Effect of mRNA Vaccine Boosters against SARS-CoV-2 Omicron Infection in Qatar.

BACKGROUND: Waning of vaccine protection against coronavirus disease 2019 (Covid-19) and the emergence of the omicron (or B.1.1.529) variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have led to expedited efforts to scale up booster vaccination. Protection conferred by booster doses of the BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines in Qatar, as compared with protection conferred by the two-dose primary series, is unclear. METHODS: We conducted two matched retrospective cohort studies to assess the effectiveness of booster vaccination, as compared with that of a two-dose primary series alone, against symptomatic SARS-CoV-2 infection and Covid-19-related hospitalization and death during a large wave of omicron infections from December 19, 2021, through January 26, 2022. The association of booster status with infection was estimated with the use of Cox proportional-hazards regression models. RESULTS: In a population of 2,239,193 persons who had received at least two doses of BNT162b2 or mRNA-1273 vaccine, those who had also received a booster were matched with persons who had not received a booster. Among the BNT162b2-vaccinated persons, the cumulative incidence of symptomatic omicron infection was 2.4% (95% confidence interval [CI], 2.3 to 2.5) in the booster cohort and 4.5% (95% CI, 4.3 to 4.6) in the nonbooster cohort after 35 days of follow-up. Booster effectiveness against symptomatic omicron infection, as compared with that of the primary series, was 49.4% (95% CI, 47.1 to 51.6). Booster effectiveness against Covid-19-related hospitalization and death due to omicron infection, as compared with the primary series, was 76.5% (95% CI, 55.9 to 87.5). BNT162b2 booster effectiveness against symptomatic infection with the delta (or B.1.617.2) variant, as compared with the primary series, was 86.1% (95% CI, 67.3 to 94.1). Among the mRNA-1273-vaccinated persons, the cumulative incidence of symptomatic omicron infection was 1.0% (95% CI, 0.9 to 1.2) in the booster cohort and 1.9% (95% CI, 1.8 to 2.1) in the nonbooster cohort after 35 days; booster effectiveness against symptomatic omicron infection, as compared with the primary series, was 47.3% (95% CI, 40.7 to 53.3). Few severe Covid-19 cases were noted in the mRNA-1273-vaccinated cohorts. CONCLUSIONS: The messenger RNA (mRNA) boosters were highly effective against symptomatic delta infection, but they were less effective against symptomatic omicron infection. However, with both variants, mRNA boosters led to strong protection against Covid-19-related hospitalization and death. (Funded by Weill Cornell Medicine-Qatar and others.).

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.

Seroprevalence of herpes simplex virus type 1 and type 2 among the migrant workers in Qatar.

BACKGROUND: Limited data exists on herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infections in migrant populations. This study investigated HSV-1 and HSV-2 seroprevalences and associations among craft and manual workers (CMWs) in Qatar who constitute 60% of Qatar's population. METHODS: A national population-based cross-sectional seroprevalence survey was conducted on the CMW population, all men, between July 26 and September 9, 2020. 2,612 sera were tested for anti-HSV-1 IgG antibodies using HerpeSelect 1 ELISA IgG kits and for anti-HSV-2 IgG antibodies using HerpeSelect 2 ELISA IgG kits (Focus Diagnostics, USA). Univariable and multivariable logistic regression analyses were conducted to identify associations with HSV-1 and HSV-2 infections. RESULTS: Serological testing identified 2,171 sera as positive, 403 as negative, and 38 as equivocal for HSV-1 antibodies, and 300 sera as positive, 2,250 as negative, and 62 as equivocal for HSV-2 antibodies. HSV-1 and HSV-2 seroprevalences among CMWs were estimated at 84.2% (95% CI 82.8-85.6%) and 11.4% (95% CI 10.1-12.6%), respectively. HSV-1 infection was associated with nationality, educational attainment, and occupation. HSV-2 infection was associated with age, nationality, and educational attainment. CONCLUSIONS: Over 80% of CMWs are infected with HSV-1 and over 10% are infected with HSV-2. The findings highlight the need for sexual health programs to tackle sexually transmitted infections among the CMW population.

Severity, Criticality, and Fatality of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Beta Variant.

Beta (B.1.351)-variant coronavirus disease 2019 (COVID-19) disease was investigated in Qatar. Compared with the Alpha (B.1.1.7) variant, odds (95% confidence interval) of progressing to severe disease, critical disease, and COVID-19-related death were 1.24-fold (1.11-1.39), 1.49-fold (1.13-1.97), and 1.57-fold (1.03-2.43) higher, respectively, for the Beta variant.

