Seroprevalence of Dengue Antibodies in One- to Nine-Year-Old Children after an Outbreak, Aguilares, Tucumán 2009

Abstract

INTRODUCTION: The 2009 dengue outbreak became the first with autochthonous cases in Tucumán. The departments of Río Chico and Capital were the most affected ones. There was low incidence in one- to nine-year-old children (2.6/1000). This finding led to a study to know the real impact of the outbreak on children. OBJECTIVE: To estimate dengue incidence in one- to nine-year-old children. METHODS: A cross-sectional seroprevalence (IgG) study was carried out in July 2009 in Aguilares (Department of Río Chico), with a probability sample composed by one- to nine-year-old children who had lived there in the last six months. Exclusion criteria were: uninhabited home, refusal to participate or seriously ill child. The laboratory study consisted of a plaque reduction neutralization test. RESULTS: A total of 118 samples were obtained. There were 18 refusals to participate. 24% (28/118) of the children had a fever or other symptoms compatible with dengue. Seven children had a positive test result; one of them showed slight symptoms, while the remaining ones had no symptoms at all. None of the positive cases were reported to the vigilance system. One had contact with a family member with symptoms. CONCLUSIONS: In one- to nine-year-old children, the disease was generally asymptomatic. The incidence during an outbreak is higher than the cases reported to the vigilance system. These results become important in view of the approach necessary for children exposed to a second infection.