Etiological surveillance results of infectious diarrhea in Wuxi, Jiangsu, 2014–2018

ObjectiveTo understand the pathogen spectrum and epidemiological characteristics of infectious diarrhea in Wuxi from 2014 to 2018.

MethodsFrom January 2014 to December 2018, stool samples were collected from 3 408 outpatients with diarrhea in sentinel hospitals in Wuxi. Salmonella, Shigella, diarrheagenic Escherichia coli and Vibrio parahaemolyticus were isolated by conventional culture, and the nucleic acid of norovirus, rotavirus, enteric adenovirus, astrovirus and sapovirus were detected with real-time fluorescence quantitative PCR.

ResultsA total of 946 positive samples, including 66 multi pathogen positive samples, were detected in 3 408 stool samples with the positive rate of 27.76%. Among the positive samples, 529 were bacteria positive with the positive rate of 15.52%. The isolation rate of diarrheagenic E. coli was highest (6.60%), followed by Salmonella (5.11%), V. parahaemolyticus (4.05%) and Shigella (0.32%). The diseases mainly occurred in summer. And among the positive samples, 460 were virus positive with the positive rate of 13.50%. The positive detection rates of norovirus (8.92%) and rotavirus (3.29%), which mainly spread in winter and spring, ranked 1-2. The positive rates of pathogens were different in different age groups. The infection rate of rotavirus in children under 5 years old was significantly higher than those in other age groups.

ConclusionThe main pathogens causing infectious diarrhea were diarrheagenic E. coli, Salmonella, V. parahaemolyticus, norovirus and rotavirus in Wuxi from 2014 to 2018. Bacterial diarrhea dominated in summer and viral diarrhea dominated in winter and spring. For infants and young children under 5 years old and the elderly, it is necessary to take different control measures in different seasons.