Pharmaceutical Care Service at Primary Health Care Centers: An Insight on Patient Satisfaction.

Background: Patient's health care experiences and satisfaction are frequently used as a healthcare quality indicator. Aim: The study aims to evaluate the level of patient satisfaction with the pharmacy services provided at the Primary Health Care Corporation's (PHCC) pharmacies in Qatar. Methods: This study is a cross-sectional survey conducted in December of 2019. The study's setting is the Primary Health Care centers' pharmacies. All adult patients (≥18 years old) with mobile phone numbers documented on file who had their prescription orders filled at the PHCC's pharmacy units in 2019 were included in the study. Descriptive and inferential statistical methods were used to present the findings. The significance level was set at the alpha level of 0.05. Results: The usable responses were 9,564 from the total participants. Around 55.2% (N = 5,283) were males, 56.5% (N = 5,405) were in the age group (25-40), 19.2% (N = 1,837) were Qatari nationals, 39.7% (N = 3,801) had their medication dispensed in the Central Region of the State of Qatar, and 72.8% (N = 6,964) had at least undergraduate or higher degrees. The overall mean (SD) satisfaction score was (3.24 ± 0.629). Participants were less satisfied with their pharmacist's communication, especially offering information about medication's side effects (2.61 ± 1.2) and general health counselling (2.39 ± 1.2). Respondents were also less satisfied with waiting time (3.02 ± 1.3). Waiting time, gender, age, nationality, geographical region of the pharmacy, educational level, and familiarity with the PHCC were significantly associated with satisfaction level. Conclusion: The patients were reasonably satisfied, and the satisfaction level differed among different sociodemographic groups. Based on the public's needs and expectations, pharmacists need to continuously improve their effort to enhance the healthcare quality in the organization.

Understanding the epidemiological characteristics of the primary healthcare corporation-based COVID-19 swabbed persons in Qatar, 2020.

BACKGROUND: In March 2020, Qatar started reporting increased numbers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing coronavirus disease 2019 (COVID-19). National preventive measures were implemented, and a testing plan was developed to respond to the pandemic with the Primary Health Care Corporation (PHCC) as the central element. PHCC is the main public primary healthcare provider in Qatar and it operates in 27 health centers with around 1.4 million registered individuals as of January 1, 2020. The latter population was distributed across four main nationality groups; Middle Eastern and North African (51.5%), Asian (41.2%), African (2.4%), and others (5.1%). At the primary healthcare level in Qatar, this study describes the epidemiological characteristics of individuals registered at PHCC who had contracted COVID-19 in 2020 during the first wave before the vaccination phase and examines the factors associated with the positivity rate. METHODS: Retrospective data analysis was conducted for persons screened for SARS-CoV-2 in primary healthcare health centers in Qatar between March 11 and December 31, 2020. The study analyzed the demographic characteristics of the tested persons and noncommunicable disease burden, positivity rate by month, nationality, and age-group, and the factors associated with the positivity rate. RESULTS:  Between March 11 and December 31, 2020, PHCC tested 379,247 persons for SARS-CoV-2, with a median age (IQR) of 32 (21-42) years. Of these, 57.0% were from the Middle East and North Africa, and 32.5% were originally from Asia. Overall, 10.9% had diabetes mellitus and 11.3% had hypertension. The epidemiological curve showed a steep increase in the positivity rate from March till May 2020, at the highest rate of 37.5% in May 2020. The highest positivity rate was observed among Asian males at 15.7%. The positivity rate was the lowest among the age-group aged 60 years and above. It was almost the same among the tested persons for SARS-CoV-2 in the three main age groups (0-18, 19-39, 40-59) at 10.1%, 12.3%, and 12.2%, respectively. In a multi regression model, being a male was associated with a higher risk (OR 1.15; 95% CI 1.13-1.17). Asians were at higher risk than those originally from the Middle East and North Africa (OR 1.29; 95% CI 1.27-1.32). COVID-19 infection was higher among those presenting clinical symptoms than asymptomatic individuals (OR. 4.52; 95% CI 4.42-4.64). CONCLUSION: The epidemic among the PHCC-registered population predominantly affected younger ages and males, namely, coming from Asia. At the primary healthcare level, the COVID-19 infection rate was higher among those who presented with clinical symptoms. The lowest positivity rate among individuals >60 years may reflect the effectiveness of public health measures related to the high-risk group. Scaled-up testing at the primary healthcare level helped to detect more cases during the peak of the first wave and was reflected in a steady increase in the positivity rate flattened later due to the established public health measures.

