A comparison between alpha and delta waves of COVID-19, in Tunisia

Several nations have seen an increase in COVID-19 cases in 2020, exhibiting a wave pattern. Different COVID-19 variants caused these waves. In this perspective, the aim of the study was  to compare epidemiological, clinical and evolutive profile of COVID-19 infection during two waves of COVID-19.

Data collection was carried out using a questionnaire self-administered in French and Arabic developed with Google Forms and shared online via social media with weekly reminders. Duration of one month was enough to get the necessary number of participants calculated. The study included all Tunisians who were infected with COVID-19 at least once and agreed to participate in the study.  Results: In total, 1328 COVID-19 patients were included. Eight hundred eighty-three patients were infected during the Alpha wave (66.5%) and 445 were infected during the Delta wave (33.5%). The median age was 37 years (interquartile range (IQR): 30-41 years). Clinically, during delta wave, these symptoms were more frequent; fever (57.8% versus 51.9%, p= 0.042), loss of smell (75.1% versus 65.1%, p On the other hand, aches were more frequent during Alpha wave (65.2% versus 56.2%, p = 0.001) and the impact of health professionals was greater (27.6% versus 15.7%, p≤10-3).

The Alpha variant had more pronounced clinical symptoms than the Delta variant. This can be explained by the high vaccination coverage during the pandemic by the Delta variant.