Genomic Characterization of Adenovirus 21 Strains Associated With Outbreaks of Febrile Respiratory Illness in United States Military Recruit Training Centers Between 1996 and 2005.

摘要

Adenovirus type 21 (Ad21) is a well-known causative agent of acute respiratory disease among both military recruits and children. In an effort to characterize the molecular epidemiology of Ad21 infections in the military environment, genome-typing work was carried out on a collection of 75 Ad21 strains isolated from the pharyngeal swabs of military recruits presenting with symptoms of febrile respiratory illness between 1996 and 2005 at eight US training centers. One further strain from an ill serviceperson deployed at sea was also characterized. Restriction enzyme analysis with BamHI discriminated two distinct DNA variants, Ad21a and Ad21b. Further analysis with Bg/I, Bg/II, BstEII, HindIII, KpnI, and SmaI discriminated two new subtypes, Ad21a1 and Ad21b1. Ad21a was the most prevalent genome type, accounting for 69 of the 76 strains examined. Genome type Ad21a1 was identified only among the strains isolated at the Marine Corps Recruit Depot, San Diego, CA. Genome types Ad21b and Ad21b1 were identified among strains isolated in 2005 and seem to have emerged after a 4-year (1999-2002) disappearance of all Ad21 genome types. After the reintroduction of the Ad4/Ad7 vaccine in 2008, Ad21 is expected to become a predominant adenovirus serotype in US recruit training centers once again. Knowledge of circulating genome types and their epidemic behavior will be of significant value to ongoing surveillance efforts in these highly susceptible and impacted populations.