Type A viral hepatitis: A summary and update on the molecular virology, epidemiology, pathogenesis and prevention

Abstract

Although epidemic jaundice was well known to physicians of antiquity, it is only in recent years that medical science has begun to unravel the origins of hepatitis A virus (HAV) and the unique pathobiology underlying acute hepatitis A in humans. Improvements in sanitation and the successful development of highly efficacious vaccines have markedly reduced the worldwide prevalence and incidence of this enterically-transmitted infection over the past quarter century, yet the virus persists in vulnerable populations and remains a common cause of food-borne disease outbreaks in economically-advantaged societies. Reductions in the prevalence of HAV have led to increases in the median age at which infection occurs, often resulting in more severe disease in affected persons and paradoxical increases in disease burden in some developing nations. Here, we summarize recent advances in the molecular virology of HAV, an atypical member of the Picornaviridae family, survey what is known of the pathogenesis of hepatitis A in humans and the host-pathogen interactions that typify the infection, and review medical and public health aspects of immunisation and disease prevention.

Selected Viruses Detected on and in our Food

“…This "paradox of hepatitis A risk" is due to the fact that in endemic areas children are infected at early age, e.g. in sub-Saharan Africa, 90% of the 10-year-olds are antibody positive [31] but the infection in young children is often asymptomatic or atypical and triggers a robust immunity [32]. In contrast, in regions with low endemicity, an increase in more severe clinical outbreaks can be observed due to a high degree of susceptible, non-vaccinated and older people.…”

“…In contrast, in regions with low endemicity, an increase in more severe clinical outbreaks can be observed due to a high degree of susceptible, non-vaccinated and older people. Population movements and globalised markets play an important additional role [32].…”

Analytical performance of newly developed rapid point‐of‐care test for the simultaneous detection of hepatitis A, B, and C viruses in serum samples

“…Infections caused by the hepatitis A, B, and C viruses (HAV, HBV, and HCV, respectively) are a major and growing global health problem. HAV infection, which is related to unhygienic living conditions, can cause acute fulminant hepatitis leading to death, and an estimated 1.5 million people are infected with HAV annually . HBV and HCV cause chronic viral hepatitis that can lead to hepatocellular carcinoma.…”

Viruses Associated With Foodborne Infections

“…However, in transitional economies, the introduction of improved sanitation may mean that the population is not exposed as children. As such, the introduction of the virus to these susceptible populations of adults can result in significant outbreaks (Lemon et al, 2018).…”