Hepatitis B Virus Infection example essay topic

Hepatitis, the Liver Disease What is Hepatitis Hepatitis in simple words, is an inflammation of the liver. Different things cause the different types of hepatitis, but they all produce inflammation of the liver. Viral hepatitis refers to several common contagious diseases caused by viruses that attack the liver. The most important types of viral hepatitis are hepatitis A, hepatitis B, and hepatitis C. Newly discovered forms of viral hepatitis also include hepatitis D, E, and G. Toxic agents, that is drugs or chemicals, can cause non-viral forms of hepatitis, alcohol, or auto-immune processes. Another form of hepatitis is toxic hepatitis. Viruses or liver damage due to toxic substances can cause toxic hepatitis.

Toxic hepatitis is a deterioration of the liver cells caused by chemicals, alcohol, drugs, and industrial compounds. Alcohol abuse is a common cause of toxic liver damage. Study of hepatitis is still under way, but as far as we are concerned we will only take a close look at three types of Hepatitis in this report: hepatitis A, hepatitis B, hepatitis C. HEPATITIS Hepatitis A is a liver disease caused by the hepatitis A virus. Hepatitis A can affect anyone. In the United States, hepatitis A can occur in situations ranging from isolated cases of disease to widespread epidemics.

Good personal hygiene and proper sanitation can help prevent hepatitis A. Vaccines are also available for long-term prevention of hepatitis A virus infection in persons of two years of age and older. Immune globulin is available for short-term prevention of hepatitis A virus infection in all ages. Persons with hepatitis A virus infection may not have any signs or symptoms of the disease. Older persons are more likely to have symptoms than children are. If symptoms are present, they usually occur abruptly and may include fever, tiredness, and loss of appetite, nausea, abdominal discomfort, dark urine, and jaundice, yellowing of the ski and eyes. Symptoms usually last less than 2 months; a few persons are ill for as long as 6 months.

The average incubation period for hepatitis A is 28 days (range: 15-50 days). Hepatitis A virus is spread from person to person by putting something in the mouth that has been contaminated with the stool of a person with hepatitis A. This type of transmission is called "fecal-oral". For this reason, the virus is more easily spread in areas where there are poor sanitary conditions or where good personal hygiene is not observed. Most infections result from contact with a household member or sex partner who has hepatitis A. Casual contact, as in the usual office, factory, or school setting, does not spread the virus. Hepatitis a is diagnosed through a blood test, using IgM anti-HAV, immune globulin that is hostile to the Hepatitis A virus. Children with hepatitis A usually have no symptoms.

Adults may become quite ill suddenly, experiencing jaundice, fatigue, nausea, vomiting, abdominal pain, dark urine / light stools, and fever. The incubation period averages 30 days, however, an infected individual can transmit the virus to others as early as two weeks before symptoms appear and one week after. Symptoms will disappear over a six-month period until complete recovery occurs. Nevertheless complications may occur if no actions are taken, these include fulminant hepatitis or relapse of the disease. In the battle against hepatitis and in an effort to prevent its spread two products are available. A virus infection: immune globulin and hepatitis A vaccine.

+ Immune globulin is a preparation of antibodies that can be given before exposure for short-term protection against hepatitis A and for persons who have already been exposed to hepatitis A virus. Immune globulin must be given within 2 weeks after exposure to hepatitis A virus for maximum protection. + Hepatitis A vaccine has been licensed in the United States for use in people' 2 years of age and older. The vaccine is recommended (before exposure to hepatitis A virus) for persons who are more likely to get hepatitis A virus infection or are more likely to get seriously ill if they do get hepatitis A. The vaccines currently licensed in the United States are HAV RIX manufactured by SmithKline Beecham Biologicals, and VARTA, which is manufactured by Merck & Co., Inc. Often people wonder if such type of vaccines and prevention techniques are safe and their side effects. Well so far hepatitis A vaccine has had an excellent safety profile.

No serious adverse events have been attributed definitively to hepatitis A vaccine. Soreness at the injection site is the most frequently reported side effect. Immune globulin is also determined very safe. No instance of transmission of HIV or other viruses has been observed with the use of immune globulin administered by the intra-muscular route. Immune globulin can be administered during pregnancy and breast-feeding. It should be noted though that protection against hepatitis A only begins four weeks after the first dose of hepatitis A vaccine.

