Background: Immunocompromised children are more susceptible to a diversity of pathogens including
norovirus, rotavirus, diarrheagenic Escherichia coli, Cryptosporidium spp. and Helicobacter pylori.
Objective: This study aimed to determine the detection rate of H. pylori and Cryptosporidium spp.; their
co-infection in a hospital-based study of diarrheic immunocompromised children and their predictive risk
factors; and to evaluate the diagnostic performance of the used assays.
Subjects and Methods: Fecal specimens were collected from 102 immunocompromised diarrheic children,
with ages ranging from few months old to 16 years. All fecal samples were examined microscopically
for detection of parasites, as well as immunologically and molecularly for detection of H. pylori and
Cryptosporidium spp. Copro-antigens of Cryptosporidium and H. pylori were detected immunologically
using rapid chromatographic copro-immunoassay tests. Amplification of H. pylori and Cryptosporidium
copro-DNA was performed using the nPCR assay targeting genes encoding H. pylori urease A and
Cryptosporidium oocysts wall protein (COWP). Amplified Cryptosporidium PCR products were digested by
a restrictive enzyme to detect genotype.
Results: H. pylori copro-DNA and copro-antigen were detected in 56 (54.9%) and 18 (17.6%) patients,
respectively. Cryptosporidium copro-DNA, and copro-antigen were detected in 22 (21.6%), and 16 (15.8%)
patients, respectively, while microscopy detected Cryptosporidium oocysts in only 6 patients (5.9%), with
a clear predominance of anthroponotic C. hominis (81%). Cryptosporidium spp. and H. pylori co-infection
occurred in 15.8% of patients. None of the studied variables had a significant association with any of the
tested pathogens, neither separately nor combined.
Conclusion: There was a high detection rate of H. pylori and Cryptosporidium spp. and their co-existence in
diarrheic immunocompromised children. Our study results highlight that PCR increased the sensitivity for
the diagnosis of Cryptosporidium spp. and H. pylori. More research is needed to establish their relevance.