What is already known about this topic?: Intestinal protozoa are common pathogens of diarrhea globally. However, the etiology of diarrhea due to intestinal protozoan infections in China is not known.
What is added by this report?: Based on active syndromic surveillance in Shanghai, Zhenjiang, and Danyang during 2011-2015 and 2019-2021, 89 (1.67%) patients were infected with intestinal protozoa (Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi, and Cyclospora cayetanensis), and positivity rates statistically differed by region and age.
What are the implications for public health practice?: This was the most comprehensive data collection in investigating parasitic diarrheal diseases in humans. Identification of these protozoa in diarrhea will provide new perspectives for detecting hidden etiological agents of diarrhea as early as possible.
Keywords: characteristics; diarrhea; intestinal protozoa.
Copyright and License information: Editorial Office of CCDCW, Chinese Center for Disease Control and Prevention 2022.