Disease name, means of transmission and usual reservoirs: Hepatitis C was called non-A, non-B hepatitis until it was identified (1). It is a viral infection that is predominately transmitted by blood with the greatest rate of infection found in intravenous drug abusers, hemophiliacs, and individuals who received unscreened blood transfusions. There are also low risks for transmission sexually and perinatally (2).
Etiologic agent, its general characteristics and key tests for identification: Hepatitis C virus (HCV) comes from the virus family of Flaviviridae (3). The enzyme immunosorbant assay is used in diagnosis of HCV by detecting serum antibodies against HCV (1). Diagnosis is usually confirmed by testing blood for HCV RNA (3). Historical information to include when and who isolated the microbe and any significance of its name: Using cDNA isolated from chimpanzees that were given serum from individuals infected with non-A, non-B hepatitis, researchers from Chiron, Inc. discovered and named hepatitis C virus in 1989 (3).
Signs and symptoms of the disease: Individuals with hepatitis C tend to be asymptomatic or have very mild symptoms but can end up having very serious liver problems later (4). Symptoms occurring in acute hepatitis C include jaundice, anorexia, malaise, or abdominal pain. Between 75-85% of person with acute hepatitis C will go on to develop chronic hepatitis C (5). The consequences of a chronic infection are serious liver problems and diseases such as cirrhosis and liver cancer (1).
Microbial virulence mechanisms contributing to the disease process: Virulence of hepatitis C is unknown (7). The mutability of its genome may be one of the reasons most individuals eventually develop a chronic infection (1).
Control or treatment for the disease: A liver biopsy is used to determine when treatment becomes necessary (6). Typical treatment involves injecting interferon by itself or combined with ribavirin. Studies indicate that interferon is more effective when taken with ribavirin, however ribavirin is ineffective by itself (1). Interferon alpha drugs are typically injected three times a week for at least six month (2). A newer, more promising treatment involves injecting interferon peginterferon once a week. Studies have shown the highest sustained response (over 50%) is in infected individuals who take peginterferon alpha and ribavirin (6). There are other steps infected persons can take before drug therapy to keep their liver in good condition. It is suggested to avoid alcohol completely, get vaccinated against hepatitis A and B, avoid any medications or products that could damage the liver, and periodically have a liver biopsy done (4).
Prevention, particularly current research about a vaccine or other means of control/prevention: There is no vaccine for hepatitis C, partly because the genome is highly variable (2). This makes minimizing the risks of transmission the only prevention. Some precautions to take include 1) screening all transfusions and transplantations, 2) using proper sterilization techniques in health care facilities, and 3) counseling those who participate in risky drug and sexual practices about how to protect themselves (1).
References:
1. World Health Organization. "Fact Sheet No. 164: Hepatitis C." 2000. URL: http://www.who.int/inf-fs/en/fact164.html accessed on 05/04/02.
2. "Hepatitis C Virus (HCV)" 02/16/99. URL: http://www.tulane.edu/~dmsander/WWW/335/HCV.html accessed on 05/04/02.
3. Worman, H. J. "The Hepatitis C Sourcebook." 2002. URL: http://cpmcnet.columbia.edu/dept/gi/hepC.html accessed on 05/04/02.
4. Centers of Excellence in Hepatitis C Research and Education. "If You Have Hepatitis C Infection." 01/15/02. URL: http://www.va.gov/hepatitisc/pted/ifhavehepc.htm accessed on 05/04/02.
5. Centers for Disease Control and Prevention. "Hepatitis C: Clinical Features & Natural History." 07/28/01. URL: http://www.cdc.gov/ncidod/diseases/hepatitis/c_training/edu/3/default.htm accessed on 05/04/02.
6. Worman, H. J. 2002. "Hepatitis C: Current Treatment." URL: http://cpmcnet.columbia.edu/dept/gi/ribavirin.html accessed on 05/04/02.
7. Duckworth, D., Crandall, R., & Rathe, R. 04/20/99 URL: http://www.medinfo.ufl.edu/year2/mmid/bms5300/bugs/hcv.html accessed on 05/04/02.