On June 9, 2020, this report was posted as an MMWR Early Release on the MMWR website (https://www.cdc.gov/mmwr). 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. In mid-January, the USS Theodore Roosevelt was deployed to the western Pacific. An outbreak of COVID-19 occurred during deployment, which resulted in the aircraft carrier stopping in Guam at the end of March. During this time, approximately 1,000 service members were determined to be infected with SARS-CoV-2, the virus that causes COVID-19. The United States Navy and CDC investigated this ongoing outbreak during April 20-24; 382 service members voluntarily completed questionnaires and provided serum specimens (a convenience sample comprising 27% of 1,417 service members staying at the base on Guam or on the ship). The 1,417 included persons who were previously infected, currently infected, or never infected. Among these 382 service members,

Enterotoxigenic Escherichia coli (ETEC) is an important diarrheagenic pathogen. We report here the high-quality whole-genome sequences of 21 ETEC strains isolated from patients in the United States, international diarrheal surveillance studies, and cruise ship outbreaks.

A total of 247 strains of streptococci isolated from humans were tested for identification in the Rapid Strep system. The identification rates and identification levels were different for each Streptococcus species. Our data indicate that the Rapid Strep system will identify nearly all the beta-hemolytic Streptococcus species if serological procedures are used in conjunction with the rapid physiological procedures. Of the group D streptococci, 98% of the enterococci and 95% of the non-enterococci were correctly identified. Of the commonly occurring viridans species, 85% were correctly identified, but only 10% of the less frequently occurring viridans species were identified. A total of 90% of the Streptococcus pneumoniae and 60% of the Aerococcus strains were correctly identified.

The API system for identification of Enterobacteriaceae was evaluated with 366 cultures. Overall accuracy of identification was 96.4%; of the 13 cultures misidentified, 7 were atypical strains.

The Enterobacteriaceae biochemical card was used in six separate laboratories to identify 170 representatives of Enterobacteriaceae. The AutoMicrobic System (Vitek Systems, Inc.) performed with an accuracy of 97.8% as compared with 98.1% by the standard method selected and 97.6% by a commercially prepared manual system approach. During this time, 5,450 clinical isolates belonging to Enterobacteriaceae were analyzed. Compared with the routine methods used in the various laboratories, the AutoMicrobic System identified 96.4% correctly.