Surveillance of congenital rubella syndrome (CRS) in tertiary care hospitals in Hanoi, Vietnam during a rubella epidemic

Abstract

Objective: To describe the epidemiology and clinical features of congenital rubella syndrome (CRS) in Hanoi, Vietnam.

Methods: Prospective surveillance of CRS between May 2011 and March 2012 in Hanoi, Vietnam. CRS burden was assessed by clinical examination and collection of serum samples from infants in neonatology, cardiology and pediatric departments of two tertiary care hospitals in Hanoi. All infants born during the study period with clinical manifestations of CRS and seropositivity (IgM) for rubella were included in this study.

Results: During the surveillance period 113 infants were identified with confirmed CRS (clinical features and positive rubella IgM). Their mean age at diagnosis was 38.4 days (range 1-152 days) and 61% were female. Clinical manifestations of CRS included low birth weight<2500 g (86.0%), congenital heart disease (63.7%), hearing impairment (63.7%) and ophthalmological abnormalities (46.9%). Other clinical features at birth included: thrombocytopenia (85.0%), neonatal purpura (74.3%), splenomegaly (63.7%), hepatomegaly (62.8%) and blueberry muffin rash (61.1%). Among the mothers of infants with confirmed CRS none had received a rubella vaccine in the past and 88.4% gave a history of rubella contact during the pregnancy under study. In most cases (84.1%) maternal infection occurred in the first trimester. During the surveillance period the estimated annual incidence of CRS was 1.13/1000 live births (95% CI 0.92-1.34).

Conclusions: These preliminary baseline data show a high burden of CRS in Hanoi, Vietnam and the urgent need for universal vaccination. Surveillance to determine and monitor the national burden of CRS is essential.

Keywords: Congenital rubella; Congenital rubella syndrome; Rubella; Vietnam.