Feline patent Toxoplasma-like coccidiosis among feral cats (Felis catus) in Doha city, Qatar and its immediate surroundings

Doha city has a high feral cat population and studies of hospital records in Doha have shown that human toxoplasmosis also occurs. Clearly, there is a need to understand the role of cats as vectors of human toxoplasmosis in the city and as a first step we assessed the extent of patent Toxoplasma-like coccidial infections among feral cats. Oocysts in cat faeces were detected between June 2008 and April 2010, from a range of locations radiating out of the city centre in concentric semi circular/elliptic rings and by north, west and south divisions within each of the rings. In total 4,652 cats were sampled and overall prevalence of oocysts was 9.1%. Prevalence was 10.1% in the first summer, and then dropped to 8.4% in the following winter and further to 6.8% in the next summer before rising to 10.6% in the final winter of the study; this interaction between annual period and season was significant. There were also significant changes in prevalence across each of the consecutive months of the study, but no clear pattern was evident. Prevalence did not vary significantly by city sector and there was no difference in prevalence between the host sexes. We conclude therefore, that despite minor and significant perturbations, the prevalence of patent Toxoplasma-like coccidial infections among cats in Doha is remarkably stable throughout the year, across years and spatially within the city’s districts.Qatar National Research Funds Student grant UREP 05 – 060 – 3 – 01

Seroprevalence of Toxoplasma gondii infection in feral cats in Qatar

Background: Cats are essential in the life cycle of Toxoplasma gondii as they can shed the environmentally resistant oocysts after acquiring infection. Human populations living in cities with high densities of feral cats are therefore likely to be at risk of infection. The current study is the first to estimate the seroprevalence of T. gondii in the feral cat population in Qatar. We investigated the seroprevalence of T. gondii among 495 adult cats from urban and suburban districts in Qatar. Using results from the Modified Agglutination Test, we fitted statistical models with host sex, area and season as explanatory factors and seropositivity as the outcome. Results: The analysis revealed an overall seroprevalence of 82%. Seroprevalence was significantly higher in the summer season (P = 0.006). No significant difference was detected (P > 0.05) between seroprevalence in female and male cats and in cats from urban and suburban districts of Qatar. Conclusions: Despite the seasonal difference, the observed seroprevalence of T. gondii suggests high environmental contamination throughout the year, with some female cats generating more intense responses compared to males. Both findings merit further investigations.NPRP grant number NPRP 4-164-4-001 from Qatar National Research Fun

Intestinal Parasitic Infections among Long-Term-Residents and Settled Immigrants in Qatar in the Period 2005 to 2011

Abstract. The expanding economy of Qatar in the last two decades has attracted immigrants, often from countries with poor socio-economic levels. Many arrive with patent intestinal parasitic infections, and recent analyses have indicated consistently rising trends in the prevalence of some infections. Here, we examined 18,563 hospital records of subjects in Qatar seeking medical assistance for a variety of ailments, combining data from 2009 to 2011 with the earlier dataset from 2005 to 2008 to enable trends to be identified across a 7-year period. We found that 8.6% were infected with one or more species of parasites, however in contrast to the earlier period (2005–2008), in the latter 3 years there were falling trends of prevalence providing some optimism that parasitic infections among the resident immigrants have begun to decline. We identified also geographic regions from which resident workers still maintain a relatively high prevalence of helminth infections despite their long-term residence in Qatar.This publication was made possible by a grant from Qatar National Research Fund (QRNF) at Qatar Foundation through National Priorities Research Program (NPRP) (Project No. NPRP 4-1283-3-327

A Whole-Genome Sequencing Association Study of Low Bone Mineral Density Identifies New Susceptibility Loci in the Phase I Qatar Biobank Cohort

Introduction: Bone density disorders are characterized by a reduction in bone mass density and strength, which lead to an increase in the susceptibility to sudden and unexpected fractures. Despite the serious consequences of low bone mineral density (BMD) and its significant impact on human health, most affected individuals may not know that they have the disease because it is asymptomatic. Therefore, understanding the genetic basis of low BMD and osteoporosis is essential to fully elucidate its pathobiology and devise preventative or therapeutic approaches. Materials and Methods: we sequenced the whole genomes of 3000 individuals from the Qatar Biobank and conducted genome-wide association analyses to identify genetic risk factors associated with low BMD in the Qatari population. Results: Fifteen variants were significantly associated with total body BMD (p < 5 × 10-8). Of these, five variants had previously been reported by and were directionally consistent with previous genome-wide association study data. Ten variants were new: six intronic variants located at six gene loci (MALAT1/TALAM1, FASLG, LSAMP, SAG, FAM189A2, and LOC101928063) and four intergenic variants. Conclusion: This first such study in Qatar provides a new insight into the genetic architecture of low BMD in the Qatari population. Nevertheless, more studies are needed to validate these findings and to elucidate the functional effects of these variants on low BMD and bone fracture susceptibility

