Search

Beta (B.1.351) variant COVID-19 disease was investigated in Qatar. Compared to Alpha (B.1.1.7) variant, odds of progressing to severe disease were 1.24-fold (95% CI: 1.11-1.39) higher for Beta. Odds of progressing to critical disease were 1.49-fold (95% CI: 1.13-1.97) higher. Odds of COVID-19 death were 1.57-fold (95% CI: 1.03-2.43) higher.

Complementing whole genome sequencing strategies with high-throughput multiplex RT-qPCR genotyping allows for more comprehensive and real-time tracking of SARS-CoV-2 variants of concern. During the second and third waves of COVID-19 in Qatar, PCR genotyping, combined with Sanger sequencing of un-typeable samples, was employed to describe the epidemiology of the Alpha, Beta and Delta variants. A total of 9792 nasopharyngeal PCR-positive samples collected between April-June 2021 were successfully genotyped, revealing the importation and transmission dynamics of these three variants in Qatar.

Human influenza viruses are occasionally detected in the stools of influenza patients. Objectives: Here, we investigated the molecular and biological characteristics of intestinal influenza viruses and their potential role in virus transmission. Methods: Fecal samples were first screened for the presence of influenza viral RNA using RT-qPCR. Positive fecal samples were subjected to cell culture. Isolated viruses were then sequenced using MiSeq platform. Replication kinetics and receptor binding affinity were also evaluated. Results: Influenza RNA was detected in stool samples of 41% (36/87) of influenza A positive patients. Among the 36 stool samples subjected to viral isolation, 5 showed virus growth. Sequence analysis of isolated viruses revealed two distinct mutation patterns in fecal viruses. Set I viruses was able to replicate to higher titers in cell culture despite the limited number of mutations (6 mutations) compared to set II viruses (>10 mutations). Functional analysis of both sets revealed the ability to replicate efficiently in differentiated human bronchial cells. Receptor binding testing has also demonstrated their ability to bind α 2,3 and α 2,6 sialic acid receptors. Conclusion: The ability of fecal influenza viruses to replicate in intestinal cells and human 3D bronchial cells might suggest their possible contribution in virus transmission.

BACKGROUND: Qatar experienced a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic that disproportionately affected the craft and manual worker (CMW) population, who comprise 60% of the total population. This study aimed to assess ever and/or current infection prevalence in this population. METHODS: A cross-sectional population-based survey was conducted during July 26 to September 09, 2020, to assess both anti-SARS-CoV-2 positivity through serological testing and current infection positivity through polymerase chain reaction (PCR) testing. Associations with antibody and PCR positivity were identified through regression analyses. RESULTS: The study included 2641 participants, 69.3% of whom were

Globally, over two million people have perished due to the recent pandemic caused by SARS-CoV-2. The available epidemiological global data for SARS-CoV-2 portrays a higher rate of severity and mortality in males. Analyzing gender differences in the host mechanisms involved in SARS-CoV-2 infection and progression may offer insight into the more detrimental disease prognosis and clinical outcome in males. Therefore, we outline sexual dimorphisms which exist in particular host factors and elaborate on how they may contribute to the pronounced severity in male COVID-19 patients. This includes disparities detected in comorbidities, the ACE2 receptor, renin-angiotensin system (RAS), signaling molecules involved in SARS-CoV-2 replication, proteases which prime viral S protein, the immune response, and behavioral considerations. Moreover, we discuss sexual disparities associated with other viruses and a possible gender-dependent response to SARS-CoV-2 vaccines. By specifically highlighting these immune-endocrine processes as well as behavioral factors that differentially exist between the genders, we aim to offer a better understanding in the variations of SARS-CoV-2 pathogenicity.

