Model-based evaluation of the COVID-19 epidemiological impact on international visitors during Expo 2020.

The impact of the COVID-19 pandemic on large events has been substantial. In this work, an evaluation of the potential impact of international arrivals due to Expo 2020 in terms of potential COVID-19 infections from October 1st, 2021, until the end of April 2022 in the United Arab Emirates is presented. Our simulation results indicate that: (i) the vaccination status of the visitors appears to have a small impact on cases, this is expected as the small numbers of temporary visitors with respect to the total population contribute little to the herd immunity status; and (ii) the number of infected arrivals is the major factor of impact potentially causing a surge in cases countrywide with the subsequent hospitalisations and fatalities. These results indicate that the prevention of infected arrivals should take all precedence priority to mitigate the impact of international visitors with their vaccination status being of less relevance.

Modelling the effect of non-pharmaceutical interventions on COVID-19 transmission from mobility maps.

The world has faced the COVID-19 pandemic for over two years now, and it is time to revisit the lessons learned from lockdown measures for theoretical and practical epidemiological improvements. The interlink between these measures and the resulting change in mobility (a predictor of the disease transmission contact rate) is uncertain. We thus propose a new method for assessing the efficacy of various non-pharmaceutical interventions (NPI) and examine the aptness of incorporating mobility data for epidemiological modelling. Facebook mobility maps for the United Arab Emirates are used as input datasets from the first infection in the country to mid-Oct 2020. Dataset was limited to the pre-vaccination period as this paper focuses on assessing the different NPIs at an early epidemic stage when no vaccines are available and NPIs are the only way to reduce the reproduction number ( R 0 ). We developed a travel network density parameter ß t to provide an estimate of NPI impact on mobility patterns. Given the infection-fatality ratio and time lag (onset-to-death), a Bayesian probabilistic model is adapted to calculate the change in epidemic development with ß t . Results showed that the change in ß t clearly impacted R 0 . The three lockdowns strongly affected the growth of transmission rate and collectively reduced R 0 by 78% before the restrictions were eased. The model forecasted daily infections and deaths by 2% and 3% fractional errors. It also projected what-if scenarios for different implementation protocols of each NPI. The developed model can be applied to identify the most efficient NPIs for confronting new COVID-19 waves and the spread of variants, as well as for future pandemics.

Impact of the Sinopharm's BBIBP-CorV vaccine in preventing hospital admissions and death in infected vaccinees: Results from a retrospective study in the emirate of Abu Dhabi, United Arab Emirates (UAE).

BACKGROUND: This is a community-based, retrospective, observational study conducted to determine effectiveness of the BBIBP-CorV inactivated vaccine in the real-world setting against hospital admissions and death. STUDY DESIGN: Study participants were selected from 214,940 PCR-positive cases of COVID-19 reported to the Department of Health, Abu Dhabi Emirate, United Arab Emirates (UAE) between September 01, 2020 and May 1, 2021. Of these, 176,640 individuals were included in the study who were aged ≥ 15 years with confirmed COVID-19 positive status who had records linked to their vaccination status. Those with incomplete or missing records were excluded (n = 38,300). Study participants were divided into three groups depending upon their vaccination status: fully vaccinated (two doses), partially vaccinated (single dose), and non-vaccinated. Study outcomes included COVID-19-related admissions to hospital general and critical care wards and death. Vaccine effectiveness for each outcome was based on the incidence density per 1000 person-years. RESULTS: The fully-, partially- and non-vaccinated groups included 62,931, 21,768 and 91,941 individuals, respectively. Based on the incidence rate ratios, the vaccine effectiveness in fully vaccinated individuals was 80%, 92%, and 97% in preventing COVID-19-related hospital admissions, critical care admissions, and death, respectively, when compared to the non-vaccinated group. No protection was observed for critical and non-critical care hospital admissions for the partially vaccinated group, while some protection against death was apparent, although statistically insignificant. CONCLUSIONS: In a COVID-19 pandemic, use of the Sinopharm BBIBP-CorV inactivated vaccine is effective in preventing severe disease and death in a two-dose regimen. Lack of protection with the single dose may be explained by insufficient seroconversion and/or neutralizing antibody responses, behavioral factors (i.e., false sense of protection), and/or other biological factors (emergence of variants, possibility of reinfection, duration of vaccine protection, etc.).

Epidemiology of asymptomatic and symptomatic Coronavirus Disease 2019 confirmed cases in the Emirate of Abu Dhabi, United Arab Emirates: Observational study.