Seroprevalence and epidemiological correlates of Toxoplasma gondii infections among patients referred for hospital-based serological testing in Doha, Qatar

Background. The city of Doha in Qatar has a high density of feral cats and there is a high risk of toxoplasmosis for the resident human population. No data currently exist for the prevalence of infection with Toxoplasma gondii in the city. Methods. We analysed the serological response to Toxoplasma gondii of 1625 subjects referred for routine hospital based serological tests in Doha, Qatar. Prevalence of current/recent infection was assessed through an enzyme-linked immunosorbent assay (ELISA) for the presence of specific anti-T. gondii IgM antibodies, and previous history of infection through IgG. Results. Overall prevalence of IgG responses was 29.8% and this did not differ between the sexes nor between the three years of the study although there was a marked age effect. Among children less than 1 year old prevalence was 22.9%, but then dropped to 45 years). The prevalence of IgG antibody also varied significantly with region of origin, with higher rates for subjects from Africa, followed by those from the Eastern Mediterranean or Asia and lowest rates for subjects from the Arabian Peninsula. No IgM antibodies were detected in any subjects younger than 19 years, but prevalence increased to plateau at 7 - 9% in subjects aged over 20 years, and also varied with region of origin. In this case prevalence was highest among subjects from the Arabian Peninsula and least among those from Asia. Prevalence of IgM was higher among male subjects but did not vary between the three years of the study. Conclusion. Although these data are based on a selected subset of the population, they nevertheless provide the first evidence that toxoplasmosis is endemic in Qatar in the human population, and that both age and region of origin play a role in the epidemiology of the infection. Concerns relating to the role of high density of feral cats in sustaining the infection were highlighted

Toxoplasma gondii Seropositivity and Co-Infection with TORCH Pathogens in High-Risk Patients from Qatar

Testing of patients who are deemed to be at high risk for TORCH pathogens, e.g., pregnant women, their fetuses, neonates, and acquired immunodeficiency syndrome (AIDS) patients, is important so that specific treatment can be initiated. This study included 1,857 such patients between 2005 and 2008. Logistic regression was used to evaluate factors associated with Toxoplasma gondii seropositivity. Among 823 women of childbearing age, 35.1% and 5.2% tested positive for T. gondii IgG and IgM, respectively. Three infants ≤ 6 months of age (0.8% of 353) were congenitally infected. Factors associated with T. gondii IgG seropositivity included older age, East Mediterranean or African nationality, positive cytomegalovirus (CMV) and herpes simplex virus (HSV)-1 serostatus, and negative rubella IgG results. The decreasing prevalence of IgM antibodies between 2005 and 2008 suggested that exposure to T. gondii from food or environmental sources declined over this period in Qatar. Population-based studies of newborns would be helpful to accurately estimate incidence of congenital toxoplasmosis

The distribution of Blastocystis subtypes in isolates from Qatar.

BACKGROUND: Blastocystis is a common single-celled intestinal parasite of humans and other animals comprising at least 17 genetically distinct small subunit ribosomal RNA lineages (subtypes (STs)), nine of which have been found in humans. The geographic distribution of Blastocystis subtypes is variable, but the subtypes present in Qatar are at present unknown. METHODS: Stool samples were collected from randomly selected, apparently healthy subjects arriving in Qatar for the first time. Blastocystis subtypes were determined by sequencing of the small subunit rRNA gene (SSU rDNA) PCR products. Phylogenetic analyses were done using Maximum Composite Likelihood method. RESULTS: 71.1 % of samples were positive for Blastocystis infection based on PCR-detection methodology compared to only 6.9 % by microscopy. Prevalence of Blastocystis did not differ between the sexes nor between age classes. However, there was a regional difference in prevalence with subjects arriving from Africa showing the highest (87.6 %), those from Western Asia intermediate (68.6 %) and from Eastern Asia the lowest prevalence (67.6 %). Genetic analysis detected only three STs. ST3 was the most common (69.3 %) and ST2 was the rarest (3.5 %), while ST1 had a prevalence of 27.2 %. ST2 showed a regional variation, being absent from the 64 Western Asian Blastocystis-positive subjects. Both ST1 and ST3 showed significant differences in prevalence between the sexes. CONCLUSIONS: This is the first report exploring the distribution of Blastocystis subtypes in our region. We recommend that stool screening via microscopy for the presence of Blastocystis should be abandoned since it is extremely insensitive. In future, the prevalence of Blastocystis infections should be based on PCR methodology and we predict that in the years ahead diagnostic PCR will become the tool of choice. More work is needed to identify the full range of Blastocystis subtypes that circulate in our region

Development and Validation of a Clinical Practicum Assessment Tool for the NAACLS-Accredited Biomedical Science Program.

