A recent study has found that more than 40 percent of COVID-19 infected patients in Abu Dhabi did not display any virus symptoms. The research was carried out by eight scientists from Abu Dhabi Public Health Centre, Khalifa University in Abu Dhabi and UAE University in Al Ain by analysing 791 cases reported between February and April in the capital city. The report highlighted the risk posed by 'silent spreaders' in the UAE's efforts to contain the pandemic. At the same time, the report also underlined the significant role played by mass testing and tracing strategy carried out by UAE authorities in identifying large numbers of COVID-19 carriers when they were pre-symptomatic.

The research also observed that elderly people were at higher risk of developing symptoms of the infection, while people with chronic disease or serious health conditions such as high blood pressure or diabetes were atleast 75 percent more prone to developing symptoms if they contracted the virus.

As per the study, people working in healthcare, aviation and tourism sectors or in public places were more likely to develop ill-effects due to Coronavirus. According to authors of the study, working in closed spaces such as healthcare settings or in aviation and tourism services significantly increases the risk of exposure and even re-exposure to the carriers of the disease which may include confirmed patients and international travellers.

The study found that a total of 447 (56.5 percent) of the cases showed symptoms, while around 344 (43.5 percent) were asymptomatic. The authors noted that the efforts of mass tracing and testing activities carried out by the UAE health authorities have helped in identifying a large number of COVID-19 carriers at a time when they were still in the pre-symptomatic phase. All these people underwent PCR COVID-19 tests which showed positive results.

People displaying COVID-19 symptoms were more likely to test positive after taking subsequent tests, with the average age of those who tested positive being 35.6 years.

While the research has been published on a medical research website, it is still considered preliminary as outside researchers have yet not assessed the findings.

Higher COVID-19 risk among those with existing health conditions

The study has also confirmed that people with underlying health conditions including diabetes and high blood pressure are more vulnerable to the disease if they contract the virus. Among the cases that were analysed, around 13.1 percent had at least one co-morbidity or serious health condition. Among people who had symptoms of the virus, the proportion with a co-morbidity was 16.7 per cent. On the other hand, those with asymptomatic infections, the proportion was 9.6 percent. This indicated that an increased prospect of COVID-19 symptoms among cases with underlying health conditions.

The study also revealed that people with co-morbidity had 76 percent higher chances of developing symptoms, adding that the most common co-morbidities were high blood pressure (5.7 percent) and diabetes mellitus or DM (six percent).

“This observation is in line with other reports that documented DM and hypertension as the most distinctive co-morbidities in Covid-19 patients,” the authors added in the report.

At the same time, people with chronic co-morbidities are highly anticipated to be older in age and to suffer from immune system impairments.

According to the authors, diabetes weakens the immunity system of the body, making people more prone to complications and even death if they contract COVID-19.

Elderly patients more likely to develop symptoms

Elderly people with serious illnesses are more at risk of contracting Coronavirus, as the research observed that older patients were more likely to have symptomatic infections. In addition, the average age of asymptomatic patients was 34.5 years, while those who developed symptoms of the disease averaged at 36.3 years. The average age difference of 1.8 years was statistically significant for the study.

Among the 447 symptomatic cases analysed by the researchers, 47.9 percent developed only one symptom, 48.5 percent had 2-3 symptoms, while 3.6 percent showed 3-4 symptoms. 58 percent of symptomatic cases developed the most common symptom that was fever, followed by cough in 41 percent of cases, sore throat in 18.9 percent of cases and headache/fatigue in 12.4 percent of the cases analysed.

The study also founded that people aged between 40 and 59, which was above the average age in the study, had a 2.3-fold greater possibility of developing symptoms in comparison with those people in other age groups.