Transmission of Viral Hepatitis

HAV is spread by the faecal–oral route. It is eliminated in the faeces of infected people and usually found in contaminated food or water. It is common in regions with poor hygiene conditions (Southeast Asia, India, Africa and parts of South America) where there is untreated water and people visiting these areas without being immunised (protected) are at risk of infection.

In European countries, it mainly affects children under 5 years old and tends to course without symptoms. Nowadays, following improvements in hygiene and sanitary conditions, most of the adult population has never been exposed to hepatitis A, so they are not immunised (protected) and carry the risk of being infected. In Catalonia, a pilot vaccination programme was initiated in 1994 for all 12-year-old schoolchildren and in 2014 the hepatitis A vaccine was included in the childhood vaccination schedule. In the rest of Spain, however, universal vaccination has not been implemented.

There is currently an outbreak of hepatitis A across Europe in men who have high-risk sex with other men, so vaccinations are recommended for this group as they are particularly at risk of infection.

Through blood (parenteral route):

• The use of contaminated blood or blood products during transfusions or medical/sanitary procedures carried out before 1992. Nowadays all blood donations are screened before they are used, so there is only a residual risk of transmission through blood products.
• Sharing infected needles or materials for injecting or inhaling drugs. Drug use is currently the main means of infection in developed societies.
• Accidental needle stick injuries (e.g., healthcare personnel).
• Sharing personal hygiene instruments and utensils (toothbrush, razor, nail clipper, etc.) with a hepatitis C carrier.
• Situations where insufficiently sterilised materials may be reused such as during dental treatments and when carrying out tattoos, piercings or micropigmentation.

Sexual and perinatal transmission (non-parenteral route):

The sexual transmission of hepatitis C is rare, but it can occur. It has been confirmed that the transmission between stable heterosexual partners is very rare and therefore no special precautions are recommended. However, the use of barrier methods such as condoms eliminates the risk of sexual transmission. The risk is increased by high-risk sexual behaviours:

• Sexual promiscuity.
• Anal sex (fissures or wounds, mucous membrane lesions).
• Oral sex (mouth ulcers or bleeding gums).
• Sex during the menstrual period (as there is direct contact with blood).
• Perinatal vertical transmission (from mother to child). There is a low risk of transmission, less than 5%.

Se transmite a través de la vía fecal-oral. Es una causa frecuente de brotes epidémicos de hepatitis en países subdesarrollados con malas condiciones higiénicas. Sin embargo, en los países europeos, incluida España, el virus de la hepatitis E se encuentra en animales como el cerdo, el jabalí o los ciervos. Su contagio suele ser con la ingesta de carne cruda o poco cocinada.