On World Hepatitis Day, Dr. Luis Ricardo Rodrigo Sáez, a specialist in the digestive system and member of Top Doctors, explains the basic aspects of the different types of hepatitis, how one of them can be contracted and the data on the number of people affected.
What is hepatitis?
Hepatitis is understood as the presence of a diffuse inflammation of the liver. It can be acute, when it is of short evolution and chronic, if it is prolonged. Its causes can be very varied. The most frequent are those related to viral infections, but there are others related to excessive alcohol consumption, toxins, medication, autoimmune, prolonged and excessive obesity, bacterial infections, parasites, fungi, etc. In other words, in the case of a patient with hepatitis, it is necessary to try to find out the cause of the hepatitis and to determine whether it is acute (short evolution) or chronic (if it lasts more than 6 months).
What are the different hepatitis viruses (types of hepatitis)?
There are several that can cause hepatitis and the most common are designated by the first letters of the alphabet, beginning with A and ending with G, with the exception of the F virus, which has not yet been identified. All types (except that produced by virus A) usually have an acute onset, although if they are not cured in time they may progress to chronicity.
What are the symptoms?
The clinical picture of acute viral hepatitis is very variable, ranging from asymptomatic or subclinical forms to cholestatic or fulminant forms. Symptoms and signs are common to the different forms of viral hepatitis and therefore the clinical features do not allow a differential diagnosis between them. The initial symptoms are nonspecific, similar to those caused by a flu-like process, with predominant general and gastrointestinal symptoms. Patients frequently report increased tiredness, lack of appetite, nausea, vomiting, lack of taste and smell, muscle and joint pain and fever. All this can be accompanied in a high percentage of cases, but not always, by the presence of jaundice, which is distinguished by the presence of a yellow coloration of the skin and mucous membranes, accompanied by very dark urine (choluric, due to the elimination of bile), which clearly indicates the diagnosis.
How many people in Spain are affected by this disease, and at European and world level?
It is variable for each type of hepatitis, but fortunately its incidence is decreasing. Thus, for cases related to the hepatitis A virus, which generally predominates in children and adolescents, a figure of approximately 1.5 million new cases is suggested worldwide. Although its distribution is universal, countries with poorer health and socioeconomic conditions have a high prevalence compared to developed countries. It is exclusively transmitted orally. The incidence of acute hepatitis B virus has fallen sharply in recent years in developed countries due to the implementation of vaccination programs in childhood. Thus in the USA its incidence fell by 80% between 1990 and 2006, as in most European countries and also in Spain. It is transmitted by blood and sex. As with virus B, there has been a notable decrease in the number of new cases of hepatitis C virus-related hepatitis, with an estimated reduction of more than 80% of cases from the 1990s to the present. Its transmission, like virus B, occurs fundamentally by percutaneous route, although it can also occur in a lesser proportion by other non-percutaneous routes.
Are there people at higher risk of suffering from this disease?
For A and E viruses, in addition to populations with low socioeconomic status, travelers to endemic areas, people who engage in risky sexual practices, parenteral drug users, recipients of blood products (hemophilia), or caregivers in direct contact with hepatitis A patients, laboratory personnel and workers in wastewater and with animals, especially primates. For B and D viruses, the most important routes of transmission are sexual, percutaneous, perinatal (from mother to child at the time of delivery), horizontal (transmission between children either in the family or school environment), transfusion (currently practically nil due to mandatory serological screening of donors), nosocomial (in hospitals or closed institutions, either from patient to patient, from patient to worker, or vice versa) and through organ transplantation. Most patients infected by the C virus in Europe and the United States acquired the infection through repeated intravenous drug use, or through blood transfusions or blood derivatives, although the latter form has been eliminated thanks to systematic screening of donors. Nosocomial infection, at the present time, is probably the most frequent mechanism of infection and through organ transplantation. In a non-negligible proportion of cases, it is not possible to identify the existence of a clear risk factor; most are thought to have occurred through inapparent percutaneous inoculations.
What tests are performed to diagnose hepatitis?
In all types of acute hepatitis the diagnosis is based on laboratory tests showing altered liver tests, with very high transaminases together with serological tests (specific antibodies for each type of virus) and virological tests (quantification of the viral load by molecular biology techniques), since neither the clinical nor the biochemical alterations allow a precise differential diagnosis to be made with other causes of acute hepatitis.
What is the treatment for hepatitis?
Hepatitis A is a self-limiting disease, i.e. it never progresses and is chronic; therefore, only symptomatic treatment is carried out. Acute hepatitis B in adults is cured without sequelae in more than 95% of the cases, being only necessary a symptomatic treatment and in some few cases the use of antiviral treatment with Entecavir or Tenofovir could be indicated. Unlike what happens in other viral hepatitis, in acute hepatitis C virus, the high rate of chronicity means that antiviral treatment should be considered. In patients with symptomatic disease, treatment with pegylated interferon (IFN-Peg) has achieved high cure rates (over 85%), regardless of viral genotype.
How can this disease be prevented?
In geographic areas where hepatitis A is endemic, hygienic-sanitary improvements are needed, including the availability of safe drinking water. A highly immunogenic and effective vaccine has been available since 1990, especially for groups at risk. Highly effective vaccines against virus B have been available since 1986. In Spain, universal vaccination in newborns has been incorporated in all the Autonomous Communities since 2002. In spite of this, vaccination of persons belonging to risk groups who have not been previously vaccinated should continue. For the prevention of hepatitis C virus, since there is still no vaccine or effective immunoglobulin, only general hygiene measures can be applied in general. Routine screening of blood and organ donors, education campaigns for injecting drug users, the use of barrier methods in high-risk sexual relations, strict adherence to aseptic recommendations in the health care setting, as well as the use of single-dose vials in the health care setting, are essential measures to try to prevent the transmission of hepatitis C virus.