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

Abstract

Background The COVID-19 RT-PCR confirmed cases could be symptomatic or asymptomatic. In the United Arab Emirates (UAE), the identified COVID-19 RT-PCR confirmed cases are yet to be characterized. In this study, we characterized the first cohort of COVID-19 RT-PCR confirmed cases reported in the Abu Dhabi Emirate, UAE, according to symptomatic state, and identified factors associated with the symptomatic state. Also, the strength of association between the symptomatic state and testing positive in three subsequent RT-PCR testing rounds was examined and quantified. Method We analyzed data collected from the first cohort of the RT-PCR confirmed COVID-19 cases reported to the health authorities in the Abu Dhabi Emirate, UAE between February 28 and April 08, 2020. Self-reported sociodemographic, working status, travel history, and chronic comorbidities of 1,249 COVID-19 cases were analyzed according to symptomatic state (symptomatic and asymptomatic). After the first RT-PCR confirmatory test, the results of three subsequent testing rounds were also analyzed. Results A total of 791 confirmed cases with a mean age of 35.6 years (range: 1-81 years) and information on the symptomatic state were analyzed. Nearly, 56.0% were asymptomatic cases. The most frequent two symptoms were fever (58.0%) and cough (41.0%). The mean age of symptomatic (36.3 year, 12.6SD) was significantly higher than that of asymptomatic cases (34.5 year, 12.7SD). Compared to non-working populations, working in public places (aOR, 1.76, 95% CI: 1.11-2.80), healthcare settings (aOR, 2.09, 95% CI: 1.01-4.31), or in the aviation and tourism sector (aOR, 2.24, 95% CI: 1.14-4.40), were independently associated with the symptomatic state. Reporting at least one chronic comorbidity was also associated with symptomatic cases (aOR, 1.76, 5% CI: 1.03-3.01). Compared to asymptomatic, symptomatic COVID-19 cases had consistent odds of two or more of testing positive to COVID-19 in three subsequent testing rounds. Conclusions A substantial proportion of the diagnosed COVID-19 cases in the Abu Dhabi Emirate was asymptomatic. Quarantine of asymptomatic cases along with prevention measures and raising awareness of populations working in high-risk settings is warranted. Further, follow up research is needed to understand viral clearance and clinical outcomes according to the symptomatic state of the COVID-19 cases.

Asymptomatic COVID-19 in the Elderly: Dementia and Viral Clearance as Risk Factors for Disease Progression

“…In line with our findings, infectivity may be weaker in asymptomatic elders than in those fully developing symptoms 22 . A recent study showed similar results in PCR retesting in SARS-CoV-2 asymptomatic and symptomatic patients, and interestingly, this could be evidenced during the first week after diagnosis 23 .…”

Excellent option for mass testing during the SARS-CoV-2 pandemic: painless self-collection and direct RT-qPCR

“…Rapid antigen testing has shown great promise for symptomatic patients; however, the sensitivity in asymptomatic and presymptomatic subjects reaches only ~ 73% [ 12 ]. Asymptomatic individuals are those who test RT-qPCR positive but experience no COVID-19 symptoms, they occur at a rate of 17–20% [ 3 , 4 , 18 ], with a higher prevalence in younger subjects [ 2 ]. Presymptomatic individuals are those who initially present as asymptomatic and develop symptoms days or weeks later [ 3 , 23 ].…”

Clinical and Laboratory Features of PCR-Confirmed and Clinically Suspected COVID-19 Pediatric Patients: A Single Hospital-Based Experience During the First COVID-19 Wave in the United Arab Emirates

“…In the United Arab Emirates (UAE), the first PCR-confirmed case of COVID-19 was reported on 29 January, 2020 (7). Since then, all efforts were put into understanding the disease characteristics, with massive testing, contact tracing, nonpharmaceutical interventions, new therapeutic modalities, and vaccination; all playing a crucial role in containing the spread of COVID-19 infection in the UAE (7). In Abu Dhabi, the capital and the largest city in the UAE, 43% of the first diagnosed cohort of the COVID-19-confirmed cases were asymptomatic (7).…”

“…Since then, all efforts were put into understanding the disease characteristics, with massive testing, contact tracing, nonpharmaceutical interventions, new therapeutic modalities, and vaccination; all playing a crucial role in containing the spread of COVID-19 infection in the UAE (7). In Abu Dhabi, the capital and the largest city in the UAE, 43% of the first diagnosed cohort of the COVID-19-confirmed cases were asymptomatic (7). Although reports demonstrated that COVID-19 infection is less severe in children compared to adultsit includes mainly mild or moderate infections (2,(4)(5)(6))yet, severe illness due to COVID-19 can occur in children, requiring hospitalization and intensive care (8).…”