Not Your Average Virus
By Charlene Buckner, RN, CIC, COHN-S, and Ann Drake, RN, CIC
- Reviews occupational exposure to HCV.
- Highlights current treatments for hepatitis C.
Cleaning lights contaminated with blood puts workers at risk.
Hepatitis C virus (HCV) infection is the most common form of chronic liver disease in the US. The chronic liver inflammation caused by this virus is estimated by the CDC to account for approximately 10,000 deaths each year. Because of the sheer volume of reported cases, about four million, and subsequent public interest, the broad clinical features and implications of this disease merit review.
At this time, it appears that the greatest risk factor, by far, is injecting-drug use. Since 1992, routine blood donor screening for HCV antibodies has identified potential cases and markedly reduced transmission via blood transfusion. As with other bloodborne pathogens, healthcare workers are at increased risk to percutaneous exposure due to the nature of their occupation. This fact has fueled the drive for safer sharps and needle devices and supporting legislation in some states, including recently Ohio. Infrequently, transmission has occurred from an infected mother to infant at childbirth and by exposure to multiple sexual partners. Hemophiliacs that received clotting factors before 1987, and patients that received blood transfusions before 1990 are also at risk. Since 10% of the chronic dialysis patients are estimated to be infected with HCV, the staff in chronic hemodialysis units should routinely take measures to minimize contamination of supplies and equipment that could lead to transmission of HCV or other bloodborne pathogens.
Repeated or large volume percutaneous blood exposure is the most common route of exposure. The approved screening test is the enzyme immunoassay (EIA), which detects the anti-HCV antibodies on average 8 to 10 weeks post exposure. The incubation period ranges from two to six weeks, but viral replication can be detected as soon as one week after exposure by polymerase chain reaction (PCR), which is not an FDA approved test at this time. Confirmation can be verified by the recombinant immunoblot assay (RIBA) test. Up to 70% of the infected persons are asymptomatic. Those seeking medical care typically present hepatitis symptoms such as jaundice, fatigue, appetite loss, and abdominal pain. Lab values indicating elevated bilirubin and fluctuating aminotransferase (ALT) levels, a liver enzyme found in the blood when there is liver damage, can be demonstrated in about 80% of this population. Only about 15% to 25% of these patients recover fully; the remainder develop chronic HCV infection. Of those with chronic HCV infection, 30% to 40% have normal liver enzymes and no symptoms. Of the asymptomatic patient population with elevated liver enzymes, 10% to 20% develop cirrhosis or hepatocellular carcinoma.
No clinical features or risk factors appear to create a reliable profile of progression to severe chronic disease. However, some data indicate that certain behavioral and demographic activities may increase the risk of chronic infection. These factors include age over 40 years, male gender, daily alcohol ingestion, and repeated percutaneous exposure to blood, especially injection drug use. Co-infection with other infectious disease, such as HIV and HBV, appear to contribute to the development of cirrhosis and chronic disease. It is not unusual for two decades or more to pass before symptoms of chronic infection appear, so years of "living clean" do not eliminate the possibility of disease development due to youthful indiscretion.
Between 1988 and 1994, the National Health and Nutrition Examination Survey (NHANES) randomly selected almost 34,000 US citizens for the purpose of conducting basic history, physical, and laboratory examinations. The homeless and incarcerated were not included in this sample. The prevalence of HCV chronic infection in this representative sample of the general population was 1.8% (3.9 million people). In addition to the risk factors and demographics already mentioned, HBV patients were more than six times more likely to also have HCV. The annual US mortality rate of approximately 10,000 deaths from HCV chronic liver disease is expected to triple in the next 10 to 20 years.
Currently, there is no vaccination available for HCV infection. Interferon has been used to treat chronic disease in the patients that are at greatest risk to develop cirrhosis. In the instance of relapse, the same drug has been used in combination with ribavirin with some success. The ultimate therapeutic procedure is liver transplant, which also has limited long-term success rates. Therefore, the search for effective treatment modalities and preventive measures is intense.
Hepatitis C and the Healthcare Worker
The healthcare worker who has contact with blood is placed at risk for exposure to hepatitis C in the same manner as for hepatitis B and HIV. Over the years, the risk to healthcare workers for contracting hepatitis B has been evaluated extensively in new infections. Much less has been documented about the risks for workers exposed to hepatitis C. Reasons for this include the lack of laboratory markers for identifying exposed workers and the feeling that HCV was not spread efficiently through occupational exposure.
