Investigation of a COVID-19 outbreak on the Charles de Gaulle aircraft carrier, March to April 2020: a retrospective cohort study.

BackgroundSARS-CoV-2 emergence was a threat for armed forces. A COVID-19 outbreak occurred on the French aircraft carrier Charles de Gaulle from mid-March to mid-April 2020.AimTo understand how the virus was introduced, circulated then stopped circulation, risk factors for infection and severity, and effectiveness of preventive measures.MethodsWe considered the entire crew as a cohort and collected personal, clinical, biological, and epidemiological data. We performed viral genome sequencing and searched for SARS-CoV-2 in the environment.ResultsThe attack rate was 65% (1,148/1,767); 1,568 (89%) were included. The male:female ratio was 6.9, and median age was 29 years (IQR: 24-36). We examined four clinical profiles: asymptomatic (13.0%), non-specific symptomatic (8.1%), specific symptomatic (76.3%), and severe (i.e. requiring oxygen therapy, 2.6%). Active smoking was not associated with severe COVID-19; age and obesity were risk factors. The instantaneous reproduction rate (Rt) and viral sequencing suggested several introductions of the virus with 4 of 5 introduced strains from within France, with an acceleration of Rt when lifting preventive measures. Physical distancing prevented infection (adjusted OR: 0.55; 95% CI: 0.40-0.76). Transmission may have stopped when the proportion of infected personnel was large enough to prevent circulation (65%; 95% CI: 62-68).ConclusionNon-specific clinical pictures of COVID-19 delayed detection of the outbreak. The lack of an isolation ward made it difficult to manage transmission; the outbreak spread until a protective threshold was reached. Physical distancing was effective when applied. Early surveillance with adapted prevention measures should prevent such an outbreak.

Prevalence of leukocyturia in a cohort of French asymptomatic aircrews.

OBJECTIVES: Sexually transmitted infections (STIs) can cause leukocyturia. We aimed to estimate the prevalence of leukocyturia in asymptomatic aircrews and the proportion of STIs in those presenting leukocyturia. METHODS: The LEUCO survey was a prospective cohort study conducted among aircrews between 14th October 2019 and 13th March 2020 at the Toulon aeromedical centre in France. All participants performed a dipstick urinalysis. Those positive for leukocyturia were offered STI screening by nucleic acid amplification test (NAAT) for Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium and Trichomonas vaginalis. RESULTS: Among the 2236 included asymptomatic participants (1912 men and 324 women), 127 (36 men and 91 women) were positive for leukocyturia. The prevalence of leukocyturia was 1.9% (1.3-2.6) in men and 28.1% (23.3-33.3) in women (p < 0.001). In men positive for leukocyturia, the NAAT positivity rate for C. trachomatis, N. gonorrhoeae, M. genitalium and T. vaginalis was 28.6% (3.7-71.0) in the age group 18-24, 20.0% (0.5-71.6) in the age group 25-34, and zero in the older age group (p 0.65). In women positive for leukocyturia it was 16.7% (4.7-37.4) in the age group 18-24, 18.2% (2.3-51.8) in the age group 25-34, and zero in the older age group (p 0.16). CONCLUSIONS: In asymptomatic individuals, leukocyturia is rare in men and more common in women. In asymptomatic adults under 35 years of age with leukocyturia, multiplex NAAT shows a high proportion of STIs and might be useful in improving STI detection.

COVID-19 Repeated Convalescent Plasma Collection: Analysis of 149 Donations from 88 French Military Health Workers.

BACKGROUND: Passive therapy with convalescent plasma (CP) could be an effective and safe treatment option in COVID-19 patients. Neutralizing antibodies present in CP generated in response to SARS-CoV-2 infection and directed against the receptor-binding domain of the spike protein are considered to play a major role in the viral clearance. CP infusion may also contribute to the modulation of the immune response through its immunomodulatory effect. We describe for the first time the effectiveness of a CP collection protocol from repeated donations in young patients. MATERIALS AND METHODS: We enrolled health service workers who experienced mild to moderate COVID-19 and from whom several donations have been collected. No minimal severity threshold and no biological cure criteria were required. Donors could return to a second plasma donation 14 days after the first donation. A minimal neutralizing antibody titer of 1:40 was considered for clinical use. RESULTS: Eighty-eight donors were included (median age 35 [28-48] years, 41 women), and 149 plasma products were collected. COVID-19 were mainly WHO stage 2 infections (96%). Among the 88 first donations, 76% had neutralizing antibody titers higher than or equal to 1:40. Eighty-eight percent of donors who came for a second donation had a neutralizing antibody titer of 1:40. Median durations were 15 (15-19) and 38 (33-46) days from the first to the second donation and from recovery to the second donation, respectively. Sixty-nine percent of donors who came for a third donation had a neutralizing antibody titer of 1:40. Median durations were 16 (13-37) and 54 (49-61) days from the second to the third donation and from recovery to the third donation, respectively. No significant difference was observed between the IgG ratio and the age of the donors or the time between recovery and donation. The average IgG ratio did not significantly vary between donations. When focused on repeated blood donors, no significant differences were observed either. CONCLUSION: The recruitment of young patients with a mild to moderate CO-VID-19 course is an efficient possibility to collect CP with a satisfactory level of neutralizing antibodies. Repeated donations are a well-tolerated and effective way of CP collection.

Safety and efficacy of oral direct inhibitors of thrombin and factor Xa in antiphospholipid syndrome.

BACKGROUND: Long-term anticoagulation is recommended in antiphospholipid syndrome with thrombosis in order to prevent recurrences. While the current mainstay relies on vitamin K antagonists, their long-term maintenance may remain challenging. OBJECTIVES: To report on the safety and the efficacy of oral direct inhibitors of thrombin and factor Xa (ODIs) in antiphospholipid syndrome (APS). METHODS: We performed a descriptive analysis of patients with APS enrolled in a French multicentre observational cohort between January 2012 and March 2014 and receiving ODIs. The main outcomes were the occurrence of a thrombotic recurrence or bleeding events. RESULTS: Twenty-six patients with APS (primary in 12) received ODIs. Twenty patients had been previously treated with VKA (n=19), or fondaparinux (n=1) for a median duration of 3years. ODIs were introduced as second-line therapy because of INR lability/therapeutic simplification (n=17), recurrent thrombosis (n=1), VKA's associated bleeding event (n=1), and atrial fibrillation (n=1). Six patients received ODIs as first-line therapy. After a median [IQR] follow-up of 19 [8-29] months, one relapse of arterial thrombosis, two bleeding events (hypermenorrhea and rectal bleeding under rivaroxaban) and one recurrent migraine were reported, leading to discontinuation of therapy in these 4 patients. CONCLUSION: ODIs might be an alternative therapeutic option in APS. Prospective studies are warranted to evaluate their safety in this condition.

Shigella flexneri bacteremia in two immune-competent adult travelers.

Shigella bacteremias are uncommon in immune-competent adults. We report two cases of Shigella flexneri bacteremia that occurred in healthy young travelers, who recovered. Self-medication with loperamide and ibuprofen without antibiotics (case 1) and concomitant falciparum malaria (case 2) were the only co-morbidities found in our two patients.