Evidence Supporting Zoonotic Transmission of Cryptosporidium spp. in Wisconsin

Abstract

Cryptosporidium hominis and Cryptosporidium parvum are the primary species of Cryptosporidium that infect humans. C. hominis has an anthroponotic transmission cycle, while C. parvum is zoonotic, infecting cattle and other ruminants, in addition to humans. Most cryptosporidiosis outbreaks in the United States have been caused by C. hominis, and this species is often reported as the primary cause of cryptosporidiosis in this country. However, outbreaks account for only 10% of the overall cryptosporidiosis cases, and there are few data on the species that cause sporadic cases. The present study identified the species/genotypes and subgenotypes of Cryptosporidium in 49 cases of sporadic cryptosporidiosis in Wisconsin during the period from 2003 to 2005. The species/genotype of isolates was determined by PCR restriction fragment length polymorphism analysis of the 18S rRNA and Cryptosporidium oocyst wall protein genes. The C. parvum and C. hominis isolates were subgenotyped by sequence analysis of the GP60 gene. Forty-four of 49 isolates were identified as C. parvum, and 1 was identified as C. hominis. Of the remaining isolates, one was identified as being of the cervine genotype, one was identified as being a cervine genotype variant, and two were identified as being of a novel human genotype, previously reported as W17. Nine different subgenotypes were identified within the C. parvum species, and two of these were responsible for 60% of the cases. In this study we found that most sporadic cases of cryptosporidiosis in Wisconsin are caused by zoonotic Cryptosporidium species, indicating that zoonotic transmission could be more frequently associated with sporadic cases in the United States.

Occurrence and molecular characterization of Cryptosporidium sp. in sheep

“…Cases of human infection have been reported in Canada (ONG et al, 2002;WONG;ONG, 2006;TROTZ-WILLIAMS et al, 2006), New Zealand (LEARMONTH et al, 2004, United States (FELTUS et al, 2006;BLACKBURN et al, 2006), United Kingdom (LEONI et al, 2006;CHALMERS et al, 2009), andSlovenia (SOBA et al, 2006), among others. The lack of specificity and habitat probably contribute to the widespread distribution of the parasite; the protozoan is routinely found in clear waters, and several animal species release oocysts into the environment (JIANG et al, 2005).…”

Occurrences and genotypes of Cryptosporidium oocysts in river network of southern-eastern China

“…Consequently, it is concluded that the animal breeding industry should be the major contamination sources of Cryptosporidium oocysts in the studied region. However, it should be noted that among the five animal originated species/genotypes detected in this study, the Cryptosporidium suis has been reported in patients in Peru and England (Leoni et al 2006) and in HIV-infected patients in China (Wang et al 2010a), and the cervine genotype Cryptosporidium has been reported in patients in Canada (Trotz-Williams et al 2006), the United Kingdom (Ong et al 2002), the United States (Feltus et al 2006), and Slovenia (Soba et al 2006). Besides humans, the cervine genotype has also been found in a wide host range including wildlife, zoo, and farm animals (Karanis et al 2007b) and could possibly emerge as an important human pathogen with increasing contact between humans and animals.…”

CryptosporidiumPig Genotype II in Immunocompetent Man

“…The infection is endemic to the Balkans (1,2). In Bulgaria, most cases are reported from the central and eastern parts of the country (3,4).…”