Sporadic Human Cryptosporidiosis Caused by<i>Cryptosporidium cuniculus</i>, United Kingdom, 2007–2008

Abstract

To investigate sporadic human cryptosporidiosis trends in the United Kingdom, we tested 3,030 Cryptosporidium spp.-positive fecal samples, submitted for routine typing in 2007-2008, for C. cuniculus. C. cuniculus prevalence was 1.2%; cases were mostly indigenous and occurred across all age groups. Most occurred during August-October and may be linked to exposure opportunities. T he protozoan parasites Cryptosporidium spp. are major causes of gastrointestinal disease worldwide. Most cases in the United Kingdom are caused by C. parvum or C. hominis; rare infections with other species and genotypes include C. meleagridis, C. felis, C. canis, C. ubiquitum, C. hominis monkey, skunk, horse, and rabbit (1 In summer 2008, the rabbit genotype caused a waterborne outbreak in drinking water (4). Previously, only 1 human infection, also identifi ed in the United Kingdom, was known (1), although routine typing based on RsaI restriction fragment-length polymorphisms (RFLPs) within the Cryptosporidium oocyst wall protein (COWP) gene (2) does not differentiate the rabbit genotype from C. hominis (4). After phylogenetic and biologic investigations, the rabbit genotype has been renamed C. cuniculus (5). However, information is lacking about the occurrence and epidemiology of animal and human infections outside the outbreak, which mainly involved adult females (5-7). To investigate trends in humans, we conducted enhanced testing of Cryptosporidium spp.-positive fecal samples from patients with sporadic diarrhea (submitted for routine typing during [2007][2008] with the purpose of identifying and characterizing C. cuniculus.