Abstract:
Background: COVID-19, caused by SARS-CoV-2, is an ongoing global pandemic. There were
three waves of the disease caused by different virus variants. Knowledge on epidemiological and
clinical features associated with the severe disease due to different variants warrants future
pandemic preparedness.
Objective: To evaluate epidemiological and clinical characteristics of patients admitted to the
intensive care unit (ICU) of the main treatment center designated to treat COVID-19 patients in
Sri Lanka
Methods: A descriptive retrospective study was conducted in National Institute of Infectious
Diseases, Colombo using records of hospitalized RT-PCR confirmed cases of COVID-19 from
January 2020 to August 2022 related to three waves of the epidemic. Data were analysed by
descriptive statistics, Chi-squared and ANOVA tests.
Results: Of the sample (n=272), 23, 132 and 117 patients were admitted to ICU in the first,
second and third waves, respectively. In the second and third waves, there was an increase in the
mean age (±SD) (58.1±17.4 and 58.5±17.1 years) compared to the first wave (50.2±14.4 years).
The majority of patients admitted were men, 69.6%, 68.2%, 66.7% from first to third wave,
respectively. On average, patients were admitted to the hospital by 2.9, 4.3 and 5.8 days of
symptom onset during first to third waves, respectively. Across three waves, 34.8% (n=8), 38.6%
(n=51) and 72.6% (n=85) were deceased. The most common symptom reported was cough in the
first wave (56.5%) while fever was the most common symptom in the other two waves (56.8%
and 66.7%). From first to third waves, the number of people with comorbidities was 47.8%,
79.5% and 75.2%. The mean duration of symptom onset to time of admission was significantly
higher in the third wave compared to first (p<0.001) and second (p<0.05) waves. Of the three
waves, greater number of deaths was significantly associated with third wave (χ2=32.13;
p<0.001).
Conclusions: There was a trend towards older and less healthy (with co-morbidities) men to be
affected over time. During latter two waves, patients presented to the hospital lately. Second and
third waves shared similar clinical profile while doubling subsequent mortality.
Keywords: COVID-19, Epidemiology, ICU
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