Like influenza viruses, adenoviruses can cause severe respiratory illness. Unlike influenza, however, not everyone has access to a vaccine.
Writing in Emerging Infectious Diseases, researchers said expanding access to a vaccine against human adenovirus type 4 (HAdV-4) that is currently available only to military personnel in the United States could prevent civilian infections, which may be underestimated due to a lack of surveillance.
Adriana E. Kajon, PhD, a scientist in the infectious disease program at Lovelace Respiratory Research Institute in Albuquerque, New Mexico, and colleagues at the New York State Department of Health and CDC studied 36 HAdV-4 isolates collected from 2011 to 2015 from college students in New York state and adults in other areas of the Northeastern U.S. with symptoms of influenza-like illness.
“On the basis of the severity of the clinical presentation of some cases in this study, the HAdV-4 vaccine currently licensed for military use should be considered a potentially valuable resource to prevent disease in susceptible populations living in closed communities, such as college settings, summer camps, and long-term care facilities,” they wrote.
According to the CDC, adenoviruses are usually spread through close personal contact, coughing or sneezing, or after touching an infected surface. They rarely cause serious illness, but Kajon said HAdV-4 is one of several epidemic adenovirus types known, and recently reported to cause severe disease and hospitalization, even among immunocompetent adults in the U.S. and other countries.
“The symptoms can be basically indistinguishable from those of flu and that is why they are described as influenza-like illness,” she told Infectious Disease News.
Kajon and colleagues said most of the HAdV-4 isolates included in their study matched variants frequently detected among military recruits before the U.S. Department of Defense reinstated use of the vaccine in 2011, which they said “dramatically’ reduced cases. But two novel variants were isolated from students enrolled at the same New York college, and another that was genetically similar to the vaccine strain was recovered from an 18-year-old woman who had contact with an active member of the military and whose infection was likely caused by a virus that evolved from the vaccine strain.
According to Kajon, the military intervention against HAdV-4 and HAdV-7 infections showed that the associated respiratory disease is vaccine preventable. She said most clinical labs have the ability to test for adenovirus infections, but the tests do not identify the type (80 have been described). In their study, Kajon and colleagues said that including adenoviruses in differential diagnostic test panels used by physicians “would be invaluable to better assess the role of HAdVs as causative agents of severe respiratory illness” and could prevent the use of antivirals in patients who do not have influenza.
“We do not have a good understanding of the current burden of disease associated with adenovirus infection or knowledge of the most prevalent types circulating in our country,” Kajon said. “A better understanding of the epidemiology of adenovirus respiratory infections is required to design efficient intervention strategies. Collaborative sentinel surveillance efforts and more research involving public health and academic laboratories are needed.” – by Gerard Gallagher
Kajon AE, et al. Emerg Infect Dis. 2018;doi:10.3201/eid2402.171407.
Disclosures: The authors report no relevant financial disclosures.