COVID-19 testing, incidence, and positivity trends among school age children during the academic years 2020-2022 in the State of Qatar: special focus on using CDC indicators for community transmission to evaluate school attendance policies and public health response.

BACKGROUND: There exists a gap in our understanding of the age-dependent epidemiological dynamics of SARS-CoV-2 among school-age children in comparison to adults within the State of Qatar. Additionally, there has been limited assessment of the timely implementation of physical distancing interventions, notably national school closures, and their impact on infection trends. METHODS: We used the national database to capture all records of polymerase-chain-reaction (PCR) testing, and rapid antigen tests (RAT) conducted at all health care venues in Qatar and administered between August 26, 2020, and August 21, 2022, across all age groups (≥ 5 years old). Study participants under 18 years old were categorized into two age brackets: (5-11) and (12-17), aligning with the Primary and Preparatory/Secondary grade levels in Qatar, respectively. We assessed age group testing rates, incidence rates, and positivity rates in relation to adults. These epidemiological metrics were compared with the CDC's thresholds for COVID-19 community transmission. RESULTS: Throughout the school years of 2020-2021 and 2021-2022, a total of 5,063,405 and 6,130,531 tests were respectively conducted. In the 2020-2021 school year, 89.6% of the tests were administered to adults, while 13.7% were conducted on children in the following year. The overall test positivity rates for the 2020-2021 and 2021-2022 school years were 5.8% and 8.1%, respectively. Adolescents underwent the fewest tests during the full study period compared to both adults and young children. Using the CDC indicators, we found that children and adolescents can significantly contribute to elevated infection rates, potentially driving community transmission upon relaxation of social restrictions. CONCLUSION: It is crucial to acknowledge the potential for higher transmission among youth and adolescents when formulating transmission control strategies and making decisions regarding school closures. Employing data-driven indicators and thresholds to monitor COVID-19 community levels is important for informing decision-making. These approaches also enable the prompt implementation of infection control transmission mitigation measures in future pandemics.

Leptin as a predictor of anthropometric cutoff points for obesity.

This study was conducted to find the association between leptin and adiposity indices. Secondly, to identify optimal threshold of various anthropometric indices for obesity, as assessed by 75th percentile of leptin levels, within a clinic sample of non-diabetic and diabetic Pakistani adults. Fasting serum leptin levels were compared with anthropometric markers of obesity in 164 diabetic and non-diabetic subjects (90 male, 74 female), aged 35 to 65 years. Obesity was defined by body mass index (BMI) of 25 kg/m2 in either sex. The cutoff point of leptin was taken as the 75th percentile in non-obese subjects. Diagnostic accuracy for detecting excess fatness was evaluated through receiver operating characteristics (ROC) analyses with leptin taken as reference test against anthropometric indices as test variables. The 75th percentile of leptin in male and female was 7.0ng/mL and 17.9ng/mL, respectively. Leptin levels were significantly higher in females (p<0.001) and had strong positive correlation (p<0.001) with most anthropometric indices of obesity in both sexes; hip circumference (HC) being most prominent among these. Largest area under ROC curve (AUC) was between WC and leptin (AUC=0.844; CI=0.764, 0.925) in males and BMI and leptin (AUC=0.832; CI=0.740, 0.923) in females. The optimum thresholds for obesity indices in our study were: BMI, WC and HC as 25 kg/m2, 96.25cm, 99.25cm for males; 27 kg/m2, 95.50cm, 105.5cm for females, respectively. Leptin can be considered as a potential marker of obesity and may be used to identify obesity cutoffs in future demographic surveys. Longitudinal studies are required that include leptin in coronary artery disease risk assessment models.

Molecular epidemiology of influenza, RSV, and other respiratory infections among children in Qatar: A six years report (2012-2017).

