Introduction: Cryptosporidiosis is a common disease of children and immune-compromised persons. This study evaluated the diversity and distribution of Cryptosporidium species in diarrheal children and HIV-infected persons on highly active antiretroviral therapy (HAART) and those not on HAART.
Methodology: A total of 394 fecal specimens were collected from patients attending clinics in Nsukka and Ebonyi, Nigeria. Detection and identification of Cryptosporidium species were conducted by PCR-RFLP of the small subunit (SSU) rRNA gene, whereas subtyping was done by sequence analysis of the 60 kDa glycoprotein (gp60) gene.
Results: Twenty-five (6.3%) specimens yielded four Cryptosporidium species, including C. hominis, C. parvum, C. felis, and C. viatorum. C. hominis was the most dominant species with 48.0% occurrence and three identified subtype families: Ia (six specimens), Ib (three specimens), Ie (two specimens), and one un-subtyped species. C. parvum had 44.0% occurrence and two subtype families: IIc (eight specimens) and IIe (three specimens), while C. felis and C. viatorum each had 4.0% occurrence. There were significant differences in Cryptosporidium species distribution between age groups in children and HIV-infected persons, between suburban and urban areas, and between low and high CD4+ cell counts in HIV-infected patients. There were no significant differences in infection rate and species distribution between HIV-infected patients on HAART and those not on HAART.
Conclusions: The results from this study show that there is a high diversity of Cryptosporidium spp. in humans in Ebonyi and Nsukka, Nigeria, and that all the C. parvum subtypes identified are most likely anthroponotic in origin.