In this video lesson we will talk about an infectious disease that affects the liver, on which the spotlight has recently turned on after several cases of contagion linked to the consumption of frozen berries.I am referring to hepatitis A, which compared to other forms of viral hepatitis is less dangerous, since it does not become chronic and is benign in most cases.
Hepatitis A is an infectious disease caused by the virus of the same name, which attacks the liver cells and damages them. This liver infection is contracted via the fecal-oral route, mainly through contact with other infected people or the ingestion of contaminated water and food. After about 15-50 days from the moment of infection, hepatitis A manifests itself with fever, malaise, jaundice (therefore with a yellowish discoloration of the skin), loss of appetite and nausea. As anticipated, this form of hepatitis generally has a benign evolution and, as a rule, heals spontaneously without the liver suffering permanent damage. Unlike hepatitis B and C, it never becomes chronic; in addition, those who recover from hepatitis A develop permanent immunity that protects them from subsequent infections.
The hepatitis A virus (known by the acronym HAV, from Human Hepatitis A Virus) proliferates in the intestine and liver, and is excreted through the bile and feces. The virus is therefore present in the excrement of infected people already a few days after the infection and continues to be eliminated up to a week after recovery. The peak of contagiousness is recorded about 7-10 days before the onset of symptoms, when the fecal excretion of the virus is maximum. Therefore, the transmission of hepatitis A occurs mainly via the fecal-oral route, through contact with an individual. infected, for example, by putting his hands to his mouth after shaking his hand or using the cutlery he manipulates without washing his hands after going to the toilet. The transmission of hepatitis A through the consumption of contaminated water or food is also very common. In fact, from the faeces and sewage liquids, the virus can contaminate the aquifers and through them reach various types of foods, such as fishery products. (therefore fish, molluscs and crustaceans), vegetables, fruit and all derived products. Poor personal hygiene conditions, together with the failure to comply with basic hygiene rules during the handling of food, can therefore favor the infection. A can also be transmitted through oral-anal sexual practices. Furthermore, although quite rare, it is possible to be infected by blood, which occurs, for example, in the case of transfusions or through the exchange of syringes used for self-treatment. drug administration.
The symptoms of hepatitis A do not present immediately, but they begin after a fairly long incubation period, which varies from 15 to 50 days. During this period of time, the disease is still contagious. In particular, excretion of viruses during the incubation period clearly favors the transmission of the disease, since in this phase the individual is still asymptomatic, therefore unaware of his condition. Only a few weeks after infection, hepatitis A manifests itself with the first symptoms. a first phase appears a symptomatology that can be misleading, suggesting a flu-like illness; in fact, tiredness, nausea, vomiting and loss of appetite, headache, fever and muscle and abdominal pain appear. Subsequently, symptoms and signs suggestive of a liver damage, such as jaundice, which is a yellowish discoloration of the skin and the whites of the eye. a high concentration of bilirubin in the blood. The damaged liver, in fact, is not able to eliminate this substance, which derives from the demolition of aged or no longer functioning red blood cells. Urine can also become dark due to bilirubin accumulating in the circulation, while stools become clear. The symptomatic phase usually lasts from 2 to 10 weeks, although in some cases it can continue for up to six months. Furthermore, in some subjects, particularly in children under the age of six, hepatitis A may not even cause specific symptoms. As mentioned several times, hepatitis A generally has a benign evolution and, in most cases, it resolves within a few weeks without leaving any consequences. Furthermore, after healing from the infection, the patient develops a permanent immunity that will protect him. from new infections throughout life. Unfortunately, albeit in rare cases, hepatitis A can also cause severe liver failure, often with a fatal outcome. These forms, called fulminant hepatitis, occur more frequently in elderly patients, especially if immunocompromised or already suffering from another liver disease.
Hepatitis A is diagnosed through a medical examination in the symptomatic phase. The clinical investigation is associated with the analysis of a blood and stool sample. Among these tests, the blood test allows the identification of the virus genome on the one hand and the antibodies directed against the virus on the other. In particular, the presence of the virus genome allows the pathology to be diagnosed early, even before the immune response is activated. Furthermore, by distinguishing the types of antibodies it is possible to understand whether the infection is ongoing or not. In particular, specific type M immunoglobulins indicate an "infection in progress, while those of class G indicate an infection that has already been overcome and the patient's immunity.
There is no specific therapy for hepatitis A. Fortunately, in most cases, the symptoms are mild and the disease resolves spontaneously in a couple of months, leaving no permanent damage to the liver. In general, the doctor advises to rest and not to carry out too intense physical activities, because one of the main symptoms of hepatitis A is a greater ease of fatigue. Furthermore, since nausea and loss of appetite can become a problem, it is useful to follow a balanced diet. In particular, the consumption of foods that are too fatty will be reduced in favor of those that are more easily digestible. Foods must be prepared with healthy cooking methods, such as steam, avoiding fried foods, barbecues and any other method of prolonged cooking at high temperatures. Furthermore, in order not to over-stress the liver and avoid further damage, it is necessary to absolutely avoid the consumption of alcohol.
Hepatitis A can be prevented with vaccination. In fact, an inactivated, ie killed, highly effective and well tolerated virus vaccine is available. In particular, 2 doses of vaccine are administered intramuscularly in the deltoid region 6-12 months apart. The first dose confers protection after 14-21 days, while the second dose prolongs the protective efficacy up to 10-20 years. Vaccination against hepatitis A is particularly recommended for all people at high risk of contracting the disease. These include, for example, the family members of a person with hepatitis A in progress, people who are preparing to travel to an area. at risk, homosexuals, military personnel and medical personnel. Furthermore, vaccination is recommended for all people for whom the infection could represent a serious danger. It is therefore recommended for subjects suffering from chronic liver diseases and those who are immunocompromised.
In addition to vaccination, to prevent the transmission of hepatitis A and other fecal-oral diseases, some basic hygiene measures must be observed. It is clearly very important to wash your hands, especially after using the bathroom, before preparing meals and before eating. Furthermore, another valuable indication is not to drink well water or water of uncertain origin. It is also necessary to be careful not to ingest water while bathing in the sea or rivers. also pay attention to the water used to brush your teeth and to ice or ice lollies. When it comes to food, it is very important to avoid raw or undercooked seafood, as it can be a source of infection. Generous and prolonged cooking, in fact, is the only effective measure to inactivate the hepatitis A virus from molluscs or other contaminated fresh products. This virus, in fact, resists freezing and short cooking very well. In addition, it is very resistant to acids, so once ingested it survives the passage into the stomach. Fruits and vegetables, before consumption, should always be washed thoroughly and, when possible, peeled. Before concluding, let's open a brief parenthesis. Thanks to the improved hygienic, health and socio-economic conditions, in recent decades there has been a decrease in the incidence of hepatitis A in Italy. However, this decrease was regularly interrupted by some epidemic peaks recorded in some Regions of "southern Italy, where" the consumption of raw or undercooked seafood is widespread. Furthermore, since January 2013 in Italy there has been a significant increase in cases of hepatitis A compared to previous years, especially in the North. The data suggest a strong correlation with the consumption of frozen berries. In this regard, the Ministry of Health therefore advises to always consume them after cooking, i.e. boiling them at 100 ° C, for at least 2 minutes. Fresh berries, on the other hand, should simply be washed carefully before consumption.
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