Epidemiological comparison of COVID-19 waves in the province of Buenos Aires, Argentina, 2020-2021

Abstract

INTRODUCTION: The development of the COVID-19 pandemic has been described in terms of waves. This work aimed at characterizing the pandemic in the province of Buenos Aires through the comparison of indicators in each wave. METHODS: A descriptive observational study with data from secondary sources was conducted. Each wave was defined based on the inflection points of the cumulative confirmed cases curve. The waves were compared by indicators of morbidity and mortality. RESULTS: Three different periods were established: first wave, summer resurgence and second wave. The maximum number of confirmed cases and deaths per day during the first wave was 5799 and 192, and during the second wave 12141 and 282, respectively. The fatality was 3.5% during the first wave and 2.3% during the second one. The mean age of confirmed and deceased cases during the second wave was significantly lower than during the first one. Among confirmed cases, the greatest difference in the proportion by age group was observed in the group aged 10 to 19 years. DISCUSSION: The second wave was of greater magnitude, probably due to the circulation of the new variant of SARS-CoV-2, Gamma (P.1), for which there is evidence of increased transmissibility. The decrease in the age of deceased may be explained by the decrease in the age of confirmed cases and by the priority given to older people in the vaccination campaign. The increase in the 10-19 age group may be related to the resumption of face-to-face classes in schools.