Outbreaks

alert icon

CDC is investigating hepatitis of unknown origin in children; some of these cases tested positive for adenovirus.

Investigators are still learning more about the cause.

CDC has released a Health Alert Notice for clinicians and a media statement for parents and caregivers.

Get clinical guidance and instructions for testing, typing, and submission.

Adenoviruses usually cause respiratory illnesses or conjunctivitis, and outbreaks can occur throughout the year. There is no specific time of year when adenovirus infections and outbreaks are more common.

Adenoviruses is not a nationally notifiable disease in the United States, meaning clinicians are not required to test for or report cases to health departments or CDC. Therefore, many outbreaks of adenovirus likely go either undetected or unreported.

Adenovirus types that can cause outbreaks

Reported sporadic cases and outbreaks of adenovirus have included:

  • Adenovirus types 3, 4 and 7 are most commonly associated with acute respiratory illness.
    • Adenovirus type 7 has been associated with more severe outcomes than other adenovirus types, particularly in people with weakened immune systems. In the last 10 years, instances of severe illness and death from adenovirus type 7 infection have been reported in the United States.
  • Adenovirus type 14, which since 2007 has been associated with outbreaks of acute respiratory illness among U.S. military recruits and the general public
  • Adenovirus types 8, 19, 37, 53, and 54, which can cause epidemic keratoconjunctivitis
  • Enteric adenovirus types 40 and 41, which cause gastroenteritis, usually in children
  • Some adenoviruses (e.g., 4 and 7) that spread in bodies of water such as small lakes or swimming pools without adequate chlorine and can cause outbreaks of febrile disease with conjunctivitis

Health Professionals should

  • Consider adenoviruses as possible causes of upper respiratory illness, and lower respiratory illness such as pneumonia
  • Report unusual clusters of illness (e.g., respiratory, conjunctivitis) potentially caused by adenoviruses to the state or local health department
  • Take appropriate infection control measures specific to adenovirus to help prevent or control outbreaks. This can include active surveillance, isolating ill patients when possible, restricting visitors and new admissions, monitoring staff for illness and sending them home when sick, environmental cleaning, using personal protective equipment, and frequent handwashing or sanitizing.
Related Pages