Achieving balance

Sir, we have read with interest the item Written off (BDJ 2006; 201: 497). The article makes a useful contribution to the international debate on healthcare workers infected with blood-borne viruses and highlights the particular difficulties for dentists because they have less scope for redeployment or re-training than other healthcare workers. We would like to comment on some of the assertions made, particularly in relation to the role of the United Kingdom Advisory Panel for Healthcare Workers Infected with Blood-borne Viruses (UKAP).

The Department of Health's policy on healthcare workers infected with HIV is based on the advice of its Expert Advisory Group on AIDS (EAGA). UKAP is a formally constituted body which meets regularly and is responsible for providing advice to healthcare workers and those looking after them on how to implement the Department of Health policy. It also keeps under review the literature on transmission of HIV (and other blood-borne viruses) in the healthcare setting, together with its own data derived from UK patient notification exercises (PNEs), feeding back advice to EAGA on the need to revise guidelines as necessary. It is recognised that the apparent risk of transmission of HIV from healthcare workers to patients is very low but real, as there have been three reported incidents world-wide of healthcare worker-to-patient transmissions associated with exposure prone procedures (EPPs). There is ongoing interaction between EAGA and UKAP regarding the current precautionary but restrictive policy on HIV-infected healthcare workers undertaking any level of EPP.

The definition of EPPs is clearly central to the issues discussed in this article. The EPP categorisation of medical and surgical procedures across specialties is a large ongoing piece of work that is being undertaken by UKAP. Dental procedures were among the first to be categorised, and the British Dental Association played a significant role in that process during 2002. The exercise identified that no Category 3 EPPs are undertaken in routine primary care dentistry. (EPPs and their categorisation according to risk of transmission are defined in the NHS guidance.¹)

Reference is made in the article to the undertaking of PNEs by primary care trusts. A PNE is always undertaken if the index case is a probable case of transmission from the infected healthcare worker to the patient. However, the earlier policy of automatically triggering a PNE when a healthcare worker was found to be HIV infected was significantly modified in November 2001, following a joint review by EAGA and UKAP, and the amended policy is now incorporated in the NHS guidance published in July 2005. Thus, PNEs are no longer recommended routinely for patients who have undergone EPPs exclusively in Categories 1 or 2. This covers all treatment carried out in primary care dentistry. Therefore, very few PNEs are now performed in relation to HIV-infected dentists. As a result of work led by UKAP, a similar policy has been agreed by the Advisory Group on Hepatitis (AGH) in relation to hepatitis C virus infected healthcare workers. However, a PNE may be recommended if there is evidence of physical or mental impairment as a result of symptomatic HIV disease, other relevant medical conditions eg certain skin diseases, or if there is evidence of deficient clinical practice, particularly poor infection control. In relation to the latter, it is accepted that recommended standards of cross infection control for the dental profession have been strengthened significantly since HIV was first described. However, these standards are not universally implemented and it is notable that some of the more recent PNEs recommended by UKAP have been triggered by evidence of poor infection control procedures in the practice, in addition to the infected status of the practitioner.

The paper implies that antiretroviral therapy-induced suppression of the viral load in patients with HIV is the same as suppression of hepatitis B virus (HBV) in those who undergo successful antiviral treatment. This is not the case. Current policy dictates that HBV-infected healthcare workers can only return to work either after successful treatment, with a viral load that does not exceed 10³ genome equivalents per ml one year after cessation of treatment, or where there is evidence that without treatment the healthcare worker has a viral load below the 10³ copies cut-off point. In relation to HIV, EAGA has already considered whether infected healthcare workers can perform EPPs if their viral load becomes undetectable on treatment. Undetectable does not equate to non-infectious. EAGA also noted that, without very close monitoring, a missed dose could result in a transient increase in viral load. Following a precautionary principle, it was recommended that those whose viral load was suppressed on therapy should not be allowed to resume unrestricted practice.

One further point requires clarification. The USA does not currently have a national policy on the management of infected healthcare workers similar to that operational in the UK. This may partly explain the observation that there have not been cases of transmission of HIV from dentist to patient other than the Florida dentist. One also cannot exclude the possibility of other transmissions having gone undetected both in the USA and elsewhere.

Finally, the article identifies correctly that there is no international consensus on the performance of EPPs by healthcare workers infected with blood-borne viruses. This reflects the complex medical, ethical and legal factors that impinge on the decision-making. The UK operates a precautionary policy in comparison with countries such as the USA, but has also put in place rigorous surveillance and reporting procedures which are continually adding to the evidence base. The USA does not currently have a national policy on the management of infected healthcare workers similar to that operational in the UK. If there is no formal surveillance, then cases of transmission, even if they occur, will not be identified.

It should be noted that some infection control experts in the USA are now calling for a revised policy to replace that issued by the CDC in 1991,² and which would mirror more closely the procedures in the UK, to ensure that patients are afforded the same protection as healthcare workers from the risks of blood-borne virus infection.³ It may be that a convergence of the two approaches will be the way forward.

In the UK, the EAGA, AGH and UKAP are collaborating to refine policy according to emerging evidence, in a way that achieves an appropriate balance between allowing highly skilled healthcare workers to continue to contribute to the health service but at the same time providing protection for patients from serious blood-borne infections.