Dengue infection in pregnancy and transplacental transfer of anti-dengue antibodies in Northeast, Brazil

Abstract

Background: Dengue affects nearly 400 million people annually worldwide and considered one of the most serious health threats in tropical and subtropical countries.

Objective: To analyze the occurrence of dengue infection among the parturient who have formed the baseline of an ongoing birth cohort study in the city of Recife, Northeast of Brazil.

Study design: From March 2011 to May 2012, we recruited 417 parturients with low-risk pregnancies at maternity ward who agreed to a follow-up of their babies. Dengue infection was accessed through DENV RT-PCR and anti-dengue antibodies (IgM and IgG). The prevalence of IgG antibodies in the parturients and their concepts were determined. The concordance among the pairs was tested using Kappa. The association of recent infection (IgM and/or DENV RT-PCR positive) with the maternal characteristics and clinical features of the neonates was analyzed through logistic regression.

Results: The prevalence of IgG antibodies in the maternal and cord blood samples was 95.1% (95% CI: 92.6-96.9%) and 95.8% (95% CI: 93.4-97.5%), respectively, with high agreement between maternal-cord pairs (Kappa=0.93). The prevalence of recent infection was 10.6% (95% CI: 7.9-14.2%) in the parturients. Reported fever during pregnancy was associated to recent infection (p=0.023).

Conclusion: The data draw attention for the high frequency of anti-dengue antibodies in the women studied and for the high occurrence of infection during pregnancy in this region of Brazil. There is a need for further studies to better characterize dengue infection in pregnant women.

Keywords: Dengue virus; Epidemiology; Pregnancy; Prevalence; Vertical infectious.