ABSTRACT: This study was conducted to describe demographics, clinical features, and outcomes of 3827 confirmed cases of Coronavirus Disease 2019 between March 12 and April 22, 2020 in the Emirates of Abu Dhabi, United Arab Emirates (UAE).Data were extracted from the Infectious Diseases Notification Surveillance System of the Department of Health. The descriptive analysis was done using Statistical Package for Social Sciences v26 and reported according to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement.We analyzed 3827 cases; 82% were men, 18% women, 14% UAE citizens, and 86% were of other nationalities. Most cases (72%) had lower exposure to low-risk occupations of infectious disease as per the classification of the department of health while high exposure risk occupations, which included healthcare worker accounts only for 3%. While 43% of cases were asymptomatic, 57% displayed symptoms, which were mostly mild. Only 12% of patients had comorbidities, which were significantly higher in men (9%) than women (3%). Among those who have comorbid conditions; hypertension (27%) and diabetes (21%) were the most common comorbidities. Viral pneumonia (11%) was the most common sequela documented in records. Only 51 patients (4%) required admission to the intensive care units, and 4 patients died (0.1%).The significant number of asymptomatic patients was identified by active case finding and contact tracing from the early period of the epidemic. A small percentage of severe, critical cases, and death reported in the Emirate of Abu Dhabi which may have been due to public health measures implemented for early detection, contact tracing, and treatment.

Epidemiological characterization of symptomatic and asymptomatic COVID-19 cases and positivity in subsequent RT-PCR tests in the United Arab Emirates.

The coronavirus disease 2019 (COVID-19) cases could be symptomatic or asymptomatic. We (1) characterized and analyzed data collected from the first cohort of reverse transcriptase polymerase chain reaction (RT-PCR)-confirmed COVID-19 cases reported in the Emirate of Abu Dhabi, United Arab Emirates, according to the symptomatic state, and (2) identified factors associated with the symptomatic state. The association between the symptomatic state and testing positive in three subsequent RT-PCR testing rounds was also quantified. Between February 28 and April 8, 2020, 1,249 cases were reported. Sociodemographic characteristics, working status, travel history, and chronic comorbidities of 791 cases were analyzed according to the symptomatic state (symptomatic or asymptomatic). After the first confirmatory test, the results of three subsequent tests were analyzed. The mean age of the 791 cases was 35.6 ± 12.7 years (range: 1-81). Nearly 57.0% of cases were symptomatic. The two most frequent symptoms were fever (58.0%) and cough (41.0%). Symptomatic cases (mean age 36.3 ± 12.6 years) were significantly older than asymptomatic cases (mean age 34.5 ± 12.7 years). Compared with nonworking populations, working in public places (adjusted odds ratio (aOR), 1.76, 95% confidence interval (95% CI): 1.11-2.80), healthcare settings (aOR, 2.09, 95% CI: 1.01-4.31), or in the aviation and tourism sectors (aOR, 2.24, 95% CI: 1.14-4.40) was independently associated with the symptomatic state. Reporting at least one chronic comorbidity was also associated with symptomatic cases (aOR, 1.76, 95% CI: 1.03-3.01). Compared with asymptomatic cases, symptomatic cases had a prolonged duration of viral shedding and consistent odds of ≥2 positive COVID-19 tests result out of the three subsequent testing rounds. A substantial proportion of the diagnosed COVID-19 cases in the Emirate of Abu Dhabi were asymptomatic. Quarantining asymptomatic cases, implementing prevention measures, and raising awareness among populations working in high-risk settings are warranted.

Human brucellosis in the Emirate of Abu Dhabi, United Arab Emirates, 2010-2015.

BACKGROUND: Worldwide, human brucellosis remains an important and widespread infection. In the past, there were limited data on the occurrence of human brucellosis in the United Arab Emirates and the reported incidence appeared to be low compared with similar areas. In 2009, a new web-based infectious disease surveillance system was introduced in the Emirate of Abu Dhabi. This paper reports data from this new system on human brucellosis for the 6 years 2010 to 2015. METHODS: A dataset was extracted for each case of human brucellosis reported to the notification system for the 6 year period January 2010 to December 2015. Annual brucellosis rates by age-group, gender, nationality and, geographical region were calculated and compared. RESULTS: A total of 480 cases of brucellosis were reported. The overall crude notification rate was 3 · 3 per 100,000 population but higher rates were seen in certain population subgroups notably expatriate males of working age in the Eastern Region (approximately 10 per 100,000) and UAE nationals of all ages and both genders in Abu Dhabi (between 4 -- 24 per 100,000). CONCLUSIONS: These findings reflect environmental and behavioral factors linked to occupation and leisure time activities associated with the large number of small non-commercial livestock farms in Abu Dhabi. Controlling human brucellosis in these circumstances will be challenging.

Response to Emergence of Middle East Respiratory Syndrome Coronavirus, Abu Dhabi, United Arab Emirates, 2013-2014.

