Hepatitis and its prevention
Dr Deepak Amrapurkar
Hepatitis is among the ten most important killers in the world. There are 350 million Hepatitis B (Hep-B) positive people worldwide and about one million die each year from Hep-B infections, making it the ninth leading cause of death worldwide. Hepatitis is a disease that can be caused by a variety of different viruses such as hepatitis A, B, C, D and E. Hepatitis is characterised by jaundice, enlarged liver, fever, fatigue and abnormal liver function tests.
The numbers of patients dying of Hep-B each year are 10 times more than that of AIDS. Hepatitis is more common and a more serious disease in India. It is estimated that nearly 40 million Indians are suffering from Hep-B and 11 million from Hep-C. These are the commonest causes of liver failure and liver cancer. The risk of death from Hep-B virus (HBV)-related liver cancer or cirrhosis is approximately 25 percent for persons who become chronically infected during childhood.
India has the highest number of Hep-E patients and second highest Hep-B patients. About four percent of Indians carry HBV with them, with a total pool of 40 million carriers, and one percent carry Hep-C virus, so another 11 million carriers. But today, Hep-A and B are preventable with vaccines and elementary life-style modifications. And since knowledge is the key to prevention, it is important to spread knowledge about its transmission among the lay public and health care workers to prevent more people from falling prey to it.
Hep-A is a serious liver disease caused by the Hep-A virus (HAV), which is found in the stool of persons infected. It usually spreads by close personal contact and sometimes by eating food or drinking water contaminating HAV. The Hep-A vaccine is the most effective means of preventing HAV infection as it provides 94 percent to 100 percent protection if you receive both shots in the vaccination series. For children, the first dose should be given at 12-23 months of age. Children who are not vaccinated by two years of age can be vaccinated at later visits. For travellers, the vaccine series should be started at least one month before travelling to provide the best protection.
HBV spreads through contact with the blood or other body fluids of an infected person. For instance, infection can occur through contact with a mother’s blood and body fluids at the time of birth; contact with blood and body fluids through breaks in the skin such as bites, cuts, or sores; contact with objects that could have blood or body fluids on them such as toothbrushes or razors; having unprotected sex with an infected person; sharing needles when injecting drugs and being stuck with a used needle on the job.
Routine vaccination of children is the solution to Hep-B. All children should get their first dose of hepatitis B vaccine at birth and should have completed the vaccine series by 6-18 months of age. Hep-B vaccine is made from a part of HBV and is usually given as a series of three or four shots. It cannot cause HBV infection. This vaccine series gives long-term protection from HBV infection, possibly lifelong. All unvaccinated adults should be vaccinated. For treatment, oral antivirals are used for Hep-B infection. The treatment duration is infinite, for a couple of years. Pegylated interferon alfa 2b or 2a is used for the treatment of chronic Hep-B.
Hep-C is a liver disease that is caused by the Hep-C virus (HCV). The virus enters the liver cells, uses the cell’s inner genetic machinery to make copies of itself, which, then infect more cells. In about 15 percent of cases, Hep-C infection is acute, meaning it is cleared spontaneously by the body and there are no long-term consequences. Unfortunately, in majority of cases (85 percent), infection becomes chronic and slowly damages the liver over many years. Over time, this liver damage can lead to cirrhosis (or scarring) of the liver, end-stage liver disease, and liver cancer.
People with Hep-C infection usually do not have characteristic disease symptoms. Unlike other forms of viral hepatitis, Hep-C infection usually does not result in jaundice. When symptoms do appear, they may be vague and include tiredness, stomach pain, and rashes. Because HCV infection often has no symptoms, many people do not know they have the disease and may be infecting others. The only way to know whether you have Hep-C is to get a blood test.
The most efficient method of transmitting Hep-C is through injection of contaminated blood. Needle and syringe exchange programs that emphasise use of clean, sterile needles are likely to stop the spread of Hep-C. Never share objects such as needles, razors, toothbrushes, nail files, and clippers. People who are exposed to blood in their work, like dentists, surgeons, police officers etc should take adequate precautions to prevent exposure to contaminated blood.
Having one form of Hepatitis does not protect someone from getting other forms. People with Hep-C who also contract Hep-A are at high-risk for fulminant hepatitis, which is a deadly and rapidly progressive form of the disease. Therefore, medical experts strongly recommend that Hep-C patients also get vaccinated against Hep-A and B. The treatment duration is finite. Pegylated interferon alfa 2b or 2a with ribavirin capsules is the recommended treatment for chronic Hep-C. Conventional interferon can also be used with ribavirin for treating Hep-C.
Hep-D or delta virus (HDV) is an infection of the liver caused by a defective virus (delta agent). Delta agent can cause infection only in those individuals who have an active Hep-B infection or who are a Hep-B carrier. Hep-D infects about 15 million people worldwide. It occurs in five percent of people with Hep-B.
Prompt recognition and treatment of Hep-B infection can help prevent Hep-D. Avoid intravenous drug abuse. If you use IV drugs, avoid sharing needles. A vaccine is available to prevent Hep-B and should be considered by people who are at high risk for the infection. There is no effective antiviral therapy available for treatment of acute or chronic type D hepatitis. Liver transplantation has been helpful for treating fulminant acute and end-stage chronic hepatitis.
Hep-E virus (HEV) was not recognised as a distinct human disease until 1980. Hep-E is caused by infection with HEV, a non-enveloped, positive-sense, single-stranded RNA virus. It produces symptoms similar to Hep-A, although it can take a fulminant course in some patients, particularly pregnant women; it is more prevalent in the Indian subcontinent. Hep-E is a waterborne disease, and contaminated water or food supplies have been implicated in major outbreaks. Consumption of faecally contaminated drinking water has given rise to epidemics, and the ingestion of raw or uncooked shellfish has been the source of sporadic cases in endemic areas. At present, no commercially available vaccines exist for the prevention of Hep-E. However, several studies for the development of an effective vaccine against it are in progress.
As almost all HEV infections are spread by the faecal-oral route, good personal hygiene, high quality standards for public water supplies and proper disposal of sanitary waste have resulted in a low prevalence of HEV infections in many well developed societies. For travellers visiting highly endemic areas, the usual elementary food hygiene precautions are recommended. These include avoiding drinking water and/or ice of unknown purity and eating uncooked shellfish, uncooked fruits or vegetables that are not peeled or prepared by the traveller.
(The author is a Consultant Gastroenterologist at Bombay Hospital, Mumbai)