Management of an exposure incident
Management of significant exposure incidents will include some or all of the following:
- obtaining a blood sample from the recipient to be sent to the laboratory as a baseline sample for storage. This will only be tested, with informed consent, at a later date if subsequent follow-up tests of the recipient prove to be positive for a BBV infection;
- starting an accelerated course of hepatitis B vaccination, if not previously immunised or administering a booster dose if the recipient has previously been immunised;
- consideration of the need to administer an immediate dose of hepatitis B immunoglobulin;
- consideration of the need for immediate post-exposure HIV prophylaxis; and
- arrangement of suitable follow-up appointments for administration of further doses of HBV vaccine, monitoring of anti-retroviral therapy, and taking of appropriate blood samples for testing to confirm or exclude transmission arising from the incident.
- For an HBV-exposure incident, blood should be taken at 6 months, and tested for anti-HBs, anti-HBc or HBsAg, the precise testing regimen being dependent on the vaccination status of the recipient and the PEP administered at the time of the incident.
- For an HCV-exposure incident, blood should be taken at 6 weeks for HCV RNA testing, 12 weeks for anti-HCV and HCV RNA testing, and at 24 weeks for anti-HCV testing.
For an HIV-exposure incident, blood should be taken at 12 weeks and tested for anti-HIV.
The source individual
Where appropriate, the individual who is the source of the blood/body fluid should be approached, given an explanation of the incident and asked for informed consent for them to be tested for HIV, HBV and HCV, where the status is not already known. Such information will clearly impact on any decisions taken with regard to the management of the recipient. This universal approach to source testing for BBV normalises the procedure and avoids perceived discrimination (EAGA HIV PEP Guidelines 2008).
BBV - Specific interventions
For each of the three main blood-borne viruses, there are possible post-exposure interventions and management strategies designed to minimise the chances of the exposed worker acquiring a blood-borne virus, as a result of the exposure. In brief, these possibilities are as follows:
Hepatitis B Virus: consideration of passive immunisation (ie administration of preformed antibodies against HBV, derived from healthy blood donors) in the form of hepatitis B immunoglobulin (HBIg), and of active immunisation with hepatitis B vaccine, usually using an accelerated course (ie doses administered 0, 1, 2, and 12 months post-exposure).
Hepatitis C Virus: monitor the recipient for evidence of acquisition of infection with HCV over the 6 months following exposure (by testing for the presence of HCV RNA and/or antibodies to HCV in samples from the recipient taken at appropriate intervals after the incident). As soon as evidence of infection is detected, the recipient should be referred immediately to an appropriate specialist for consideration of antiviral therapy, as evidence shows that treatment at this stage is very successful.
Human Immunodeficiency Virus: following exposure to HIV administration of post-exposure prophylaxis (ie a regimen of 3 anti-HIV drugs taken for 4 weeks post exposure). The EAGA guidance provides detailed schedules recommended for HIV PEP.
The interventions above can only be instituted after careful risk assessment of the exposure incident by appropriately trained clinical personnel. Exposed individuals should seek immediate specialist post-exposure care at a recognised specialist centre. This phase of treatment or observation is most likely to be administered by a local accident and emergency department, or by other specialist personnel at the local hospital. For those working outside of the NHS, occupational health facilities and expertise may be accessible but will vary in different occupational settings. Whilst the primary responsibility for post exposure medical services lies with the NHS, it is recommended that all occupational health providers ensure that local arrangements are in place for risk assessment, advice and the provision of PEP, in particular to ensure that the correct BBV medical support is immediately available.