Introduction and expansion of the SARS-CoV-2 B.1.1.7 variant and reinfections in Qatar: A nationally representative cohort study.

BACKGROUND: The epidemiology of the SARS-CoV-2 B.1.1.7 (or Alpha) variant is insufficiently understood. This study's objective was to describe the introduction and expansion of this variant in Qatar and to estimate the efficacy of natural infection against reinfection with this variant. METHODS AND FINDINGS: Reinfections with the B.1.1.7 variant and variants of unknown status were investigated in a national cohort of 158,608 individuals with prior PCR-confirmed infections and a national cohort of 42,848 antibody-positive individuals. Infections with B.1.1.7 and variants of unknown status were also investigated in a national comparator cohort of 132,701 antibody-negative individuals. B.1.1.7 was first identified in Qatar on 25 December 2020. Sudden, large B.1.1.7 epidemic expansion was observed starting on 18 January 2021, triggering the onset of epidemic's second wave, 7 months after the first wave. B.1.1.7 was about 60% more infectious than the original (wild-type) circulating variants. Among persons with a prior PCR-confirmed infection, the efficacy of natural infection against reinfection was estimated to be 97.5% (95% CI: 95.7% to 98.6%) for B.1.1.7 and 92.2% (95% CI: 90.6% to 93.5%) for variants of unknown status. Among antibody-positive persons, the efficacy of natural infection against reinfection was estimated to be 97.0% (95% CI: 92.5% to 98.7%) for B.1.1.7 and 94.2% (95% CI: 91.8% to 96.0%) for variants of unknown status. A main limitation of this study is assessment of reinfections based on documented PCR-confirmed reinfections, but other reinfections could have occurred and gone undocumented. CONCLUSIONS: In this study, we observed that introduction of B.1.1.7 into a naïve population can create a major epidemic wave, but natural immunity in those previously infected was strongly associated with limited incidence of reinfection by B.1.1.7 or other variants.

Epidemiology of SARS-CoV2 in Qatar's primary care population aged 10 years and above.

BACKGROUND: There is an urgent need to elucidate the epidemiology of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) and characterize its potential impact. Investing in characterising the SARS-CoV2 will help plan and improve the response to the pandemic. Furthermore, it will help identify the most efficient ways of managing the pandemic, avoiding public health policies and interventions that may be unduly restrictive of normal activity or unnecessarily costly. This paper describes the design and reports findings of a population based epidemiological study undertaken to characterise SARS-CoV2 in Qatar using limited resources in a timely manner. METHODS: Asymptomatic individuals ≥10 years registered with Qatar's publicly funded primary health provider were eligible. A stratified random sampling technique was utilized to identify the study sample. Participants were invited to an appointment where they completed a questionnaire and provided samples for polymerase chain reaction and Immunoglobulin M and G immunoassay tests. Data collected were analyzed to calculate point and period prevalence by sociodemographic, lifestyle and clinical characteristics. RESULTS: Of 18,918 individuals invited for the study, 2084 participated (response rate 10.8%). The overall point prevalence and period prevalence were estimated to be 1.6% (95% CI 1.1-2.2) and 14.6% (95% CI 13.1-16.2) respectively. Period prevalence of SARS-CoV2 infection was not considerably different across age groups (9.7-19.8%). It was higher in males compared to females (16.2 and 12.7% respectively). A significant variation was observed by nationality (7.1 to 22.2%) and municipalities (6.9-35.3%). CONCLUSIONS: The study provides an example of a methodologically robust approach that can be undertaken in a timely manner with limited resources. It reports much-needed epidemiological data about the spread of SARS-CoV2. Given the low prevalence rates, majority of the population in Qatar remains susceptible. Enhanced surveillance must continue to be in place, particularly due to the large number of asymptomatic cases observed. Robust contact tracing and social distancing measures are key to prevent future outbreaks.

Association of Prior SARS-CoV-2 Infection With Risk of Breakthrough Infection Following mRNA Vaccination in Qatar.

