Management of healthcare workers after occupational exposure to hepatitis C virus

The reported risk of HCV transmission after needlestick injury from an HCV-infected patient is considered to be 1.8%–3%.8-13 The transmission risk is predominantly from patients with hepatitis C viraemia detectable by polymerase chain reaction (PCR).8 The lower limit of HCV detection by PCR under optimal processing and storage conditions is generally 100 virus copies/mL, but variability in hepatitis C viraemia among some chronic HCV carriers means that PCR detection can fluctuate, even among those considered to be continuously viraemic.14,15 Perinatal maternal–fetal transmission, although not necessarily analogous to needlestick-injury transmission, appears more likely when maternal viral titres are above 106 copies/mL and is rare when mothers are PCR-negative.16,17

Current third-generation enzyme immunoassays for HCV antibody have nearly 100% sensitivity and detect seroconversion 4–10 weeks after infection. Delayed antibody detection and even false-negative results can occur among recently infected patients with renal failure, HIV infection and HCV-associated mixed essential cryoglobulinaemia.14 Elevation of serum alanine aminotransferase (ALT) concentration occurs after 4–12 weeks. Although used by some as a marker of recent HCV infection, raised ALT levels are not specific to this infection, and may fluctuate.14,18 In contrast, HCV viraemia can be detected by PCR between 10 days and 6 weeks after infection.19 Thus, PCR detection of hepatitis C viraemia appears more useful than HCV antibody or ALT testing in the early detection of acute HCV hepatitis.4,20 The Medicare schedule fee for HCV PCR is currently $90, compared with $15.30 for HCV antibody determination and $16.35 for liver function tests.21

We collaborated with six major metropolitan hospitals in Melbourne, Victoria, to determine the number of occupational exposures to blood and body fluids (including needlestick injuries) reported at each institution, and the number of these that involved a source patient with HCV infection as defined by the presence of HCV antibody. Consent was obtained from the source patient before testing for HCV (as well as HIV and HBV). Reported occupational exposures of healthcare workers to HCV at these hospitals is shown in Box 1. Of 1450 reported occupational exposures over 111 months, 138 were from HCV-infected patients. At all institutions, needlestick injuries made up more than 60% of the total number of exposures. There is currently no national Australian standard for the reporting of blood and body fluid exposures. Information was not available from all institutions on the rate of HCV among all inpatients, but at Hospital 1 the overall rate was 1.5% in 2002 (unpublished data), suggesting a possible reporting bias (approximately tenfold) towards exposures from HCV-positive source patients.

As information on the number and working hours of healthcare workers potentially exposed to needlestick injuries at each institution was not available, a healthcare worker- and time-dependent rate of needlestick injury could not be calculated. Given that our survey included only larger Melbourne hospitals, and that the predicted risk of HCV acquisition associated with each needlestick injury is 1.8%–3%,8-13 two to five healthcare workers are likely to be infected with HCV through occupational exposure in Victoria each year.

Acute HCV infection is symptomatic in 15%–20% of patients, but is rarely severe enough to require hospitalisation.20 However, about 75%–85% of HCV-infected patients develop chronic hepatitis, and about 15%–25% develop cirrhosis. Half of these individuals develop hepatic decompensation or hepatocellular carcinoma.14,22 Until recently, in the absence of evidence that any treatment was effective in preventing chronic hepatitis, early detection of acute HCV infection was considered to be of limited therapeutic importance. However, recent data show that early treatment with interferon-alfa monotherapy results in viral clearance in over 90% of recipients.7 Results for combined interferon and ribavirin in acute treatment of hepatitis C infection are currently inconclusive. The optimal timing of acute therapy after exposure remains uncertain, but some studies report similar results for immediate therapy and therapy that is delayed by 3–6 months.7,14,23-25

Many healthcare workers are extremely anxious after needlestick injuries, with widespread effects on work performance, personal relationships and psychological health, leading to depression and, at times, a sense of abandonment and isolation.26 This may occur regardless of counselling. Given the relatively low rate of HCV seroconversion after needlestick injury, it is often these psychological issues that have the greatest impact on injured healthcare workers. Anxiety can last for over a year, and the psychological counselling costs appear similar to the direct medical costs of these injuries.27,28 Many healthcare workers express concern about possible sexual transmission of HCV to partners, as well as maternal–fetal transmission for those who are currently pregnant or attempting to become pregnant. There is even a report of therapeutic abortion being sought.27 Although data on couples where one partner has chronic hepatitis C suggest that the rate of sexual transmission of HCV is low,29-32 the risk during seroconversion is less certain. Hence some HCV-exposed healthcare workers opt either to use condoms or to abstain from sexual contact until they are certain they have not acquired HCV,27 which may exacerbate interpersonal stress, depression and sense of social isolation. Early confirmation that HCV acquisition is unlikely could have positive effects on sexual and psychological health.

Ross and colleagues suggest that the risk of surgeons with known HCV infection (ie, HCV-positive on PCR) transmitting HCV to their patients is 1 in 1750 to 16 000 operations.33 However, the actual risk is likely to be influenced by factors such as viral load, the number and complexity of surgical procedures performed, and the surgeon’s technique and experience. It is often the less experienced junior medical staff who perform at-risk procedures after hours, when experienced supervision is least available, and fatigue is likely to be greatest. Fortunately, relatively few cases of HCV transmission from healthcare workers to patients have been reported, but such episodes have been associated with time-consuming and expensive “look-back” programs and considerable patient morbidity.34-37 Although there are few data, the risk of HCV transmission to patients is negligible among healthcare workers with no detectable HCV viraemia (ie, negative HCV PCR).8

Defining risk of transmission from healthcare workers may be helpful for legal as well as infection control reasons. There has been an instance where a surgeon had a work-related needlestick injury from an HCV-positive source patient at a major Australian hospital, and legal opinion obtained by the hospital’s administration was that the surgeon should cease all surgical procedures until confirmed as not having acquired HCV (Melbourne Infectious Diseases Group, personal communication, Jun 2001). This is contrary to recommendations from the US Centers for Disease Control and Prevention (CDC).1 A risk assessment structure regarding HCV transmission may have assisted decision-making in this case. Without it, management of needlestick injuries will become unworkable, as healthcare workers will become reluctant to report injuries involving HCV-infected patients if they believe they will be forced to cease clinical practice without any risk assessment or compensation.

A balance needs to be found between the rights of the injured healthcare worker and those of the healthcare worker’s future patients. Hospital administrations need to feel confident that needlestick injury reporting is accurate and that healthcare workers who are exposed to HCV are not placing their patients at significant risk of HCV transmission. Investigations that promptly identify acute HCV infection (eg, HCV PCR) could assist in identifying healthcare workers who should be re-deployed from exposure-prone procedures, while allowing other injured healthcare workers to continue routine practice. HCV antibody and ALT levels detect acute infection later than PCR, and neither gives an accurate assessment of healthcare worker infectivity. Clearly, the appropriate management of needlestick injuries poses a new challenge to the healthcare sector, both in terms of reducing the overall risk of needlestick injury, the fair and reasonable management of injured staff and the protection of patients.