Frequency, associated factors and clinical symptoms of intestinal parasites among tuberculosis and non-tuberculosis groups in Iran: a comparative cross-sectional study

Background: Co-infection of human tuberculosis (TB) and intestinal parasites infections (IPIs) is a public health problem, especially in low- and middle-income countries. There is no data on this issue in Iran. Therefore, we investigated the prevalence of IPIs among patients with TB in Iran.

Methods: Stool samples were collected from 161 patients with TB and 181 healthy people (non-TB group). Standard parasitological methods including direct slide smear, formalin-ether concentration, trichrome, modified Ziehl-Neelsen and chromotrope 2R staining techniques were used for detection of intestinal protozoa and helminths. Nested-PCR and sequence analysis were used to identify the genotypes of Cryptosporidium and human-infecting species of microsporidia. Data analysis was performed using SPSS version 16.

Results: The frequency of IPIs in the non-TB group (16.5%) was slightly lower than in patients with TB (21.1%), although statistical significance was not observed (OR, 0.74; 95% CI, 0.43-1.27; P= 0.28). Blastocystis (11.8%) was the most common parasite detected in patients with TB. Infection with multiple parasites in the non-TB group (2.2%) was significantly lower than in patients with TB (7.5%) (OR, 0.28; 95% CI, 0.08-0.88; P=0.02). The ova of Taenia spp., Ascaris lumbricoides and Hyamenolepis nana were identified in three patients with TB (1.9%), while only one person (0.5%) in the non-TB group was infected with Enterobius vermicularis. The results of genotyping revealed two C. parvum subtype families (IIa and IId) and three E. bieneusi genotypes (Ebcar4, IH and jLD-1).

Conclusion: Our results showed a higher prevalence of IPIs in patients with TB in comparison with non-TB subjects. Moreover, our findings suggest a proper health education program for good personal hygiene habits, and also preventative measures to avoid the acquisition of IPIs in patients with TB.