Identifying the role of household immunity in driving individual dengue virus infection risk

Dengue virus (DENV) infection risk is known to vary substantially, even across small communities, with infections in and around the home driving transmission. However, It remains unclear how the immune status of an individual or household dictate this risk in part due to transmission being dominated by subclinical infections. In this study, we used demographic, household characteristic, and serological data from a multigenerational cohort study of 2860 individuals from 470 households in Kamphaeng Phet, Thailand, to determine the incidence and risk factors for DENV infections. We used hemagglutination inhibition (HAI) antibody titers measured in sequential serum samples to identify subclinical infections through a gradient boosted regression model. This approach identified ∼10% more cases than commonly used methods with approximately 90% of all infections being subclinical. As expected, we found that having higher DENV antibody titers was protective against infection. Individuals were additionally protected if other household members had higher titers suggesting that there are indirect effects of household immunity on the individuals found within a household. Our study provides a framework for inferring subclinical infections and characterizing the epidemiology of DENV infection in households.