Contribution of hospitals to the occurrence of enteric protists in urban wastewater

We assessed the potential contribution of hospitals to contaminations of wastewater by enteric protists, includingCryptosporidiumspp.,Giardia duodenalis, andEnterocytozoon bieneusiin raw wastewater. Wastewater samples were collected from storage tanks in two hospitals and one associated wastewater treatment plant in Shanghai, China, from March to November 2009. Enteric pathogens were detected and identified using PCR and DNA sequencing techniques. Among a total of 164 samples analyzed, 31 (18.9%), 45 (27.4%), and 122 (74.4%) were positive forCryptosporidiumspp.,G. duodenalis, andE. bieneusi, respectively. Altogether, threeCryptosporidiumspecies, fourG. duodenalisassemblages, and 12E. bieneusigenotypes were detected.Cryptosporidium hominis,G. duodenalissub-assemblage AII, andE. bieneusigenotype D were the dominant ones in wastewater from both hospitals and the wastewater treatment plant. A similar distribution in genotypes of enteric pathogens was seen between samples from hospitals and the wastewater treatment plant, suggesting that humans are one of the major sources for these pathogens and hospitals are important contributors of enteric parasites in urban wastewater. Data from this study might be useful in the formulation of preventive measures against environmental contamination of waterborne pathogens.