Hepatitis A

Hepatitis A, (formerly known as infectious hepatitis), is an acute infectious disease of the liver caused by Hepatitis A virus,^[1] which is most commonly transmitted by the fecal-oral route via contaminated food or drinking water. Every year, approximately 10 million people worldwide are infected with the virus.^[2] The time between infection and the appearance of the symptoms, (the incubation period), is between two and six weeks and the average incubation period is 28 days.^[3]

In developing countries, and in regions with poor hygiene standards, the incidence of infection with this virus is high^[4] and the illness is usually contracted in early childhood. The Hepatitis A virus has also been found in samples taken to study ocean water quality.^[5] Hepatitis A infection causes no clinical signs and symptoms in over 90% of these children and since the infection confers lifelong immunity, the disease is of no special significance to the indigenous population. In Europe, the United States and other industrialized countries, on the other hand, the infection is contracted primarily by susceptible young adults, most of whom are infected with the virus during trips to countries with a high incidence of the disease.^[3]

Hepatitis A does not have a chronic stage and does not cause permanent liver damage. Following infection, the immune system makes antibodies against the hepatitis A virus that confer immunity against future infection. The disease can be prevented by vaccination and hepatitis A vaccine has been proved effective in controlling outbreaks worldwide.^[3]

Causes

Foodborne illness usually arises from improper handling, preparation, or food storage. Good hygiene practices before, during, and after food preparation can reduce the chances of contracting an illness. There is a general consensus in the public health community that regular hand-washing is one of the most effective defenses against the spread of foodborne illness. The action of monitoring food to ensure that it will not cause foodborne illness is known as food safety. Foodborne disease can also be caused by a large variety of toxins that affect the environment. For foodborne illness caused by chemicals, see Food contaminants.

Foodborne illness can also be caused by pesticides or medicines in food and naturally toxic substances like poisonous mushrooms or reef fish.

Foodborne illness (also foodborne disease and colloquially referred to as food poisoning) is any illness resulting from the consumption of food.

There are two types of food poisoning: food infection and food intoxication. Food infection refers to the presence of bacteria or other microbes which infect the body after consumption. Food intoxication refers to the ingestion of toxins contained within the food, including bacterially produced exotoxins, which can happen even when the microbe that produced the toxin is no longer present or able to cause infection. In spite of the common term food poisoning, most cases are caused by a variety of pathogenic bacteria, viruses, prions or parasites that contaminate food,^[1] rather than chemical or natural toxins.