Estudo: armadilhas contra mosquitos reduziram pela metade as infecções de Zika em comunidades

The CDC's Emerging Infectious Diseases journal published in volume 32, issue 4 (April 2026), a community assessment on autocidal ovitraps (AGO) to reduce Zika virus infection in Puerto Rico. The work, led from the CDC's Dengue Branch in San Juan, compares four communities in Salinas and Guayama and provides concrete figures of human seroprevalence, not just mosquito counts.

El artículo recuerda que el brote de Zika de 2016 infectó aproximadamente el 26% de la población en Puerto Rico y que Aedes aegypti sigue siendo el vector principal de dengue, chikungunya y Zika en el Caribe. Aunque no se han reportado infecciones confirmadas de Zika en la isla desde 2019, el texto enlaza el riesgo residual con el brote de dengue de 2024 —el primero en más de una década— con más de 6,000 casos confirmados y 11 muertes. Esa coyuntura, dice el CDC, refuerza la necesidad de herramientas de control vectorial sostenibles y sin pesticidas.

In the design, two intervention communities (La Margarita and Villodas) maintained AGO deployment from 2011–2013 with coverage close to 85% of households; each house received three traps, checked every two months. Two communities without AGO (Arboleda and La Playa) served for comparison. In 2015, Salinas had 30,114 inhabitants and Guayama 43,700, with densities of 434 to 672 people per square mile. The four communities were semi-urban, with households averaging 2.6 to 3.6 people and water and garbage collection services.

The serological survey was conducted between March and May 2017, about six to nine months after the peak of Zika transmission in August 2016. A total of 330 people from 242 households participated; after excluding indeterminate results and IgM-positive dengue cases, the primary analysis included 271 participants (82.1%) from 208 households. All were over five years old and had slept in the home at least four of the previous seven days.

The central finding: recent Zika seroprevalence of 14.8% in the whole group (40 of 271). In communities with AGO it was 9.6% (13 of 136); in those without AGO, 20.0% (27 of 135). The crude prevalence ratio was 0.48 (95% CI 0.26–0.89) and the one adjusted for age, sex, and time spent at home, 0.49 (95% CI 0.27–0.90). In other words, living in an area with traps was associated with approximately half of the seroprevalence observed in areas without traps.

The protective effect was more pronounced in adults over 60 years old (5.1% versus 23.3%; aPR 0.22), in households with more than four people, and in those who spent more than 61 hours per week at home (5.1% versus 22.0%). It also decreased among those who kept windows or doors open (6.5% versus 24.0%). In the intervention, 77.2% of participants reported perceiving fewer mosquitoes at home thanks to the AGO.

In parallel, the average weekly abundance of Ae. aegypti per surveillance trap between January 2016 and May 2017 was 1.40 mosquitoes in the intervention group versus 9.98 in the non-intervention group. Adjusted Poisson models linked higher mosquito abundance with a higher probability of seropositivity. The study is not randomized and has limitations —sampling months after the peak, possible underestimation due to IgM decline—, but it emphasizes that AGOs are a viable community tool against insecticide resistance.

For borinquenmade.blog, the institutional PEG is clear: the CDC does not announce a new grant here, but peer-reviewed evidence of vector control in PR. 'Obliged' does not appear; what does appear is impact on human infection. This note replaces an EPA Federal Register notice already used by another journalist in the same batch; the primary URL remains unique within the batch Sep 3–16.

The date of the note in the batch is 2026-09-09, within the board's 14-day window, while the EID article has a volume date of April 2026. This is a durable institutional primary from the CDC, not a note invented that day. Whoever wants the 2024 dengue thread can cross-reference it with the MMWR already archived in 802; whoever wants the 2016 vector unit, with the CDC archive of 803. Here the new contribution is the measurement of human seroprevalence under AGO.