Incidence of dengue illness in Mexican people aged 6 months to 50 years old: A prospective cohort study conducted in Jalisco.

Rodrigo DeAntonio,Melanie de Boer,Silvia Damaso,Gloria Huerta,Gabriela Ibarra‐Nieto,Adrienne Guignard,Gerardo Amaya‐Tapia,Humberto Lanz-Mendoza

doi:10.1371/journal.pone.0250253

Abstract

The burden of dengue virus (DENV), a mosquito-borne pathogen, remains difficult to assess due to misdiagnosis and underreporting. Moreover, the large proportion of asymptomatic dengue cases impairs comprehensive assessment of its epidemiology even where effective surveillance systems are in place. We conducted a prospective community-based study to assess the incidence of symptomatic dengue cases in Zapopan and neighboring municipalities in the state of Jalisco, Mexico. Healthy subjects aged 6 months to 50 years living in households located in the Zapopan and neighboring municipalities were enrolled for a 24-month follow-up study (NCT02766088). Serostatus was determined at enrolment and weekly contacts were conducted via phone calls and home visits. Participants had to report any febrile episode lasting for at least two days. Suspected dengue cases were tested by reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR), detection of non-structural protein 1 (NS1), anti-DENV immunoglobulin G and M (IgG and IgM) assays. A total of 350 individuals from 87 households were enrolled. The overall seroprevalence of anti-DENV IgG at enrolment was 19.4% (95% confidence interval [CI] 14.5-25.6) with the highest seroprevalence rate observed in the adult group. Over the 27-month study period from July 2016 to September 2018, a total of 18 suspected dengue cases were reported. Four cases were confirmed by RT-qPCR and serotyped as DENV-1. A fifth case was confirmed by the NS1 assay. The 13 remaining suspected cases were tested negative by these assays. Based on the 5 virologically confirmed cases, symptomatic dengue incidence proportion of 1.4% (95%CI 0.5-3.8) was estimated. No severe cases or hospitalizations occurred during the study. Community-based active surveillance was shown as efficient to detect symptomatic dengue cases. NCT02766088.

Highlights

Suspected dengue cases were tested by reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR), detection of non-structural protein 1 (NS1), anti-dengue virus (DENV) immunoglobulin G and M (IgG and immunoglobulin M (IgM)) assays
The overall seroprevalence of anti-DENV IgG at enrolment was 19.4% (95% confidence interval [CI] 14.5–25.6) with the highest seroprevalence rate observed in the adult group
Four cases were confirmed by RT-qPCR and serotyped as DENV-1

Summary

Introduction

Dengue is a viral disease caused by four types of dengue viruses (DENV-1, DENV-2, DENV-3, and DENV-4) [1] that are transmitted by mosquito vectors, being primarily Aedes aegypti and secondarily Aedes albopictus [2, 3]. Most dengue infections are asymptomatic, clinical manifestations can range from febrile illness to potentially fatal dengue shock syndrome [2, 5, 6]. Most patients recover from the hemorrhagic episode, though the disease can progress to potentially fatal dengue shock syndrome, severe bleeding or organ failure [6]. The large proportion of asymptomatic dengue cases impairs comprehensive assessment of its epidemiology even where effective surveillance systems are in place. We conducted a prospective community-based study to assess the incidence of symptomatic dengue cases in Zapopan and neighboring municipalities in the state of Jalisco, Mexico

Methods

Results

Conclusion