Incidence of diarrheal diseases in Shanghai city,2013-2015:results of integrated surveillance

Objective To explore a new pattern of surveillance on diarrheal diseases by integrating clinical medicine and public health for dynamic monitoring changes in pathogen spectrum and epidemiological characteristics of diarrheal diseases.Methods We conducted a cross-sectional study and used probability proportion to size (PPS) to estimate sample size of the study from July 2013 through June 2015.Clinical and epidemiological information were collected with clinical interviews and input into a dedicated online system by doctors; stool specimens of suspected diarrheal patients were collected simultaneously and tested for eleven types of bacteria and five types of virus.Drug sensitivity tests were carried out for pathogenic bacteria isolated.Results A diarrhea surveillance online network was successfully set up in Shanghai city,which linked relevant information collected in centers for disease control and prevention (CDC) at municipal and district level and in sentinel hospitals.During the study period,totally 58 336 outpatient visits for diarrhea were recorded and stool specimens were collected among 6 543 diarrheal patients.Of all the specimens,3 059 were positive for at least one pathogen,with a pathogen positive rate of 46.75%,a bacteria positive rate of 12.07%,and a virus positive rate of 30.46%,respectively.For all the pathogen positive specimens,a total of 7 types of bacteria and 5 types of virus were detected; the main bacteria identified were Vibrio Parahaemolyticus (256),diarrheagenic E.coli (239),and Salmonella (209); the main viruses detected were norovirus (1172) and rotavirus (546).The pathogen positive rate was obviously higher for specimens sampled during summer seasons than for those sampled during autumn and winter seasons; the virus positive rate (52.54%,1 295/2 465) was significantly higher than the bacteria positive rate (3.57%,88/2 465) for the specimens sampled during autumn and winter seasons,while the bacteria positive rate (21.31%,541/2 539) was significantly higher than the virus positive rate (10.05%,255/2539) during summer seasons (P<0.05 for all).Conclusion A new diarrhea surveillance pattern was constructed in Shanghai city,which was characterized by one specimen for multiple monitoring and the linkage between clinical data and public health information via online network.The pattern could be applied in dynamic monitoring on diarrheal diseases in big cities.