Importance: The effect of prior SARS-CoV-2 infection on vaccine protection remains poorly understood. Objective: To assess protection from SARS-CoV-2 breakthrough infection after mRNA vaccination among persons with vs without prior SARS-CoV-2 infection. Design, Setting, and Participants: Matched-cohort studies in Qatar for the BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines. A total of 1 531 736 individuals vaccinated with either vaccine between December 21, 2020, and September 19, 2021, were followed up beginning 14 days after receiving the second dose until September 19, 2021. Exposures: Prior SARS-CoV-2 infection and COVID-19 vaccination. Main Outcomes and Measures: Incident SARS-CoV-2 infection, defined as a polymerase chain reaction (PCR)-positive nasopharyngeal swab regardless of reason for PCR testing or presence of symptoms. Cumulative incidence was calculated using the Kaplan-Meier estimator method. Results: The BNT162b2-vaccinated cohort comprised 99 226 individuals with and 290 432 matched individuals without prior PCR-confirmed infection (median age, 37 years; 68% male). The mRNA-1273-vaccinated cohort comprised 58 096 individuals with and 169 514 matched individuals without prior PCR-confirmed infection (median age, 36 years; 73% male). Among BNT162b2-vaccinated persons, 159 reinfections occurred in those with and 2509 in those without prior infection 14 days or more after dose 2. Among mRNA-1273-vaccinated persons, 43 reinfections occurred in those with and 368 infections in those without prior infection. Cumulative infection incidence among BNT162b2-vaccinated individuals was an estimated 0.15% (95% CI, 0.12%-0.18%) in those with and 0.83% (95% CI, 0.79%-0.87%) in those without prior infection at 120 days of follow-up (adjusted hazard ratio for breakthrough infection with prior infection, 0.18 [95% CI, 0.15-0.21]; P < .001). Cumulative infection incidence among mRNA-1273-vaccinated individuals was an estimated 0.11% (95% CI, 0.08%-0.15%) in those with and 0.35% (95% CI, 0.32%-0.40%) in those without prior infection at 120 days of follow-up (adjusted hazard ratio, 0.35 [95% CI, 0.25-0.48]; P < .001). Vaccinated individuals with prior infection 6 months or more before dose 1 had statistically significantly lower risk for breakthrough infection than those vaccinated less than 6 months before dose 1 (adjusted hazard ratio, 0.62 [95% CI, 0.42-0.92]; P = .02 for BNT162b2 and 0.40 [95% CI, 0.18-0.91]; P = .03 for mRNA-1273 vaccination). Conclusions and Relevance: Prior SARS-CoV-2 infection was associated with a statistically significantly lower risk for breakthrough infection among individuals receiving the BNT162b2 or mRNA-1273 vaccines in Qatar between December 21, 2020, and September 19, 2021. The observational study design precludes direct comparisons of infection risk between the 2 vaccines.

Epidemiological health assessment in primary healthcare in the State of Qatar- 2019.

BACKGROUND: In the public sector in Qatar, the Primary Health Care Corporation (PHCC) is the major provider of primary healthcare services to families. Therefore, the PHCC conducted the first epidemiological health assessment to understand the burden of diseases and their subsequent risk factors impacting its registered population, to design better services, implement it and allocate resources to respond to the population health needs. METHODS: A cross-sectional study design was adopted among all PHCC registered populations between September 1, 2018, and August 31, 2019. The study target population was all persons residing in Qatar aged 0+ years and registered at the 27 health centers affiliated with the PHCC; excluding patients with an expired residence permit on August 31, 2019, and craft male workers were provided their primary healthcare services at the Qatar Red Crescent health facilities. The data were extracted from patients' electronic medical records (EMR). RESULTS: The burden of type 2 diabetes, hypertension, and dyslipidemia were the highest among the population of the central region at 13.9%, 15.7%, and 11.1%, respectively. Tobacco consumption among males was higher than females and ranged from 25.4% to 27.8%, with the highest rate in the northern region. Obesity rates ranged between 34.7% and 37.0% among the total population registered with the lowest rate in the central region, while 39.9% of females in the northern region had a body mass index above 30 kg/m2. Exclusive breastfeeding at 6 months was significantly lower than that at 4 months across all regions. Children in the northern region had the highest rate of overweight/obesity based on Z-scores. The western region population had the highest number of communicable diseases notifications. CONCLUSION: Understanding the patterns of disease in the local population will enable the PHCC to plan a clear set of services that meet the population's health needs, which include tailored health education and promotion components.

School-time physical activity among Arab elementary school children in Qatar.

