Evaluation of laboratory diagnostic methods for cryptosporidiosis among HIV-seropositive patients in Kano, Nigeria

Abstract

Background: The laboratory diagnosis of Cryptosporidium parum infection involves the demonstration of the infective oocysts in stool specimen. The conventional method of modified Ziehl-Neelsen (MZN) is very laborious, and stool debris can be mistaken for the parasite oocytes.
Objective: This research was set to evaluate the diagnostic efficacy of microscopic Modified Ziehl-Neelsen (MZN) stain, Florescence Auramine-O-phenol (AOP) stain and ELISA method.
Methodology: This is a prospective descriptive cross – sectional study of182 consecutive adults and children of both genders, aged 1-65years, who were HIV-seropositive and receiving treatment at Prof Sadiq Wali Treatment Centre, Aminu Kano Teaching Hospital, Kano State, Nigeria.
Result: The overall seropositivity of C. parvum among HIV-seropositive clients receiving treatment at the Sadiq Wali Centre, using all the three techniques, was 29.7% (range 26.9% - 31.9%). Furthermore, the sensitivity of the techniques ranged 57.1% - 93.1% (MZN to ELISA) with ELISA techniques showing the highest sensitivity at 93.1% and specificity of the three techniques ranged 51.6% - 96.1%. The highest specificity at 96.1% was recorded with the Auramine-O-phenol fluorescence stain while 93.2% and 51.6% specificity were recorded with the MZN and ELISA techniques, respectively.
Conclusion: The ELISA technique proved more suitable for the determination of the presence of cryptosporidium oocysts in stool. All stool specimens should be examined for opportunistic parasites, especially in immunosuppressed patients.

Keywords: ELISA, modified Ziehl-Neelsen stain, immunosuppressed, opportunistic infection