Molecular Detection and Epidemiological Assessment of Giardia lamblia in Symptomatic Patients from Wasit Province, Iraq: A Comparative Study Using Real-Time PCR (qPCR)

Zainab Abdalameer Kadhem; Abbas Jameel Oudah

doi:10.58709/niujhs.v12i1.2608

Zainab Abdalameer Kadhem Open Education College, Ministry of Education, Education Wasit Center, Iraq
Abbas Jameel Oudah Ministry of Education, General Directorate of Education in Wasit, Iraq

DOI: https://doi.org/10.58709/niujhs.v12i1.2608

Abstract

Giardia lamblia is the most prevalent intestinal protozoan responsible for waterborne gastrointestinal illness globally, especially in areas of the world with poor sanitation and water quality conditions, in developing countries. Although conventional microscopy is the primary technique used in routine diagnosis in Iraq, it is not very sensitive in the detection of low-density infections.

The present study was designed to investigate the molecular prevalence of G. lamblia in symptomatic cases of Wasit province (Iraq) and also to compare the results of microscopic examination with Real-Time PCR (qPCR) method.

The study was conducted from January to October 2025 with a cross-sectional study design on 200 patients who presented with symptoms in Al-Karama Teaching Hospital in Wasit Province. Formal-ether concentration microscopy and TaqMan-based Real-Time PCR of the small subunit ribosomal RNA (ssu rRNA) gene of the stool were examined. IBM SPSS version 26 was used for statistical analysis.

The prevalence of G. lamblia detected by qPCR was 19.0% (38/200), which was higher than the prevalence detected by microscopy (11.0% (22/200)) (P = 0.021). The ages 0-9 years had the highest prevalence rate (32.0%) and showed significant association with infection (P = 0.002). The sensitivity of the microscopy was 57.9% and the specificity was 100% compared to qPCR. The qPCR positive samples had significantly higher cycle threshold (Ct) values, representing low density infections that were not seen under conventional microscopy.

Giardiasis is still endemic in Wasit Province, especially children. Real-Time PCR was found to be more sensitive and reliable than microscopy, and is recommended to be an indispensable method for accurate epidemiological surveillance and clinical diagnosis.

Keywords: Molecular, Epidemiology of Giardia lamblia, RT-PCR, Iraq, Wasit, ssu rRNA.