Surveillance of congenital rubella syndrome in Brazil, 1995–2005

Abstract

In Brazil, routine childhood rubella vaccination was introduced during 1992?2000 and a campaign targeted to women of childbearing age was conducted during 2001?2002 to accelerate control of congenital rubella syndrome (CRS). Surveillance of CRS was implemented in 2000, to detect CRS cases and evaluate impact of rubella vaccination strategies and an elimination goal was established in 2003. National CRS surveillance data were analyzed to describe CRS incidence and positive predictive value (PPV). International standard CRS case definitions were used. Completeness of coverage was estimated by a capture-recapture method using surveillance data and a retrospective study in maternity hospitals. Case detection strategies were evaluated using data from three CRS clusters investigated in Brazil during 1999?2002. In 2001, CRS incidence was 2.3 per 100,000 children < 1 year of age and PPV was 18%, decreasing to 0.1 and 4%, respectively, in 2004. No new confirmed or compatible cases of CRS were identified in 2005. Of 2,443 suspected CRS cases reported during 1995?2005, 1,889 (77%) were born during 2000?2005. Of these, 1,486 (79%) had one blood sample for IgM testing; 93% (n = 1, 024) within six months of age. A total of 280 (12%) infants had confirmed or compatible CRS, of which 51% (93/184) had fatal outcome. Completeness of coverage was estimated at 7%. PPV of active case finding (63%) was 4.3-fold greater than follow-up of pregnant women with confirmed rubella (15%). Rubella and CRS incidence have declined dramatically in Brazil demonstrating the impact of national rubella control strategies, and representing surveillance challenges in the end-stage of elimination. High routine rubella vaccination coverage and a high-quality surveillance system will be critical to achieve the elimination goal. Active CRS surveillance at maternity and referral tertiary hospitals is recommended.