Impact of Rotavirus Infections on Outpatient Clinic Visits in Chile

Abstract

Incorporation of new rotavirus vaccines into national programs of developing countries will rely on well-designed cost-effective analysis based on accurate assessment of disease burden. For Chile, rotavirus disease burden is determined mostly by outpatient clinic and emergency room visits and by hospitalizations. We previously estimated a yearly incidence of 8000 and 53,000 hospitalizations and emergency room visits respectively for children <or=3 years of age. The objective of this study was to quantify the impact of rotavirus as a cause of outpatient clinic visits. A prospective surveillance protocol between the Health Ministry and the University of Chile in 11 outpatient clinics from 6 regions included reporting of all acute diarrhea cases in children <5 years of age and collection of a stool sample for the first 5 children per week. A total of 5217 acute diarrhea episodes requiring an outpatient medical visit for a total assigned population of 41,927 children <5 years of age were reported from August 1, 2004, to October 30, 2005, in the 11 clinics. A total of 179 rotavirus positive samples were detected from 1313 stools collected for an overall positivity of 13.6% (95% confidence limit: 11.8-15.6%). Rotavirus outpatient visits occurred during all 15 months without a clear seasonal predominance and peaked between 6 months and 2 years of age. G4 types predominated during the 15-month period. For Chilean children </=3 years of age, a yearly estimate of 11,658 to 16,305 outpatient medical visits need to be added to previous disease burden estimates.