Epidemiological aspects of rotavirus infections in Minas Gerais, Brazil.

In order to develop good polices regarding public health measures and vaccine use to prevent rotavirus induced gastroenteritis, the epidemiology of the illness in various regions of Brazil is necessary. Accordingly, this study was to detect the frequency and types of rotavirus in one city in a tropical part of Brazil. This is an epidemiological survey of pediatric gastroenteritis caused by rotavirus conducted in Juiz de Fora, Minas Gerais State, Brazil. We analyzed 656 in-patient (190) and out-patient (466) stool samples from children ages 0 to 5 years during 1998. Rotavirus detection was performed using polyacrylamide gel electrophoresis (PAGE). Rotavirus was isolated from 62/190 stool samples (32.6%) from hospitalized children and 16/466 (3.4%) from out-patients. The overall rotavirus frequency in this population was 11.9%. The highest rotavirus detection was found in hospitalized children ages 6 to 24 months. Rotaviruses were detected from March to September, with a peak incidence in June (33.3%), the coldest and driest month in the region. Electrophoretic analysis identified 10 different profiles, all long and compatible with group A rotavirus, termed L(A) through LJ. The L(B) and L(D) profiles circulated throughout most of the study period. However, in June, when the highest detection rate occurred, the vast majority (92.5%) of the positive samples displayed the L(B) profile, thus suggesting an outbreak caused by this rotavirus profile. Rotavirus induced gastroenteritis is common in one tropical region of Brazil, it is an important cause of diarrhea in hospitalized children ages 6 to 24 months, it is most common during dry, cold months of the year, and it may occur in electrophoretype restricted epidemics. Such analyses throughout Brazil will assist in developing sound guidelines regarding its prevention.