key: cord-0834248-zfcijt01
authors: Gautret, Philippe; Colson, Philippe; Lagier, Jean Christophe; Camoin-Jau, Laurence; Giraud-Gatineau, Audrey; Boudjema, Sophia; Finance, Julie; Chaudet, Hervé; Raoult, Didier
title: Different pattern of the second outbreak of COVID-19 in Marseille, France
date: 2020-10-07
journal: Int J Infect Dis
DOI: 10.1016/j.ijid.2020.10.005
sha: f9004b306bb857f5d007b43c666c8d646cc171f5
doc_id: 834248
cord_uid: zfcijt01

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%), 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.

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

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%), 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%).

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.

Key words: COVID-19; seasonality; severity markers; lethality J o u r n a l P r e -p r o o f Since its emergence in China at the end of 2019, SARS-CoV-2 spread worldwide with more than 29 Million cases of COVID-19 reported, as of 15 September, 2020. Currently, most cases have been reported from the US, India, Brazil and Russia (https://gisanddata.maps.arcgis.com/apps/opsdashboard/index.html#/bda7594740fd40299423 467b48e9ecf6). In Europe, since the beginning of the pandemic, the EU/EEA and the UK have reported 1,733,550 COVID-19 cases and 182,639 deaths, as of 2 August, 2020 (10% of all cases reported worldwide). In early April, the EU/EEA and the UK reached a peak in reported cases. Then the trend declined until June to reach a plateau. however in recent weeks there has been a resurgence, although it is currently lower than the first peak which occurred in April 1 . In France, the incidence of PCR-confirmed cases peaked on early April with 50.1/100,000 and declined to less than 10/100,000 in early May, however, on late July the incidence rose again over this threshold and reached 75/100,0000 in early September 2 .

In Marseille, the largest city in south of France and the second one in France, our institute adopted a strategy consisting in early and massive screening of SARS-CoV-2 infections and COVID-19 treatment using hydroxychloroquine and azithromycin, since the first case was documented. We recently described the characteristics of 3737 adult COVID-19 patients seen at our institute between 3 March and 27 April 3 . In this paper, we describe these characteristics in 743 new adult patients seen between 15 June and 15 August with the aim to investigate possible changes in the disease between these two time periods.

Starting from early March, our institute proposed massive testing of any person presenting at our facility regardless they had or not COVID-19 symptoms. On 16 March, the WHO Director-General called for testing every suspected COVID-19 case 4 Compared to patients seen during late winter and spring, those seen in summer were significantly younger with a lower proportion of patients aged ≥65 years, and were more likely to be male, although differences were not marked ( Table 1) . No significant differences were seen with regards to anosmia and agueusia prevalence, according to period of study.

Hospitalization rate, proportion of patients transferred to ICU, and lethality rates were significantly lower in patients seen in summer than in those seen earlier. The mean Ct value of positive PCR results was significantly lower in patients seen in summer than in those seen earler, with a proportion of patients with high viral load (Ct≤ 16) tending to be higher in summer. Lymphocyte and platelet counts and fibrinogen and D-dimer levels were significantly lower in patients seen in summer as compared to those seen earlier. 

COVID-19) in the EU/EEA and the UK -eleventh update: resurgence of cases

Outcomes of 3,737 COVID-19 patients treated with hydroxychloroquine/azithromycin and other regimens in Marseille, France: A retrospective analysis

World Health Organization. WHO Director-General's opening remarks at the media briefing on COVID-19 -16

Arrêté du 3 mai 2020 complétant l'arrêté du 23 mars 2020 prescrivant les mesures d'organisation et de fonctionnement du système de santé nécessaires pour faire face à l'épidémie de covid-19 dans le cadre de l'état d'urgence sanitaire : NOR : SSAZ2011117A

Destin des maladies infectieuses

Genetic Recombination, and Pathogenesis of Coronaviruses

SARS and other coronaviruses as causes of pneumonia

The authors declare that they have no competing interests.

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.