BACKGROUND: Recent data from a self-administered questionnaire show that approximately 75% of school children in Qatar do not meet the daily recommended levels of physical activity (PA). Since children spend half of their waking hours in school, it is important to understand when and how much PA children accumulate during the school day. This study aimed to objectively assess school-time PA among elementary school children in Qatar and to determine association of PA with age, gender, body mass index (BMI) status, or day of the week. METHODS: A cross-sectional epidemiological study was conducted in four randomly selected elementary schools in Qatar. Two classes representing grade 1 children (age 5) and grade 4 children (age 9) were randomly selected within each school. A total of 183 elementary school children (86 boys and 97 girls) ages 6-12 years participated in this study. PA was assessed using a three-axial accelerometer (ActiGraph® wGT3X-BT). Participants wore accelerometers on their non-dominant wrist at school (7:00 a.m. to 1:00 p.m.) for five consecutive school days during the week. A cutoff points of 818 counts per 5 s was classified as moderate-to-vigorous physical activity (MVPA). RESULTS: The average duration of MVPA in our study was 28.2 ± 13.5 min per day. Only 39% of participated children reach the recommended school-based MVPA of 30 min or more per day. Students spent on average 58.1 ± 8.4% of school time on sedentary activities. MVPA of boys and girls was similar in age 5 while girls age 9 were less active (23.7 ± 1.5 min/day) than boys of the same age (42.7 ± 1.8 min/day), ES = 0.269, P < 0.001. Neither overweight children nor children at risk for being overweight showed any differences in physical activity parameters when compared to children of normal weight. Our results showed, percentage of MVPA on the first (7.7 ± 5.1%) and last (7.1 ± 4.1%) day of the week was generally lower compared to other weekdays (P < 0.001). CONCLUSION: This was the first study to objectively assess PA during school hours among elementary school-children in Qatar. This study found that many of school children do not perform sufficient time being physically active at school. All students in two age categories (age 5 and age 9) spend the majority of school time engaged in sedentary activities. The low participation of girls age 9 in MVPA is a cause for concern and need to be addressed.

Assessing the impact of annual health screenings in identifying noncommunicable disease risk factors within Qatar's primary health care corporation Qatari registered population.

Background: Noncommunicable diseases (NCDs) are a significant global health burden, including in Qatar, where cardiovascular diseases cause mortality. This study examines the outcomes of the annual health checkup implemented by the Primary Health Care Corporation (PHCC) in Qatar in detecting NCDs risk factors among Qataris aged 18+ years. Methods: A cross-sectional study design was implemented to calculate the prevalence of behavioural and metabolic NCDs risk factors among Qataris who underwent annual health checkups between 2017 and 2019. Data on age, gender, tobacco consumption, height, weight, blood pressure, glycated haemoglobin (HbA1c), and cholesterol levels were extracted from electronic medical records. Results: In 2019, Qatar experienced an 80% rise in Annual Health checkups attendance compared to 2017. Tobacco use fluctuated between 11.79 and 12.91%, peaking at 35.67% among males in 2018. Qataris with elevated blood pressure dropped from 29.44% in 2017 to 18.52% in 2019. Obesity decreased from 48.32 to 42.29%, more prevalent in females. High HbA1c levels reduced from 13.33 to 8.52%, while pre-diabetic levels rose from 21.1 to 25.52%. High cholesterol ranged from 7.31 to 9.47%. In a regression analysis, males had 2.28 times higher odds of elevated blood pressure and 1.54 times higher odds of high HbA1c, with a 0.68 lower odds of obesity compared to females. Ages 36 and above had 2.61 times higher odds of high cholesterol compared to younger age groups. Conclusion: The annual health screening has shown promising results in detecting and addressing NCDs risk factors among Qataris. The attendance rate has increased over the three-year period, and there has been a decrease in the prevalence of elevated blood pressure, obesity, and high HbA1c levels. However, tobacco consumption and pre-diabetic levels remain significant concerns. These findings can guide the implementation of tailored preventative and curative services to improve the health and well-being of the Qatari population.

Post-COVID-19 syndrome, who at risk and why: an insight from Qatar 2022.

