Hepatitis B, hepatitis C, and other blood-borne infections in healthcare workers (2005)

The subject of hospital- or healthcare-related infections is a topical one. However, although the spread of methicillinresistant Staphylococcus aureus (MRSA) in the hospital environment is rarely out of the headlines, the ongoing problem discussed at this meeting in Rome is one that rarely receives public attention, but is of major concern to public health professionals and epidemiologists.

Blood-borne infections such as HBV, HCV, and HIV infections vary in prevalence between countries in both the developed and developing world. The risk of parenteral transmission of each of these viruses also varies, with HBV being ten times more likely to be transmitted than HCV, and HIV much less likely to be transmitted than either of these. Much is known about the role of viral load in the transmission of HBV and HIV, but there is little information available on the role of viral load, genotype, or other virological factors in the spread of HCV.

Epidemiology and risk

Blood-borne viruses are most commonly spread within the healthcare environment by needlestick or sharps injuries during medical procedures, or through mucocutaneous exposure. With estimates of the number of healthcare workers worldwide varying between 35 and 100 million, the potential number of people at risk is extremely high. Fortunately, numbers of actual infections attributed to occupational exposure are relatively low with 65,000 HBV infections, 16,400 HCV and 1000 HIV infections in 2000. However, most, if not all of these infections could have been prevented, usually by the health professional him- or herself.

Transmission

Transmission of blood-borne infections occurs most frequently between patients, is less common from patient to healthcare worker, and even less common from healthcare worker to patient. The introduction of immunisation against HBV and the equally important promotion and observation of universal precautions, including hand washing and safe needle disposal, have made major contributions to the reduction in numbers of infections passed from patients to HCWs. However, some areas still carry a high risk of transmission, particularly for staff working in cardiac or orthopaedic surgery, obstetrics, or gynaecology.

The number of transmissions from HCWs to patients is extremely low, but these are the infections that reach the public’s attention. A serious topic for discussion here is the HCW and the performance of exposure-prone procedures. The main problems are defining the risk according to the type of procedure, for example whether blind suturing may lead to unobserved injury and HCW-patient blood contact, the compliance with universal precautions, the skill of the HCW, the availability of special equipment such as blunt needles etc.

Patient-to-patient transmission through haemodialysis equipment, via multi-dose vials, or from re-used needles sadly still occurs and is often a result of inadequate training in infection control procedures or of staff simply ignoring the rules. Some outpatient settings have also been involved in outbreaks, raising questions about access to essential basic training for workers.

Risk evaluation

Information about the way different individual establishments and also central authorities deal with the training in procedures and of maintaining standards is lacking. The way the staff themselves view the problem of blood-borne infections is also difficult to assess, although the fact that many sharps incidents are apparently not reported at the time they occur implies that the problem is not being taken seriously enough.

In case of infection, prompt evaluation and subsequent followup of the involved HCW is essential, especially with regard to post-exposure prophylaxis for HBV and HIV infection, and written protocols on this are strongly recommended.

Prevention

Although it is generally accepted that hepatitis B vaccination is an essential tool in reducing the number of HBV infections, coverage remains variable and frequently inadequate. Policies on vaccination need to be more fully discussed and guidelines established.

A recurring theme is clearly the preventability of transmission and this depends to a large extent on compliance with universal precautions. These need to be instilled into staff in such a way that they are used automatically and not in a haphazard manner. Regular reminders in the form of practical training sessions and not just written instructions may produce a more concrete response from HCWs. They need to be convinced that the cost of ignoring or forgetting to comply with a comparatively simple procedure may have devastating consequences.

Policies and guidelines

Policies on the employment of infected HCWs also vary, with some countries adhering to established guidelines and others lacking any formal structural guidance. The European Consensus Group [1] drew up guidelines recommending that HCWs with HBV DNA levels of 104 genome equivalents/ml should be restricted from performing exposure-prone procedures, a cut-off level that attempted to balance the risk of infection against the withdrawal of essential specialist staff. These guidelines also recommended that all healthcare workers be vaccinated against hepatitis B, apply standard precautions, and also know their hepatitis B and C status. No consensus was established on the restriction of HCWs with hepatitis C virus infection.

Nomenclature

The discussions consistently refer to healthcare workers, but this term may be inadequate if all those involved in healthcare, from doctors and nurses to maintenance and janitorial staff are to be considered. Healthcare personnel or health personnel may be more adequate terms for the broad group of workers potentially at risk from blood-borne infections.

Consensus of the meeting

The participants in the VHPB meeting reached the following consensus in addition to those points discussed by the European Consensus Group:

• Universal infection control precautions must be applied and there must be regular review of practice to ensure compliance with guidelines and recommendations. 
• Counselling must be made available for infected healthcare workers and patients.
• Immunisation of students and healthcare workers against hepatitis B should take place early on in their careers and immunologically bad responders need to be identified and given appropriate advice.
• Criteria for the restriction of practice for infected healthcare workers involved in exposure-prone procedures need to be defined. HBV-infected healthcare workers should be screened for HBeAg and monitored for viral load. The management of HCV-infected healthcare workers remains a problem requiring further discussion.
• Further consideration needs to be given to ethical and legal issues, including safeguarding privacy and confidentiality.
• There is a need for the assessment of risk and costs before decisions are taken with regard to establishing threshold values to determine immunity, or to grant or withdraw permission to work.
• Countries need to manage their own epidemiological situation, but the general consensus is that there should be universal immunisation against hepatitis B for specific age cohorts.
• The VHPB urges countries that do not yet have policies or guidelines on the restriction of working practices for blood-borne virus-infected healthcare personnel to review this situation as a matter of priority.

Reference

[1] Gunson RN, Shouval D, Roggendorf M, et al., on behalf of the European Consensus Group. Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in health care workers (HCWs): guidelines for prevention of transmission of HBV and HCV from HCW to patients. J Clin Virol 2003; 27:213-230.

Further information on this topic is available in the corresponding Viral Hepatitis Issue or  meeting web page.