By Dr Modupe Ajibawo
What is hepatitis?
Hepatitis means inflammation or swelling of the liver. This impairs the functions of the liver and, in turn, affects the well-being of the affected individual. The liver is a very important organ occupying the right upper part of the abdomen. It produces important proteins that maintain pressure in the blood and help transport fats, hormones and drugs around the body. It also produces factors responsible for blood clotting. It filters the blood and helps in the breakdown of drugs, toxins, bacteria and other wastes and their removal from the body. The liver produces bile that helps digestion.
What are the general causes of hepatitis?
Many things can cause injury to the liver, leading to inflammation. Hepatitis viruses are the most common causes of hepatitis in the world. Other viral causes of hepatitis include Epstein-Barr virus and yellow fever virus. Hepatitis can also be caused by non-viral infections like toxoplasma, certain drugs, alcohol, poisons like aflatoxins and other medical conditions. Aflatoxins are a group of poisons produced by certain fungi found on agricultural produce, like groundnuts and grain that have been stored improperly.
What are the different types of hepatitis and their major causes?
Hepatitis A, B, C, D and E viruses are the five main types of hepatitis viruses. They cause a major burden of illness and death, with the potential for outbreaks around the world. Hepatitis B and C are of particular interest because they lead to chronic infection and, together, are a major cause of complications such as liver cirrhosis, cancer and viral hepatitis-related deaths. The World Health Organisation estimates that 325 million people globally live with Hepatitis B and or C.
Hepatitis A and E viruses are transmitted by consumption of contaminated food or water. Overcrowding and poor sanitation facilitate their spread and they often occur in epidemics. Hepatitis A and E viruses are completely cleared from the body following an illness and do not progress to chronic disease. Hepatitis A is the most common type of viral hepatitis, affecting mainly children and young adults.
How are they transmitted?
Hepatitis A is contracted by ingesting faecal matter from food, drinks and objects that have been contaminated by stool from an infected individual. Safe and effective vaccines are available to prevent Hepatitis A virus but not yet widely available for Hepatitis E virus. Hepatitis B virus is transmitted through exposure to infected blood, semen and other body fluids. This can be through transfusions of Hepatitis B virus-infected blood and blood products; or contaminated needles during medical procedures, tattooing or use by intravenous drug addicts. Vertical transmission from infected mothers to their infants during or following delivery is a major form of transmission.
Transmission also occurs between family members, especially during childhood. Healthcare workers stand a high risk of infection with Hepatitis B virus from accidental needle stick injuries during the care of Hepatitis B virus-infected patients. Hepatitis D virus infection can only occur along with Hepatitis B virus-infection. It is found mostly in intravenous drug abusers but can be transmitted in much the same way as hepatitis B virus. Hepatitis B virus vaccines give protection from hepatitis D virus infection. Hepatitis C virus infection is transmitted through exposure to infected blood, mainly and less so through sexual intercourse. It is more common among people that require frequent blood transmission and intravenous drug abusers. There is no vaccine for Hepatitis C virus.
Which among the types are the most common in Nigeria?
Hepatitis B virus infection is the most common in Nigeria, with a prevalence of 8.1 per cent, with Hepatitis C virus at 1.1 per cent. In the USA, Hepatitis C virus is the most common cause of chronic viral hepatitis infection, with a prevalence of 0.93 per cent, with Hepatitis B virus infection at 0.4 per cent. The high prevalence of Hepatitis B virus infections in Nigeria can be attributed to some mode of transmission particularly relevant in our context — mother-to-child transmission; healthcare-related transmission due to poor infection prevention and control; and traditional, or cultural practices, which include scarification, female genital mutilation, male circumcision and uvulectomy- amputation of the uvula by traditional healers for minor throat infections.
Are there certain categories of people more prone to the inflammatory condition?
Travellers who do not have access to properly cooked foods and people living in overcrowded and poor sanitary conditions such as prisons are prone to the faeco-orally transmitted viral hepatitis. Hepatitis A virus infection is common in children. Healthcare workers, patients who regularly require blood transfusion or dialysis and people who practise unprotected sex with multiple sexual partners are more at risk of Hepatitis B and C infections. These people would also benefit from vaccination to prevent infection.
Can Hepatitis B and C be transmitted through saliva?
Hepatitis B virus can be found in saliva but transmission has not been absolutely documented after exposure to infected saliva. Hepatitis B or C viruses are not thought to be spread through kissing or sharing of utensils. However, since Hepatitis B virus is present in saliva, the risk of spread through deep kissing cannot be eliminated, especially if one partner has open cuts or sores in the mouth, wears dental braces or there is a bite. Babies may not get Hepatitis B or C infection through mouth-to-mouth contact with their caregivers, based on the above reasons. However, mouth-to-mouth kissing of infants should be discouraged because there is risk of transmission of cold viruses and other bacteria, which may cause severe infection in these babies whose immunities are not yet mature.