Epidemiological study on rotavirus-borne diarrhea in infants and children in different areas.

OBJECTIVE: To analyze and compare the epidemiological features of rotavirus diarrhea among infants in the different areas so as to provide data for rotavirus vaccine research. METHODS: From Sep. 2001 through Sep. 2003, sentinel sites were set up in Suzhou Children's Hospital and Maanshan Hospital. Fecal samples from children (< 5 years) with acute diarrheal were collected and enzyme linked immunosorbent assay was used to detect rotavirus antigen. Reverse transcription-polymerase chain reaction was used to determine the G serotypes and P genotypes of rotavirus strains. The features of strains in the two places and other areas of China were analyzed and compared. RESULTS: (1) Rotavirus infection appeared in autumn and winter, but the peaks varied. In Suzhou the peaks were from December to next February in 2001, and November to next January in 2002. But in Maanshan, it was November to next January for both two years. (2) Rate of rotavirus infection in Suzhou was much higher than that in Maanshan, infective rates of Inpatient Department and Outpatient Department are 47.28%, 28.39% and 30.38%, 14.77% respectively in the two hospitals. (3) Rates of infection in two hospitals showed age difference but the highest group was in 6 - 35 month-olds. No gender difference was found. (4) Secular distribution of G-typing and P-typing of rotavirus strain was different in Suzhou and Maanshan. G3 was mainly found in Suzhou and G1 in Maanshan. From 2002-2003 on, G3 became dominant in Maanshan. CONCLUSION: Rotavirus caused diarrhea among infant and children were different in terms of areas, period and types, suggesting that the introduction of rotavirus vaccine should be adjusted according to different strains with specific types and optimal timeline.