Hepatitis B
Hepatitis B vaccines have been available since 1982 and, as a result, the number of new infections per year has declined from an average of 260,000 in the 1980s to about 78,000 in 2001, according to the CDC. Approximately 1.25 million people are chronically infected with HBV in the
Vaccination against hepatitis B is also recommended for:
- All children under age 18
- Persons with multiple sex partners or diagnosis of a sexually transmitted disease
- Men who have sex with men
- Sex contacts of infected persons
- Injection drug users
- Household contacts of chronically infected persons
- Infants born to infected mothers
- Infants/children of immigrants from areas with high rates of HBV infection
- Health care and public safety workers
- Hemodialysis patients
- Patients with other liver diseases
Hepatitis C
Hepatitis C, or HCV, has been the focus of recent attention because an estimated 3.9 million Americans are believed to have been exposed and 2.7 million are chronically infected. Hepatitis C causes up to 10,000 deaths a year, due to complications of cirrhosis and liver cancer. Treatments are available but they are not effective in all patients. Most infections occurred in the 1970s and 1980s from contaminated blood used during transfusions and from injection drug use. The virus was first identified in 1988 and, in 1989, a reliable test was developed that could identify antibodies to the virus in blood supplies. Today, using more sensitive and specific antibody tests and RNA testing there is less than one case of HCV infection per million units of transfused blood.
HCV poses serious health problems for some people while for others there may be no long-term consequences. Natural history studies suggest that the rate of progression to cirrhosis (scarring of the liver) is highly variable, ranging from 0.5 to 25 percent of patients with chronic disease who have had the infection for 10 to 30 years. Liver cancer develops in approximately 2 percent of cirrhotic patients each year.
Although the annual number of new HCV infections has decreased dramatically-from a high of 240,000 in the 1980s to 25,000 in 2001-most infected people don't know they have the virus. Only recently have health officials made a concerted effort to notify those who received blood or blood products contaminated with HCV before routine screening began.
Testing for hepatitis C by detection of a specific antibody for the virus is recommended for injection drug users, recipients of blood clotting factors, hemodialysis patients, recipients of blood transfusions or solid organ transplants before 1992 and infants born to infected mothers (after 12 to 18 months).
Hepatitis D
Hepatitis D virus, or HDV, is uncommon, except in IV drug users. It can lead to cirrhosis in up to 70 percent of cases, often within a few years. HDV, acquired through contact with infected blood, occurs only in those already infected with hepatitis B. Also at risk are those with HBV who have sex or live with a person infected with HDV. For those not infected with HBV, a vaccine can shield them from that virus and therefore provide protection against HDV as well.
No comments:
Post a Comment