Hepatitis A: Symptoms, Transmission, and Prevention

Posted on Dec 4, 2024 in Medicine & Health

Hepatitis A

What is Hepatitis A?

Hepatitis A is an acute viral illness affecting the liver.

Stages of Hepatitis A

  1. Incubation: The initial phase after infection.
  2. Prodromal (Pre-jaundice): This phase lasts an average of seven days and involves symptoms such as malaise, headache, low fever, anorexia, weakness, intense fatigue, joint pain, nausea, vomiting, abdominal discomfort in the right upper quadrant, aversion to certain foods and cigarette smoke.
  3. Jaundice: This phase has varying intensity and duration, usually 4-6 weeks. It is preceded by two to three days of dark urine. Symptoms may include pale stools, itching, and an enlarged liver or spleen. Fever, joint pain, and headache typically disappear at this stage.
  4. Convalescence: A return to well-being, with jaundice gradually subsiding and stool and urine returning to normal color.

Etiologic Agent

Hepatitis A is caused by the Hepatitis A virus (HAV), an RNA virus belonging to the Picornaviridae family.

Reservoir

Humans are the primary reservoir for HAV. Primates such as chimpanzees and marmosets can also be infected.

Mode of Transmission

HAV is primarily transmitted through the fecal-oral route, including contaminated water, person-to-person contact (especially within families and institutions), and contaminated food and inanimate objects. The virus’s stability in the environment and the high viral load shed by infected individuals facilitate transmission. Percutaneous (e.g., needlestick injury) and parenteral (e.g., blood transfusion) transmission are rare due to the short period of viremia.

Individuals who have recovered from Hepatitis A develop immunity but remain susceptible to other types of hepatitis.

Incubation Period

The incubation period ranges from 15 to 45 days, with an average of 30 days.

Period of Communicability

HAV is communicable from two weeks before symptom onset until the end of the second week of illness.

Complications

  • Prolonged or Recurrent Forms: Characterized by persistently elevated liver enzymes for months or even a year.
  • Fulminant Hepatitis A: A rare but severe form with high mortality (above 80%), involving massive liver necrosis and acute liver failure within 10 to 30 days. Symptoms may include toxemia, drowsiness, mental confusion (hepatic coma), and hemorrhagic manifestations. Sepsis is rare.

Treatment

There is no specific treatment for acute Hepatitis A. Treatment is primarily supportive and focuses on managing symptoms like nausea, vomiting, and rash. Relative rest is recommended until liver enzymes normalize. A low-fat, high-carbohydrate diet is often suggested but primarily to accommodate the patient’s potential anorexia. Patients should generally follow their appetite and food preferences. Alcohol should be avoided for at least six months, preferably a year. Medications should only be taken under medical supervision to avoid exacerbating liver damage. Hepato-associated drugs or vitamin complexes have no therapeutic value in this context.

Epidemiological Characteristics

  • Hepatitis A has a global distribution, occurring sporadically or in outbreaks.
  • Prevalence is higher in areas with poor sanitation and hygiene.
  • Common in closed institutions.
  • Primarily affects children and young adults in developing countries and adults in developed countries.
  • Morbidity and mortality are generally low, but mortality risk increases with age.

Control Measures

Control measures include outbreak notification, patient care (including isolation and exclusion from school or childcare during the first two weeks of illness), and hygiene practices such as disinfecting objects and surfaces with chlorine bleach.

Preventive Measures

  • Promoting good hygiene practices, especially handwashing after using the toilet, preparing food, and before eating.
  • Ensuring safe water and sanitation.
  • Implementing strict hygiene measures in daycare centers, preschools, and closed institutions, including handwashing and disinfection of objects and surfaces.
  • Properly cooking seafood and disinfecting raw foods with chlorine.
  • Vaccination is available for individuals at high risk, such as those with chronic liver disease, transplant recipients, and individuals traveling to areas with high HAV prevalence.