Study On Epidemiological Characteristics Of Rotavirus And Their Serotype Of G And P Types Among Children Under 5 Years Old With Acute Diarrhea

Objectives This study aimed to recognize the molecular epidemiological characteristics and determine the predominant types of this virus through the study on epidemiological characteristics of rotavirus and their serotype of G and P types among children under 5 years old with acute diarrhea in Suzhou and Ma-An-shan City from 2001 to 2002 and therefore to provide basic evidences for the develop the candidate specific vaccines and evaluate the effectiveness of vaccines. Risk factors of persistent diarrhea induced by rotavirus were also explored in this study to provide the evidence for preventing them. Methods A totol of 1 267 stool specimens were collected from children under 5 years old with acute diarrhea. Enzyme-linked immunosorbant assay (ELISA) and nested polymeras chain reaction (Nested-PCR) was used to detect rotavirus and serotypes. Case-control study was conducted to explore the risk factors of diarrhea infected by rotavirus in this study. 29 cases with persistent diarrhea infected by rotavirus and 349 controls with non- persistent diarrhea infected by rotavirus were selected from hospitals. Multiple non-conditional Logistic regressions were applied for data analysis. Results Of 1 267 stool specimens, 378 were detected positive, the infection rate was 29.83% in two areas totally. Most cases were found under 3 years old and epidemiological seasonal peaks lasted from the November to the January of next year. Serotype G was the prevalent type in the two cities with number 250. and the G3 and Gl were the most prevalent which accounted for 40%(100/250)and 44.40 %(111/250), respectively. While the G2 ,G4, G9 and mixed infections were 3, 3, 8 in number and the un-identified type were 8.40%(21/250). Gl was the most prevalent in Ma-An-shan City which accounted for 58.54% of all cases while the G3 type accounted for the most of case(47.85%) in Suzhou City. The P genotype study revealed that P[4] and P[8] werethe only two types in these two areas which took up 52.33% and 47.67% respectively. G1P[4] combinations were followed by that of G1P[8] in term of percentage. Case-control study on the risk factors of continuous rotavirus infection revealed that the most susceptible age was among the 6 to 11 months. 89% of cases were founded among children less than 12 months. Living in rural areas, age of patient, blooding feces, mothers' schooling less than 5 years, more than 10 times of feces before seeing doctors, were the risk factors of persistent diarrhea.Conclusions The results indicated that rotavirus was the most important etiologic agent in Suzhou and Ma-An-shan among children under 5 years old. Infection rate show no significant difference between boys and girls. Serotype G was the prevalent type in the two cities. The uncommon type of G3 were detected in suzhou as the major serotype. The G9 type was also found in Suzhou which was suspected to be infected through the closely contacting with animals. Health education for the common people and vaccine for the infants aged 3 to 5 months may be the effective ways to prevent the infant and children rotavirus infection and reduce the prevalence of rotavirus persistent diarrhea.