Comparative study of patients hospitalized for SARS-CoV-2 infection in two consecutive waves in Tunisia

IntroductionSince December 2019, a novel coronavirus (SARS-CoV-2) has triggered a global pandemic with a heavy medical and societal-economic toll. The health consequences were not similar during the successive waves that affected several countries. The aim of our study was to compare the sociodemographic, clinical and evolutionary features of COVID-19 patients hospitalized at the Military Hospital of Tunis (HMPIT) during the 2nd and 3rd waves that affected the country. Patients and methodsObservational prospective study involving 1,527 COVID-19 patients hospitalized at HMPIT over 11 months, divided into two periods: from July 2020 to December 2020 called the second wave (V2) and from January 2021 to May 2021 called the third wave (V3). We compared the epidemiological data, the clinical form and the evolution of the patients for each period. ResultsThe number of hospitalized patients was 636 during V2 compared to 891 during V3. Average age was 63.5 ± 15.3 years during V2 versus 65.8 ± 17.8 years during V3 (P = not significant [NS]). The percentage of young adults [18-40 years] was 6.5% during V2 compared to 6.7% during V3 (P = NS). The gender ratio (M/F) was 1.59 for V2 and 1.42 for V3 (P = NS). Comorbidities were present in 65% of V2 patients and 66.3% of V3 patients (P = NS), with hypertension being the most prevalent one in both groups (47.2% for V2 versus 44.9% for V3; P = NS), followed by overweight, dyslipidemia and diabetes (33% for V2 versus 39.3% for V3; P = 0.012). The median duration between symptoms onset and hospitalization was 7 days [5-10] during V2 versus 8.5 days during V3 [5-12] (P = 0.0004). The severe clinical form was present in 49% of patients admitted during V2 compared to 34.8% during V3 (P < 10-3). The critical form represented 18.6% of cases during V2 against 16.8% during V3 (P = NS). The average hospital length of stay in COVID units (outside of intensive care unit) was 8.4 ± 5.4 days during V2 and 9.8 ± 5.7 days during V3. The average length of stay was significantly longer for the intensive care unit (11.3 ± 3.4 days for V2 versus 13.8 ± 3.9 days for V3; P = 0.01). The case fatality rate was 24.5% during V2 and 20.7% during V3 (P = NS). Median age of death was 70.2 years [42-88] during V2 and 70.4 years [22-96] during V3 with 2 patients less than 40 years of age (1%) for the latter period. The gender ratio (M/F) of deceased patients was 3.21 for V2 and 1.5 for V3 (P = 0.001). The case fatality rate was higher in the intensive ca