An Outbreak of Covid-19 on an Aircraft Carrier.

BACKGROUND: An outbreak of coronavirus disease 2019 (Covid-19) occurred on the U.S.S. Theodore Roosevelt, a nuclear-powered aircraft carrier with a crew of 4779 personnel. METHODS: We obtained clinical and demographic data for all crew members, including results of testing by real-time reverse-transcriptase polymerase chain reaction (rRT-PCR). All crew members were followed up for a minimum of 10 weeks, regardless of test results or the absence of symptoms. RESULTS: The crew was predominantly young (mean age, 27 years) and was in general good health, meeting U.S. Navy standards for sea duty. Over the course of the outbreak, 1271 crew members (26.6% of the crew) tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by rRT-PCR testing, and more than 1000 infections were identified within 5 weeks after the first laboratory-confirmed infection. An additional 60 crew members had suspected Covid-19 (i.e., illness that met Council of State and Territorial Epidemiologists clinical criteria for Covid-19 without a positive test result). Among the crew members with laboratory-confirmed infection, 76.9% (978 of 1271) had no symptoms at the time that they tested positive and 55.0% had symptoms develop at any time during the clinical course. Among the 1331 crew members with suspected or confirmed Covid-19, 23 (1.7%) were hospitalized, 4 (0.3%) received intensive care, and 1 died. Crew members who worked in confined spaces appeared more likely to become infected. CONCLUSIONS: SARS-CoV-2 spread quickly among the crew of the U.S.S. Theodore Roosevelt. Transmission was facilitated by close-quarters conditions and by asymptomatic and presymptomatic infected crew members. Nearly half of those who tested positive for the virus never had symptoms.

SARS-CoV-2 Infections and Serologic Responses from a Sample of U.S. Navy Service Members - USS Theodore Roosevelt, April 2020.

Compared with the volume of data on coronavirus disease 2019 (COVID-19) outbreaks among older adults, relatively few data are available concerning COVID-19 in younger, healthy persons in the United States (1,2). In late March 2020, the aircraft carrier USS Theodore Roosevelt arrived at port in Guam after numerous U.S. service members onboard developed COVID-19. In April, the U.S. Navy and CDC investigated this outbreak, and the demographic, epidemiologic, and laboratory findings among a convenience sample of 382 service members serving aboard the aircraft carrier are reported in this study. The outbreak was characterized by widespread transmission with relatively mild symptoms and asymptomatic infection among this sample of mostly young, healthy adults with close, congregate exposures. Service members who reported taking preventive measures had a lower infection rate than did those who did not report taking these measures (e.g., wearing a face covering, 55.8% versus 80.8%; avoiding common areas, 53.8% versus 67.5%; and observing social distancing, 54.7% versus 70.0%, respectively). The presence of neutralizing antibodies, which represent antibodies that inhibit SARS-CoV-2, among the majority (59.2%) of those with antibody responses is a promising indicator of at least short-term immunity. This report improves the understanding of COVID-19 in the U.S. military and among young adults in congregate settings and reinforces the importance of preventive measures to lower risk for infection in similar environments.

Predictors of on-duty coronary events in male firefighters in the United States.

Coronary heart disease (CHD) accounts for 39% of "on-duty" deaths in firefighters in the United States. No studies have examined the factors that distinguish fatal from nonfatal work-associated CHD events. Male firefighters experiencing on-duty CHD events were retrospectively investigated to identify cardiovascular risk factors predictive of case fatality; 87 fatalities (death within 24 hours of the event) were compared with 113 survivors who retired with disability pensions for heart disease after on-duty nonfatal events. Cardiovascular risk factors were then examined for associations with case fatality. Predictors of CHD death in multivariate analyses were a previous diagnosis of CHD (or peripheral/cerebrovascular disease) (odds ratio [OR] 4.09, 95% confidence intervals [CI] 1.58 to 10.58), current smoking (OR 3.68, 95% CI 1.61 to 8.45), and hypertension (OR 4.15, 95% CI 1.83 to 9.44). Age < or =45 years, diabetes mellitus, and serum cholesterol level were not significant predictors of case fatality. In conclusion, previous CHD, current smoking, and hypertension are strong predictors of fatality in male firefighters experiencing on-duty CHD events. Accordingly, prevention efforts should include early detection and control of hypertension, smoking cessation/prohibition, and the restriction of most firefighters with significant CHD from strenuous duties.