Student perspectives on their final year clinical placements in biomedical sciences at Qatar University are assessed using the clinical practicum assessment tool (CPAT), which was developed in-house following accreditation body requirements. The tool, which we call the CPAT-Qatar University (CPAT-QU), covers the three clinical practicum domains: practicum content, preceptors, and competencies. Here, we validate this tool. The CPAT-QU has 27 Likert-scale questions and free-text open questions. CPAT-QU readability was calculated using the Flesch-Kincaid Reading Ease (FKRE) instrument. Content validity was assessed using the average and universal average scale-level content validity indices (S-CVI/Average and S-CVI/UA). For construct validity, 50 employed graduates who had completed the practicum were consented for study participation, and the validity was calculated by a principal component analysis (PCA). Reliability was analyzed by Cronbach's alpha. The S-CVI/Average and S-CVI/UA were 0.90 and 0.59, respectively, indicating that an adequate proportion of the content was relevant. The PCA extracted two core components, which explained 63% of the variance in the CPAT-QU. Cronbach's alpha values for the items were within the acceptable range of 0.60-1.00, showing that internal consistency has a good level. CPAT-QU appears to be a useful tool for assessing student perspectives on their clinical placements; however, construct validity needs continuous improvement.This study was supported by Qatar University, internal grant No. (QUST-1-CHS-2021-7). The findings achieved herein are solely the responsibility of the authors

Platelets as a Possible Reservoir of HCV And Predictor of Response to Treatment

In the era of new Hepatitis C Virus (HCV) therapy, and the detection of extrahepatic HCV reservoirs such as peripheral blood mononuclear cells and platelets, it is important to understand the factors underlying resistance to treatment. Detection and quantitation of HCV-RNA in platelets or leucocytes from patients under antiviral therapy is poorly studied and the limited studies generated contradictory results. Aim: To detect and quantify HCV-RNA in platelets, and to evaluate the relation between HCV-RNA in the serum and the kinetics of HCV-RNA in platelets, in response to treatment. Method: Viral kinetic was tested in 20 chronic HCV genotype4, during the course of therapy. Results: HCV-RNA was detected in sera of all infected patients. The baseline platelet viral load was significantly lower in responders compared to non-responders. Platelet viral load was also related to serum viral load (t=3.39, p=0.001), but not related to platelet count (t=-0.56, p=0.58). ROC curve analysis revealed that in general, platelet viral load at different time points was a better predictor of SVR compared to serum viral load. Conclusion: HCV RNA analysis in whole blood may be more sensitive than platelet-poor plasma, which might underestimate circulating viral load. Early eradication of viremia from platelets is associated with higher rates of SVR. Our data, reconfirm higher HCV-RNA levels in serum compared to platelets. Thrombocytopenia occurring during interferon-based therapy might be a manifestation of viral eradication rather than adverse effects. Our findings warrant testing the sensitivity of platelet viral load as a predictor of poor response

Sex distinctive patterns in the association between serum bicarbonate and uric acid levels among healthy adults. Qatar biobank data

Background: Uric acid is the final product of purine metabolism and is a potent plasma antioxidant but with pro-inflammatory effects. At high levels, it may increase the risk of developing multiple chronic diseases, such as gout, atherosclerosis, hypertension, and renal diseases. The aim of this study was to assess the sex-specific association between serum bicarbonate and uric acid levels among healthy adults. Methodology: This retrospective cross-sectional study included 2,989 healthy Qatari adults (36.4 ± 11.1  years) from the Qatar Biobank database. Serum uric acid and bicarbonate levels were estimated alongside other serological markers. Participants free from chronic diseases were divided into four quartiles based on serum bicarbonate levels. The sex-specific relationship between serum bicarbonate and uric acid levels was assessed through univariate and multivariate analyses. Results: In men, low serum uric acid levels were significantly associated with higher quartiles of serum bicarbonate levels after adjusting for age. The association remained significant after further adjustment for BMI, smoking, and renal function. The subgroup analysis using the restricted cubic spline method confirmed a significant dose–response association between the variation coefficients of uric acid by serum bicarbonate level in men with adjustments for age, BMI, smoking, and renal function. In women, no significant association was found between quartiles of serum bicarbonate and uric acid levels following the same adjustments. However, using the restricted cubic spline method, a significant bidirectional relation was demonstrated between serum bicarbonate and the variation coefficients of uric acid that were positive for serum bicarbonate levels below 25 mEq/L and negative at higher levels. Conclusion: Serum bicarbonate levels are linearly associated with reduced serum uric acid levels among healthy adult men, which may be a potential protective factor against hyperuricemia-related complications. Further research is needed to determine the underlying mechanisms.The authors would like to acknowledge the contribution of Qatar biobank in this study. Open Access funding provided by QU Health, Qatar University.Scopu