Impact of rotavirus vaccination on diarrhea-related hospitalizations in São Paulo State, Brazil.

INTRODUCTION

Following introduction of routine infant rotavirus vaccination, severe diarrhea hospitalization rates declined among children aged <5 years throughout Brazil. Ensuring equity of rotavirus vaccine impact is important in countries that self-finance immunization programs. The objective of this study was to examine rotavirus vaccine impact on diarrhea admission rates among children aged <5 years in Brazil's public health system, according to area-based measures of human development in the state of São Paulo, Brazil.

METHODS

Ecological analysis of public health system hospitalization rates for acute gastroenteritis among children aged <5 years in the state of São Paulo, Brazil, according to five categories of municipal development based on a modified Human Development Index for municipalities. Acute gastroenteritis hospitalization rates among children aged <5 years after national rotavirus vaccine introduction (2008-2011) were compared to rates in pre-vaccine years (2000-2005) to calculate percent decline in rates (1-rate ratio) and 95% confidence intervals (CI) for each municipal development category. Direct hospitalization costs during the two periods were compared.

RESULTS

Annual rates declined by 40% (95% CI, 39-42%) from 631 diarrhea hospitalizations per 100,000 person years pre-rotavirus vaccination to 377 per 100,000 post-vaccination among children aged <5 years and 50% (95% CI, 48-52%) from 1009 to 505 per 100,000 among infants. Highest rates were observed in least developed municipalities. Significant declines of 26-52% among children <5 years and 41-63% among infants were observed in all categories of municipal development. Lower diarrhea hospitalization rates resulted in annual savings of approximately 2 million USD for the state of São Paulo. Savings in direct hospitalization costs benefitted municipalities in all five categories.

CONCLUSION

The introduction of rotavirus vaccination was associated with substantial reductions of diarrhea-related admissions at all levels of municipal development in São Paulo State, Brazil.