Pancreatic cancer (PC) is the fourth leading cause of all cancer-related deaths. Despite major improvements in treating PC, low survival rate remains a major challenge, indicating the need for alternative approaches, including herbal medicine. Among medicinal plants is Ziziphus nummularia (family Rhamnaceae), which is a thorny shrub rich in bioactive molecules. Leaves of Ziziphus nummularia have been used to treat many pathological conditions, including cancer. However, their effects on human PC are still unknown. Here, we show that the treatment of human pancreatic ductal adenocarcinoma cells (Capan-2) with Ziziphus nummularia ethanolic extract (ZNE) (100–300 μg/mL) attenuated cell proliferation in a time- and concentration-dependent manner. Pretreatment with N-acetylcysteine, an ROS scavenger, attenuated the anti-proliferative effect of ZNE. In addition, ZNE significantly decreased the migratory and invasive capacity of Capan-2 with a concomitant downregulation of integrin α2 and increased cell–cell aggregation. In addition, ZNE inhibited in ovo angiogenesis as well as reduced VEGF and nitric oxide levels. Furthermore, ZNE downregulated the ERK1/2 and NF-κB signaling pathways, which are known to drive tumorigenic and metastatic events. Taken together, our results suggest that ZNE can attenuate the malignant phenotype of Capan-2 by inhibiting hallmarks of PC. Our data also provide evidence for the potential anticancer effect of Ziziphus nummularia, which may represent a new resource of novel anticancer compounds, especially ones that can be utilized for the management of PC.

Acute gastroenteritis (AGE) remains a significant cause of diarrhea that affects children worldwide. It is usually caused by viral agents, including rotavirus (RV), norovirus (NoV), adenovirus (AdV), astrovirus (AstV), and sapovirus (SaV), and the disease severity varies accordingly. Here, we report the association of clinical severity among AGE-infected pediatrics caused by a single viral pathogen, coinfection (viral-viral), mixed infection (viral-bacterial), and AGE-negative samples. A total of 901 pediatric patients were admitted with AGE to the Pediatric Emergency Center of Hamad Medical Corporation in Qatar from June 2016 to June 2018. The age of the subjects ranged between 3 months and 14 years (median of 16 months). Virus antigens detection was performed by using Film Array Gastrointestinal (GI) Panel kit. AGE severity was assessed using the Vesikari Clinical Severity Scoring System. Multivariable multinomial logistic regression was used to model the five AGE viral agents' likelihood in relation to severity versus co-infection, mixed infection, and AGE-negative samples. AGE was most common in pediatrics aged 1-3 years (median age = 1.25 years) and more frequent in males than females, with a ratio of 1:0.8. About 19.2% of the infections were caused by NoV, followed by RV (18.2%), AdV (6.5%), SaV (2.3%), and AstV (1.8%). The majority of viral agents were detected higher in mixed infection (32.1%) than coinfection (4.9%). Based on the Vesikari score system, severe clinical illness was recorded among pediatrics infected with RV (82.2%) and NoV (75.7%). Further on multivariable analysis, compared to testing negative, the odds of detecting RV was three times significantly higher in children with severe symptoms relative to those with moderate (adjusted-odds ratio [a-OR] = 3.10; 95% confidence interval [CI] = 1.82-5.28). Similar results were observed when considering RV relative to co-infection and mixed infection (a-OR = 2.59; 95% CI = 1.23-5.48 and a-OR = 2.06; 1.28-3.30, respectively). About one-third of the study sample were Qatari children with AGE (33%), whereas 35% and 32% were pediatrics from the Middle East and North Africa region, excluding Qatari and nonregions. This study underlines the association of disease severity among AGE-infected pediatrics in Qatar. The overall Vesikari median score was significantly high, followed by more frequent hospitalization among RV-infected pediatrics compared to others. There was no reduction in the disease severity among RV-infected regardless of the vaccine dose.

BackgroundVaccines against SARS-CoV-2 have been developed, but their availability falls far short of global needs. This study aimed to investigate the impact of prioritizing available doses on the basis of recipient antibody status, that is by exposure status, using Qatar as an example.MethodsVaccination impact was assessed under different scale-up scenarios using a deterministic meta-population mathematical model describing SARS-CoV-2 transmission and disease progression in the presence of vaccination.ResultsFor a vaccine that protects against infection with an efficacy of 95%, half as many vaccinations were needed to avert one infection, disease outcome, or death by prioritizing antibody-negative individuals for vaccination. Prioritization by antibody status reduced incidence at a faster rate and led to faster elimination of infection and return to normalcy. Further prioritization by age group amplified the gains of prioritization by antibody status. Gains from prioritization by antibody status were largest in settings where the proportion of the population already infected at the commencement of vaccination was 30-60%, which is perhaps where most countries will be by the time vaccination programs are up and running. For a vaccine that only protects against disease and not infection, vaccine impact was reduced by half, whether this impact was measured in terms of averted infections or disease outcomes, but the relative gains from using antibody status to prioritize vaccination recipients were similar.ConclusionsMajor health, societal, and economic gains can be achieved more quickly by prioritizing those who are antibody-negative while doses of the vaccine remain in short supply.

