Health care transmission of a newly emergent adenovirus serotype in health care personnel at a military hospital in Texas, 2007

BACKGROUND: Adenoviruses can cause outbreaks of febrile respiratory illness in military trainees, but until 2007, adenovirus serotype 14 (Ad14) was never associated with such outbreaks. From April through June 2007, 15 trainees at one base were hospitalized for pneumonia due to Ad14. Subsequent reports of febrile respiratory illness among health care personnel suggested nosocomial transmission.

METHODS: Health care personnel participants completed a questionnaire and provided blood and nasal wash specimens for Ad14 diagnostic testing. We defined a confirmed case of Ad14 infection as one with titers > or = 1:80 or nasal wash specimens positive for Ad14 by polymerase chain reaction, whereas a possible case was defined by titers of 1:20 or 1:40. We also collected environmental samples.

RESULTS: Among 218 tested health care personnel, 35 (16%) had titers > or = 1:20; of these, 7 had possible cases and 28 had confirmed cases of infection. Confirmed case patients were more likely to report febrile respiratory illness (57% vs 11%; P< .001) and to have had direct contact with patients with Ad14 infection (82% vs 62%; P.04 ). Of the 23 confirmed case patients with direct contact with Ad14-infected patients, 52% reported that patients were not in contact and droplet precautions at the time of exposure. Ad14 was recovered from several hospital surfaces.

CONCLUSION: Our findings of possible nosocomial transmission of Ad14 highlight the need to reinforce infection control guidelines.