Syndromic polymerase chain reaction (PCR) panels are used to test for pathogens that can cause rash illnesses, including measles. Rash illnesses have infectious and noninfectious causes, and approximately 5% of persons experience a rash 7-10 days after receipt of a measles, mumps, and rubella (MMR) vaccine. MMR vaccine includes live attenuated measles virus, which is detectable by PCR tests. No evidence exists of person-to-person transmission of measles vaccine virus, and illness does not typically result among immunocompetent persons. During September 2022-January 2023, the Tennessee Department of Health received two reports of measles detected by syndromic PCR panels. Both reports involved children (aged 1 and 6 years) without known risk factors for measles, who were evaluated for rash that occurred 11-13 days after routine MMR vaccination. After public health responses in Tennessee determined that both PCR panels had detected measles vaccine virus, six state health departments collaborated to assess the frequency and characteristics of persons receiving a positive measles PCR panel test result in the United States. Information was retrospectively collected from a commercial laboratory testing for measles in syndromic multiplex PCR panels. During May 2022-April 2023, among 1,548 syndromic PCR panels, 17 (1.1%) returned positive test results for measles virus. Among 14 persons who received a positive test result and for whom vaccination and case investigation information were available, all had received MMR vaccine a median of 12 days before specimen collection, and none had known risk factors for acquiring measles. All positive PCR results were attributed to detection of measles vaccine virus. Increased awareness among health care providers about potential measles detection by PCR after vaccination is needed. Any detection of measles virus by syndromic PCR testing should be immediately reported to public health agencies, which can use measles vaccination history and assessment of risk factors to determine the appropriate public health response. If a person recently received MMR vaccine and has no risk factors for acquiring measles, additional public health response is likely unnecessary.

Legionellosis is an infection acquired through inhalation of aerosolized water droplets containing Legionella bacteria. In August 2018, public health officials in New Hampshire launched an investigation into a legionellosis outbreak. They identified 49 illnesses likely associated with the outbreak and implicated an improperly maintained hot tub at a hotel. The same strain of Legionella pneumophila serogroup 1 was found in both the hot tub and in samples from two patients with Legionnaires disease. The indoor hot tub vented to the outdoors, which is how some patients with confirmed legionellosis likely acquired the infection despite not entering the hotel during the incubation period. This outbreak is notable for 1) likely illness acquisition through the exterior vent of the hot tub room and 2) use of whole genome sequencing to link environmental and patient specimens. Collaboration among public health and environmental officials, laboratorians, and building managers was essential to determining the source of the outbreak and preventing further illness. 2022, National Environmental Health Association. All rights reserved.

We report an outbreak of severe acute respiratory syndrome coronavirus 2 involving 3 Malayan tigers (Panthera tigris jacksoni) at a zoo in Tennessee, USA. Investigation identified naturally occurring tiger-to-tiger transmission; genetic sequence change occurred with viral passage. We provide epidemiologic, environmental, and genomic sequencing data for animal and human infections.