Temporal and age distributions of SARS-CoV-2 and other coronaviruses, southeastern France

Abstract

Objectives: The SARS-CoV-2 epidemic presents a poorly understood epidemiological cycle. We aimed to compare the age and weekly distributions of the five human coronaviruses, including SARS-CoV-2, that circulated in southeastern France.

Methods: We analyzed all available diagnoses of respiratory viruses, including SARS-CoV-2, performed between 09/2013 and 05/2020 at the University Hospital Institute Méditerranée Infection in Marseille, southeastern France.

Results: For SARS-CoV-2, positive children <15 years of age represented 3.4% (228/6,735) of all positive cases, which is significantly less than for endemic coronaviruses (46.1%; 533/1,156; p < 0.001). Among 10,026 patients tested for SARS-CoV-2 and endemic coronaviruses in 2020, children <15 years represented a significantly lower proportion of all positive cases for SARS-CoV-2 than for endemic coronaviruses [2.2% (24/1,067) vs. 33.5% (149/445), respectively; p < 0.001]. Epidemic curves for endemic coronaviruses and SARS-CoV-2 in 91,722 patients showed comparable bell-shaped distributions with a slight time lag. In contrast, the age distribution of endemic coronaviruses and 14 other respiratory viruses differed significantly compared to that of SARS-CoV-2, which was the only virus to relatively spare children.

Conclusions: We observed for SARS-CoV-2 a temporal distribution resembling that of endemic coronaviruses but an age distribution that relatively spares the youngest subjects, who are those the most exposed to endemic coronaviruses.

Keywords: Age; Children; Cross-immunity; Endemic coronavirus; SARS-CoV-2; Southeastern France.