Dengue virus infections and maternal antibody decay in a prospective birth cohort study of Vietnamese infants
Chau, T.N.B.; Hieu, N.T.; Anders, K.L.; Wolbers, M.; Lien, L.B.; Hieu, L.T.M.; Hien, T.T.; Hung, N.T.; Farrar, J.; Whitehead, S.; Simmons, C.P.
Journal of Infectious Diseases 200(12): 1893-1900
2009
ISSN/ISBN: 1537-6613 PMID: 19911991 DOI: 10.1086/648407Document Number: 212113
Dengue hemorrhagic fever can occur in primary dengue virus (DENV) infection of infants. The decay of maternally derived DENV immunoglobulin (Ig) G and the incidence of DENV infection were determined in a prospectively studied cohort of 1244 Vietnamese infants. Higher concentrations of total IgG and DENV-reactive IgG were found in cord plasma relative to maternal plasma. Maternally derived DENV-neutralizing and E protein-reactive IgG titers declined to below measurable levels in >90% of infants by 6 months of age. In contrast, IgG reactive with whole DENV virions persisted until 12 months of age in 20% of infants. Serological surveillance identified 10 infants with asymptomatic DENV infection for an incidence of 1.7 cases per 100 person-years. DENV-neutralizing antibodies remained measurable for > or = 1 year after infection. These results suggest that whereas DENV infection in infants is frequently subclinical, there is a window between 4 and 12 months of age where virion-binding but nonneutralizing IgG could facilitate antibody-dependent enhancement.