BACKGROUND: Studies on the etiology of respiratory infections among children in Qatar and surrounding countries are limited. OBJECTIVES: To describe the prevalence and seasonality of RSV, influenza, and other respiratory pathogens among children in Qatar. METHODS: We retrospectively collected and analyzed data of 33,404 children (<15 years) presented with influenza-like illness from 2012 to 2017. RESULTS: At least one respiratory pathogen was detected in 26,138 (78%) of patients. Together, human rhinoviruses (HRV), respiratory syncytial virus (RSV), and influenza viruses comprised nearly two-thirds of all cases, affecting 24%, 19.7%, and 18.5%, respectively. A prevalence of 5-10% was recorded for adenovirus, parainfluenza viruses (PIVs), human bocavirus (HboV), and human coronaviruses (HCoVs). Human metapneumovirus (HMPV), enteroviruses, M. pneumonia, and parechovirus had prevalences below 5%. While RSV, influenza, and HMPV exhibited strong seasonal activity in the winter, HRV was active during low RSV and influenza circulation. The burden of RSV exceeds that of influenza among young age groups, whereas influenza correlated positively with age. Further, HRV, adenovirus, influenza, and RSV infection rates varied significantly between male and females. CONCLUSION: This comprehensive multi-year study provides insights into the etiology of ILI among children in Qatar, which represents the Gulf region. Our results reinforce the significance of active surveillance of respiratory pathogens to improve infection prevention and control strategies, particularly among children.

Epidemiology of severe cases of influenza and other acute respiratory infections in the Eastern Mediterranean Region, July 2016 to June 2018.

BACKGROUND: Influenza surveillance systems in the Eastern Mediterranean Region have been strengthened in the past few years and 16 of the 19 countries in the Region with functional influenza surveillance systems report their influenza data to the EMFLU Network. This study aimed to investigate the epidemiology of circulating influenza viruses, causing SARI, and reported to the EMFLU during July 2016 to June 2018. METHODS: Data included in this study were collected by 15 countries of the Region from 110 SARI sentinel surveillance sites over two influenza seasons. RESULTS: A total of 40,917 cases of SARI were included in the study. Most cases [20,551 (50.2%)] were less than 5years of age. Influenza virus was detected in 3995 patients, 2849 (11.8%) were influenza A and 1146 (4.8%) were influenza B. Influenza A(H1N1)pdm09 was the predominant circulating subtype with 1666 cases (58.5%). Other than influenza, respiratory syncytial virus was the most common respiratory infection circulating, with 277 cases (35.9%). CONCLUSION: Influenza viruses cause a high number of severe respiratory infections in EMR. It is crucial for the countries to continue improving their influenza surveillance capacity in order detect any unusual influenza activity or new strain that may cause a pandemic.

Epidemiology of respiratory infections among adults in Qatar (2012-2017).

BACKGROUND: Limited data is available about the etiology of influenza like illnesses (ILIs) in Qatar. OBJECTIVES: This study aimed at providing preliminary estimates of influenza and other respiratory infections circulating among adults in Qatar. METHODS: We retrospectively collected data of about 44,000 patients who visited Hamad General Hospital clinics, sentinel sites, and all primary healthcare centers in Qatar between 2012 and 2017. All samples were tested for influenza viruses, whereas about 38,000 samples were tested for influenza and a panel of respiratory viruses using Fast Track Diagnostics (FTD) RT-PCR kit. RESULTS: Among all ILIs cases, 20,278 (46.5%) tested positive for at least one respiratory pathogen. Influenza virus was predominating (22.6%), followed by human rhinoviruses (HRVs) (9.5%), and human coronaviruses (HCoVs) (5%). A detection rate of 2-3% was recorded for mycoplasma pneumonia, adenoviruses, human parainfluenza viruses (HPIVs), respiratory syncytial virus (RSV), and human metapneumovirus (HMPV). ILIs cases were reported throughout the year, however, influenza, RSV, and HMPV exhibited strong seasonal peaks in the winter, while HRVs circulated more during fall and spring. Elderly (>50 years) had the lowest rates of influenza A (13.9%) and B (4.2%), while presenting the highest rates of RSV (3.4%) and HMPV (3.3%). While males had higher rates of HRVs (11.9%), enteroviruses (1.1%) and MERS CoV (0.2%), females had higher proportions of influenza (26.3%), HPIVs (3.2%) and RSV (3.6%) infections. CONCLUSION: This report provides a comprehensive insight about the epidemiology of ILIs among adults in the Qatar, as a representative of Gulf States. These results would help in improvement and optimization of diagnostic procedures, as well as control and prevention of the respiratory infections.