Outbreak of severe respiratory disease associated with emergent human adenovirus serotype 14 at a US air force training facility in 2007.
BACKGROUND
In 2007, a US Air Force training facility reported a cluster of severe respiratory illnesses associated with a rare human adenovirus (Ad) serotype, Ad14. We investigated this outbreak to better understand its epidemiology, clinical spectrum, and associated risk factors.


METHODS
Data were collected from ongoing febrile respiratory illness (FRI) surveillance and from a retrospective cohort investigation. Because an Ad7 vaccine is in development, Ad7 antibody titers in pretraining serum samples from trainees with mild and those with severe Ad14 illness were compared.


RESULTS
During 2007, an estimated 551 (48%) of 1147 trainees with FRI were infected with Ad14; 23 were hospitalized with pneumonia, 4 required admission to an intensive care unit, and 1 died. Among cohort members (n = 173), the Ad14 infection rate was high (50%). Of those infected, 40% experienced FRI. No cohort members were hospitalized. Male sex (risk ratio [RR], 4.7 [95% confidence interval {CI}, 2.2-10.1]) and an ill close contact (RR, 1.6 [95% CI, 1.2-2.2]) were associated with infection. Preexisting Ad7 neutralizing antibodies were found in 7 (37%) of 19 Ad14-positive trainees with mild illness but in 0 of 16 trainees with Ad14 pneumonia (P = .007).


CONCLUSIONS
Emergence of Ad14, a rare Ad serotype, caused a protracted outbreak of respiratory illness among military recruits. Most infected recruits experienced FRI or milder illnesses. Some required hospitalization, and 1 died. Natural Ad7 infection may protect against severe Ad14 illness.
Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. jqt8@cdc.gov
Jacqueline E
JE
Tate
Michel L
ML
Bunning
Lisa
L
Lott
Xiaoyan
X
Lu
John
J
Su
David
D
Metzgar
Lorie
L
Brosch
Catherine A
CA
Panozzo
Vincent C
VC
Marconi
Dennis J
DJ
Faix
Mila
M
Prill
Brian
B
Johnson
Dean D
DD
Erdman
Vincent
V
Fonseca
Larry J
LJ
Anderson
Marc-Alain
MA
Widdowson
D000258:Adenovirus Infections, Human / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission; D000260:Adenoviruses, Human / Q000145:classification* / Q000235:genetics; D003428:Cross Infection / Q000453:epidemiology / Q000517:prevention & control / Q000821:virology; D003429:Cross Reactions; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D006801:Humans; D008889:Military Personnel; D012189:Retrospective Studies; D012307:Risk Factors; D012703:Serotyping; D013997:Time Factors; D014481:United States / Q000453:epidemiology