HEPATITIS Hepatitis B is also a serious disease caused by a virus that attacks the liver. The virus, which is called hepatitis B virus (HBV), can cause lifelong infection, cirrhosis (scarring) of the liver, liver cancer, liver failure, and death. Hepatitis B vaccine is available for all age groups to prevent hepatitis B virus infection. Hepatitis B can affect anyone. Each year in the United States, more than 200,000 people of all ages get hepatitis B and close to 5,000 die of sickness caused by HBV.

If you have had other forms of hepatitis, you can still get hepatitis B. One out of 20 people in the United States will get hepatitis B some time during their lives. Your risk is higher if you: + Have sex with someone infected with HBV + Have sex with more than one partner + Live in the same house with someone who has lifelong HBV infection + Have a job that involves contact with human blood + Shoot drugs + Are a patient or work in a home for the developmentally disabled + Have hemophilia + Travel to areas where hepatitis B is common Your risk is also higher if your parents were born in Southeast Asia, Africa, the Amazon Basin in South America, the Pacific Islands, and the Middle East. You also get hepatitis B by direct contact with the blood or body fluids of an infected person; for example, you can become infected by having sex or sharing needles with an infected person. Even babies get the disease, a baby can get hepatitis B from an infected mother during childbirth. Hepatitis B is not spread through food or water or by casual contact. If you have the hepatitis virus, HBV, in your blood you can give hepatitis B to your baby.

Babies who get HBV at birth may have the virus for the rest of their lives, can spread the disease and can get cirrhosis of the liver or liver cancer. Sometimes, people who are infected with HBV never recover fully from the infection; they carry the virus and can infect others for the rest of their lives. In the United States, about one million people carry HBV. You may have hepatitis B, and be spreading the disease and not know it; sometimes a person with HBV infection has no symptoms at all. The only way to know if you are currently infected with HBV or if you are a carrier of the virus is to have a specific blood test for HBV. The test will not show positive during the incubation period (45 to 60 days, average 120 days).

If you have symptoms + Your eyes or skin may turn yellow + You may lose your appetite + You may have nausea. vomiting, fever, stomach or joint pain + You may feel extremely tired and not be able to work for weeks or months There is no cure for hepatitis B; this is why prevention is so important. Hepatitis B vaccine is the best protection against HBV. Three doses are needed for complete protection. All pregnant women should be tested for HBV early in their pregnancy. If the blood test is positive, the baby should receive vaccine along with another shot. Hepatitis B immune globulin, called H-BIG, at birth.

The vaccine series should be completed during the first 6 months of life. Therefore who should be vaccinated against hepatitis B+ All babies, at birth should be + All children 11-12 years of age who have not been vaccinated + Persons of any age whose behavior puts them at high risk for HBV infection+ Persons whose jobs expose them to human blood People who have not cleared HBV from their blood within 6 months are considered to be chronically infected and are called hepatitis B carriers. There are about 1 million persons chronically infected with HBV in the U.S. at the present time. While there is no treatment for acute hepatitis B, there are two approved treatments for chronic hepatitis B: interferon alfa-2 b and lamivudine. Only patients with active HBV replication are candidates.

HEPATITIS Hepatitis C (HCV) is a form of hepatitis caused by an RNA virus. HCV accounts for the majority of the hepatitis cases previously referred to as non-A, non-B hepatitis. The hepatitis C virus was first identified and described in 1989, and in 1990 a hepatitis C antibody test (anti-HCV) became commercially available to help identify individuals exposed to HCV. Currently, there are 175 million people worldwide who are infected with the Hepatitis C virus, 4+ million of those are in the United States. For every one person that is infected with the AIDS virus, there are more than four infected with Hepatitis C. The CDC estimates that there are up to 230,000 new hepatitis C infections in the U.S. every year. In mid-1995 the hepatitis C virus was seen for the first time ever by scientists with the aid of an electron microscope.

It is a linear single-strand RNA (ribonucleic acid) virus 40-50 nano-meters in size. It is covered with a lipid envelope and is encased with glycoprotein polymers. Unlike hepatitis A which is caused by fecal contamination of food and water; or hepatitis B which is spread through contact with infected blood or other body fluids; hepatitis C is spread by direct contact with the blood of an infected person. Prior to the discovery of the virus, it was known that some agent caused hepatitis or inflammation of the liver in people who had been given blood, and it was known that the agent could be transmitted to patients and to experimental animals in blood.

