Hepatitis B Hepatitis B is a liver disease that results from infection with the Hepatitis B virus. It can range in severity from a mild illness lasting a few weeks to a serious, lifelong illness. Hepatitis B is usually spread when blood, semen, or another body fluid from a person infected with the Hepatitis B virus enters the body of someone who is not infected. Onset is usually insidious with anorexia, abdominal discomfort, nausea, vomiting and jaundice. Differentiation from hepatitis A is clinically difficult. Chronic infections are mostly due to infections in infancy and childhood. STANDARD CASE DEFINITION Suspect (History) An acute illness typically including acute jaundice, dark urine, anorexia, malaise, extreme fatigue and right upper quadrant tenderness. Confirmed (Laboratory Tests) Serum positive for IgM anti-hbc or, hepatitis B surface antigen (HbsAg). Hepatitis B is caused by the hepatitis B virus (HBV) which is a 42 nm DNA virus composed of a 27 nm nucleocapsid core antigen (HBcAg) surrounded by an outer coat containing the surface antigen (HBsAg). OCCURRENCE There is no seasonal variation. In developing countries, the infection is widespread in children but is most common in young adults in the West. RESERVOIR Man is the chief source of infection. Mode of Transmission Transmission may occur by the following routes: Parenteral or Percutaneous
Through infected blood, blood products, syringes, transfusion apparatus, and even razors and nail clippers. HBV infection is thus more common in nurses, surgeons, drug addicts and those receiving repeated transfusion, such as hemophiliacs, coronary bypass patients and those on hemodialysis. Vertical or Perinatal Spread Mother to infant transmission can occur when the mother is a chronic carrier or suffers from acute HBV infection during the last trimester of pregnancy. The infection might occur during birth More than 90 % of infants infected by their mothers become chronic carriers as their immature immunological system is not able to clear the virus. Permucosal Spread HBsAg found in all body secretions and excretions, only blood, saliva, vaginal fluid and semen have been found to be infective. Sexual partners of HBV infected persons stand the risk of contacting the infection (homo as well as heterosexual partners). Hepatitis B can be transmitted from child to child during play or from an adult to child by contact of body fluids through minor cuts, sores, abrasions. Who is at risk for Hepatitis B? Have sex with an infected person Have multiple sex partners Have a sexually transmitted disease Inject drugs or share needles, syringes, or other drug equipment Live with a person who has chronic Hepatitis B Infants born to infected mothers Exposed to blood on the job Hemodialysis patients Travel to countries with moderate to high rates of Hepatitis B INCUBATION PERIOD Varies from 45 to 180 days, average 60 to 90 days, may be rarely as long as 6 to 9 months. It may take as short as two weeks for HBsAg to appear in the blood. SUSCEPTIBILITY AND RESISTANCE There is general susceptibility to infection. Immunity conferred is solid.
If the virus persists in blood for more than 6 months. These are called chronic carriers. The carrier state usually lasts in these persons indefinitely PREVENTIVE MEASURES The following steps are important: Avoid spilling blood during collection, storage and transport. Avoid all unnecessary injections, infusions. Always use disposable needles and syringes for HBsAg positive patients. Wash thoroughly hands contaminated with blood. Blood donors and the staff of blood banks, hemodialysis units, pathology laboratories and operation theatres should be screened for HBsAg positivity every 3 to 6 months. Blood transfusion should be given only when absolutely necessary. Pooled plasma should be avoided. Patients needing multiple blood transfusions should be immunized with vaccine if found to be negative for anti-hbs (antibody to HBsAg). Antenatal care should include routine screening for HBsAg to prevent perinatal transmission to infants. Passive immunization by administration of immune serum globulin (ISG) or hepatitis B immunoglobulin (HBIG). The latter contains a high titer of anti-hbs compared to ISG. The indications are as follows: Household contacts, especially children, of patients with hepatitis When blood transfusion is given to a patient 5 ml may be given intramuscularly on the day of transfusion to prevent development of post-transfusion hepatitis. HBIG: Its specific indication is in case of infants born to HBsAg and HBcAg positive mothers, the dose being 0.5 ml IM at birth and repeated at 2 and 6 months. Active immunization: Hepatitis B vaccine is the first vaccine against a cancer (primary liver cancer). This vaccine is available either as monovalent or in combination (DPT-HepB, DPT-HepB+ Hib and HepB-Hib, etc.). hepatitis B vaccine are prepared by using the HBsAg by DNA recombinant technology and it contains only the outer coat (surface antigen) of the virus. Route is intramuscular and the site being anterolateral aspect of thigh in infants.
