The hepatitis A virus is transmitted by the fecal-oral route, which means that consumed food has been contaminated by feces containing the A virus. The incubation period is about 30 days from time of contamination to clinical disease. Symptoms begin with fatigue, nausea, vomiting, headache, and low grade fever and progress to dark urine, clay colored stools and jaundice. The treatment is restricted physical activity and a high calorie diet. Recovery usually occurs in one to two months.
Prevention lies in drinking sterile bottled water and eating well cooked foods.
Fruit should be peeled with clean hands, and salads and raw shellfish should be avoided when traveling in developing countries. Hepatitis A vaccine is available. Two injections are required from 6 to 12 months apart. This virus is transmitted by infected body fluids including blood, saliva, tears, seminal fluid, breast milk, sexual contact and perinatal transmission. More than 200 million hepatitis B carriers in the world constitute the main source of hepatitis B in humans.