Hepatitis C Exposure at Work: CDC's 2020 Testing Guidance for Health Care Personnel

Summary

Exposure to hepatitis viruses is a known occupational risk for health care personnel. This 2020 CDC guidance sets out how to test and manage workers who may have been exposed to hepatitis C virus (HCV), replacing the 2001 recommendations. It is based on expert opinion, current understanding of early HCV infection, and guidance from the American Association for the Study of Liver Diseases and the Infectious Diseases Society of America to treat acute infection promptly.

Anyone found HCV RNA–positive should be referred to care. Preventive treatment (postexposure prophylaxis) is not recommended.

The risk

Workers can be exposed by a used needle or a splash of blood or body fluid into the eye or mouth. Sharps injuries have declined but still happen: in 2018, 34 U.S. hospitals reported 12.6 blood and body fluid exposures per 100 average daily census days, and similar exposures occur in nursing homes, clinics, emergency departments and home care.

• Among about 885 workers stuck by a needle or sharp contaminated with antibody-positive blood or fluid in 2002–2015, the infection risk was about 0.2% (two of 885); among 458 with mucous membrane or skin exposure, 0%. Older studies reported 0% to 10%.
• Risk may be higher with hollow-bore needles, and appears to depend on the source having HCV RNA in the blood.
• Acute HCV is rising, mostly from injection drug use — reported cases rose 3.7-fold in 2010–2017 — so workers may meet patients in the window period, infected but not yet antibody-positive.

Testing the source patient

Option A (HCV RNA) is preferred, especially if the patient may have recent risk behaviors — such as injection drug use within 4 months — or if risk can't be reliably judged, since HCV RNA is detectable as early as 1–2 weeks after infection. Under Option B, draw enough blood to test for RNA on the same sample if the antibody test is positive. Positive source patients should be reported to the health department and referred for care.

When the worker needs follow-up: if the source is HCV RNA–positive, antibody-positive with no RNA result, or of unknown status — for example, a needle found in the trash. Follow-up isn't needed if the source is antibody-positive but RNA-negative, which usually means a cleared or cured infection — unless the sample may have been compromised or the worker shows signs of infection.

Testing the source patient. Figure from the CDC report.

Testing the worker

• Baseline testing rules out an existing infection. A worker who is RNA-positive at baseline should be referred for care. One who is antibody-positive but RNA-negative probably had a cleared infection, so later testing should look for RNA, not antibody, which stays positive.
• 3–6 weeks: an RNA test. HCV RNA is usually detectable within 1–2 weeks of infection. Testing at 6 weeks can coincide with HIV follow-up testing if that is also needed.
• 4–6 months: a final antibody test — newly added because RNA can drop out temporarily during acute infection. Antibodies appear on average 8–11 weeks after exposure, later in people with weakened immunity. Testing at 6 months can coincide with hepatitis B follow-up. Anyone who develops symptoms of acute hepatitis C should be tested for RNA at once.
• After that: no more follow-up for workers still antibody-negative, though an extra RNA test can be considered for those who are immunocompromised or have liver disease. Tests should be repeated if a sample may have been mishandled.

Testing the exposed worker. Figure from the CDC report.

Why not preventive treatment?

• Transmission is rare: at 0.2%, about 1,000 workers with needlestick exposures would have to be treated for every two who might become infected — and none would benefit after mucous membrane or skin exposure.
• Neither the effectiveness nor the duration of preventive treatment has been established; a 2019 pilot trial of a 2-week course began for workers exposed through hollow-bore needlesticks to RNA-positive patients.
• Direct-acting antiviral drugs cure acute and chronic infections very effectively, so the strategy is to test, and treat if infection occurs — promptly, rather than waiting to see if it clears, as about 25% to 45% of acute infections do. Waiting can bring anxiety, lost work, possible transmission and loss to follow-up.

If infected: workers with HCV RNA or new antibodies after an exposure should be referred for evaluation and treatment.

Sources

Based on Anne C. Moorman, Marie A. de Perio, Ronald Goldschmidt and others, "Testing and Clinical Management of Health Care Personnel Potentially Exposed to Hepatitis C Virus — CDC Guidance, United States, 2020," MMWR Recommendations and Reports, Centers for Disease Control and Prevention; a work of the United States government in the public domain.