Elevation of serum transaminases with norovirus infection

Does norovirus induce acute hepatitis?

Background

Norovirus is the commonest cause of acute viral gastroenteritis with significant morbidity. Extra intestinal manifestation following norovirus infection is rare and the mechanism is unknown.

Methods

We undertook a review of the English literature published from January 1967 to April 2019 to evaluate the risk of acute viral hepatitis due to norovirus gastroenteritis. Data sources included MEDLINE, EMBASE, Cochrane library, and references within identified articles.

Results

We identified 126 potential studies and included 5 publications involving 17 cases of norovirus induced hepatitis, and all had elevated ALT (31.7–458IU/l) and AST levels (45.6–1150IU/l). Majority of the cases were below the age of 18 (88%, n = 15) and almost two-third (64.7%, n = 11) had supportive treatment, mainly intravenous fluid administration. In cases reporting sex, there were more females than males (62.5%, 5/8 vs. 37.5%, 3/8). The duration of illness was longer, on average 10 days, compared to 3 days in those without elevated transaminitis and it took an average of 22.5 days for liver enzymes to settle. All patients recovered fully with no progression to chronic liver disease.

Conclusion

Norovirus gastroenteritis is a self-limiting illness with majority not requiring hospitalisation and invasive investigations. We recommend that clinicians should be aware of norovirus induced transaminitis, and to suspect this especially in children who are likely to have protracted illness and require hospitalisation due to norovirus acute hepatitis.

Norovirus

Norovirus, an RNA virus of the family Caliciviridae, is a human enteric pathogen that causes substantial morbidity across both health care and community settings. Several factors enhance the transmissibility of norovirus, including the small inoculum required to produce infection (<100 viral particles), prolonged viral shedding, and its ability to survive in the environment. In this review, we describe the basic virology and immunology of noroviruses, the clinical disease resulting from infection and its diagnosis and management, as well as host and pathogen factors that complicate vaccine development. Additionally, we discuss overall epidemiology, infection control strategies, and global reporting efforts aimed at controlling this worldwide cause of acute gastroenteritis. Prompt implementation of infection control measures remains the mainstay of norovirus outbreak management.