In January 2013, several months after Middle East respiratory syndrome coronavirus (MERS-CoV) was first identified in Saudi Arabia, Abu Dhabi, United Arab Emirates, began surveillance for MERS-CoV. We analyzed medical chart and laboratory data collected by the Health Authority-Abu Dhabi during January 2013-May 2014. Using real-time reverse transcription PCR, we tested respiratory tract samples for MERS-CoV and identified 65 case-patients. Of these patients, 23 (35%) were asymptomatic at the time of testing, and 4 (6%) showed positive test results for >3 weeks (1 had severe symptoms and 3 had mild symptoms). We also identified 6 clusters of MERS-CoV cases. This report highlights the potential for virus shedding by mildly ill and asymptomatic case-patients. These findings will be useful for MERS-CoV management and infection prevention strategies.

Transmission of Middle East Respiratory Syndrome Coronavirus Infections in Healthcare Settings, Abu Dhabi.

Middle East respiratory syndrome coronavirus (MERS-CoV) infections sharply increased in the Arabian Peninsula during spring 2014. In Abu Dhabi, United Arab Emirates, these infections occurred primarily among healthcare workers and patients. To identify and describe epidemiologic and clinical characteristics of persons with healthcare-associated infection, we reviewed laboratory-confirmed MERS-CoV cases reported to the Health Authority of Abu Dhabi during January 1, 2013-May 9, 2014. Of 65 case-patients identified with MERS-CoV infection, 27 (42%) had healthcare-associated cases. Epidemiologic and genetic sequencing findings suggest that 3 healthcare clusters of MERS-CoV infection occurred, including 1 that resulted in 20 infected persons in 1 hospital. MERS-CoV in healthcare settings spread predominantly before MERS-CoV infection was diagnosed, underscoring the importance of increasing awareness and infection control measures at first points of entry to healthcare facilities.

ß-Thalassemia in Abu Dhabi: consanguinity and tribal stratification are major factors explaining the high prevalence of the disease.

Tribalism and consanguineous marriages are common in parts of the world with a high prevalence of the ß-thalassemia (ß-thal) mutations, and increase the risks of homozygosity for this and other recessive disorders. We explored the frequency of ß-thal genes and ß-thal carriers in 5672 subjects screened before marriage, of whom 2262 were couples. The mean coefficient of inbreeding (F) in the population was estimated from self-reported relationships to prospective spouses in 383 subjects. Overall frequency of ß-thal mutations and ß-thal carriers in the population were 1.16 and 2.3%, respectively. Among the 14 largest tribes, ß-thal carrier frequencies varied from 0 to 13.6%. The estimated F in the population was 0.022. The expected number of couples needed to be screened to detect one couple who were both ß-thal carriers in the non inbreeding (F = 0) and inbreeding (F = 0.022) population was 1858 and 646, respectively. However, among 2262 couples, 10 were both ß-thal carriers, i.e., 1 in 226 couples, significantly (p = 0.02) more than expected by taking only inbreeding into account. Although ß-thal mutations are relatively rare, the burden of ß-thal disease is increased eight-fold by tribalism and consanguinity.

Cigarette, Water-pipe, and Medwakh Smoking Prevalence Among Applicants to Abu Dhabi's Pre-marital Screening Program, 2011.

BACKGROUND: This study assesses self-reported tobacco use prevalence (cigarette, water-pipe, and medwakh) among applicants to Abu Dhabi's Premarital Screening program during 2011. METHODS: Premarital Screening data reported to the Health Authority - Abu Dhabi from April to December 2011 were utilized to estimate tobacco use prevalence among applicants. Smoking prevalence was examined by nationality, age group and gender. RESULTS: Overall, 24.7% of Premarital Screening Program applicants were current smokers; 11.5% smoked cigarettes, 5.9% smoked medwakh (hand-held pipe), 4.8% smoked water-pipe and 2.5% smoked a combination (more than one type). Men (19.2%) were more likely than women (3.5%) to be current cigarette smokers. Women were much less likely to smoke medwakh (0.1%) than men (11.5%), with male UAE Nationals having the highest medwakh smoking prevalence (16.1%). The overall prevalence of water-pipe smoking was 6.8% among men and 2.8% for women with the highest water-pipe smoking prevalence (10.2%) among Arab expatriate men. CONCLUSIONS: Variations in tobacco use prevalence among Premarital Screening Program applicants reflect preferences for different modes of tobacco consumption by nationality, age group and gender. Enforcement of tobacco control laws, including implementation of clean indoor air laws and tobacco tax increases, and targeted health education programs are required to reduce tobacco consumption and concomitant tobacco-related morbidity and mortality.