Kosar Khezri, Nahid Maspi, Shahab Falahi, Hassan Nourmohammadi, Asad Mirzaei
This first report from Ilam Province demonstrates a notable prevalence of microsporidia, particularly E. bieneusi in hemodialysis and cancer patients. The BEB6 genotype raises the possibility of a zoonotic source, although no animal or environmental samples were analyzed to confirm transmission routes. While our findings are preliminary due to the limited sample size, they suggest that molecular diagnostic screening could be beneficial in similar high-risk populations. However, larger multicenter studies are needed to confirm these findings before routine screening can be recommended.
BACKGROUND AND AIMS: Microsporidia are opportunistic intestinal pathogens causing chronic diarrhea in immunocompromised patients. Limited data exist on their prevalence in western Iran. This study aimed to investigate intestinal microsporidia in hemodialysis and cancer patients in Ilam Province.
METHODS: Stool samples from 78 immunocompromised patients (44 females, 34 males; mean age 53.5 ± 12.8 years) were examined microscopically after modified trichrome staining and molecularly by nested PCR targeting the ITS region. Phylogenetic analysis was performed using MEGA v10. Group comparisons were performed using the chi-square or Fisher's exact test, as appropriate.
RESULTS: Microscopy detected microsporidia in 10/78 samples (12.8%), while nested PCR identified 19/78 positive cases (24.4%; 95% CI: 16.2%-34.9%). Enterocytozoon bieneusi (E. bieneusi) was the predominant species (16/78; 20.5%), followed by Encephalitozoon intestinalis (2/78; 2.6%) and mixed infection (1/78; 1.3%). The prevalence was higher in hemodialysis patients (9/30; 30.0%) compared to cancer patients (10/48; 20.8%), but this difference was not statistically significant (χ 2 = 0.84, df = 1, p = 0.36). Due to the small sample size, this finding should be interpreted with caution and is presented as exploratory. No significant difference was observed by microscopy (Fisher's exact test, p = 0.842). Phylogenetic analysis revealed the BEB6 genotype in all E. bieneusi isolates.
CONCLUSION: This first report from Ilam Province demonstrates a notable prevalence of microsporidia, particularly E. bieneusi in hemodialysis and cancer patients. The BEB6 genotype raises the possibility of a zoonotic source, although no animal or environmental samples were analyzed to confirm transmission routes. While our findings are preliminary due to the limited sample size, they suggest that molecular diagnostic screening could be beneficial in similar high-risk populations. However, larger multicenter studies are needed to confirm these findings before routine screening can be recommended.