Hepatitis E

Notification requirement for hepatitis E

Hepatitis E infection is a ‘routine’ notifiable condition and must be notified by medical practitioners and pathology services in writing within 5 days of diagnosis.

This is a Victorian statutory requirement.

Primary school and children’s services centre exclusion for hepatitis E

Exclusion is not applicable.

Infectious agent of hepatitis E

Hepatitis E virus (HEV) is the causative agent. The virus has at least four different genotypes.

Identification of hepatitis E

Clinical features

The clinical course of disease due to HEV is similar to that of hepatitis A. For infection acquired in developing countries, it is a self-limiting acute illness, most commonly in adults aged 15–44 years. Signs and symptoms are similar to hepatitis A, with fever, fatigue, loss of appetite, nausea, vomiting, abdominal pain, jaundice, dark urine, clay-coloured stools and joint pain. Children infected with HEV usually have mild or no symptoms.

Pregnant women are more likely to have severe illness, such as fulminant hepatitis and death. A high case-fatality rate (up to 20 per cent) has been described in pregnant women affected in their third trimester of pregnancy.

For infection acquired in developed countries, symptoms are more common among older people (>45 years) and men.

Diagnosis

Diagnosis depends on clinical and epidemiological features, and exclusion of hepatitis A and other causes of hepatitis.

Acute hepatitis E is diagnosed in the presence of IgM anti-HEV.

HEV RNA can be detected by polymerase chain reaction (PCR) in acute-phase faeces in 50 per cent of cases.

HEV may be detected by immune electron microscopy of faeces collected during the acute phase.

Serological tests to confirm HEV infection are available through the Victorian Infectious Diseases Reference Laboratory.

Incubation period of hepatitis E virus

The incubation period varies from 3 to 8 weeks. In different epidemics, the average incubation period has varied from 26 to 42 days.

Public health significance and occurrence of hepatitis E

HEV is most commonly found in developing countries with inadequate environmental sanitation.

Sporadic cases and epidemics in adults have occurred in east and south Asia, India, the Middle East, north and west Africa, Mexico and Central America. Some outbreaks have involved thousands of people over a short period of time. People living in temporary, overcrowded housing after natural disasters, or in refugee camps, are at particular risk.

The disease is not endemic in Australia, and the majority of cases reported to date have occurred in travellers. In Victoria in 2010, 11 cases were notified to the department.

Reservoir of hepatitis E virus

Humans and some primates act as reservoirs. Genotype 3 is associated with swine, but rarely causes disease in humans.

Mode of transmission of hepatitis E virus

Hepatitis E is transmitted via contaminated water and possibly through person-to-person transmission via the faecal–oral route. Evidence of infection in rats and other rodents in some endemic countries suggests that other mechanisms of transmission are likely.

Period of communicability of hepatitis E

The period of communicability is unknown. HEV has been detected in stools 14 days after the onset of jaundice and 4 weeks after ingestion of contaminated food or water.

Susceptibility and resistance to hepatitis E

Susceptibility is unknown; however, disease tends to occur in adults. Pregnant women in the third trimester of pregnancy are at particular risk of fulminating disease.

Control measures for hepatitis E

Preventive measures

Prevention relies on good sanitation and the availability of clean drinking water.

Good personal hygiene and hand hygiene are important, particularly after defecation and before eating. Travellers to endemic areas should be advised of the risk and avoid ingestion of faecally contaminated drinking water.

There is no vaccine against HEV.

Control of case

Treatment is supportive only, particularly the maintenance of hydration. Patients are advised to rest, ensure adequate nutrition and fluids, and avoid alcohol.

Hospitalisation is sometimes required with severe cases and should be considered for pregnant women.

Control of contacts

Consider the diagnosis in symptomatic contacts. Immunoglobulin is not effective in preventing hepatitis E.

Control of environment

Infected people should be advised to maintain strict personal hygiene, and avoid preparing meals for others unless adequate food safety can be guaranteed.

Outbreak measures for hepatitis E

A case with no history of overseas travel would constitute an outbreak in Victoria. Immediate notification is critical to identify the source and prevent further disease. A detailed epidemiological, environmental and laboratory investigation of common exposures (particularly water) among cases is necessary.