BackgroundQatar has experienced a large SARS-CoV-2 epidemic. Our first objective was to assess the proportion of the urban population that has been infected with SARS-CoV-2, by measuring the prevalence of detectable antibodies. Our second objective was to identify predictors for infection and for having higher antibody titers.MethodsResidual blood specimens from individuals receiving routine and other clinical care between May 12-September 9, 2020 were tested for anti-SARS-CoV-2 antibodies. Associations with seropositivity and higher antibody titers were identified through regression analyses. Probability weights were applied in deriving the epidemiological measures.ResultsWe tested 112,941 individuals (∼10% of Qatar’s urban population), of whom 51.6% were men and 66.0% were 20-49 years of age. Seropositivity was 13.3% (95% CI: 13.1-13.6%) and was significantly associated with sex, age, nationality, clinical-care type, and testing date. The proportion with higher antibody titers varied by age, nationality, clinical-care type, and testing date. There was a strong correlation between higher antibody titers and seroprevalence in each nationality, with a Pearson correlation coefficient of 0.85 (95% CI: 0.47-0.96), suggesting that higher antibody titers may indicate repeated exposure to the virus. The percentage of antibody-positive persons with prior PCR-confirmed diagnosis was 47.1% (95% CI: 46.1-48.2%), severity rate was 3.9% (95% CI: 3.7-4.2%), criticality rate was 1.3% (95% CI: 1.1-1.4%), and fatality rate was 0.3% (95% CI: 0.2-0.3%).ConclusionsFewer than two in every 10 individuals in Qatar’s urban population had detectable antibodies against SARS-CoV-2 between May 12-September 9, 2020, suggesting that this population is still far from the herd immunity threshold and at risk from a subsequent epidemic wave.

We document two cases of viremic and prolonged active infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) where the viral genome was conserved for two months, but infection was with little or no symptoms. The first infection persisted for 80 days and the second for 62 days. Clearance of infection occurred 40 and 41 days, respectively, after development of detectable antibodies. Both cases were identified incidentally in an investigation of reinfection in a cohort of 133,266 laboratory-confirmed infected persons., Highlights • Two cases had substantial viral RNA concentration and conserved viral genome for ~2 months. • Infection clearance occurred >60 days after first positive swab. • Infection clearance occurred ~40 days after development of detectable antibodies. • Prolonged active infection was not associated with severity.

Additional file 1: Table S1.. Study strata. Table S2. Sample size determination and response rate by strata. Table S3. Validity parameters for IgG serology. Table S4. Nationality categories. Table S5. Point prevalence ratios of SARS-CoV2 by age, gender, nationality and municipality. Table S6. Period prevalence ratios of SARS-CoV2 by age, gender, nationality and municipality. Table S7. Period prevalence ratios of SARS-CoV2 by sociodemographic, lifestyle and clinical characteristics.

