Hepatitis C Virus Testing

http://www.sracansw.org/JOURNAL_17_3/173_HEPC.htm

The hepatitis C virus (Hepatitis C Virus) is a major cause of chronic liver disease worldwide and in Australia the number of people with the infection is believed to be 250,000. At least 85% of people infected with Hepatitis C Virus are likely to develop a chronic hepatitis C infection.

Most Hepatitis C Virus transmission is associated with direct percutaneous exposure to blood, which means healthcare workers are at occupational risk for acquiring the disease. There is no vaccine available for Hepatitis C Virus.

The US Morbidity and Mortality Weekly Report (MMWR) recently highlighted a study of healthcare workers who had sustained a percutaneous exposure to blood from a Hepatitis C Virus-positive patient. The reported incidence of sero- conversion was 6% in the United States and 10% in Japan. The Japanese incidence was based on detection of Hepatitis C Virus RNA by polymerase chain reaction.

The MMWR emphasised that there are many issues which need to be considered when defining a protocol for the follow-up of healthcare workers exposed to Hepatitis C Virus at work.

According to Professor Bill Reed, Professor of Medicine at the University of Western Australia and Chairman of the NH&MRC Working Party on Hepatitis C: “The first step is to find out if the source patient was hepatitis C positive and then it is up to the healthcare worker to decide whether they would like to be tested. Testing is a sensitive issue and sometimes indicates a previous exposure to hepatitis C.”

There is limited data about the occupational risk for transmission of Hepatitis C Virus both in Australia and overseas. Therefore, meaningful estimates of the risk of infection cannot be provided to healthcare workers who sustain such exposures.

Limitations also exist in testing for infection, according to the MMWR. The rate for false positivity for anti-Hepatitis C Virus in low-risk individuals can be as high as 50% and approximately 5% of infections will not be detected unless polymerase chain reaction is used to detect Hepatitis C Virus RNA. The tests are not well standardised and each test is very expensive.

“Despite the difficulties we should still be looking at testing healthcare workers as soon as possible after an incident to establish a baseline for treatment if required,” Professor Reed said.

“The cost of treatment is high with a six month course of interferon costing around $4,500.”

“Whilst hepatitis C transmission to healthcare workers from needlestick injuries may be lower than other blood-borne diseases, it is a very real thing and poses a serious problem”, Professor Reed said.

“Prevention of needlestick injuries is of utmost importance to ensure that follow up procedures and treatments can be avoided altogether,” Professor Reed said.

Reference:

Hepatitis Board, CDC, 'Recommendations for Follow-up of Health-Care Workers After Occupational Exposure to Hepatitis C Virus', MMWR, July 4,1997, Vol. 46/No. 26, p603-606.