Bartonella henselae in African Lion, South Africa

Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 10, No. 12, December 2004 2257 species can cause disease (symptomatic infection) and death. C. felis and C. meleagridis infections showed low oocyst shedding (all seven patients had low to moderate oocyst loads in samples). On the contrary, C. parvum produced similar clinical manifestations but showed higher oocyst shedding; 46% had high to very high parasite loads. C. hominis infections had parasite loads even higher than C. parvum infections; 54% of patients had high to very high parasite loads. In immunocompetent persons, C. hominis infections produce higher oocyst loads in feces than infections caused by C. parvum or zoonotic species (2,9). The transmission route for the unusual Cryptosporidium species is unclear. Because human infection by unusual Cryptosporidium species is less common, the principal transmission route for these parasites is likely through direct contact with infected animals. In our study, one of the four immunocompromised patients with C. felis was a child who had been in close contact with cats at home. No data on animal contact were available for other patients infected with unusual Cryptosporidium species. Cats are found in many homes with no evidence of cryptosporidiosis; therefore, it is difficult to attribute the occasional human C. felis infection to contamination by cats. Careful epidemiologic studies are needed to elucidate the transmission route of human infections with unusual Cryptosporidium species.