Overview
Recognise enterically transmitted viral hepatitis, diagnose hepatitis A and E accurately, identify acute liver failure, and apply UK prevention and public-health measures.
HAV and HEV are RNA viruses that usually produce an acute hepatitic syndrome with malaise, anorexia, nausea, fever, right-upper-quadrant discomfort, dark urine, pale stools, pruritus and jaundice. Children with HAV may have few symptoms, whereas symptomatic and severe disease is more likely with increasing age or pre-existing liver disease. Incubation means exposure can be remote and patients may be infectious before jaundice. HAV is transmitted through contaminated food or water and close contact; outbreaks also occur within sexual networks and other settings where faeco-oral exposure is facilitated.
HEV is not merely travel-related. Genotypes circulating in the UK are zoonotic, with undercooked pork, pork products, wild boar and venison relevant exposures; transfusion or transplantation transmission is rare but important. In immunocompetent people infection is usually self-limited. In solid-organ recipients and some other immunosuppressed people, HEV RNA can persist and cause chronic hepatitis, fibrosis and cirrhosis. Pregnancy-associated severe HEV is particularly described with genotypes prevalent in endemic regions, so a pregnant patient with compatible acute hepatitis deserves urgent specialist assessment regardless of where she lives.