AUTHOR=Elmahallawy Ehab Kotb , Gareh Ahmed , Ghallab Marwa M. I. , Köster Pamela C. , Dashti Alejandro , Aboelsoued Dina , Toaleb Nagwa Ibrahim , Alzaylaee Hind , Gonzálvez Moisés , Saleh Amira A. , Alhegaili Alaa S. , Eldehn Ahmed Fathy , Hernández-Castro Carolina , Bailo Begoña , González-Barrio David , Carmena David 

TITLE=Microscopy detection and molecular characterisation of Giardia duodenalis infection in outpatients seeking medical care in Egypt

JOURNAL=Frontiers in Public Health

VOLUME=12

YEAR=2024

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2024.1377123

DOI=10.3389/fpubh.2024.1377123

ISSN=2296-2565

ABSTRACT=<sec id="sec1"><title>Introduction</title><p>Giardiosis remains one of the most prevalent enteric parasitic infections globally. Earlier molecular-based studies conducted in Egypt have primarily focused on paediatric clinical populations and most were based on single genotyping markers. As a result, there is limited information on the frequency and genetic diversity of <italic>G. duodenalis</italic> infections in individuals of all age groups.</p></sec><sec id="sec2"><title>Methods</title><p>Individual stool samples (<italic>n</italic> = 460) from outpatients seeking medical care were collected during January–December 2021 in Kafr El-Sheikh governorate, northern Egypt. Initial screening for the presence of <italic>G. duodenalis</italic> was conducted by coprological examination. Microscopy-positive samples were further confirmed by real-time PCR. A multilocus sequence typing approach targeted amplification of the glutamate dehydrogenase (<italic>gdh</italic>), beta-<italic>giardin</italic> (<italic>bg</italic>), and triose phosphate isomerase (<italic>tpi</italic>) genes was used for genotyping purposes. A standardised epidemiological questionnaire was used to gather basic sociodemographic and clinical features of the recruited patients.</p></sec><sec id="sec3"><title>Results</title><p><italic>Giardia duodenalis</italic> cysts were observed in 5.4% (25/460, 95% CI: 3.6–7.9) of the stool samples examined by conventional microscopy. The infection was more frequent in children under the age of 10 years and in individuals presenting with diarrhoea but without reaching statistical significance. Stool samples collected during the winter period were more likely to harbour <italic>G. duodenalis</italic>. All 25 microscopy-positive samples were confirmed by real-time PCR, but genotyping data was only available for 56.0% (14/25) of the isolates. Sequence analyses revealed the presence of assemblages A (78.6%, 11/14) and B (21.4%, 3/14). All assemblage A isolates were identified as sub-assemblage AII, whereas the three assemblage B sequences belonged to the sub-assemblage BIII. Patients with giardiosis presenting with diarrhoea were more frequently infected by the assemblage A of the parasite.</p></sec><sec id="sec4"><title>Conclusion</title><p>This is one of the largest epidemiological studies evaluating <italic>G. duodenalis</italic> infection in individuals of all age groups in Egypt. Our molecular data suggest that <italic>G. duodenalis</italic> infections in the surveyed population are primarily of anthropic origin. However, because assemblages A and B are zoonotic, some of the infections identified can have an animal origin. Additional investigations targeting animal (domestic and free-living) and environmental (water) samples are warranted to better understand the epidemiology of giardiosis in Egypt.</p></sec>