The Contamination Of Cryptosporidium And Enterocytozoon Bieneusi In Raw Water In Shanghai, China

Cryptosporidium spp. and Enterocytozoon bieneusi are important waterborne pathogens, and are easy to cause public health problems in regional or worldwide. Shanghai is a densely populated city in China, the water supply pattern of which have been providing by Yangtze River (70%) and Huangpu River (30%). Thus far, there is no data about the contamination of Cryptosporidium and E. bieneusi in Yangtze River (Qingcaosha Reservoir). In March 2013, the outbreak of "Pig Carcass Disposal Incident" in the upper Huangpu River let us also question to the water quality which were impacted by pig carcasses.To fully investigate the occurrence, source and human-infective potential of Cryptosporidium and E. bieneusi in raw water in Shanghai, China, in this study,178 raw water samples were collected form the upper Huangpu River, and 32 raw water samples were collected form the Qingcaosha Reservoir. All the samples were concentrated by calcium carbonate flocculation and examined for host-adapted Cryptosporidium and E. bieneusi by SSU rRNA and internal transcribed spacer (ITS) nested ploymerase chain reaction (PCR).Of the 178 Huangpu raw water samples analyzed,67 (37.6%) and 56 (31.5%) were PCR-positive for Cryptosporidium and E. bieneusi, respectively. The occurrence rates of Cryptosporidium and E. bieneusi in March 2013 (83.3%; 41.7%) and May 2013 (73.5%; 44.1%) were significantly higher than rates in later sampling times (2013/10,2014/01, 2014/03). Among the 13 Cryptosporidium species/genotypes identified, Cryptosporidium andersoni and C. suis were the most common species, being found in 38 and 27 samples, respectively. Seventeen E. bieneusi genotypes were found, belonging to 11 established genotypes (EbpC, EbpA, D, CS-8, PtEb IX, Peru 8, Peru 11, PigEBITS4, EbpB, G, O) and six new ones (RWSH1 to RWSH6), most of which belonged to pig-adapted Groups Id and le. EbpC was the most common genotype, being found in 37 samples. The distribution of Cryptosporidium species and E. bieneusi genotypes suggest that pig carcasses contributed significantly to Cryptosporidium and E. bieneusi contamination in the Huangpu River, Although most Cryptosporidium species found in river water were not major human pathogens, the majority of E. bieneusi genotypes detected were considered zoonotic. This requires the attention of relevant departments and improves the prevention and control efforts.In contrast, of the 32 Qingcaosha raw water samples analyzed,1(3.1%) and 2 (6.2%) were PCR-positive for Cryptosporidium (C. andersoni) and E. bieneusi (I and PtEB IX), respectively. Overall the contaminations of Cryptosporidium and E. bieneusi in Qingcaosha are quite low, and both the species/genotype of Cryptosporidium and E. bieneusi in Qingcaosha pose little risk to human health.Data from this study should be useful in the development of strategies in addressing future contamination events in drinking water supplies.