Dengue seroprevalence in a cohort of schoolchildren and their siblings in Yucatan, Mexico (2015-2016)

Abstract

BackgroundThe implementation of vector control interventions and potential introduction new tools requires baseline data to evaluate their direct and indirect effects. The objective of the study is to present the seroprevalence of dengue infection in a cohort of children 0 to 15 years old followed during 2015 to 2016, the risk factors and the role of enhanced surveillance strategies in three urban sites (Merida, Ticul and Progreso) in Yucatan, Mexico.MethodsA cohort of school children and their family members was randomly selected in three urban areas with different demographic, social conditions and levels of transmission. We included results from 1,844 children aged 0 to 15 years. Serum samples were tested for IgG, NS1 and IgM. Enhanced surveillance strategies were established in schools (absenteeism) and cohort families (toll-free number).ResultsSeroprevalence in children 0 to 15 years old was 46.8 (CI 95% 44.1–49.6) with no difference by sex except in Ticul. Prevalence increased with age and was significantly lower in 0 to 5 years old (26.9%, 95% CI:18.4–35.4) compared with 6 to 8 years old (43.9%, 95% CI:40.1–47.7) and 9 to 15 years old (61.4%, 95% CI:58.0–64.8). Sharing the domestic space with other families increased the risk 1.7 times over the individual families that own or rented their house, while risk was significantly higher when kitchen and bathroom were outside. Complete protection with screens in doors and windows decreased risk of infection. Seroprevalence was significantly higher in the medium and high risk areas.ConclusionsThe prevalence of antibodies in children 0 to 15 years in three urban settings in the state of Yucatan describe the high exposure and the heterogenous transmission of dengue virus by risk areas and between schools in the study sites. The enhanced surveillance strategy was useful to improve detection of dengue cases with the coincident transmission of chikungunya and Zika viruses.

Peer Review #2 of "Characterization of dengue cases among patients with an acute illness, Central Department, Paraguay (v0.1)"

“…Manuscript to be reviewed Dengue cases were less likely to report living in a house or apartment (recorded as "other" in the study questionnaire). This was also observed in a seroprevalence study in Mexico where these patients reported a "shared" living arrangement (Pavia-Ruz et al 2018). Other aspects of the home environment evaluated in our study did not differ between dengue and non-dengue cases.…”

“…The absence of air conditioning and window screens did not appear to increase the risk for DENV infection. However, complete screening of the home and air conditioning have been associated with decreased vector indices and dengue incidence in other settings (Manrique-Saide et al 2015;Pavia-Ruz et al 2018;Reiter et al 2003;Waterman et al 1985), and the addition of screens has been proposed as a means of DENV control through improvements to the built environment (Lindsay et al 2017;Vazquez-Prokopec et al 2016). Our findings may indicate that patients acquired DENV outside the home or that the use of these interventions is incomplete (e.g.…”

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

“…The incidence of symptomatic dengue infections observed during the same period was 3.5 cases per 1000 person-years (95% CI 1.9, 5.9). The majority of seroconversions occurred in the younger age groups (≤ 14 years old) [37][38][39]. 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].…”

“…ABV transmission in Merida is seasonal, beginning in July and peaking in October-November. Baseline serological information (captured by ELISA methods) on natural ABV infection rates has been collected from Merida in 2015-2016 through a school-based cohort that followed all family members living in the same household as the enrolled children [37][38][39]. In 2015, DENV seroprevalence in the cohort was 70.2%, which increased with age from 31% in 0-8-year-olds to 79% in adults ≥ 20 years.…”

“…2). The previously conducted cohort study in Merida indicated that the majority of dengue-naïve infections and seroconversions occurred in children ≤ 14 years old [37][38][39]. By following children aged 2-15 years at enrollment, we will capture the segment of the population with the highest probability of ABV illness.…”