Currently, the estimated prevalence rates for HCV among healthcare workers is about 1% less than the national average of 1.8%. This should not detour one into a false sense of security. Because there is not a vaccine available, even a low risk for infection (<3%) may result in hundreds of infected workers. OSHA's 1991 Bloodborne Pathogen Standard required employers to establish a program to protect workers at risk from infection with hepatitis C as well as hepatitis B and HIV. The program includes an orientation for new employees with discussion of the diseases, their signs and symptoms, and health outcomes. The plan also includes engineering controls, personal protective equipment, and the required use of universal precautions. The standard has benefited employees by greatly reducing their risk of exposure to all bloodborne pathogens.
To comply with OSHA's standard, employers should have policies and procedures addressing the post-exposure follow-up evaluation for any worker suffering a needlestick or mucosal exposure to human blood or other potentially infectious material.
If a worker suffers an exposure, the evaluation should be performed as soon as possible. The healthcare worker should be tested for baseline information relative to their HBV, HCV, and HIV status as well as the source individual unless their status is already known.
Presently, there are not recommendations for prophylaxis with any anti-viral agents. The worker should be informed that there is a 2 to 3% risk of infection. He or she might also have concerns about personal issues such as sex or pregnancy that require answers from a qualified healthcare professional.
If the worker becomes infected, additional information should be provided that includes the risk for alcohol and drugs increasing the liver damage, recommending vaccination for HBV and HAV, and a discussion of the risks associated with some alternative cures such as herbs or vitamins. Although most infected individuals will manage to live normal lives and eventually die of other causes, it is advisable that they have regular check-ups by a physician familiar with the disease. In many parts of the country, there are support groups that can help keep those infected current on issues and treatments. In the event that your region does not have such a group, access to on-line services such as the Hepatitis Information Network (www.hepnet.com) can also be a valuable resource.
The risk of transmission to a patient appears to be very low. The HCW should not be restricted from duty during the test period nor should the worker with a confirmed positive HCV infection. Instead, the employee should be instructed to follow strict aseptic technique with the use of good handwashing adherence to universal precautions. Some states have policies requiring infected HCWs any bloodborne infections reporting to their employers or other governing boards. The employee is advised to check for requirements in their state.
It is advisable that employees understand the importance of reporting any exposures that occur. Complications from an infection with Hepatitis C might take years to develop, and well-documented exposures will expedite compensation claims. Since workers change jobs and places of employment move or merge, the worker should also keep copies of any report they make in their own home files.
Public Health Issues
Prevention remains the cornerstone in managing hepatitis C. An ongoing educational effort for the general public as well as targeted groups, such as healthcare workers, will raise awareness and ultimately reduce the numbers of new cases of chronic infections. Future costs to society for drug therapies and transplants for those with chronic HCV infections cannot be predicted easily. However, we know that current drug therapy can cost over $1,000 per month and liver transplants over $100,000. Diagnostic tests, such as laboratory tests and liver biopsies, will also add to the financial burden that all of us will share.
The effort to control this infectious disease must be supported by the public and private sector. Education, management of existing cases, and research into new drugs and therapies are needed. Financial resources must be found to fund these endeavors. It should be apparent that HCV is not just an average disease but one that requires exemplary action.
Charlene Buckner, RN, CIC, COHN-S, and Ann Drake, RN, CIC, are Infection Disease Consultants for the Ohio Department of Health (Columbus, Ohio).
For a list of references, access the ICT Web site.
Table 1: Estimated average prevalence of HCV infection in the US by various characteristics and estimated prevalence of persons with these characteristics in the population.
|Characteristic||HCV-infection prevalence||Prevalence of persons with characteristic, %|
|Persons with hemophilia treated with products made before 1987||87||(74-90)||< 0.01|
|Injecting-drug users current||79||(72-86)||0.5|
|history of prior use||No data||--||5|
|Persons with abnormal alanine amino trasferase levels||15||(10-18)||5|
|Chronic hemodialysis patients||10||(0-64)||0.1|
|Persons with multiple sex partners (lifetime)
|Persons reporting a history of sexually transmitted diseases||6||(1-10)||17|
|Persons receiving blood transfusions before 1990||6||(5-9)||6|
|Infants born to infected mothers||5||(0-25)||0.1|
|Men who have sex with men||4||(2-18)||5|
|Volunteer blood donors||0.16||--||5|
|Courtesy of Centers for Disease Control and Prevention|
For a complete list of references click here