Epidemiological observations on cryptosporidiosis and molecular characterization of Cryptosporidium spp. in sheep and goats in Kuwait

Abstract

Molecular epidemiological analysis of cryptosporidiosis in Middle Eastern countries suggests that small ruminants could play a major role in the transmission of Cryptosporidium spp. to humans, with a dominance of Cryptosporidium parvum, especially its IId subtypes. However, little information is available on the epidemiology and risk factors of cryptosporidiosis as well the distribution of Cryptosporidium species/genotypes and subtypes in small ruminants in this area, including Kuwait. In the present study, 47 farms from several areas in Kuwait were visited once during October 2014 to September 2015 to collect data on risk factors associated with Cryptosporidium infection. Fecal samples from 334 sheep and 222 goats were examined for Cryptosporidium oocysts by Ziehl-Neelsen staining (ZN) and antigens by enzymatic immunoassay (EIA). The Cryptosporidium prevalence was higher when samples were examined by EIA than ZN (11.4 and 7.2% in sheep and goats by EIA, compared with 4.2 and 3.6% by ZN, respectively). Young age (less than 3months) and closed housing system are risk factors of Cryptosporidium infection. A correlation between fecal consistency and the occurrence of Cryptosporidium spp. was observed; non-formed fecal samples were often found positive. Molecular characterization of 30 ovine and caprine samples using PCR-RFLP analysis of the small subunit rRNA gene revealed the presence of C. parvum in 23 samples, Cryptosporidium ubiquitum in five samples, and Cryptosporidium xiaoi in two samples. Sequence analysis of C. parvum at the 60 KDa glycoprotein gene locus identified two subtypes, IIaA15G2R1 and IIdA20G1, with the latter being more common (in 2 and 20 successfully subtyped samples, respectively). Only one subtype of C. ubiquitum (XIIa) was recorded. Cryptosporidiosis in small ruminants apparently poses public health problem in Kuwait.