Different pattern of the second outbreak of COVID-19 in Marseille, France

Int J Infect Dis. 2021 Jan;102:17-19. doi: 10.1016/j.ijid.2020.10.005. Epub 2020 Oct 7.


Objective: To describe the characteristics of COVID-19 patients seen in March-April and June-August 2020 in Marseille, France with the aim to investigate possible changes in the disease between these two time periods.

Methods: Demographics, hospitalization rate, transfer to intensive care unit (ICU), lethality, clinical and biological parameters were investigated.

Results: Compared to those seen in March-April, COVID-19 patients seen in June-August were significantly younger (39.2 vs. 45.3 years), more likely to be male (52.9% vs. 45.6%), and less likely to be hospitalized (10.7 vs. 18.0%), to be transferred to ICU (0.9% vs. 1.8%) and to die (0.1% vs. 1.1%). Their mean fibrinogen and D-dimer blood levels were lower (1.0 vs. 1.5 g/L and 0.6 vs. 1.1 μg/mL, respectively). By contrast, their viral load was higher (cycle threshold ≤16 = 5.1% vs. 3.7%).

Conclusions: Patients in the two periods did not present marked age and sex differences, but markers of severity were undoubtedly less prevalent in the summer period, associating with a 10 times decrease in the lethality rate.

Keywords: COVID-19; Lethality; Seasonality; Severity markers.

MeSH terms

  • Adult
  • Aged
  • COVID-19 / blood
  • COVID-19 / epidemiology*
  • COVID-19 / mortality
  • Disease Outbreaks
  • Female
  • Fibrin Fibrinogen Degradation Products / analysis
  • France / epidemiology
  • Hospitalization
  • Humans
  • Intensive Care Units
  • Male
  • Middle Aged
  • SARS-CoV-2
  • Seasons
  • Time Factors


  • Fibrin Fibrinogen Degradation Products
  • fibrin fragment D