Hepatitis A

Hepatitis A occurs sporadically globally. Infection is common in low-income countries with poor sanitary conditions and hygienic practices. In those contexts, nearly 90 per cent of children have been infected with the hepatitis A virus before the age of ten years and often do not experience any noticeable symptoms. In middle- and high-income countries with good sanitation and hygiene conditions, infection rates are low. When the virus gets introduced in such communities, the presence of good sanitation and hygiene practices prevents person-to-person transmission, stopping the outbreak rapidly.

The following are standard case definitions to allow national health authorities to interpret data in an international context. However, during an outbreak case definitions may be adapted to the local context and the Red Cross Red Crescent should use those agreed/established by national health authorities. NB: Consider that during community-based surveillance, volunteers should use broad (simplified) case definitions (referred to as community case definitions) to recognize most or all possible cases, provide relevant risk communication and appropriate actions and encourage them to seek care. Other actors such as healthcare workers or investigators studying the cause of a disease, on the other hand, can use more specific case definitions that may require laboratory confirmation.

Suspected case: Discrete onset of an acute illness with signs/symptoms of acute viral illness (e.g. fever, malaise, fatigue) associated with:

• Clinical signs of liver damage, which include anorexia, nausea, jaundice, dark urine, right upper quadrant tenderness)
• This includes: laboratory testing of liver function showing raised values in tests such as ALT, AST and Bilirubin (raised alanine aminotransferase [ALT] levels more than 10 times the upper limit of normal laboratory levels).

Confirmed case: a case with laboratory confirmation OR an epidemiological link to a confirmed case.

WHO case definition source of information: https://www.who.int/docs/default-source/outbreak-toolkit/latest-update---11-october/hepatitis-a-outbreak-toolbox---250919.pdf?sfvrsn=2a4711ed_2

An outbreak of hepatitis is often suspected by a clinical healthcare worker, who notices an unusual number of patients with acute jaundice syndrome within a short period of time. These patients present with one or more of the following features: similar clinical symptoms, residence in the same area or location, sharing the same water supply.

If baseline information from the same geographical area for previous years is available, it can be used to verify whether the number of cases in the present year is unusually high compared to that in previous years over the same period.

For acute jaundice syndrome in emergency settings, alert thresholds of “five or more cases with acute jaundice syndrome in one location in one to a few weeks” and of “five cases with acute jaundice syndrome or 1.5 times the baseline rate” have been suggested to help early detection of potential outbreaks of hepatitis.

• Poor sanitary conditions and hygienic practices like lack of handwashing possibilities or lack of functioning toilets.
• Areas of conflict and humanitarian emergencies where sanitation and safe water supply pose special challenges and settings that are crowded.
• Using or injecting drugs.
• Sexual activity with an infected person.
• Water contaminated with human faeces, for example from sewage, septic tanks and latrines, is a source of infection. Unsafe domestic water storage and handling.
• Food when prepared or stored in unhygienic conditions.
• Fish and seafood from faecal waste polluted water that is consumed raw or not properly cooked.
• Men who have sex with men are at a higher risk of contracting the disease.

Attack rates will vary from one outbreak to another. In case of an outbreak, consult the latest information provided by health authorities.

• Between 2.6 per cent and 27.6 per cent in nurseries, 2.9 per cent and 50 per cent in primary schools, and 12 per cent and 25 per cent in households.

• People with chronic liver disease.
• Immunosuppressed persons such as those receiving chemotherapy, transplant recipients or HIV carriers.
• People with chronic diseases such as renal disease, cancer, chronic lung or liver disease and diabetes.

Hepatitis A virus.

Humans.

• Faecal oral transmission: Person-to-person contact (unwashed hands, object contaminated with human waste). Food and water contaminated with human waste (stools), mainly fruits, vegetables, shellfish, ice and water. Sharing eating utensils that are contaminated.
• Sexual transmission: Can occur from any sexual activity with an infected person (such as oral-anal sex).
• Vehicle-borne transmission: Exposure to infectious body fluids as a result of contamination of drugs and needle-sharing among people who inject drugs.

14—50 days.

Two weeks before onset of first symptoms until two weeks after the onset of jaundice.

• Some sufferers, especially children, show no signs of having the disease at all. Hepatitis A is very contagious, and people can even spread the virus before they feel unwell.
• Symptoms include fatigue, fever, loss of appetite, abdominal pain, nausea, rash, itching, dark urine and pale stool, and yellowing of the skin or whites of the eyes (jaundice).
• Hepatitis A virus does not cause chronic hepatitis. Rarely it can lead to fulminant liver failure and death.

Other viral hepatitis, yellow fever, leptospirosis, dengue fever, malaria.

• Cases of hepatitis A are not clinically distinguishable from other types of acute viral hepatitis.
• Specific diagnosis is made by the detection of HAV-specific IgM antibodies in the acute disease and IgG antibodies lifelong in the blood after an infection or vaccination.
• Additional tests include reverse transcriptase polymerase chain reaction (RT-PCR) to detect the hepatitis A virus RNA and may require specialized laboratory facilities.

Please refer to the appropriate local or international guidelines for clinical management. All clinical management including the administration of any treatment or vaccine should be conducted by health professionals.

• There is no specific treatment for hepatitis A. Recovery from symptoms following infection may be slow and may take several weeks or months. Sometimes hospitalization is required.
• Hepatitis A vaccine is used in a few countries; greater use of the vaccine has the potential to control outbreaks. No vaccine is licensed for children younger than one year of age. Planning for large-scale immunization programmes should involve careful economic evaluations and consider alternative or additional prevention methods, such as improved sanitation and health education for improved hygiene practices. Whether or not to include the vaccine in routine childhood immunizations depends on the local context.

• Lifelong immunity after natural infection.
• Vaccination results in long-term protection.