Before the virus was identified, this form of hepatitis was called non A non B hepatitis because the viruses causing hepatitis A and hepatitis B were already identified and could be tested for. Patients with hepatitis following exposure to blood that had negative tests for hepatitis A and for hepatitis B were said to have non-A non-B hepatitis. It is now known that the majority of these patients were infected with the virus identified and named hepatitis C virus or HCV for short. As tests for this virus have improved over the years since 1989, more and more people who have hepatitis which could not be diagnosed with accuracy are now being correctly diagnosed as infected with the hepatitis C. Not too long ago, the CDC, Center for Disease, control has release criteria that lets you know of the risk you run of having this disease.

You may be at risk for hepatitis C if you: + Were notified that you received blood from a donor who later tested positive for hepatitis C. + Have ever injected illegal drugs, even if you experimented a few times many years ago + Received a blood transfusion or solid organ transplant before July, 1992 + Received a blood product for clotting problems produced before 1987 + Have ever been on long-term kidney dialysis + Have evidence of liver disease (CDC Homepage web) HCV is spread primarily by direct contact with human blood. For example, you may have gotten infected with HCV if: + You ever injected street drugs, as the needles and / or other drug "works" used to prepare or inject the drug (s) may have had someone else's blood that contained HCV on them. + You received blood, blood products, or solid organs from a donor whose blood contained HCV. + You were ever on long-term kidney dialysis as you may have unknowingly shared supplies / equipment that had someone else's blood on them. + You were ever a healthcare worker and had frequent contact with blood on the job, especially accidental needle sticks. + Your mother had hepatitis C at the time she gave birth to you.

During the birth her blood may have gotten into your body. + You ever had sex with a person infected with HCV. + You lived with someone who was infected with HCV and shared items such as razors or toothbrushes that might have had his / her blood on them. Current studies indicate that most (80%) people infected with hepatitis C will develop a chronic state of infection. About 30% those with chronic infection will go on to develop cirrhosis of the liver. The disease appears to progress slowly, symptoms often do not appear for ten or twenty years.

The overall severity of chronic hepatitis C is controversial. There is no question that HCV can lead to cirrhosis and primary hepatocellular carcinoma (HCC) and that end-stage chronic hepatitis C is now the leading indication for liver transplantation. Avoidance of spread of this virus is an important public health issue. The current limited data suggest that sexual transmission is extremely rare, but it is certainly prudent to advise any sexual partners of any infection that you know you have.

Although the risk of transmission of hepatitis C by unprotected intercourse, that is without the use of condoms, is far less than the risk of transmitting many other infections including hepatitis B, people with multiple sexual partners should always practice safe sex. Unlike hepatitis B, which is almost entirely preventable with routine use of the very effective vaccine available for that disease, at this time there is no vaccine available which is capable of protecting anyone from hepatitis C infection. The development of an effective vaccine against hepatitis C is a goal of researchers, but progress has been slow in this. Currently, there are three types of interferon and a combination of interferon and ribavirin used to treat hepatitis C. Selection of patients for treatment may be determined by biochemical, virologic, and when necessary, liver biopsy findings, rather than presence or absence of symptoms.

Interferon must be given by injection, and has a number of side effects including flu-like symptoms: headaches, fever, fatigue, loss of appetite, nausea, vomiting, depression and thinning of hair. It may also interfere with the production of white blood cells and platelets by depressing the bone marrow. Periodic blood tests are required to monitor blood cells and platelets. Ribavirin can cause sudden, severe anemia and birth defects so women should avoid pregnancy while taking it and for 6 months following treatment. The severity and type of side effects differ for each individual. Treatment of children with HCV is under investigation.

Currently, almost one half of all liver transplants in the U.S. are performed for end-stage hepatitis C. However, re-infection of the transplanted liver by HCV occurs at a high rate. Fortunately, this infrequently requires a second transplant. What is the most effective therapy for the hepatitis patients By studying the immune response to the hepatitis viruses, scientists hope to identify the mechanisms that lead to patient recovery and cure. Medical researchers are hopeful that anti-viral drug treatment, immune stimulators, and gene therapy will lead to the eradication of the hepatitis viruses.

Bibliography

1. H.W. Rees ink, Hepatitis C virus, Basel; New York: Karger, c 19982.
Hepatitis Foundation International online, web Tong MJ, Rei kes AR, Clinical outcomes associated with hepatitis C, New Engl Journal of Med. 19954.