Laboratorio de Arbovirus, Instituto de Virología "Dr. J. M. Vanella", Facultad de Medicina, Universidad Nacional de Córdoba, Córdoba, Argentina.
Instituto de Investigaciones Biológicas y Tecnológicas, CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina.
Med Vet Entomol. 2024 Jun;38(2):234-243. doi: 10.1111/mve.12712. Epub 2024 Mar 15.
Mayaro virus (MAYV; Alphavirus: Togaviridae) is an emerging pathogen in Latin America, causing fever and polyarthritis. Sporadic outbreaks of MAYV have occurred in the region, with reported human cases being imported to Europe and North America. Although primarily a risk for those residing in the Amazon basin's tropical forests, recent reports highlight that urbanization would increase the risk of MAYV transmission in Latin America. Urban emergence depends on human susceptibility and the ability of mosquitos like Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae) to transmit MAYV. Despite the absence of active MAYV transmission in Argentine, the risk of introduction is substantial due to human movement and the presence of Ae. aegypti in the region. This study aimed to evaluate the susceptibility of different Argentine Ae. aegypti populations to MAYV genotype L (MAYV-L) using dose-response assays and determine barriers to virus infection, dissemination and transmission. Immature mosquito stages were collected in Buenos Aires, Córdoba and Rosario cities. Female Ae. aegypti (F2) were orally infected by feeding on five concentrations of MAYV-L, ranging from 1.0 to 6.0 log PFU/mL. Abdomens, legs and saliva were analysed using viral plaque assays. Results revealed that MAYV-L between infection and dissemination were associated with viral doses rather than the population origin. Infection rates varied between 3% and 65%, with a 50% infectious dose >5.5 log PFU/mL. Dissemination occurred at 39%, with a 50% dissemination dose of ~6.0 log PFU/mL. Dissemination among infected mosquitoes ranged from 60% to 86%, and transmission from disseminated mosquitoes ranged from 11% to 20%. Argentine Ae. aegypti populations exhibited a need for higher viral doses of MAYV-L than those typically found in humans to become infected. In addition, only a small proportion of infected mosquitoes were capable of transmitting the virus. Understanding MAYV transmission in urban areas is crucial for public health interventions.
玛雅罗病毒（MAYV；甲病毒科：披膜病毒科）是拉丁美洲一种新兴的病原体，可引起发热和多发性关节炎。该地区已发生散发性 MAYV 暴发，据报道，输入欧洲和北美的人类病例。尽管主要风险是居住在亚马逊流域热带森林中的人群，但最近的报告强调，城市化会增加拉丁美洲 MAYV 传播的风险。城市出现取决于人类易感性和埃及伊蚊（Linnaeus，1762）（双翅目：蚊科）传播 MAYV 的能力。尽管阿根廷没有活跃的 MAYV 传播，但由于人类的流动和该地区埃及伊蚊的存在，引入该病毒的风险仍然很大。本研究旨在使用剂量反应测定法评估不同阿根廷埃及伊蚊种群对 MAYV 基因型 L（MAYV-L）的易感性，并确定病毒感染、传播和传播的障碍。在布宜诺斯艾利斯、科尔多瓦和罗萨里奥市收集了幼蚊阶段。通过喂食五种浓度的 MAYV-L（范围为 1.0 至 6.0 log PFU/mL）对雌性埃及伊蚊（F2）进行经口感染。使用病毒噬斑测定法分析了腹部、腿部和唾液。结果表明，MAYV-L 从感染到传播与病毒剂量有关，而与种群来源无关。感染率在 3%至 65%之间，50%感染剂量>5.5 log PFU/mL。传播发生率为 39%，50%传播剂量约为 6.0 log PFU/mL。感染蚊子中的传播率为 60%至 86%，从传播蚊子中的传播率为 11%至 20%。阿根廷埃及伊蚊种群需要更高剂量的 MAYV-L 才能感染，而不是通常在人类中发现的剂量。此外，只有一小部分感染蚊子能够传播病毒。了解城市地区的 MAYV 传播对公共卫生干预措施至关重要。
