背景:2016-18年期间,巴西再次出现黄热病疫情,死亡率高达30%。尽管自1942年以来没有城市传播的报道,但黄热病重新城市化的风险很大,由于埃及伊蚊存在于世界上大多数热带和亚热带城市中,并且仍然是城市YFV的主要媒介。尽管YFV疫苗是安全有效的,它并不总是到达感染风险最大的人群,而且公认的全球疫苗供应短缺。Wolbachia细菌渗入Ae。埃及伊蚊种群正在几个国家进行试验(www。worldsmovito.org)作为一种针对登革热的生物防治方法,寨卡和基孔肯雅。这里,我们研究了Wolbachia降低Ae传播潜力的能力。埃及伊蚊对黄热病病毒(YFV)。方法:使用两种最近分离的YFV(灵长类动物和人类)攻击田间来源的野生型和Wolbachia感染的(wMel)Ae。埃及伊蚊.口服喂养(dpf)后7、14和21天跟踪YFV感染状态。通过将唾液纳米注射到未感染的蚊子中或通过在小鼠中接种来评估蚊子的YFV传播潜力。结果:我们发现Wolbachia能够显着降低两种病毒分离株的YFV感染头部和胸部的蚊子的患病率。此外,分析蚊子的唾液,通过间接注射到幼稚的蚊子或通过干扰素缺乏的小鼠模型,表明Wolbachia与蚊子的YFV传播潜力(14dpf)的大大降低有关。结论:我们的结果表明,Wolbachia基因渗入可以用作预防城市黄热病传播的补充策略,以及人类疫苗接种计划。
Background: Yellow fever outbreaks have re-emerged in Brazil during 2016-18, with mortality rates up to 30%. Although urban transmission has not been reported since 1942, the risk of re-urbanization of yellow fever is significant, as Aedes aegypti is present in most tropical and sub-tropical cities in the World and still remains the main vector of urban YFV. Although the YFV vaccine is safe and effective, it does not always reach populations at greatest risk of infection and there is an acknowledged global shortage of vaccine supply. The introgression of Wolbachia bacteria into Ae. aegypti mosquito populations is being trialed in several countries ( www.worldmosquito.org) as a biocontrol method against dengue, Zika and chikungunya. Here, we studied the ability of Wolbachia to reduce the transmission potential of Ae. aegypti mosquitoes for Yellow fever virus (YFV). Methods: Two recently isolated YFV (primate and human) were used to challenge field-derived wild-type and Wolbachia-infected ( wMel +) Ae. aegypti mosquitoes. The YFV infection status was followed for 7, 14 and 21 days post-oral feeding (dpf). The YFV transmission potential of mosquitoes was evaluated via nano-injection of saliva into uninfected mosquitoes or by inoculation in mice. Results: We found that Wolbachia was able to significantly reduce the prevalence of mosquitoes with YFV infected heads and thoraces for both viral isolates. Furthermore, analyses of mosquito saliva, through indirect injection into naïve mosquitoes or via interferon-deficient mouse model, indicated Wolbachia was associated with profound reduction in the YFV transmission potential of mosquitoes (14dpf). Conclusions: Our results suggest that Wolbachia introgression could be used as a complementary strategy for prevention of urban yellow fever transmission, along with the human vaccination program.