Etiological epidemiology of viral diarrhea on the basis of sentinel surveillance in children younger than 5 years in Gansu, northwest China, 2009-2013.

To explore the etiological spectrum of diarrhea and its epidemiological characteristics in diarrhea symptoms surveillance cases younger than 5 years from 2009 to 2013 in Gansu province, northwest China. Systematic diarrhea symptoms surveillance were conducted in 27 sentinel sites in Gansu province and outpatients with three or more loose, watery, or sticky pus stools per day were defined as surveillance cases. All stool specimens were tested for Rotavirus, Human calicivirus, Adenovirus, and Astrovirus. Totally, 1,119 cases (51.54%) were identified as any enteric virus. The average isolation rate of Rotavirus was 51.13%, Astrovirus was 10.84%, Adenovirus was 6.94%, and Human calicivirus was 6.60% (P < 0.01). Rotavirus was identified with the highest frequency among these enteric pathogens except in 2011, with a notable downward trend over time (P < 0.01). Rotavirus A was the most proportion in rotavirus, G3P[8] and G9P[8] were the most common combination. Rotavirus mixed Human calicivirus infections was the most common mixed infected patterns. Viral-positive rate was higher among children aged group of 0-12 and 13-24 months (P < 0.01, respectively). The isolation rates of four enteric viral pathogens showed a similar distinct seasonal variation with a higher rate in spring, autumn, and winter months. Rotavirus was the major epidemiological viral pathogen in diarrhea symptom surveillance cases in Gansu province, northwest China, during period 2009-2013. Seasonal and age-related variations were observed in enteric viral pathogen isolation rate. The comprehensive and continuous surveillance is needed to identify the prevalence of different enteric viral pathogens.