Dengue virus serological prevalence and seroconversion rates in children and adults in Medellin, Colombia: implications for vaccine introduction

Mabel Carabali,Jacqueline Kyungah Lim,Diana Carolina Velez,Andrea Trujillo,Jorge Egurrola,Kang Sung Lee,Jay S Kaufman,Luiz Jacinto Dasilva,Ivan Dario Velez,Jorge E Osorio

doi:10.1016/j.ijid.2017.02.016

Abstract

Dengue is an important public health problem worldwide. A vaccine has recently been licensed in some countries of Latin America and Asia. Recommendations for dengue vaccine introduction include endemicity and a high serological prevalence of dengue in the territories considering its introduction. A community-based survey was conducted to estimate dengue seroprevalence and age-specific seroconversion rates in a community in Medellin, Colombia, using a dengue serological test (IgG indirect ELISA). Residents were selected at random and were first screened for dengue infection; they were then followed over 2.5 years. A total of 3684 individuals aged between 1 and 65 years participated in at least one survey. The overall dengue seroprevalence was 61%, and only 3.3% of seropositive subjects self-reported a past history of dengue. Among dengue virus (DENV)-naïve subjects with more than two visits (n=1002), the overall seroconversion rate was 8.7% (95% confidence interval 7.3-10.4) per 1000 person-months, over the study period. Overall, the mean age of DENV prevalent subjects was significantly higher than the mean age of seroconverted subjects. Specifically, DENV seropositivity over 70% was observed in participants over 21 years old. Serotype-specific plaque-reduction neutralization tests (PRNT) revealed that all four dengue serotypes were circulating, with DENV4 being most prevalent. These laboratory-based findings could inform dengue vaccine decisions, as they provide age-specific seroprevalence and seroconversion data, evidencing permanent and ongoing dengue transmission in the study area. This study provides evidence for the existing rates of secondary and heterotypic responses, presenting a challenge that must be addressed adequately by the new vaccine candidates.

Highlights

Dengue is considered a major cause of morbidity and mortality in tropical and sub-tropical countries.[1,2,3,4] It was estimated that in 2015, 79.6 million dengue cases occurred in 196 countries.[5](M
Written informed consent was obtained from adult participants and informed consent was obtained from the parents or legal guardians of minors, by a signature or thumbprint prior to blood collection
Similar findings have been reported in other Latin American settings,[25,26] a change in people’s awareness is foreseeable due to the increasing public health strategies in place to diagnose and control the infections transmitted by Aedes mosquitoes, for dengue virus (DENV) and Zika virus

Summary

Introduction

Dengue is considered a major cause of morbidity and mortality in tropical and sub-tropical countries.[1,2,3,4] It was estimated that in 2015, 79.6 million dengue cases occurred in 196 countries.[5](M. Dengue is considered a major cause of morbidity and mortality in tropical and sub-tropical countries.[1,2,3,4] It was estimated that in 2015, 79.6 million dengue cases occurred in 196 countries.[5]. The IgG antibodies may be found in serum at the end of the convalescent period (9–10 days) in primary infections, and may be detected earlier in the case of secondary infections. IgG is found at higher titers up to 30–40 days after infection, but may remain detectable for decades, which allows the identification of individuals who have been in contact with the virus.[4,9,10,11]

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Conclusion