Viral hepatitis causes progressive inflammation of the liver that can be acute or chronic. The infection can also cause harm to parts of the intestine (duodenum, jejunum) and the kidneys. The virus penetrates through abrasions or lesions on the skin and mucous membranes and, when reaching the liver, replicates quickly. There are several types of viral hepatitis, the most common of which are viral hepatitis A, B, C, D and E, where each letter indicates a different strain.
VIRAL HEPATITIS A – This is an acute infection caused by the Hepatitis A Virus (HAV virus). Infection is caused by drinking and eating drinks and food that are contaminated or preserved and treated in bad hygienic conditions, eating sea shellfish that is raw or not cooked sufficiently and bred in contaminated waters, or eating unwashed vegetables or fruit. It is mainly transmitted through the fecal-oral route, and therefore also sexually through oral or anal sex, especially among men. It has an incubation period of 15 to 50 days. The virus is present in the stools 7-10 days before the onset of symptoms and up to a week afterward, while it is present in the blood for only a few days.
It has a tendency to be generally asymptomatic, self-limiting and benign, but sometimes it can have more severe forms with a prolonged progression and even fast-acting, rapidly fatal forms (0.1-0.3% with peaks up to 1.8% in adults over 50 years of age). The infection, which lasts for 1-2 weeks, manifests with fever, discomfort, nausea, abdominal pain and jaundice, accompanied by increased bilirubin and liver enzymes (transaminases). In some cases, especially if the infection is contracted at a young age, it remains asymptomatic. Patients heal completely without ever having a recurrence. Therefore, there is no chronic condition of virus A either in the blood or the feces.
VIRAL HEPATITIS B – This is the most common form of viral hepatitis in the world, caused by the Hepatitis B Virus (HBV virus). It is transmitted through infected blood (transfusions, use of infected instruments in surgical and dental procedures, acupuncture, laboratory practices, and tattoos and piercings performed with unsterilized instruments) and unprotected vaginal, oral and anal sex with people carrying the virus, which is present in sperm, menstrual blood and saliva. It can also be transmitted during childbirth. The risk of contagion through transfusion, although still present in developing countries, has been virtually eliminated in industrialized countries due to blood donation controls and subsequent processing mechanisms that can destroy the virus.
Considering that the virus is resistant to environmental surfaces for at least 7 days, contamination can also occur by indirect inoculation or by contaminated objects through minimal skin or mucous membrane lesions (toothbrushes, scissors, combs, razors, bath brushes contaminated by infected blood). Therefore, be very careful not to exchange these types of objects!
At risk, therefore, are addicts, those who engage in unprotected sex, health workers in contact with infected people or who work in a lab in contact with the infectious agent. Family and sexual partners of infected people are also at risk, as are all practices involving the use of non-sterilized needles and syringes, such as tattoos, piercings, manicures, and pedicures.
The virus is not transmitted through casual contact, hand-shakes, hugs, sneezing, coughing or breastfeeding.
Currently, Italy is a low-endemic country for viral hepatitis B (approximately 1% of chronic carriers). Sexual transmission represents the most frequent method of infection. Significant progress in preventing HBV infection has been achieved over the last thirty years due to improved socio-economic conditions and the introduction in 1999 of the requirement for the anti-hepatitis vaccination within the first year of life. Finally, the availability of serological (HBsAg) and biomolecular (Nucleic Acid Technology, HBV-NAT) tests has been more and more effective for the identification of at-risk donors, and has made transmission through transfusion or hemodialysis a particularly rare event.
The incubation period of viral hepatitis B varies between 45 and 180 days, but usually occurs between 60 and 90 days. Especially if acquired at a young age, viral hepatitis B tends to be recurrent 9 times out of 10. In 20% of cases, it can progress to liver cirrhosis over a period of about 5 years. Liver cancer (hepatocellular carcinoma) is another common complication of chronic hepatitis, especially in patients who already have liver cirrhosis.
VIRAL HEPATITIS C – This is caused by the Hepatitis C Virus (HCV virus). It is transmitted primarily through infected blood and more rarely through sexual intercourse. The infection can be transmitted vertically from mother to child in less than 5% of cases. Blood donation controls using the anti-HCV antibody test have considerably reduced the risk of infection following blood and blood-derivative transfusions. It cannot be transmitted by kissing, handshakes or common, everyday-life objects. The incubation period ranges from 2 weeks to 6 months, but is mostly between 6 to 9 weeks.
The majority of infected people (85%) develop chronic hepatitis that in 20-30% of cases will develop into liver cirrhosis within 10 to 20 years, and in about 1 to 4%, subsequent hepatocellular carcinoma.
In Italy, the prevalence of chronic HCV carriers is 0.6-2.5% in the North and 2-20% in the South. Currently in our country, the most important risk factors for HCV infection are the use of intravenous drugs, unprotected sex with more than one partner, tattoos and aesthetic treatments when no effective methods of sterilization and maintenance of instruments are used. Maternal-fetal transmission and breastfeeding are possible methods of contagion, but rarely occur.
VIRAL HEPATITIS D – This is caused by the Hepatitis D Virus (HDV virus). It can be transmitted through unprotected sex, but its multiplication depends on the hepatitis B virus (hence it is called a satellite virus). The infection manifests, therefore, in subjects affected by HBV at the same time or as a superinfection. This latter is the more aggressive form. In some cases, HDV infection can become chronic and have a more serious progression than that of viral hepatitis B. The incubation period ranges from 2 to 8 weeks.
Prevention with the anti-hepatitis B vaccine also protects against the risk of viral hepatitis D.
VIRAL HEPATITIS E – This is caused by the Hepatitis E Virus (HEV virus). Viral hepatitis E is an acute, often self-limiting infection that is very similar to viral hepatitis A. Chronic cases are rare, as are the fast-acting forms that occur primarily in pregnant women in the third trimester of pregnancy. Contagion occurs via the fecal-oral route, and water contaminated by feces is the main vehicle for infection. The incubation period ranges from 15 to 64 days. Viral hepatitis E is present all over the world; sporadic outbreaks and epidemics have been recorded primarily in geographic areas with inadequate levels of hygiene. In industrialized countries, on the other hand, most cases involve people returning from traveling in endemic countries.
