Human adenovirus 31 (HAdV‑31) is a type A adenovirus with a double‑stranded DNA genome enclosed in a 70‑100 nm icosahedral capsid. It is one of over 100 recognized human adenovirus types but is less common than the respiratory types such as 7 or 14. HAdV‑31 is mainly associated with gastroenteritis and can infect both the respiratory and gastrointestinal tracts.
Biology and pathogenesis
Adenoviruses replicate in the nucleus of epithelial cells. HAdV‑31 infections are transmitted via the faecal‑oral route or respiratory droplets. After entering through the oropharynx or gastrointestinal tract, the virus infects mucosal epithelial cells and lymphoid tissue, producing large numbers of virions before cell lysis. Persistent infection may occur in lymphoid tissue, and immunocompromised patients are at risk for prolonged viraemia. Neutralising antibodies and cytotoxic T cells are important for clearing infection.
Clinical relevance
HAdV‑31 has been identified in outbreaks of paediatric gastroenteritis. Infections often present with fever, vomiting and watery diarrhoea similar to infections caused by adenovirus types 40 and 41. While most cases are self‑limited, severe dehydration can occur in infants. HAdV‑31 can also cause respiratory disease and sepsis in immunocompromised hosts, particularly in stem cell transplant recipients, where it may lead to pneumonia, haemorrhagic cystitis or disseminated disease. Timely diagnosis using PCR and supportive care with rehydration are essential, and antiviral agents such as cidofovir are sometimes used in severe cases. Human adenovirus 31 illustrates the diversity of adenoviral diseases. Although it is less common than the enteric types 40 and 41, clinicians should be aware of its potential to cause both gastrointestinal and systemic disease, especially in vulnerable patient populations. Related Terms: Human Adenovirus 40, Human Adenovirus 41, Human Adenovirus 55, Human Adenovirus 14