What is the optimal In2Care stations density to achieve Aedes aegypti population reduction in a dengue endemic setting?

Background: Autodissemination traps are among the most innovative strategies for suppressing mosquito vector populations. These traps are particularly effective against Aedes aegypti due to the species' skip oviposition behavior, where eggs from a single clutch are distributed across multiple breeding sites. Evaluating the efficacy of In2Care stations under field conditions, especially in a dengue-endemic setting, is crucial for understanding their potential impact.Methodology/Principal Findings: A total of 3,250 In2Care stations were deployed in Goiânia, the 10th largest city in Brazil, with an estimated population of 1.45 million. The field study lasted 14 months, with each station serviced bi-monthly. To assess the impact of In2Care, 318 ovitraps were installed and inspected weekly to measure changes in the number of positive ovitraps and the average number of eggs laid by Ae. aegypti females in intervention areas compared to control neighborhoods. Over the course of the study, 666,204 eggs were sampled.Conclusions/Significance: The density of In2Care stations varied across neighborhoods, ranging from 220 to 555 stations per km². In the Tremendão area, which had the highest density (~555 stations per km²), the Ovitrap Positivity Index (OPI) decreased from 56.9% to 31.5%, while the average number of eggs per positive paddle dropped from 41.2 to 18.1—representing a 56% reduction in egg counts. Conversely, in SL Universitário, which had the lowest station density (~220 stations per km²), no significant effect was observed. These results demonstrate that In2Care stations can effectively suppress Ae. aegypti populations over large geographic areas, with efficacy likely influenced by trap density.

背景：自动散播诱捕器（autodissemination traps）是抑制蚊媒种群的创新性策略之一。这类诱捕器对埃及伊蚊（Aedes aegypti）尤为有效，因为该物种存在跳跃产卵行为——即单个卵块的卵会被分散到多个滋生地中。在野外条件下，尤其是登革热流行区域中评估In2Care诱杀站（In2Care）的防控效果，对明确其潜在应用价值至关重要。
研究方法与主要结果：本研究共在巴西第十大城市、预估人口145万的戈亚尼亚市（Goiânia）部署了3250台In2Care诱杀站。野外研究持续14个月，每两个月对每台诱杀站进行一次维护。为评估In2Care诱杀站的防控效果，研究人员设置了318个诱卵器（ovitraps）并每周开展巡查，以对比干预组街区与对照组街区的阳性诱卵器数量变化，以及埃及伊蚊雌蚊在诱卵器内的平均产卵量。本研究全程共采集到666204枚蚊卵。
结论与意义：各街区的In2Care诱杀站部署密度存在差异，范围为每平方公里220至555台。在部署密度最高（约每平方公里555台）的特雷门当（Tremendão）区域，诱卵器阳性指数（Ovitrap Positivity Index，OPI）从56.9%降至31.5%，单张阳性诱卵片的平均产卵量从41.2枚降至18.1枚，卵总数减少了56%。与之相反，在部署密度最低（约每平方公里220台）的SL大学区（SL Universitário），未观察到显著防控效果。上述结果表明，In2Care诱杀站可在较大地理范围内有效抑制埃及伊蚊（Aedes aegypti）种群，其防控效果大概率受诱捕器部署密度的影响。