Clinical And Molecular Epidemiology Of Rotavirus In Children With Community-acquired And Hospital-acquired Acute Diarrhea In Shanghai

ObjectiveRotavirus is the most common cause of severe gastroenteritis and dehydration in young children in both industrialized and developing countries.It is estimated that about 110 million episodes of gastroenteritis require home care,25 million require clinic visits,2 million require hospitalizations,and 352,000-592,000 result in the death of children＜5 years of age annually.Vaccines currently under development have the potential to reduce morbidity and mortality due to rotavirus infection.It is needed to reassess the prevalence of rotavirus and field rotavirus strains circulating in Shanghai before making decision on introducing rotavirus vaccine into Shanghai by public health organization.We conducted a hospital-based prospective investigation to understand the epidemiological profile of rotavirus diarrhea in the community and health-care setting from November 2006 to January 2008 in Shanghai.In the meantime,risk factors of diarrhea caused by rotavirus infection were also explored. Our current research aimed to estimate the incidence of rotavirus diarrhea in the community and hospital setting and monitor the temporal fluctuation of distribution of rotavirus genotype,which provide the background data for the prophylaxis of rotavirus diarrhea in China.MethodsA total of 1895 stool specimens were collected from outpatients and inpatients with community-acquired and hospital-acquired acute diarrhea.All stool specimens were transported to the research laboratory within 24 hours and frozen under -20℃.10 percent of the supernatant was used for detection of rotavirus antigen with rotavirus Group A Diagnostic Kit(Colloidal Gold Device,Beijing Wantia Biological Pharmacy Enterprise Co.Ltd) and polymerase chain reaction nested-PCR was performed to detect rotavirus genotypes.Results1.Of 1895 stool specimens,735 were positive for rotavirus.The overall positive rate was 38.8%.1461 stool samples were collected from outpatients and rotavirus was detected in 546(37.4%).216 children who were hospitalized primarily for acute diarrhea were enrolled and 83(38.4%) were rotavirus positive.218 inpatients who developed nosocomial diarrhea were analyzed and 108(49.5%) were rotavirus-associated nosocomial diarrhea.Rotavirus infection mainly occurred in children less than 36 months of age and peaked in 6-11month group.There was a statistic difference in the infection rate of rotavirus among age-specific groups. Diarrhea cases were not common in patients above 5 years old,but the detection rate of rotavirus was as high as 31%.Rotavirus-positive rate was significantly higher in nosocomial group than that in community-acquired group.2.Rotavirus was prevalent year-round in shanghai.The detection rates of rotavirus were statistically different in different months.Rotavirus peaking season lasted from the October to the January of next year in the community.We observed occurence of nosocomial outbreak of rotavirus diarrhea in neonatal ward in April,2007.3.Clinical symptoms were more severe in inpatient group.50%of inpatient with rotavirus diarrhea had concomitantly extra-intestinal symptoms.Liver enzyme abnormality,upper respiratory tract infection and electrolytes disturbance were commonly observed.Liver enzyme abnormality was related with younger age,more vomiting times and lactose intolerance.4.Hospitalization cost of rotavirus diarrhea for children was positive correlated to the length of hospital stay.One more prolonged day of hospitalization increases 500 RMB of direct medical cost.The age was inversely correlated to hospitalization cost and the younger the age group was,the more the economic burden of hospitalization was. Compared with pneumonia patients without nosocomial rotavirus diarrhea,those who were admitted to wards for pneumonia and developed nosocomial rotavirus diarrhea had prolonged hospital stay and increased medical cost.5.Month age and sharing one room with diarrhea cases were risk factors which were correlated with nosocomial rotavirus infection.Breast feeding was a protective factor for rotavirus diarrhea. 6.490 rotavirus-positive strains were typed and G3(54.5%) was the most common G serotype followed by G1(15.9%),Gland G3 coinfection(3.7%),G2(2.7%) and G9(1.8%),respectively.There was no significant difference in clinical presentation except for dehydration between G1 and G3 serotypes.P[8]was the most predominant P genotype which accounted for 83.1%and P[4]comprised 4.5%.In a descending order of frequency,G3P[8]was found in 51.6%,G1P[8]in 15.1%,G2P[4]in 2.0% and G9P[8]in 1.8%.G1P[4]and G3P[4]were rarely detected also.ConclusionsRotavirus was an important pathogen in diarrhea children in Shanghai area.Rotavirus infection mainly occurred in children less than 36 months of age and peaked in 6-11moth age group.Rotavirus was prevalent year-round in shanghai,and the peaking seasons were autumn and winter.Rotavirus diarrhea had concomitant extra-intestinal symptoms.Nosocomial rotavirus diarrhea had prolonged hospital stay and increased medical cost.Breast feeding was a protective factor for rotavirus infection.G3 was the most common G serotype and G9 strain was endemic in Shanghai.G3P[8]was the most predominant.