Soumis par admin le lun 18/03/2024 - 16:35

Topic: Assessing the potential seasonality of COVID-19 dynamic in Africa: a mathematical modeling study

In the three-year span of SARS-CoV-2 infections, many influencing factors remain unclear, including its seasonality. Despite numerous studies, findings on seasonal patterns vary over time and location, necessitating further investigations, particularly in Africa, where the low number of cases was surprising, to avoid a looming health shock of the pandemic on the continent. This study aims to explore SARS-CoV-2 seasonality across three climate zones. An extended SEIR model incorporating eight classes: susceptible (S), vaccinated susceptible (S), exposed (E), pre-symptomatic infectious (Ip), asymptomatic infectious (Ia), symptomatic infectious (Is), detected infectious (Id) and recovered (R), was utilized, with seasonality integrated via transmission rates using cosine seasonal forcing. Seasonality amplitudes were estimated for each country, and a Kruskal-Wallis H test assessed their variations among climate zones. Sensitivity analysis has been used to assess the impact of the amplitudes of transmission rate seasonality on the control reproduction number using the Partial Rank Correlation Coefficient (PRCC). Notably, the amplitude of the asymptomatic transmission's seasonality emerged as the key driven factor of the pandemic, especially in colder Temperate zones. Thus, in potential SARS-CoV-2 re-emergence scenarios in such zone, alongside isolating symptomatic cases, preventing the spread of SARS-CoV-2 from asymptomatic infectious individuals through mass testing could significantly mitigate pandemic burdens, particularly during colder seasons. Similar strategies could be beneficial across the continent, especially during cold and rainy periods.

Keywords: SARS-CoV-2, SEIR model, periodic transmission rates, climate zones.