Background: Elderly individuals are considered an at-risk population, susceptible to enteric infections;
and Cryptosporidium spp. is an apicomplexan protozoan considered to be one of the most common
protozoa causing diarrhea. Cryptosporidiosis causes elevation of many pro-inflammatory cytokines like
tumor necrosis factor-alpha (TNF-α) which may play a role in pathogenesis of the disease.
Objectives: This study was designed for detection and genotyping of Cryptosporidium spp. in elderly
patients and the relationship of infection with copro TNF-α. Diagnosis was by evaluation of permanent
acid-fast cold Kinyoun's (AF) staining, immunochromatographic detection (ICT), and ELISA in comparison
to molecular diagnosis as gold standard diagnostic method.
Subjects and Methods: Stool samples were collected from 270 elderly patients aged above 60 years
old attending outpatient clinics of Internal Medicine Hospital, Cairo University. Samples were examined
microscopically by direct wet mount, and AF staining, and then subjected to ICT, ELISA, and nested PCR
(nPCR) assays. Positive samples by nPCR were then subjected to Restriction fragment length polymorphism
(RFLP) to detect Cryptosporidium genotypes. Copro-levels of TNF-α were measured to assess their
relationship with cryptosporidiosis.
Results: Cryptosporidiosis detection rates of 3.7%, 6.3%, 6.7%, 3.7% were determined by microscopic
examination after AF staining, ICT, ELISA and nPCR, respectively. When RFLP was performed on nPCR
positive samples, eight and two samples were assigned as genotype 1 and 2, respectively. Moreover, TNF-α
was significantly correlated with cryptosporidiosis.
Conclusion: The elderly are highly vulnerable to cryptosporidiosis. Immunodiagnosis and molecular
techniques are fundamental for the diagnosis of cryptosporidiosis. Cryptosporidiosis significantly affects
copro TNF-α.