The History of Hepatitis A
The World Health Organization identifies Hepatitis A as one of the oldest known diseases the humankind has faced. First discovered by Steven M.Feinstone back in 1973, Hepatitis A was called various names since it started infecting people (epidemic jaundice, epidemic hepatitis, catarrhal jaundice and infectious hepatitis).
WHO defined hepatitis as spherical, non-developed, positive stranded RNA virus that inflames the liver. This inflammation can be caused by any hepatitis strain, including A, B, C, D and E. In the case of HAV, this virus is absorbed from the small intestines into the bloodstream, after which it reaches the liver.
HAV belongs to the piconavirus family and is classified as a hapatovirus, but due to the many possibilities of getting infected with it, HAV is singled out as the cause. Therefore, in order to detect its presence in a human body, one has to test the patient’s sera for anti-viral antibodies. When tested positive, the patient has either been exposed to, or is currently infected by the hepatitis A strain.
At this point, we humans are the only known infected species of HAV. Primarily transmitted through sexual relations and the fecal-oral route, there are very few instances of people who got infected through blood transfusions. This means that the best way to prevent its spread is to take care of your personal hygiene, which includes washing the hands after using the restroom.
Outbreaks are very common in the food industry, which is why people who work here are recommended to wash their hands often. HAV can be often found in some foods such as fruits, milk, cold cuts, vegetables and salads.
Facts about Hepatitis A
- The name of the disease dates back to the early Mesopotamian civilizations. ‘Hepato’ means ‘liver’ and ‘tropic’ means ‘replicating in the liver’.
- During the wars of the seventeenth and nineteenth century, epidemics of hepatitis-caused ‘jaundice’ broke out. During World War II, the outbreaks became more widespread, even after the measles and yellow fever vaccination. All this led scientists to the conclusion that the ‘jaundice’ is actually a blood-borne virus.
- Mac Callum classified the two types of viral hepatitis in 1947, distinguishing between Hepatitis A or infectious, and Hepatitis B or Seum hepatitis.
- In 1965, Blumberg discovered the Hepatitis B surface antigen in the aborigines’ blood. He worked at the National Health Institute at the time and had been studying sera samples from transfused antibodies. In addition to this, Blumberg showed that the HBsAg antigen showed high presence in Down’s syndrome and leukemia patients.
- In 1968, Okochi and Prince isolated the Australia antigen in patients diagnosed with hepatitis B.
- The first vaccine for hepatitis B was produced after the Dane particle in 1970. In 1981, this vaccine was licensed and called ‘Heptavax’.
- At this point, the US is seen ‘low’ on the endemicity infection list when it comes to hepatitis A cases.
- The group that is most susceptible to this infection is people aged five to forty.
- The primary mean of transmission in the United States is through water and food.
- The number of new Hepatitis A cases in 1976 was 32,288 in the United States. Once the vaccine was administered for the first time in 1996, the number reduced to 31,032.
- WHO recorded its latest date in 2003, when the number of infected people in the US fell to 7,653. This shows that the vaccine works very well.
- Outbreaks and infections are most common in areas where the standards for sanitation are very poor, especially territories that find themselves in great poverty or war. Some of these places include the Middle East, Africa, Southeast Asia and certain parts of South America.
- The average age of an infected individual at the areas of high risk is only five years of age. People get infected by contact with other infected people, as well as through contaminated water and food.
- At this point, there are 7.4 million annual cases reported on a worldwide level.
- The largest hepatitis A outbreak in the world was recorder back in 1988 in Shangai. According to researchers, this outbreak was closely linked to contaminated water and food. The Shangai outbreak infected over 300,000 people.
History of Hepatitis A
To get a clearer picture of the entire history of the virus, we created a timeline that includes the most important discoveries in terms of hepatitis A:
Scientists suggested that HBV has an infectious nature
17th, 18th and 19th centuries:
Several grand outbreaks of jaundice epidemics in civilian populations and military during wars
Outbreaks of the serum hepatitis are reported by Lurman, followed by dockers’ vaccination
McDonald suggests that the so called ‘jaundice’ is actually caused by a virus
1939 – 1946
Series of outbreaks during World War II, after the vaccination for yellow fever and measles
MacCallum defines two types of viral hepatitis, hepatitis A and hepatitis B. The first is also called ‘infectious hepatitis’, while the latter is called ‘serum hepatitis’
Blumberg discovers HBsAg or the Australia antigen in the results of aborigines. He shows the presence of an antigen that is at increased frequency in patients who suffer from leukemia, as well as children with Down’s syndrome
The complete HBV particle called the Dane particle is discovered by Dane
The discovery of HBeAg
Purcell and Feinstone identify the Hepatitis A virus
Rizzetto identifies the delta antigen or HDV
Choo, Kuo and Houghton (the Chiron group) identify HCV
The NTUH group led by Chang report the successful prevention of the HBV infection by the vaccination of newborn babies on a worldwide level. This report is published in JAMA, while the vaccination is launched in Taiwan in 1984
The NTUH group and Chang report a decrease in number of children with hepatocellular carcinoma due to the nation-wide vaccination of newborn babies against HBV in 1984.
The history of the hepatitis A virus is unbelievably detailed. Even though research has gone slowly in the past century, scientists work hard on discovering everything there is to know about the virus and its treatment, as well as the cure.