Pertussis in Brazil: an Overview from 1988 to 2009

Background: The introduction of pertussis vaccination in the past decades reduced substantially the number of cases; however, despite the high vaccination coverage rates, pertussis is still a major threat to public health all over the world including Brazil. In this study we present an overview of pertussis in Brazil in the last two decades. Methods: Between 1988 and 2009, the National Reference Laboratory for Pertussis, Instituto Adolfo Lutz, São Paulo, Brazil, received a total of 985 presumptively identified Bordetella spp strains, isolated from sporadic cases and/or some pertussis outbreaks. The strains were forwarded by the Regional Laboratories in São Paulo State and by the Central Public Health Laboratories throughout the country. Identification of the species was done by standard methods. Detection of O1 antigen, and the serotyping were done by slide agglutination test using O1, and Fim 2 and Fim 3 antibodies, respectively. Molecular characterization was done by Pulsed Field Gel Electrophoresis (PFGE). Results: All the 985 strains were confirmed as Bordetella pertussis and the most of them belonged to the serotype 1,3. Strains from southeastern states accounted for 67% (660/985), most of them from São Paulo State (646/985; 65.6%). The remaining 325 strains were from south region (147/985, 15%), northeastern states (87/985, 8.8%), north region (48/985, 5%) and central area (43/985, 4.4%). The great majority (81.1%, 799/985) was from children under twelve years of age, and among them 84.4% (675/799) was from infants aged less than six months. Strains from adolescents and adults accounted for 3.2% (32/985) and 8% (78/985), respectively. The age group was unknown in approximately 7.7%. Strains belonging to several PFGE patterns were identified and some were prevalent. Conclusion: Different B. pertussis clones circulate all over the country. These data do not cover all the country, and may represent only a fraction of the actual number of pertussis cases due to the underreporting, despite pertussis is, in Brazil, a reportable disease since 2001. Data on age distribution of pertussis cases may contribute to develop the policy of booster doses of vaccine in adolescents and adults. Abstracts for SupplementInternational Journal of Infectious DiseasesVol. 14Preview Full-Text PDF Open Archive