Postnatal Zika and Dengue Infection and their Effects on Neurodevelopment Among Children Living in Rural Guatemala.

BACKGROUND

Prenatal Zika virus (ZIKV) infection leads to microcephaly and adverse neurodevelopment. The effects of postnatal ZIKV infection on the developing brain are unknown. We assessed the neurodevelopmental outcomes of children exposed postnatally during the ZIKV epidemic.

METHODS

A prospective study enrolled infants 0-3 months of age and their mothers, and children 1.5-3.5 years of age in rural Guatemala from 2017 and were followed for 12 months until 2019. Neurodevelopment was evaluated using the Mullen Scales of Early Learning (MSEL). ZIKV and dengue virus (DENV) infections were identified by polymerase chain reaction (PCR) using active surveillance. Serological analyses, stratified by age group flavivirus serostatus at enrollment, were conducted using a focus reduction neutralization test.

RESULTS

Of 1371 enrolled participants, 1187 (86.6%) completed the study. No PCR-confirmed ZIKV infections were identified during the study period. One-third of 1.5-3.5-year-old children were ZIKV-seropositive at enrollment (likely postnatal infection). Twenty participants (5.8%) tested positive for DENV by PCR (11 infants, 5 children and 4 mothers); 15 (75%) were DENV-3 infections and 5 were DENV-2. The incidence of DENV infection in infants was 2.6%. No significant differences in MSEL scores were found between infants born seropositive versus seronegative for ZIKV or DENV. DENV seropositivity at enrollment in 1.5-5-year-old children was associated with lower MSEL scores for fine motor, visual reception and language, and microcephaly at 12 months versus seronegative children (all P < 0.05).

CONCLUSIONS

Postnatal ZIKV infection in children from rural Guatemala was not associated with worse neurodevelopmental outcomes. DENV seropositivity was associated with a higher risk of microcephaly in infants and worse neurodevelopmental outcomes in children.