Zika Virus Infection in Pregnant Women, Yucatan, Mexico

Romer, Yamila; Valadez-González, Nina; Contreras-Capetillo, Silvina; Manrique-Saide, Pablo; Vázquez-Prokopec, Gonzalo M.; Pavía-Ruz, Norma

doi:10.3201/eid2508.180915

Cited by 9 publications

(11 citation statements)

References 41 publications

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“…Zika was first recorded in the city in 2016 and was the most frequent Aedes -transmitted disease (78.4%) reported in Merida [ 32 ]. A cohort study conducted in pregnant woman at the same time of our study found ZIKV attack rates of ~30% [ 33 ], indicating high levels of virus transmission in Merida. Such high transmission was evidenced in the number of positive pools found within our study houses.…”

Section: Discussionmentioning

confidence: 65%

Insecticide-treated house screening protects against Zika-infected Aedes aegypti in Merida, Mexico

et al. 2021

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Background The integration of house-screening and long-lasting insecticidal nets, known as insecticide-treated screening (ITS), can provide simple, safe, and low-tech Aedes aegypti control. Cluster randomised controlled trials in two endemic localities for Ae. aegypti of south Mexico, showed that ITS conferred both, immediate and sustained (~2 yr) impact on indoor-female Ae. aegypti infestations. Such encouraging results require further validation with studies quantifying more epidemiologically-related endpoints, including arbovirus infection in Ae. aegypti. We evaluated the efficacy of protecting houses with ITS on Ae. aegypti infestation and arbovirus infection during a Zika outbreak in Merida, Yucatan, Mexico. Methodology/Principal findings A two-arm cluster-randomised controlled trial evaluated the entomological efficacy of ITS compared to the absence of ITS (with both arms able to receive routine arbovirus vector control) in the neighbourhood Juan Pablo II of Merida. Cross-sectional entomological surveys quantified indoor adult mosquito infestation and arbovirus infection at baseline (pre-ITS installation) and throughout two post-intervention (PI) surveys spaced at 6-month intervals corresponding to dry/rainy seasons over one year (2016–2017). Household-surveys assessed the social reception of the intervention. Houses with ITS were 79–85% less infested with Aedes females than control houses up to one-year PI. A similar significant trend was observed for blood-fed Ae. aegypti females (76–82%). Houses with ITS had significantly less infected female Ae. aegypti than controls during the peak of the epidemic (OR = 0.15, 95%CI: 0.08–0.29), an effect that was significant up to a year PI (OR = 0.24, 0.15–0.39). Communities strongly accepted the intervention, due to its perceived mode of action, the prevalent risk for Aedes-borne diseases in the area, and the positive feedback from neighbours receiving ITS. Conclusions/Significance We show evidence of the protective efficacy of ITS against an arboviral disease of major relevance, and discuss the relevance of our findings for intervention adoption.

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Section: Discussionmentioning

confidence: 65%

Insecticide-treated house screening protects against Zika-infected Aedes aegypti in Merida, Mexico

et al. 2021

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“…One of them is the urban one, in which humans (accidental hosts with high viremia) and mosquitoes of the Aedes genus (biological vectors and amplifying hosts) participate, thereby maintaining endemicity (Althouse et al, 2016). In this sense, in years following our sampling, infection rates with ZIKV have been reported in people from Merida (Romer et al, 2019) Considering this evidence, it can be inferred that some epidemiological elements (vectors and hots with viremia), necessary for ZIKV and other flaviviruses transmission to susceptible mammals (such as bats) are converging in Yucatan state (González-Salazar et al, 2017).…”

Section: Discussionmentioning

confidence: 87%

West Nile and Zika viruses in bats from a suburban area of Merida, Yucatan, Mexico

