Hepatitis A Symptoms, Transmission, Diagnosis and Treatment

Hepatitis A (formerly known as infectious hepatitis) is an acute infectious disease of the liver caused by the hepatitis A virus (HAV), 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. 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.

Prevalence
Hepatitis A Virus is found in the feces of infected persons and those who are at higher risk include travelers to developing countries where there is a higher incidence rate and those having sexual contact or drug use with infected persons

Transmission
The virus spreads by the fecal-oral route and infections often occur in conditions of poor sanitation and overcrowding. Hepatitis A can be transmitted by the parenteral route but very rarely by blood and blood products. Food-borne outbreaks are not uncommon, and ingestion of shellfish cultivated in polluted water is associated with a high risk of infection.

Prevention
Hepatitis A can be prevented by vaccination, good hygiene and sanitation. Hepatitis A is also one of the main reasons not to surf or go in the ocean after rains in coastal areas that are known to have bad runoff. The vaccine protects against Hepatis A Virus in more than 95% of cases for 10 years. It contains inactivated Hepatitis A virus providing active immunity against a future infection. The vaccine is given in two doses in the muscle of the upper arm. The first dose provides protection two to four weeks after initial vaccination; the second booster dose, given six to twelve months later, provides protection for up to twenty years.

Symptoms
Early symptoms of hepatitis A infection can be mistaken for influenza, but some sufferers, especially children, exhibit no symptoms at all. Symptoms typically appear 2 to 6 weeks, (the incubation period ), after the initial infection. Symptoms can return over the following 6–9 months and include, fatigue, Fever, Abdominal pain, Nausea, Diarrhea, Appetite loss, Depression, Jaundice, a yellowing of the skin or whites of the eyes, Sharp pains in the right-upper quadrant of the abdomen, Weight loss, Itching.

Diagnosis
Serum IgG, IgM and ALT following Hepatitis A virus infection. Although Hepatitis A Virus is excreted in the feces towards the end of the incubation period, specific diagnosis is made by the detection of HAV-specific IgM antibodies in the blood. IgM antibody is only present in the blood following an acute hepatitis A infection. It is detectable from one to two weeks after the initial infection and persists for up to 14 weeks. The presence of IgG antibody in the blood means that the acute stage of the illness is past and the person is immune to further infection. IgG antibody to Hepatitis Virus is also found in the blood following vaccination and tests for immunity to the virus are based on the detection of this antibody. During the acute stage of the infection, the liver enzyme alanine transferase (ALT) is present in the blood at levels much higher than is normal. The enzyme comes from the liver cells that have been damaged by the virus. Hepatitis A virus is present in the blood, (viremia), and feces of infected people up to two weeks before clinical illness develops.

Treatment
There is no specific treatment for hepatitis A. Sufferers are advised to rest, avoid fatty foods and alcohol (these may be poorly tolerated for some additional months during the recovery phase and cause minor relapses), eat a well-balanced diet, and stay hydrated. Approximately 15% of people diagnosed with hepatitis A may experience one or more symptomatic relapse(s) for up to 24 months after contracting this disease