 to 24.6 microfilariae/mosquito). Fifteen days after the infected blood meal, the infection and infective rates were low in all populations of Cx. quinquefasciatus. The mean number of infective larvae detected in the head and proboscis of these mosquitoes was 1-1.5. The vector efficiency, the number of microfilariae ingested/number of infective larvae, was low for all populations of Cx. quinquefasciatus. However, the survival rate for all populations was high (range 50-75%). The survival rate of Aedes aegypti assayed simultaneously for comparison was low (24.7%), while the vector efficiency was much higher than for Cx. quinquefasciatus. These data suggest that the vector competence of all assayed populations of Cx. quinquefasciatus to D. immitis in Brazil is similar and that this species is a secondary vector due to its low susceptibility. Nevertheless, vector capacity may vary between populations due to differences in biting frequency on dogs that has been reported in Brazil.
对来自巴西五个地区的致倦库蚊针对犬恶丝虫的媒介能力进行了实验评估。每个地区的雌性致倦库蚊叮咬一只感染犬（每微升血液中约有6条微丝蚴）。在饱血后约1小时解剖一部分饱血的蚊子。这些结果表明，所有蚊子都摄取了微丝蚴（平均每只蚊子摄取4.8至24.6条微丝蚴）。在感染性饱血15天后，所有致倦库蚊种群的感染率和感染性率都很低。在这些蚊子的头部和喙部检测到的感染性幼虫平均数量为1 - 1.5条。致倦库蚊所有种群的媒介效率，即摄取的微丝蚴数量/感染性幼虫数量，都很低。然而，所有种群的存活率都很高（范围为50 - 75%）。同时进行检测用于比较的埃及伊蚊的存活率很低（24.7%），而其媒介效率远高于致倦库蚊。这些数据表明，巴西所有检测的致倦库蚊种群针对犬恶丝虫的媒介能力相似，并且由于其低易感性，该物种是次要媒介。尽管如此，由于巴西报道的不同种群对犬叮咬频率的差异，媒介能力可能在不同种群间有所不同。