Torres–Castro

Noh-Pech

Hernández-Betancourt

et al. 2021

Zoonoses and Public Health

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With approximately 1,386 species distributed worldwide, bats (order Chiroptera) are the second most numerous and diverse mammalian taxon (Burgin et al., 2018). These animals are fundamental to the study of viruses with relevance to public health; however, their epidemiological role in the transmission cycles is unclear. The Flavivirus genus, which includes dengue (DENV 1-4), Zika (ZIKV) and West Nile (WNV) viruses, is one of the most studied viral genera in bats (Fagre & Kading, 2019).The Yucatan state is an area where some Flavivirus infect

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“…The incidence of symptomatic chikungunya illness was 8.6 per 1000 person-years (95% CI 5.8, 12.3) and the incidence rate of symptomatic Zika illness was 2.3 per 1000 person-years (95% CI 0.9, 4.5) [37]. Zika virus symptomatic attack rate in pregnant women from the cohort was 31% [40].…”

Section: Study Areamentioning

confidence: 92%

The TIRS trial: protocol for a cluster randomized controlled trial assessing the efficacy of preventive targeted indoor residual spraying to reduce Aedes-borne viral illnesses in Merida, Mexico

Manrique-Saide

Dean

Halloran

et al. 2020

Trials

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Background Current urban vector control strategies have failed to contain dengue epidemics and to prevent the global expansion of Aedes-borne viruses (ABVs: dengue, chikungunya, Zika). Part of the challenge in sustaining effective ABV control emerges from the paucity of evidence regarding the epidemiological impact of any Aedes control method. A strategy for which there is limited epidemiological evidence is targeted indoor residual spraying (TIRS). TIRS is a modification of classic malaria indoor residual spraying that accounts for Aedes aegypti resting behavior by applying residual insecticides on exposed lower sections of walls (< 1.5 m), under furniture, and on dark surfaces. Methods/design We are pursuing a two-arm, parallel, unblinded, cluster randomized controlled trial to quantify the overall efficacy of TIRS in reducing the burden of laboratory-confirmed ABV clinical disease (primary endpoint). The trial will be conducted in the city of Merida, Yucatan State, Mexico (population ~ 1million), where we will prospectively follow 4600 children aged 2–15 years at enrollment, distributed in 50 clusters of 5 × 5 city blocks each. Clusters will be randomly allocated (n = 25 per arm) using covariate-constrained randomization. A “fried egg” design will be followed, in which all blocks of the 5 × 5 cluster receive the intervention, but all sampling to evaluate the epidemiological and entomological endpoints will occur in the “yolk,” the center 3 × 3 city blocks of each cluster. TIRS will be implemented as a preventive application (~ 1–2 months prior to the beginning of the ABV season). Active monitoring for symptomatic ABV illness will occur through weekly household visits and enhanced surveillance. Annual sero-surveys will be performed after each transmission season and entomological evaluations of Ae. aegypti indoor abundance and ABV infection rates monthly during the period of active surveillance. Epidemiological and entomological evaluation will continue for up to three transmission seasons. Discussion The findings from this study will provide robust epidemiological evidence of the efficacy of TIRS in reducing ABV illness and infection. If efficacious, TIRS could drive a paradigm shift in Aedes control by considering Ae. aegypti behavior to guide residual insecticide applications and changing deployment to preemptive control (rather than in response to symptomatic cases), two major enhancements to existing practice. Trial registration ClinicalTrials.gov NCT04343521. Registered on 13 April 2020. The protocol also complies with the WHO International Clinical Trials Registry Platform (ICTRP) (Additional file 1). Primary sponsor National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIH/NIAID).

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Zika Virus Infection in Pregnant Women, Yucatan, Mexico

Abstract: Infection was associated with a high incidence of symptomatic disease but no congenital syndrome.

Cited by 9 publications

References 41 publications

Insecticide-treated house screening protects against Zika-infected Aedes aegypti in Merida, Mexico

Insecticide-treated house screening protects against Zika-infected Aedes aegypti in Merida, Mexico

West Nile and Zika viruses in bats from a suburban area of Merida, Yucatan, Mexico

The TIRS trial: protocol for a cluster randomized controlled trial assessing the efficacy of preventive targeted indoor residual spraying to reduce Aedes-borne viral illnesses in Merida, Mexico

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