Guntur Darmawan, Jakarta | Sat, 07/16/2011 8:00 AM
Do you know that there is a virus that is 100 times more contagious than human immunodeficiency virus (HIV)?
The virus does not just infect the body and produce inflammation in the liver; moreover, it may cause massive death of liver cells and develop into liver scarring (cirrhosis), cancer and chronic infection.
Hepatitis B virus (HBV) infection is one major threat to global health. It is estimated that 2 billion people around the world have been infected with HBV and around 350 million people have contracted chronic (long-term) hepatitis B infection. Moreover, approximately 500,000-700,000 people die from hepatitis B every year.
The prevalence of hepatitis B infection varies geographically and it is categorized into low, intermediate, high prevalence.
Indonesia, along with other countries in Southeast Asia, China and some countries in Africa are classified as high prevalence areas. In Indonesia, there are 12 million people infected by HBV; the third-greatest number in the world after China and India.
HBV, discovered by Prof. Baruch Blumberg in 1965, is a DNA virus and a member of the hepadnavirus family.
There are eight known genotypes of hepatitis B virus (genotype A-H) and additionally, it reported one putative new genotype (genotype I) was recently found in Asia. Each of the genotypes has a distinct geographical distribution and has different responses to treatment.
The virus is transmitted by exposure to infectious blood or body fluids (such as vaginal fluid, semen). The possible routes of transmission are contaminated blood transfusion, sexual contact, sharing contaminated razors or toothbrushes, using contaminated needles for injecting drugs, ear piercing, tattooing, acupuncture, using contaminated tools in some manicure or pedicure procedures and vertical transmission from mother to child during childbirth.
Unfortunately, up to 90 percent of infected newborns develop chronic HBV infection, which consequently gives a higher risk of liver cancer later in adulthood. About 25 percent of adults chronically infected during childhood die from chronic hepatitis B complications such as liver cancer or cirrhosis.
In contrast, approximately 5-10 percent of infections acquired in adulthood will develop into chronic infection. HBV is not spread by shaking hands, coughing, sneezing, hugging, using the same toilet, food or water.
The symptoms of HBV infection vary — from no symptoms into fatigue, joint aches, fever, nausea, vomiting, stomachache, jaundice (yellowing of the eyes and skin), dark urine, clay-colored stools.
The complications are fulminate hepatitis (acute massive death of liver cells), cirrhosis which can present with asides (accumulation of fluid in the abdominal cavity), legs edema, spleen enlargement, bleeding disorder, gynecomastia (enlargement of the male breast), disturbance in consciousness and liver cancer. Patients with HBV are also susceptible to hepatitis D virus infection.
This double infection might lead to fulminate hepatitis. There are advances in drugs for treatment of chronic HBV infection, including more potent anti-viral agents and interferon.
Nevertheless, complete eradication of HBV is still not possible. Liver transplantation is considered when liver damage is severe.
It seems that HBV is a disastrous and unbeatable virus. However, there are quite simple things that can prevent and break the spread of the HBV.
HBV infection can be effectively prevented by vaccination. Prof. Blumberg invented the vaccine in 1969. It is the first vaccine in the world preventing human cancer.
There has been a substantial increase in the number of countries that include hepatitis B vaccine in their national infant immunization programs, from 31 countries in 1992 to 177 countries in 2009.
The hepatitis B vaccination is the mainstay of HBV prevention and has been proven to reduce the rate of chronic infection in many countries, from 8-15 percent to less than 1 percent among children vaccinated. Moreover, in Taiwan, the vaccination program had decreased the incidence of liver cancer in children.
In Indonesia, the hepatitis B immunization for newborns was first introduced in 1987 and has been part of the routine immunization program since 1997.
The WHO recommends hepatitis B vaccination to all infants; first at birth followed by two subsequent vaccinations with each minimum interval of 1 and 2 months respectively.
Children and adolescents younger than 18 years old who haven’t been vaccinated before, should be vaccinated. Adults in high risk groups, such as having an HBV infected spouse, frequently requiring blood transfusions, hemodialized patients, needle drug users, having occupational risk of HBV infection (healthcare workers) and international travelers to areas with high rates of HBV should also receive the vaccine.
The vaccine is safe and effective, but the antibody level induced by vaccination may decline over time. Therefore, booster vaccination is needed when the antibody level has declined.
In addition to vaccination, there are things to do to keep us safe. These consist of using sterilized and disposable needles, not sharing toothbrushes or razors with others, wearing gloves when touching blood or other infectious body fluids, knowing your spouse’s HBV infection status and practicing safe sex.
July 28th is World Hepatitis Day. One of the purposes of this event is to increase awareness, prevention, screening and control of viral hepatitis, especially HBV and hepatitis C virus (HCV), the two types of hepatitis virus most often associated with cirrhosis and cancer complications.
Although many countries have implemented hepatitis B vaccination as part of their national immunization programs, helping to decrease infection rates, the number of people infected with HBV is still high.
Since there is no hepatitis C vaccine available and the hepatitis B vaccine indirectly prevents hepatitis D infection, adequate hepatitis B vaccination is really important, especially for those categorized as high risk groups.
From the economic aspect, the cost for buying oral HBV drugs is around 10 times higher than buying a hepatitis B vaccine and it will increase several times when the injection type drug is needed for treatment.
Furthermore, there are also huge costs for procurement to treat complications, hospitalization cost and laboratory examination costs.
Last but not least, the disease impacts human productivity, not only individually, but also on a global scale. So let’s take part in the global war against HBV.
Know the HBV, the route of transmission, the measures to keep safe and be sure you have received the hepatitis B vaccine adequately.
The writer is a physician.
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