Additional file 1: Figure S1. Microbiome comparison among gastroenteritis severity groups arranged according to Vesikari index, Microbiome composition between severe (n = 31) and moderate (n = 8) gastroenteritis groups. (S1a) presents relative percentage of the selected bacterial phyla. (S1b) presents mean abundances of the bacterial species/genera. Statistical comparisons were made using Mann-Whitney U test. (S1c) presents Shannon-entropy of the study groups. Statistical comparisons were made using Mann-Whitney U test. (S1d) presents beta diversity PCoA plots. Beta diversity comparisons were made using weighted unifrac index and statistical comparisons were made using PERMANOVA. p ≤ 0.05 was considered statistically significant and presented here. Figure S2.Microbiome comparison among diarrhea severity-index groups. Microbiome composition among mild (n = 16), moderate (n = 13), and severe (n = 10) diarrhea groups. (S2a) presents relative percentage of the selected bacterial phyla. (S2b) presents mean abundances of the bacterial species/genera. Statistical comparisons were made using Kruskal Wallis test. (S2c) presents Shannon-entropy of the study groups. Statistical comparisons were made using Kruskal Wallis test. (S2d) presents beta diversity PCoA plots. Beta diversity comparisons were made using weighted unifrac index and statistical comparisons were made using PERMANOVA. P ≤ 0.05 was considered statistically significant and presented here. Figure S3. Microbiome comparison among vomiting severity-index groups. Microbiome composition among mild (n = 15), moderate (n = 11), and severe (n = 13) diarrhea groups. (S3a) presents relative percentage of the selected bacterial phyla. (S3b) presents mean abundances of the bacterial species/genera. Statistical comparisons were made using Kruskal Wallis test. (S3c) presents Shannon-entropy of the study groups. Statistical comparisons were made using Kruskal Wallis test. (S3d) presents beta diversity PCoA plots. Beta diversity comparisons were made using weighted unifrac index and statistical comparisons were made using PERMANOVA. P ≤ 0.05 was considered statistically significant and presented here. Figure S4. Microbiome comparison among age groups. Microbiome composition among infants (n = 13), toddlers (n = 23), and pre-School (n = 11) children. (S4a) presents relative percentage of the selected bacterial phyla. (S4b) presents mean abundances of the bacterial species/genera. Statistical comparisons were made using Kruskal Wallis test. (S4c) presents Shannon-entropy of the study groups. Statistical comparisons were made using Kruskal Wallis test. (S4d) presents beta diversity PCoA plots. Beta diversity comparisons were made using weighted unifrac index and statistical comparisons were made using PERMANOVA. P ≤ 0.05 was considered statistically significant and presented here. Figure S5. Microbiome comparison between gender. Microbiome composition among male (n = 28) and female (n = 19) children. (S5a) presents relative percentage of the selected bacterial phyla. (S5b) presents mean abundances of the bacterial species/genera. Statistical comparisons were made using Mann-Whitney U test. (2c) presents mean abundances of significantly different bacterial phyla. Statistical comparisons were made using Mann-Whitney U test. (S5d) presents Shannon-entropy of the study groups. Statistical comparisons were made using Mann-Whitney U test. (S5e) presents beta diversity PCoA plots. Beta diversity comparisons were made using weighted unifrac index and statistical comparisons were made using PERMANOVA. P ≤ 0.05 was considered statistically significant and presented here. Figure S6. Microbiome comparison among Rotavirus genotypes. Microbiome composition among rotavirus genotypes; G3P8 (n = 25), G1P8 (n = 6), G2P4 (n = 4), G3P4 (n = 2), and G9P8 (n = 2). (S6a) presents relative percentage of the selected bacterial phyla. (S6b) presents mean abundances of the bacterial species/genera. Statistical comparisons were made using Kruskal Wallis test. (S6c) presents Shannon-entropy of the study groups. Statistical comparisons were made using Kruskal Wallis test. (S6d) presents beta diversity PCoA plots. Beta diversity comparisons were made using weighted unifrac index and statistical comparisons were made using PERMANOVA. P ≤ 0.05 was considered statistically and significant presented here. Figure S7. Correlation between microbiome and quantitative clinical features of the study participants. Spearman’s correlation analysis was performed using R package “corrplot 0.84” (RStudio version 3.5.0). The color intensity and shape of ellipse indicate the strength of the correlation depicted as r-value. Asterisks in each box indicate the p-value; ** ≤ 0.001 and * ≤ 0.01.

BackgroundPerformance of three automated commercial serological IgG-based assays was investigated for assessing SARS-CoV-2 ever (past or current) infection in a population-based sample in a high exposure setting.MethodsPCR and serological testing was performed on 394 individuals.ResultsSARS-CoV-2-IgG seroprevalence was 42.9% (95% CI 38.1%-47.8%), 40.6% (95% CI 35.9%-45.5%), and 42.4% (95% CI 37.6%-47.3%) using the CL-900i, VidasIII, and Elecsys assays, respectively. Between the three assays, overall, positive, and negative percent agreements ranged between 93.2%-95.7%, 89.3%-92.8%, and 93.8%-97.8%, respectively; Cohen kappa statistic ranged from 0.86-0.91; and 35 specimens (8.9%) showed discordant results. Among all individuals, 12.5% (95% CI 9.6%-16.1%) had current infection, as assessed by PCR. Of these, only 34.7% (95% CI 22.9%-48.7%) were seropositive by at least one assay. A total of 216 individuals (54.8%; 95% CI 49.9%-59.7%) had evidence of ever infection using antibody testing and/or PCR during or prior to this study. Of these, only 78.2%, 74.1%, and 77.3% were seropositive in the CL-900i, VidasIII, and Elecsys assays, respectively.ConclusionsAll three assays had comparable performance and excellent agreement, but missed at least 20% of individuals with past or current infection. Commercial antibody assays can substantially underestimate ever infection, more so when infection rates are high.