For immunocompetent adults vaccine is administered at 0, 1 and 6 months as an intramuscular injection in the deltoid Hepatitis B vaccination is recommended for: All infants, starting with the first dose of Hepatitis B vaccine at birth All children and adolescents younger than 19 years of age who have not been vaccinated People whose sex partners have Hepatitis B Sexually active persons. Men who have sexual contact with other men People who share needles, syringes, or other drug-injection equipment People who have close household contact with someone infected with the Hepatitis B virus Health care and public safety workers at risk for exposure to blood or blood-contaminated body fluids on the job People with end-stage renal disease, including predialysis, hemodialysis, peritoneal dialysis, and home dialysis patients Travelers to region with moderate or high rates of hepatitis B. People with chronic liver disease. People with HIV infection. Anyone who wishes to be protected from Hepatitis B virus infection Side Effects Most common side effects are soreness at injection site, fatigue, headache, irritability and fever higher than 37.7 C. Efficacy Complete vaccine series induces protective antibody levels in 95 percent infants. Hepatitis C Hepatitis C is a contagious liver disease that ranges in severity from a mild illness lasting a few weeks to a serious, lifelong illness that attacks the liver. It results from infection with the Hepatitis C virus (HCV), which is spread primarily through contact with the blood of an infected person. Hepatitis C can be either acute or chronic.
Chronicity is common, occurring more frequently than with hepatitis B in adults. Acute Hepatitis C virus infection is a short-term illness that occurs within the first 6 months after someone is exposed to the Hepatitis C virus. For most people, acute infection leads to chronic infection. Chronic Hepatitis C virus infection is a long-term illness that occurs when the Hepatitis C virus remains in a person s body. Hepatitis C virus infection can last a lifetime and lead to serious liver problems, including cirrhosis (scarring of the liver) or liver cancer. Diagnosis depends on the exclusion of hepatitis A, B and delta viruses and other causes of liver injury. A serologic test for antibody to the agent has been developed. The lipid-enveloped agent is between 30 and 50 nm in diameter, RNA virus, probably a flavivirus. Hepatitis C is parenterally transmitted. Hepatitis C is usually spread when blood from a person infected with the Hepatitis C virus enters the body of someone who is not infected. Sharing needles, syringes, or other equipment to inject drugs Needle stick injuries in health care settings Being born to a mother who has Hepatitis C INCUBATION PERIOD Ranges from 2 weeks to 6 months; most commonly, within 6 to 9 weeks. PERIOD OF COMMUNICABILITY From one or more weeks before onset of the first symptoms through the acute clinical course of the disease, and indefinitely in the chronic carrier states. Some people are at increased risk for Hepatitis C, including Current injection drug users Past injection drug users, including those who injected only one time or many years ago
Recipients of donated blood, blood products, and organs Hemodialysis patients or persons who spent many years on dialysis for kidney failure People who received body piercing or tattoos done with non-sterile instruments People with known exposures to the Hepatitis C virus, such as Health care workers injured by needlesticks Recipients of blood or organs from a donor who tested positive for the Hepatitis C virus HIV-infected persons Children born to mothers infected with the Hepatitis C virus METHODS OF CONTROL interferon alfa is used to treat acute hepatitis C for 6 to 24 weeks. Ribavirin may also be used if HCV RNA fails to clear after 3 months of interferon alfa therapy. Hepatitis D Onset is usually abrupt, with signs and symptoms resembling those of hepatitis B. Hepatitis may be severe and is always associated with a coexistent hepatitis B virus infection. Delta hepatitis may be self-limiting or it may progress to chronic hepatitis. Hepatitis delta virus (HDV) and hepatitis B virus (HBV) may coinfect, or delta virus infection may be superimposed upon the HBV carrier state. HDV is a 35 to 37 nm virus-like particle consisting of a coat of HBsAg and a unique internal antigen, delta antigen. HDV is unable to infect a cell by itself and requires coinfection with HBV. Occurrence Worldwide, with marked variation in prevalence. Occurs epidemically or endemically in populations at high risk of HBV infection. MODE OF TRANSMISSION AND METHODS OF CONTROL Similar to that of HBV.
Hepatitis E The epidemiology and clinical course are similar to that of hepatitis A; there is no evidence of a chronic form. The case fatality rate is similar to that of hepatitis A, except in pregnant women where the rate may reach 20 percent during the third trimester of pregnancy. Diagnosis depends on exclusion of other etiologies of hepatitis, especially hepatitis A, by serologic means There is evidence that one virus or virus family is responsible for hepatitis E. A 32-nm virus-like particle has been found in stools during the early acute phase of infection. RESERVOIR Man, transmissible to chimpanzees. MODE OF TRANSMISSION Contaminated water. Also probably from person to person by the fecal-oral route. INCUBATION PERIOD Fifteen to 64 days; mean incubation period has varied from 26 to 42 days in different epidemics. PERIOD OF COMMUNICABILITY Not known, but may be similar to hepatitis A. METHODS OF CONTROL Similar to hepatitis A. Hepatitis G This virus was discovered in January 1996. It is a flavivirus that is percutaneously transmitted and associated with chronic viremia that lasts for at least 10 years. HGV has been detected among blood donors, injection drug users, hemophiliacs, hemodialysis patients and with chronic hepatitis B or C infection, but it does not cause important liver disease.