Molecular epidemiology and multilocus genotyping of Giardia duodenalis in individuals attending major public hospitals in Shiraz, southwestern Iran: A public health concern.

Giardia duodenalis is one of the most common causes of waterborne disease worldwide, and is often associated with outbreaks of diarrhea in areas with poor sanitation and hygiene. This study aimed to assess the prevalence and genetic diversity of G. duodenalis assemblages in individuals attending major public hospitals in Shiraz, southwestern Iran. From August 2022 to May 2023, a total of 614 stool samples from individuals were collected and initially examined for G. duodenalis cysts using parasitological techniques, sucrose flotation, and microscopy. Microscopy-positive samples were validated by SSU-PCR amplification of the parasite DNA. A multilocus genotyping (MLG) scheme, which focused on the triose phosphate isomerase (tpi) and the glutamate dehydrogenase (gdh) genes, was employed for genotyping purposes. G. duodenalis cysts were found in 7.5% (46/614) and 8.5% (52/614) of samples through microscopy and SSU-PCR, respectively. Successful amplification and sequencing results were obtained for 77.3% (17/22) and 45.5% (10/22) of the infected samples at the tpi and gdh loci, respectively. MLG data for the two loci were available for only five samples. Out of the 22 samples genotyped at any loci, 54.5% (12/22) were identified as assemblage A, while 45.5% (10/22) were identified as assemblage B. AII was the most predominant sub-assemblage identified [54.5% (12/22)], followed by BIII [27% (6/22)], discordant BIII/BIV [13.6% (3/22)], and BIV [4.5% (1/22)]. In the present study, no assemblages suited for non-human animal hosts (e.g., C-F) were detected. This suggests that the transmission of human giardiasis in Shiraz is primarily anthroponotic. Further molecular-based analyses are necessary to confirm and expand upon these findings. These analyses will also help determine the presence and public health importance of the parasite in environmental samples, such as drinking water.

Prevalence and molecular characterization of Giardia duodenalis in small ruminants of Shiraz, southwestern Iran: A zoonotic concern.

Livestock are commonly affected by gastrointestinal protozoan parasites, including Giardia duodenalis. In small ruminants, G. duodenalis infection may decrease carcass weight and dressing percentage. Current study was done to determine the prevalence, assemblage distribution, and zoonotic significance of Giardia infection in sheep and goats in Shiraz, southwestern Iran. In total, 200 fecal samples were randomly collected from 100 sheep and 100 goats in 10 farms in Shiraz, southwest of Iran (June 2021-February 2022) and directly examined for G. duodenalis cyst by saline/iodine wet mount examination using a light microscope (400 ×). Positive samples were further genotyped using a nested-PCR and sequencing methods. A mean prevalence of 5.5% (11/200) was estimated for G. duodenalis infection among small ruminants, with 7% and 4% for sheep and goats, respectively. Next, 9 out of 11 positive samples were amplified and only 5 were successfully sequenced at the tpi locus. Our results showed that 80% (4/5) isolates belonged to assemblage E, while only 20% (1/5) were associated with the assemblage A (subtype AI). Of note, 2 E assemblages were isolated from goats and 2 E assemblages plus 1 assemblage A were isolated from sheep. The major finding in the present study was the isolation of assemblage A from sheep in Shiraz, highlighting the zoonotic transmission of Giardia infection in the study area. In general, the information mentioned in the present study is very limited and more extensive studies in this field are needed to achieve more conclusive results.

Global epidemiology of Giardia duodenalis infection in cancer patients: a systematic review and meta-analysis.

BACKGROUND: Application of chemotherapeutics in cancer patients may provide an immunosuppressive milieu, favourable for parasitic infections. Giardia duodenalis is an important zoonotic intestinal parasite responsible for diarrhoea in humans worldwide. METHODS: The present systematic review and meta-analysis was conducted to estimate the prevalence of G. duodenalis and respective odds ratios (ORs) in cancer patients around the globe. Four online databases-PubMed, Scopus, Web of Science and Google Scholar-were carefully explored for relevant literature without time limitation until 28 November 2020. Meta-analysis was done based on a random effects model to pool the estimations and define 95% confidence intervals (CIs). RESULTS: The overall weighted prevalence of G. duodenalis infection in cancer patients was calculated to be 6.9% (95% CI 0.5 to 9.3) globally, based on data from 32 studies. Although not statistically significant, eight case-control studies revealed that cancer patients were 1.24 times (95% CI 0.66 to 2.31; p=0.501) more exposed to G. duodenalis infection than healthy controls. Moreover, the prevalence of infection was not significantly associated with quantitative variables, including publication year (regression coefficient -0.0135, p=0.578), sample size (regression coefficient -0.0007, p=0.074) and human development index (regression coefficient -1.6263, p=0.419). Also, subgroup analysis of the pooled G. duodenalis infection was performed for publication year, World Health Organization regions, countries, continents, cancer types and country income. CONCLUSIONS: Altogether, the epidemiology of G. duodenalis infection and its associated risk factors in immunocompromised individuals, especially cancer patients, is still open to question and deserves comprehensive investigations.