Hepatitis A

Hepatitis refers to inflammation of the liver, which is usually the result of a viral infection or liver damage caused by excessive consumption of alcohol. However, hepatitis can also be caused by other toxic agents, such as medication or chemicals (Farlex Partner Medical Dictionary, 2012; NHS, 2022).

Hepatitis A virus is one of the infectious agents that causes inflammation in the liver. It is a small, unenveloped (there is no lipid bilayer membrane on the outer part of the virus) ribonucleic acid (RNA) virus within the genus hepatovirus, a member of the picornaviridae family (Virology Research Services, 2022; Travel Health Pro, 2023). Unenveloped viruses can be more virulent and tend to be more resistant to heat, dryness, extreme pH levels and simple disinfectants (Virology Research Services, 2022). Following ingestion, it penetrates and replicates in the gut mucosa, then travels to the liver cells via the portal blood.

The infection induces

Hepatitis A virus often causes mild illness and is commonly an asymptomatic disease, especially in children. However, it tends to become more severe with advancing age and can have fatal outcomes (Travel Health Pro, 2023; World Health Organization, 2023).

The infection has an average incubation time of 28 days, but can last from 15–50 days (Travel Health Pro, 2023). There are four phases of hepatitis A infection, but not all patients will experience all stages.

First, there is the incubation period, which can last for 2–6 weeks (British Liver Trust, 2017). Although there may not be symptoms during this stage, the carrier can potentially be infectious. The second stage is known as the early symptom or prodromal phase, usually lasting around 10 days (British Liver Trust, 2017). The symptoms during this phase are often mild and influenza-like, and can include:

• malaise
• fatigue
• weight loss
• vomiting
• abdominal discomfort
• diarrhoea (British Liver

Hepatitis A is contracted via the faecal–oral route either by direct person-to-person contact or more commonly via contaminated food and water (Travel Health Pro, 2023; World Health Organization, 2023; UK Health Security Agency, 2024a). Hepatitis A is highly infectious; people only need to be in contact with a very small amount of the virus to contract it. It is passed out of the bowel in faeces, and passed on orally. This is usually through close contact with someone who has the virus or by ingesting contaminated food and water either directly from the host or indirectly via sewage. This virus can also be spread through blood-to-blood contact, but this is very rare (British Liver Trust, 2017).

Hepatitis A still persists in vulnerable populations – anyone who has not had the disease or been vaccinated – with an estimated 1.4 million annual cases globally and 7000 deaths (World Health Organization, 2023).

Clinically, it can be difficult to distinguish hepatitis A from other acute viral hepatitis. The only definitive diagnosis is via a blood screen for hepatitis A virus-specific immunoglobulin G or M antibodies (World Health Organization, 2023). Additional tests may include reverse transcriptase polymerase chain reaction to detect the hepatitis A virus RNA, but this may require specialised laboratory facilities (World Health Organization, 2023).
Hepatitis A is a notifiable disease in the UK (Public Health England, 2018; Travel Health Pro, 2023). If a healthcare professional suspects a patient to have hepatitis A, they should fill out the Hepatitis virus investigation request form from the UK Health Security Agency (2023).

There is no specific treatment for hepatitis A infection; it is managed using supportive interventions and symptom control. It is advised that patients avoid hepatoxic medication and alcohol while they are unwell. Hospitalisation and higher-level medical interventions would usually only be required in severe disease and acute liver failure, or occasionally for fluid balance maintenance (World Health Organization, 2022, 2023).