Background: First isolated in the Netherlands in 1955 during an outbreak of acute respiratory disease (ARD) among military recruits, human adenovirus 14 (HAdV-14) has historically been considered rare. With no precedent of circulation in North America, HAdV-14 has been isolated from military and civilian cases of ARD of variable severity since 2003 in the United States.
Methods: Ninety-nine isolates from military and civilian cases from different geographic locations and circulation periods were characterized by restriction enzyme analysis of viral DNA and select gene sequencing.
Results: All examined viruses were found to be identical and to belong to a new genome type designated "HAdV-14p1" (formerly known as "14a"). Comparative alignments of E1A, hexon, and fiber gene sequences with other subspecies B2 HAdVs suggest that HAdV-14p1, like the closely related HAdV-11a, arose from recombination among similar HAdV-11 and HAdV-14 ancestral strains. A deletion of 2 amino acids in the knob region of the fiber protein is the only identified unique characteristic of HAdV-14p1.
Conclusion: The current geographic distribution of HAdV-14p1 involves at least 15 states in the Unites States. The role of the fiber mutations in the recent emergence of HAdV-14p1 ARD in North America warrants further study.