VIRAL HEPATITIS: The Smallest Demon Imaginable Part 1 [Archives:2001/35/Health]
Marwan Ahmed Alghafory,
Faculty of Medicine,
Ain Shams – Cairo, Egypt
The subject of hepatitis infections in Yemen and other developing countries has become a major issue of concern for Yemenis and foreigners alike. Do you know that one third of Yemenis are infected with hepatitis? Do you know that there are vaccinations available in the country? Do you know that you could become infected any time in your stay in Yemen and never know until it is too late? The Hepatitis issue is beginning to attract the attention of many individuals who care for themselves and their children.
In an effort to provide more information about this issue, I will focus on this particular disease starting from this week. I will start these series of beneficial articles on the different viral hepatitis diseases, with the hope that they will be of great interest of YT readers.
Hepatitis and Liver
The liver, the largest gland in the body, is the real factory of the most important body proteins (e.g. those of clotting, and those carrying the drug particles in the circulation) and is also the home of metabolizing the unwanted substances that for some reason entered the human body. This important organ has become a target for those offending creatures called the hepatitis viruses.
How do these viruses attack the liver?
The invading viruses enter the hepatocytes (liver cells) initially causing them no harm, but the infected cells produce new antigens on their surfaces. This causes the immune system to combat those antigens thinking that they are foreign structures. Hence the defense system starts destroying them, thinking that it is only protecting the body from foreign objects, but in reality it is causing a catastrophe to the liver by destroying its cells.
How many types of hepatitis viruses exist?
There are at least 5 types of hepatitis viruses (A, B, C, D, and E) all causing hepatitis in human.
Hepatitis A Virus (HAV)
Hepatitis A Virus (HAV) causes short-incubation infectious hepatitis, that is transmitted by fecal-oral route, and has the ability to cause epidemics, particularly when it contaminates the water or food we consume.
Although HAV infection occur worldwide, the epidemiology differs according to conditions, e.g. water purification, sewage disposal, and interactions with crowds. A large portion of inhabitants of many economically developing countries including Yemen are infected with HAV during their first 2 to 3 years of childhood. Most of those infections occur without HAV symptoms, but some of them occur with those symptoms. HAV is also a threat to persons who travel to endemic areas from non-endemic areas.
Routes of Transmission
Basically, HAV is transmitted from person to person by a fecal-oral route. Transmission requires more than one causal contact, e.g. interactions within a family, or between playmates or colleagues.
Food and water-borne HAV infections also occur. Contamination of inadequately chlorinated water could lead to both epidemic and sporadic infections.
The risk factors of HAV infections in developed countries include close contact and interaction with people infected or jaundice with hepatitis, homosexuality, travelling to a less developed country, or contact among children in daycare centers.
Clinical Manifestations of Viral Hepatitis?
First of all, the incubation period of Viral Hepatitis is 2-6 weeks, then one of the following ensues:
1- A symptomatic infection that recovers without any manifestations and complications.
2- Acute hepatitis characterized by: fever, anorexia, nausea, vomiting, followed by jaundice with dark urine.
3- Recovery occurs within 2-4 weeks, and no permanent harm or chronicity occurs.
HAV is hence the simplest form of viral hepatitis (in comparison to HCV & HBV)
Prevention & Control
1- Sanitation: this is the most important measure to reduce HAV infection. This includes improving the sewage disposal, avoiding crowds, and general hygiene. Workers in food-stores or food-related jobs who are infected with viral hepatitis or who have unexplained jaundices should be restricted from work.
2- Passive immunization- prophylaxis by giving specific antibodies to those who are liable to be infected, i.e., who frequently interact with possibly infected people.
3- Active immunization: this is the vaccinations process, by inoculating the subject with the most antigenic part of virus (genetically synthesized) to enhance the immune system to defend the body if once gets attacked by those invaders. Travelers to endemic areas should receive their first dose of vaccine at least one month before departure.
Next Week: Hepatitis B Virus:
The Most Dangerous of all.