- Reason for surveillance
- Case definition
- Notification criteria and procedure
- The disease
- Managing single notifications
- Managing special situations
1. Reason for surveillance
- To identify source of the infection and so prevent further cases
- To monitor the epidemiology and so inform the development of better prevention strategies.
2. Case definition
Only confirmed cases should be notified
- A confirmed case requires laboratory definitive evidence, or
- Laboratory suggestive evidence and clinical evidence
Laboratory definitive evidence
- Detection of hepatitis E virus in faeces by electron microscopy, or
- IgG seroconversion or a significant rise in antibody level or a fourfold or greater rise in titre to hepatitis E virus.
Laboratory suggestive evidence
Detection of IgM or IgG to hepatitis E virus
A clinically compatible illness without other apparent cause.
3. Notification criteria and procedure
Hepatitis E is to be notified by:
- Medical practitioners and hospital CEOs on provisional clinical diagnosis of acute viral hepatitis (ideal reporting by telephone on same day of diagnosis)
- Laboratories on confirmation (ideal reporting by telephone on same day of diagnosis).
Probable and confirmed cases should be entered onto NCIMS
4. The disease
The hepatitis E virus (HEV), an RNA virus.
Mode of transmission
Hepatitis E is mainly transmitted by the faecal-oral or foodborne routes, however blood borne and perinatal transmission also occur. Faecally contaminated drinking water is the most commonly documented vehicle of transmission in developing countries. Consumption of raw or undercooked pork products, particularly pork liver, has been known to cause hepatitis E infection in developed countries, including Australia.
The incubation period ranges from 15 to 64 days with, a mean of 26 to 42 days reported in various epidemics.
The period of communicability is not known, but HEV has been detected in the stool 14 days after the onset of jaundice.
Symptoms do not occur in all people infected. Hepatitis E infection usually produces only mild disease and most people recover completely within one to four weeks. The usual clinical presentation is very similar to that of hepatitis A. Symptoms include anorexia, abdominal pain, jaundice, nausea, vomiting & fever and are usually self-limiting. Persistent hepatitis E infections may occur in immune-compromised persons. The case-fatality rate is similar to that of hepatitis A, except for women in the third trimester of pregnancy where it is about 20 percent.
5. Managing single notifications
Within 1 working day of notification of a probable or confirmed case begin follow-up investigation.
Within 1 working day of notification enter probable or confirmed cases on NCIMS.
The response to a notification will normally be carried out in collaboration with the case's health carers. But regardless of who does the follow-up, PHU staff should ensure that action has been taken to:
- Confirm the onset date and symptoms of the illness
- Confirm results of relevant pathology tests, or recommend the tests be done
- Find out if the case or relevant care-giver has been told what the diagnosis is before beginning the interview
- Seek the doctor's permission to contact the case or relevant care-giver
- Review case and contact management, ensuring that relevant exclusions have been made
- Ensure proper control measures are taken to prevent further spread.
Investigation and treatment
Treatment is supportive only.
Immunosuppression can delay viral clearance and lead to viral persistence in patients with solid organ transplant and HIV infection. Persistent infections may require management using antivirals.
The case or relevant care-giver should be informed about the nature of the infection and the modes of transmission. Education should include information about hygienic practices, particularly hand-washing before preparing food, eating and after going to the toilet.
Adult cases should also be advised, during the infectious period:
- Not to donate blood
- Not to prepare or handle food or drinks to be consumed by other people
- Not to practise oral or anal sex
- Not to share drug paraphernalia
- To advise health care workers of their infection.
Information regarding exposures during the period 2 to 9 weeks before onset of jaundice should be sought. This should include information about travel.
If the patient has not travelled to an endemic area, then it is very important to confirm that the diagnosis is correct and if so, identify the likely source of infection. Ask about:
- Consumption of pork products, particularly pork liver
- Household and sexual contacts who have had an illness consistent with hepatitis
- Restaurants where the case has eaten or worked
- Social gatherings where the case has eaten
- All sources of drinking water
- Consumption of raw or partially cooked shellfish
- Attendance or employment at child care centres by case or household contacts
- Illicit drug use
- Travel by household contacts to countries with endemic hepatitis E
- Recreational water exposure
- Exposure to sewage
- Blood transfusion and organ transplants.
Isolation and restriction
Confirmed and probable cases should not attend child care facilities during the infectious period (i.e., for 14 days after onset of symptoms). Cases must not provide personal care to individuals in child care or health care settings or handle food for others during the infectious period and for 14 days after the onset of symptoms.
Drinking water systems are potential sources of HEV infection if there is opportunity for faecal contamination. Where an unexpected cluster is reported, an evaluation may include review of water treatment procedures and bacteriological quality.
Determine if the case has been exposed to a failed sewage disposal system.
Food service facility
Where contaminated food is a suspected source, PHU staff should seek assistance from the NSW Food Authority to ensure that the premises where food was prepared is evaluated to determine the likelihood of disease transmission.
Child care facility
PHU staff should review the facility's infection control procedures to determine the likelihood of disease transmission, and establish if carers of children <2 years old have changed nappies and prepared food in the same shift.
Identification of contacts
Immediate family, household members and sexual partners should be considered at risk.
Investigation and treatment
Provide contacts (or parents/guardians) with advice about the risk of infection; counsel them to watch for signs or symptoms of hepatitis occurring within 9 weeks of exposure and seek medical attention early if symptoms develop. Advice about careful hygiene should be given, particularly about hand washing after going to the toilet. It is especially important that any food handlers monitor their own development of hepatitis symptoms after contact with the disease and seek medical attention promptly if symptoms are detected.
Isolation and restriction
Contacts are not normally excluded from child-care, school or work.
6. Special situations
A case in a food handler
Most food handlers with hepatitis E do not transmit hepatitis E to others. The public health response is based on a risk assessment as outlined in the HAV Control Guideline. The risk assessment includes whether the food handler was working while infectious, reports from the food handler and his/her supervisor and co-workers about illness (including diarrhoea) and hygiene practices (glove use, hand hygiene), evidence of hygiene training, and previous assessments of the sanitation practices in the facility. There is no post exposure treatment available for hepatitis E. Where a risk is identified, the benefits of alerting patrons are to warn people who may be already incubating the infections (and their doctors) about their exposure, educating them about the symptoms and signs of hepatitis E, in order to facilitate rapid diagnosis and management, and to prevent a subsequent generation of cases.
Consult with the Communicable Disease Branch (CDB) staff and the Media Unit before going public. The CDB may convene an expert panel to advise in special situations.
Appendix 1 - Hepatitis E Investigation Form [PDF]
Appendix 2 - Hepatitis E Factsheet