Background: Cryptosporidiosis is of utmost importance especially in vulnerable age groups in developing countries. Malnourished children are more susceptible to recurrent diarrheal episodes, which can lead to chronic nutritional and cognitive sequelae or even death.
Objective(s): to evaluate four different diagnostic approaches for Cryptosporidium infection in stools of diarrheic children.
Methods: One hundred stool specimens were collected from diarrheic children in Alexandria University Children Hospital (El-Shatby). All samples were investigated by four techniques; directly by microscopic detection of Cryptosporidium oocysts using modified Ziehl-Neelsen (MZN) stain. Indirectly, through detection of coproantigen by enzyme linked immunosorbent assay (ELISA) and rapid strip test. Cryptosporidium DNA was detected by conventional polymerase chain reaction (PCR).
Results: Using the four methods, 65% of examined children had Cryptosporidium infection, while Cryptosporidium oocysts were shown by MZN stain technique among 41%. However, by rapid strip test, ELISA, and PCR the percentages were 45%, 48%, and 59%, respectively. PCR elicited the highest diagnostic efficiency (64%) among the three diagnostic non-microscopic techniques when the MZN technique was used as the gold standard test. However, rapid strip test showed the least diagnostic efficiency (48%) when compared to PCR that was considered as the gold standard test. Meanwhile, ELISA was of moderate performance when compared to either PCR or to MZN technique used as gold standard test.
Conclusion: PCR was more sensitive than rapid strip test and ELISA. It is time saving, but not cost effective. The rapid strip test could be considered as a complementary (additional) tool rather than a substitute for microscopic examination. It could be used for screening in cases of outbreaks of diarrhea for faster management of the problem.