The term hepatitis means inflammation of the liver. Hepatitis can have several causes, such as drugs, alcohol, autoimmune diseases or infectious agents.
Hepatitis A, the focus of this article, is caused by a virus called HAV, which stands for "hepatitis A virus".
The hepatitis A virus was only discovered in 1973. Until the 1960s, none of the 3 main known hepatitis viruses had been identified. At that time, we knew that patients had hepatitis, but the cause of inflammation in the liver was unknown.
Contrary to common sense, the hepatitis A virus is completely different from the hepatitis B virus, which in turn has nothing to do with hepatitis C. They are, therefore, distinct diseases, despite the almost identical.
Although there is already a vaccine, the incidence of hepatitis A in the world is still very high, especially in developing countries where vaccination is low and exposure to the virus is high.
In this article we will explain the following points about hepatitis A: forms of transmission, symptoms, diagnosis, prevention and treatment.
Hepatitis A is transmitted via the fecal-oral route. Infected people eliminate the virus in their stool steadily. To be infected it is necessary that the virus comes into contact with our mouth. Oral contact with stool from others, at first glance, may seem like an improbable route, but it is much more common than we imagine. The worse the hygiene condition of the medium, the easier the transmission.
Examples of how hepatitis A can be transmitted:
Meals prepared by people who do not wash their hands after evacuation.
Diving in beaches or lagoons that receive untreated sewage (HAV can remain viable for up to 6 months).
Seafood from polluted waters with untreated sewage.
Touching on contaminated objects and soon after inadvertently bringing the hand to mouth.
Hepatitis A is not a sexually transmitted disease, but having sex with infected people is a risk factor, especially if there is anal sex followed by oral sex or a habit of licking the partner's anus. In this case the use of a condom does not alter the risk of contamination.
One of the major problems with hepatitis A is that the infected patient begins to eliminate the virus even before the symptoms start. For example, cooks with poor hygiene habits can work weeks transmitting the virus without being suspected of contamination.
The HAV incubation period is 2 to 6 weeks. In children, the picture may be mild enough to go unnoticed. When there are symptoms, these are often mistaken for a flu or mild gastroenteritis. It is not unusual for people to only find out they have had hepatitis A through serologically requested serologies.
In adults, hepatitis A is usually more symptomatic. This is the group that usually seeks medical care during the acute phase of the disease.
Initially hepatitis A presents as a non-specific gastrointestinal virus, with loss of appetite, nausea, vomiting, weakness, muscle pain, headache and fever. After 1 week, jaundice develops, a classic symptom of acute hepatitis A, characterized by yellowing of the skin and eyes, generalized itching, dark urine and very light colored stools. 80% of the patients also present hepatomegaly, which is the enlargement of the liver.
Hepatitis A lasts on average 2 months. Unlike hepatitis B and especially hepatitis C, which often become chronic infections, hepatitis A in most cases cures spontaneously, rarely becoming chronic hepatitis.
If on the one hand hepatitis A is usually a benign disease that rarely becomes chronic, on the other hand it is the viral hepatitis that most often occurs as fulminant hepatitis, leading to death due to liver failure if an urgent liver transplant is not performed. Fortunately, this condition occurs in less than 1% of hepatitis A virus.
In blood tests, the main finding is the change in the so-called liver enzymes: OGT, TGP and bilirubin. In acute hepatitis, the TGO and TGP values are usually above 1000 IU/dL.
Liver enzymes, however, only indicate that there is an ongoing acute hepatitis, not being able to determine the cause.
In order to identify HAV as a causative agent of hepatitis, a serology for hepatitis A must be performed. In serology we look for 2 types of antibodies: IgM and IgG.
IgM antibody indicates active hepatitis A. It is already positive when symptoms appear and remains detectable for up to 6 months, when it then disappears. IgG antibody indicates old infection. It is positive after a few weeks of infection and so stays for the rest of your life.
We have 3 possibilities:
HAV IgG positive and IgM negative = Old and cured infection
HAV IgG positive and IgM positive = Infection active and on the way to cure
HAV IgG negative and IgM positive = active infection at the onset of the disease
As it is a benign disease with spontaneous cure in almost all cases, there is no specific treatment for hepatitis A.
Only rest, good nutrition and hydration are indicated. Obviously alcohol and drugs that can cause liver damage, such as acetaminophen, should be avoided.
Vaccine for Hepatitis A
There is already a vaccine for hepatitis A and its administration is recommended in children at 12 and 18 months of age. The vaccine can also be given to adults at any time.
Vaccination of food professionals is helpful in avoiding epidemics by transmission through food.
The vaccine is also important for patients who already have some other liver disease, since this group has a higher risk of complications when exposed to HAV.
