Risk to healthcare workers
Contaminated sharps exposure in UK healthcare work is confirmed by Health Protection Agency (HPA) as the most common mode of occupational exposure to blood-borne viruses, though transmission rates remain low, as a proportion of reported incidents.
The overall risks of the three most common blood-borne viruses being transmitted by an infected patient to a healthcare worker (HCW) have been estimated, as shown in the table below. Hepatitis B is the most readily transmitted virus and human immunodeficiency virus (HIV) the least. Healthcare workers are at greater risk of infection from patients than vice-versa. The UK rates of transmission may appear to be higher than in other countries. This is probably as a result of the more active approach to surveillance and the identification of such cases taken in the UK.
Risk of transmission of blood-borne viruses from patient to healthcare worker
- Hepatitis B (HBV) - Up to 30%*
- Hepatitis C (HCV) - 1-3%
- HIV - 0.3%
Note: Risk of transmission above relates to percutaneous injury; data for HBV are based on exposure in unvaccinated individuals. The sharps causing these injuries are variable.
*There is a wide variability in infectiousness of hepatitis B carriers and this rate reflects transmission from Hepatitis B surface antigen positive source.
The risk of infection after mucocutaneous exposure is much lower. For HIV, the transmission risk after a single mucocutaneous exposure is probably less than one in thousand (0.1%).
Practitioners providing post-exposure care are asked to contribute to a voluntary confidential reporting system for significant occupational exposure incidents that involve HIV, HCV and HBV in the UK. At the time of preparation of this guidance, an HCV reporting system is not currently active in Scotland, although Health Protection Scotland does hold HCV diagnosis data for epidemiological purposes.
Further details may be obtained from the Health Protection Agency Centre for Infections for England, Wales and Northern Ireland, and Health Protection Scotland for Scotland. Mandatory reporting schemes exist for occupational exposures to blood-borne viruses, (HBV, HCV and HIV), reportable to the Health and Safety Executive.
Further information on incident reporting is given on this site.
There have been recorded cases where infected healthcare workers have transmitted BBVs to patients. Policies exist in the UK to prevent healthcare workers from performing procedures that put patients at risk of infection, and these policies have substantially reduced transmission in this setting. Guidance is available for both existing healthcare workers, and those new to the NHS.
The number of healthcare workers that have become infected with HIV as a result of workplace exposure is small, considering the frequency of exposure to blood and body fluids in clinical and laboratory work.
The greatest risk to healthcare workers of acquiring HIV is following a percutaneous injury involving a hollow needle that has been in the vein or artery of an HIV positive source patient, especially if that patient has late-stage disease and a high viral load.
The number of cases of acute hepatitis B reported in healthcare workers has declined in recent years, due to increased awareness of risk, adoption of safer working practices, and widespread immunisation. The Department of Health and Scottish Government recommends that all employers ensure that healthcare workers, including students, who have direct contact with blood, blood-stained body fluids, or patients' tissues, are offered hepatitis B immunisation, with post-immunisation testing of response. Those who receive a primary course of the vaccine should be tested for their immune status 1-4 months post-immunisation, to determine if they require further management (if they have not produced an adequately protective response).
More information about immunisation is available on this site.
Transmission of HCV through workplace exposure does occur, with the greatest risk of transmission from patients to healthcare workers being via needle stick injuries and other sharps exposures.
Serological surveys conducted to date show that HCV infection is detectable in healthcare workers but present evidence suggests that the prevalence is low and, in some countries, no higher than that found in the general populations.
Statistics for cases of seroconversions and mucocutaneous exposure in healthcare workers in the UK can be found in Health Protection Agency's Eye of the Needle report.
Newly employed healthcare workers
New healthcare workers who will perform exposure-prone procedures are required to demonstrate that they are non-infectious for HIV and hepatitis C, and at low risk of transmitting hepatitis B. These clearance checks must be completed before confirmation of an appointment to a post that will require performance of exposure prone procedures.
Further information on incident management is given on this site.