Clinical and Epidemiological Aspects of the Emerging Adenovirus 14p1, Part I

Human adenovirus serotype 14 (HAdV-14; agent de Wit), a subspecies B2 member, was first identified in The Netherlands in 1955 in a military training camp and last reported in Eurasia in 1963. This virus has been conspicuous by its absence in global serosurveys and surveillance in subsequent decades. In early 2006, HAdV-14 was described at five military training centers in the United States and was subsequently associated with civilian cases of severe respiratory disease and fatalities in New York and California. In 2007, 140 cases of HAdV-14 were identified in outbreak clusters across the U.S. (Oregon, Washington, and Texas), with 37% requiring hospitalization, 17% admittance to intensive care units, and a 5% mortality rate. Genetic characterization of this emerging HAdV-14 revealed a novel genome variant (termed HAdV-14p1), and an identical virus has recently been detected in Europe, also associated with morbidity and mortality in both immunocompromised and immunocompetent individuals. As a recently emerged virus, HAdV-14 has an increased potential for high rates of transmission and high attack rates due to low levels of herd immunity, simply because the vast majority of individuals are extremely likely to have never been exposed. Part I of this two-part article reviews the discovery and classification of HAdV-14p1; the clinical symptoms associated with the virus, including case reports, and, finally, the risk factors associated with these infections. Part II of this article reviews the epidemiology, diagnosis, prevention, and treatment modalities of HAdV-14p1.