Background: Despite the recovery from the COVID-19 pandemic, many people experience post-COVID-19 syndrome, which negatively impacts their health and function. This condition has become a significant public health problem that requires immediate attention. Objective: To study the prevalence, clinical characteristics, and predictors of post-COVID-19 Syndrome in Qatar during 2022. Methods: An analytic cross-sectional study was conducted among COVID-19 confirmed cases from January 2022 to July 2022 in Qatar. A simple random sample was employed to include (n = 588) participants from the list of cases and invited to participate in a telephone survey. The World Health Organization's standard case definition for PCS was adopted. Results: Out of 368, the prevalence of post-COVID-19 syndrome was 43.2% (n = 159). Most PCS cases were females (67.9%; n = 108), married (73.6%; n = 117), and university and higher educational level (83.6%; n = 133). However, 78.7% (n = 125) reported poor to moderate levels of social support. Only 30.2% (n = 48) of PCS patients had a history of chronic diseases, and 5.7% (n = 9) required hospital admission during acute illness. Among PCS cases, the most commonly reported symptoms were fatigue (75.5%), followed by anxiety (49.1%), forgetfulness (46.5%), mood alteration (45.3%), and general weakness (39.6%). The logistic regression revealed that female gender (AOR: 2.58 95%CI: 1.58-4.225, p < 0.0001), university and high educational level (AOR: 2.2, 95%CI: 1.256-3.98, p < 0.006), poor level of social support (AOR: 2.45; 95%CI: 1.55-4.13; p < 0.002), were significant predictors for PCS. Conclusion: Post-COVID-19 syndrome may go under-recognized. More efforts are needed to raise awareness and mobilize the resources to respond to this ongoing public health problem.

Tobacco control in Qatar from 2002 to 2022: 20 years of progress and challenges.

Tobacco use and exposure has been known as one of the leading causes of premature mortality worldwide. Tobacco control measures have been considered one of the strategies for reducing the burden of NCDs, improving public health, and strengthening the health system's response to threats and pandemics. The State of Qatar has put tobacco control a national public health priority as it has adopted various tobacco control measures that the WHO classified as high-impact measures. This has resulted in achieving tobacco control milestones which led to constant monitoring of tobacco use and the provision of smoking cessation services at all healthcare levels. However, there is still much work to be done to fill the gaps and respond to the emergence of novel tobacco products and market strategies in an effective way. This review highlights the status of tobacco use and exposure in the State of Qatar, and focus on the progress, and challenges in the implementation of tobacco control policies and smoking cessation services between 2002 and 2022.

Short-term side effects of BNT162b2 vaccine in primary care settings in Qatar: a retrospective study.

Background: Despite the established effectiveness of the BNT162b2 Vaccine, the novel technology demands careful safety monitoring. While global studies have explored its safety, local data remains limited and exhibits some variability. This study investigated short-term side effects among BNT162b2 vaccinated individuals in Qatar. Methods: A retrospective analysis was conducted using data extracted from the electronic health records of individuals aged 18 or older across 8 primary health centers who received either the first or second dose of the BNT162b2 vaccine during the period from December 23, 2020, to April 24, 2021. The proportions of individuals experiencing short-term side effects after each dose were calculated. Logistic regression and log binomial regression analyses were used to explore associations with the side effects. Results: Among 7,764 participants, 5,489 received the first dose and 2,275 the second, with similar demographics between the groups. After the first dose, 5.5% reported at least one local side effect, compared to 3.9% after the second, with a 1.4 times higher incidence after the first dose (RR 1.4, 95% CI 1.14-1.75) compared to the second. Systemic side effects after the second dose were 2.6 times more common than after the first (RR 2.6, 95% CI 2.15-3.14). Gender, nationality, history of prior COVID-19 infection, and obesity were significantly associated with side effects after the first dose, while age, gender, and nationality, were significant factors after the second dose. Conclusion: The rates of side effects following the BNT162b2 vaccine in Qatar were relatively low, with age, gender, nationality, previous infection, and obesity identified as significant predictors. These results emphasize the need for tailored vaccination strategies and contributes valuable insights for evidence-based decision-making in ongoing and future vaccination campaigns.

Addressing bias in the definition of SARS-CoV-2 reinfection: implications for underestimation.

