| Group A rotaviruses are the single most important etiological agent of diarrhea in infants and young children worldwidely. In developing countries, it is estimated that rotavirus is responsible for 600,000-873,000 infant deaths annually. In developed countries, where mortality due to rotavirus is very low, ho were, high rates of morbidity of rotavirus diarrhea results in enormous socioeconomic costs. In view of the following facts: first, rotavirus infection is widespread and nearly all children experience an episode of rotavirus diarrhea in the first 5 years of life; second, the measures of improving public hygienic conditions can't effectively control the prevalence of rotavirus diarrhea; third, no specific treatment can be used , development of effective rotavirus vaccines has long been considered a priority by WHO. It is necessary for formulating the prophylactic strategy to making the extensive epidemiological surveys concerning rotavirus diarrhea in different geographical areas. Rotavirus vaccines under development hold the promise of substantially reducing the huge impact of this disease. The first vaccine has been developed to provide specific protection against the predominant serotypes of rotaviral G1 to G4. Before a rotavirus vaccine is introduced to use, it is required to estimate the epidemiological status of rotavirus diarrhea and to survey the change pattern of the circulating rotavirus strains in the local region. This study was performed to investigate the current clinical epidemiological situation of rotavirus diarrhea in children in Shanghai, aiming to provide the background data associated with the prophylaxis of rotavirus diarrhea for our country.This study was carried out from the four aspects:1.The current situation about rotavirus infection in children inShanghaiBetween November 1st, 1999 and December 31 st,2001, stool samples from 1230 in-patients with diarrhea were detected for rotavirus by polyacrylamide gel electrophoresis(PAGE). Group A rotavirus-positive rate was 40.1%(493/1230). Neither group B nor group C rotavirus was found. Of these 493 specimens with RNA positive, 397 (80.5%)contained long patterns, 55 @ 11.2%) contained short patterns, 18(3.7%) contained mixtures of long and long (16) or long and short (2), 23(4.7%) were untypeable for containing only several of the 11 rotavirus RNA segments. Long pattern electropherotype was predominant. The detailed clinical data from 471 cases of rotavirus diarrhea children revealed that group A rotavirus was the major pathogen of diarrhea among hospitalized children 5 years of age or younger in Shanghai. Rotavirus diarrhea was more prevalent among children 3 to 24 months old, the mean age was 14.2 months old. Rotavirus positive rates were above 50% in November and December of winter in three years, winter epidemics was observed in Shanghai.2.The information about the distribution of group A rotavirus G serotypes in Shanghai493 rotavirus-positive stool samples by PAGE were re-extracted with Trizol and 328 feacal specimens containing sufficient RNAs were used to amplify VP7 whole genes by RT-PCR .cDNAs products were achieved from 254(77.4%) samples in all. G-typing by dot blot hybridization showed serotype G1 comprised 141 (55.5%) strains, serotype G3 comprised 70 (27.6%) strains, serotype G2 comprised 24 (9.4%) strains, daul infections comprised 16 (6.3%) strains, only 1 strain was serotype G4 and 2 strains were untypeable. Serotypes Gl to G3 constituted 98.8% of all typed strains , The RNA patterns of all G2 strains were short and those of G1, G3, G4 strains were long. There were no differences in age distribution and clinical symptoms between different G types.3.The study on rotavirus coinfection with human calicivirus493 rotavirus-positive stool samples were re-extracted with Trizol and then detected for calicivirus by RT-PCR. 9 (1.8%) samples were positive. 9 cases of patients were sporadic in the period of Dec, 2000 to Oct, 2001. 5 cases were due to community- acquired infection and 4 cases were due to nosoco...
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