CHENNAI: The liver is the largest solid organ in the human body and plays a pivotal role in the detoxification of toxins. Hepatitis B is a preventable viral infection that damages the liver. Hepatitis B infection is widespread in most developing nations, especially in Asian and African countries. India has intermediate endemicity for Hepatitis B with chronic (lifelong) infection in 40 million people and more than 1.2 lakh individuals die every year because of its complications.
The extent of liver injury produced by this virus varies between individuals. Despite a considerable number of individuals who become infected with this virus, only a small proportion (approximately 10%), especially those who are infected in childhood are unable to clear the virus and progress to develop chronic infection. Over time, it results in permanent liver damage in the form of cirrhosis (fibrosis of the liver) and liver cancer.
MODES OF TRANSMISSION
Hepatitis B is nearly 50 to 100 times more infectious than HIV. Hepatitis B virus (HBV) mainly spreads through the blood and blood products of infected individuals. The most commonly encountered modes are from mother to child during delivery, unsafe injections, unsafe transfusions, needle stick injuries and unprotected sexual contact. Other less common modes include direct contact with blood or open wound of an infected person, sharing of razors and toothbrush with an infected person, unsafe tattooing/ piercing, etc.
SYMPTOMS
Hepatitis B virus infection can result in a wide spectrum of liver disease ranging from acute hepatitis (including acute liver failure) to chronic hepatitis, cirrhosis, and hepatocellular carcinoma (liver cancer).
Most Hepatitis B virus-infected individuals are asymptomatic but a small proportion may present with acute illness in the form of fever, extreme fatigue, and high coloured urine, yellowish discolouration of eyes and skin, nausea, vomiting and abdominal pain. Almost 90% of infected people will recover with the development of antibodies and complete elimination of virus from their body within six months.
A smaller proportion, especially those infected by HBV in early childhood become chronic carriers of the virus and in due course develop progressive damage of the liver.
Almost 80-90% infants and 30-50% children infected before six years of age develop chronic infection.
Those with chronic infection will finally land up with cirrhosis of the liver or liver cancer. Apart from liver damage, HBV infection can also cause skin rashes, anaemia, and damage to blood vessels, joints, kidneys and nerves.
DIAGNOSIS
Alterations in liver function test with an increase in liver enzymes such as AST (Aspartate Amino transferase) and ALT (Alanine Amino Transferase) levels with/ without increase in serum bilirubin and lymphocytosis in acute Hepatitis. In acute Hepatitis B virus infection, laboratory diagnosis mainly focuses on the detection of HBsAg and IgM antibodies to HBcAg. HBsAg may be detected as early as 3–12 weeks after exposure. IgM Antibody to HBcAg (Ig M anti-HBc) generally appears shortly before the onset of clinical illness and is usually replaced by IgG Antibodies to HBcAg (IgG anti-HBc) within six months.
Antibody to HBsAg usually appears during recovery or convalescence after clearance of HBsAg. The persistence of Anti-HBs is associated with immunity against HBV. In persons with chronic Hepatitis B, viral replication persists and HBsAg, HBeAg, and HBV DNA are detectable in serum in high titers.
TREATMENT
Treatment of acute Hepatitis B is mainly supportive with adequate hydration, nutrition and symptomatic measures. All individuals who develop chronic HBV infection will require treatment with oral antiviral medications like entecavir, tenofovir.
These medications are usually easier to take once a day with very minimal side effects.However, they do not provide a complete cure and hence need to be continued for life. This will in turn slow down the progression to cirrhosis, improve long-term survival and reduce the probability of developing liver cancer.
PREVENTION
Hepatitis B infection is preventable with vaccination. As per WHO recommendation and the Universal Immunization Program (UIP) implemented in India since 1985, the Hepatitis B vaccine should be administered to all neonates, preferably within 24 hours of birth. The initial dose should be followed by three consecutive doses at 6, 10 and 14 weeks (currently given in the form of pentavalent vaccine along with diphtheria, pertussis, tetanus and H.influenza vaccines).
This complete course will induce protective antibody levels in almost 95% infants and remains protective for more than 20 years and even lifelong. In countries with low and intermediate endemicity, vaccination is recommended for people at high risk of acquiring the infection. This high-risk group includes: health care workers, sanitary workers involved in biomedical waste disposal, people who require frequent blood and blood product transfusion, those on dialysis, solid organ transplant recipients, people who inject drugs, people with multiple sexual partners, people frequently travelling to high endemicity areas, household and sexual contacts of chronic HBV infected persons.
Use of disposable injection needles, safe injection practice, avoiding unnecessary and unsafe injections may help in preventing transmission. Blood safety strategies like proper selection of blood donors, quality-assured screening of all blood products before transfusion has reduced transmission of HBV.
Safe sexual practice using barrier protection measures and avoiding multiple sexual partners also plays a crucial role in the prevention of transmission.
Even though an anti-vaccination movement always existed among the general public, it has considerably increased during the COVID-19 pandemic. However, Hepatitis B is one of the safest and most-administered vaccines worldwide, with very few side effects. The Hepatitis B Foundation emphasises that all individuals at risk for HBV infection should receive the vaccine. This facile step can prevent Hepatitis B related cirrhosis, liver cancer, and let you live a long and healthy life. If anyone reading this article is still not vaccinated for Hepatitis B, we highly recommend you to contact your physician/primary care provider for the vaccination at the earliest. (The writer is the director - Hepatology & Transplant Hepatology, Gleneagles Global Health City, Chennai)