Introduction: Reinfections are increasingly becoming a feature in the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, accurately defining reinfection poses methodological challenges. Conventionally, reinfection is defined as a positive test occurring at least 90 days after a previous infection diagnosis. Yet, this extended time window may lead to an underestimation of reinfection occurrences. This study investigated the prospect of adopting an alternative, shorter time window for defining reinfection. Methods: A longitudinal study was conducted to assess the incidence of reinfections in the total population of Qatar, from February 28, 2020 to November 20, 2023. The assessment considered a range of time windows for defining reinfection, spanning from 1 day to 180 days. Subgroup analyses comparing first versus repeat reinfections and a sensitivity analysis, focusing exclusively on individuals who underwent frequent testing, were performed. Results: The relationship between the number of reinfections in the population and the duration of the time window used to define reinfection revealed two distinct dynamical domains. Within the initial 15 days post-infection diagnosis, almost all positive tests for SARS-CoV-2 were attributed to the original infection. However, surpassing the 30-day post-infection threshold, nearly all positive tests were attributed to reinfections. A 40-day time window emerged as a sufficiently conservative definition for reinfection. By setting the time window at 40 days, the estimated number of reinfections in the population increased from 84,565 to 88,384, compared to the 90-day time window. The maximum observed reinfections were 6 and 4 for the 40-day and 90-day time windows, respectively. The 40-day time window was appropriate for defining reinfection, irrespective of whether it was the first, second, third, or fourth occurrence. The sensitivity analysis, confined to high testers exclusively, replicated similar patterns and results. Discussion: A 40-day time window is optimal for defining reinfection, providing an informed alternative to the conventional 90-day time window. Reinfections are prevalent, with some individuals experiencing multiple instances since the onset of the pandemic.

Effectiveness of two and three doses of COVID-19 mRNA vaccines against infection, symptoms, and severity in the pre-omicron era: A time-dependent gradient.

BACKGROUND: Vaccines were developed and deployed to combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to characterize patterns in the protection provided by the BNT162b2 and mRNA-1273 mRNA vaccines against a spectrum of SARS-CoV-2 infection symptoms and severities. METHODS: A national, matched, test-negative, case-control study was conducted in Qatar between January 1 and December 18, 2021, utilizing a sample of 238,896 PCR-positive tests and 6,533,739 PCR-negative tests. Vaccine effectiveness was estimated against asymptomatic, symptomatic, severe coronavirus disease 2019 (COVID-19), critical COVID-19, and fatal COVID-19 infections. Data sources included Qatar's national databases for COVID-19 laboratory testing, vaccination, hospitalization, and death. RESULTS: Effectiveness of two-dose BNT162b2 vaccination was 75.6% (95% CI: 73.6-77.5) against asymptomatic infection and 76.5% (95% CI: 75.1-77.9) against symptomatic infection. Effectiveness against each of severe, critical, and fatal COVID-19 infections surpassed 90%. Immediately after the second dose, all categories-namely, asymptomatic, symptomatic, severe, critical, and fatal COVID-19-exhibited similarly high effectiveness. However, from 181 to 270 days post-second dose, effectiveness against asymptomatic and symptomatic infections declined to below 40%, while effectiveness against each of severe, critical, and fatal COVID-19 infections remained consistently high. However, estimates against fatal COVID-19 often had wide 95% confidence intervals. Analogous patterns were observed in three-dose BNT162b2 vaccination and two- and three-dose mRNA-1273 vaccination. Sensitivity analyses confirmed the results. CONCLUSION: A gradient in vaccine effectiveness exists and is linked to the symptoms and severity of infection, providing higher protection against more symptomatic and severe cases. This gradient intensifies over time as vaccine immunity wanes after the last vaccine dose. These patterns appear consistent irrespective of the vaccine type or whether the vaccination involves the primary series or a booster.

Beliefs and attitudes about breast cancer and screening practices among Arab women living in Qatar: a cross-sectional study.

BACKGROUND: Despite rising breast cancer incidence and mortality rates, breast cancer screening (BCS) rates among women in Qatar remain low. Previous studies indicate the need to better understand the many complex beliefs, values, and attitudes that influence Arab women's health seeking behavior for the development of culturally appropriate and effective intervention strategies to address breast cancer in the Middle East. This study investigates beliefs, attitudes, and BCS practices of Arabic-speaking women in Qatar. METHODS: A multicenter, cross-sectional quantitative survey of 1,063 (87.5% response rate) Arabic-speaking female Qatari citizens and non-Qatari residents, 35 years of age or older, was conducted in Qatar from March 2011 to July 2011. Associations between beliefs and BCS practice were estimated using chi-square tests and multivariate logistic regression analyses. Participants who adhered to BCS guidelines (BCS practice = Yes) were compared to those who did not (BCS practice = No). RESULTS: In addition to low levels of awareness and low participation rates in BCS, one quarter of the participants stated their doctors talked to them about breast cancer, and less than half of the women interviewed believed breast cancer can be prevented. Women who engaged in BCS practice were more likely to have a doctor who talked to them about breast cancer, to believe they were in good-excellent health, that cancer can be prevented, or that cancer might be hereditary. The majority wanted to know if they had cancer and felt their health care needs were being met. The main reasons given for not planning BCS were lack of a doctor's recommendation, fear, and embarrassment. CONCLUSIONS: These findings indicate that a variety of channels (health care providers, media, breast cancer survivors, community leaders) should be utilized to create culturally appropriate breast cancer intervention programs and increased awareness of breast cancer, BCS, and the benefits of early detection of breast cancer. Employment of these measures will reduce breast cancer mortality rates among Arabic-speaking women living in the State of Qatar.

Sickness absenteeism among primary health care workers in Qatar before and during the COVID-19 pandemic.

OBJECTIVES: To explore the patterns, trends, nature, and extent of changes in sickness absence among health care workers (HCWs) at the Primary Health Care Corporation (PHCC) in Qatar-during the COVID-19 pandemic compared to previous years and uncover the main associated factors. METHODS: We conducted a retrospective analysis of all sick leaves' records of PHCC HCWs regardless of their profession from January 2019 till August 2021. RESULTS: A total of 41,132 sick leaves were taken during the studied period. The majority of HCWs who availed sick leaves were between 30-39 years (45.9%), females (65.1%), and expatriates (65.1%). Compared with pre-COVID-19 (Jan 2019-Feb 2020), Wave 1 of COVID-19 had significantly less incidence of sick leaves per day per 1000 HCWs. While wave 2 had significantly higher incidence of sick leaves compared to both pre-COVID-19 and wave 1. The number of sick leaves per person among female HCWs was significantly higher than that of male HCWs. Moreover, the number of sick leaves per person among locals were about two times the number among expatriate HCWs. Physicians and nurses had significantly lower number of sick leave per person compared to other professions. The rates of sick leaves due to suspected or confirmed COVID-19 infection, back/neck pain and gastroenteritis were significantly higher in the second wave compared to the first wave of COVID-19. CONCLUSION: Overall and cause specific sick leave rates among HCWs varied significantly across different periods of the COVID-19 pandemic. COVID-19 related sick leave rate was higher during the second wave compared to first one. By addressing the root causes of sick leaves, it is possible to reduce the burden on HCWs and ensure their continued ability to provide essential care to those in need.

Population immunity of natural infection, primary-series vaccination, and booster vaccination in Qatar during the COVID-19 pandemic: an observational study.

Background: Waning of natural infection protection and vaccine protection highlight the need to evaluate changes in population immunity over time. Population immunity of previous SARS-CoV-2 infection or of COVID-19 vaccination are defined, respectively, as the overall protection against reinfection or against breakthrough infection at a given point in time in a given population. Methods: We estimated these population immunities in Qatar's population between July 1, 2020 and November 30, 2022, to discern generic features of the epidemiology of SARS-CoV-2. Effectiveness of previous infection, mRNA primary-series vaccination, and mRNA booster (third-dose) vaccination in preventing infection were estimated, month by month, using matched, test-negative, case-control studies. Findings: Previous-infection effectiveness against reinfection was strong before emergence of Omicron, but declined with time after a wave and rebounded after a new wave. Effectiveness dropped after Omicron emergence from 88.3% (95% CI: 84.8-91.0%) in November 2021 to 51.0% (95% CI: 48.3-53.6%) in December 2021. Primary-series effectiveness against infection was 84.0% (95% CI: 83.0-85.0%) in April 2021, soon after introduction of vaccination, before waning gradually to 52.7% (95% CI: 46.5-58.2%) by November 2021. Effectiveness declined linearly by ∼1 percentage point every 5 days. After Omicron emergence, effectiveness dropped from 52.7% (95% CI: 46.5-58.2%) in November 2021 to negligible levels in December 2021. Booster effectiveness dropped after Omicron emergence from 83.0% (95% CI: 65.6-91.6%) in November 2021 to 32.9% (95% CI: 26.7-38.5%) in December 2021, and continued to decline thereafter. Effectiveness of previous infection and vaccination against severe, critical, or fatal COVID-19 were generally >80% throughout the study duration. Interpretation: High population immunity against infection may not be sustained beyond a year, but population immunity against severe COVID-19 is durable with slow waning even after Omicron emergence. Funding: The Biomedical Research Program and the Biostatistics, Epidemiology, and the Biomathematics Research Core, both at Weill Cornell Medicine-Qatar, Ministry of Public Health, Hamad Medical Corporation, Sidra Medicine, Qatar Genome Programme, Qatar University Biomedical Research Center, and Qatar University Internal Grant ID QUCG-CAS-23/24-114.