Occupational exposure and HIV

Occupational exposure and HIV

If precautions are not followed healthcare workers may be at risk of HIV infection as a result of their work. The main cause of infection in occupational settings is exposure to HIV-infected blood via a percutaneous injury (i.e. from needles, instruments, bites which break the skin, etc.). The average risk for HIV transmission after such exposure to infected blood is low - about 3 per 1,000 injuries. Nevertheless, this is still understandably an area of considerable concern for many health care workers.¹²¹

Certain specific factors may mean a percutaneous injury carries a higher risk, for example:

• A deep injury
• A high viral load in the patient (which means they will be more infectious)
• Visible blood on the device that caused the injury
• Injury with a needle that had been placed in a source patient's artery or vein

If percutaneous exposure occurs then the site of exposure should be washed liberally with soap and water but without scrubbing. Bleeding should be encouraged by pressing gently around the site of the injury (but taking care not to press immediately on the injury site). It is best to do this under a running water tap.

"If intact skin is exposed to HIV infected blood then there is no risk of HIV transmission"

There are a small number of instances where HIV has been acquired through contact with non-intact skin or mucous membranes (i.e. splashes of infected blood in the eye). Research suggests that the risk of HIV infection after mucous membrane exposure is less than 1 in 1000.¹²² If mucocutaneous exposure occurs then the affected area should be washed thoroughly with soap and water. If the eye is affected, it should be irrigated thoroughly.

If intact skin is exposed to HIV infected blood then there is no risk of HIV transmission.¹²³

How many occupational infections have been reported?

Up until December 2006, health care workers in the USA reported 57 occupational HIV infections. Of these, 48 had percutaneous exposure; 5, mucocutaneous exposure; 2, both percutaneous and mucocutaneous exposure; and 2, an unknown route of exposure. In addition, 140 possible occupational transmissions have occurred among healthcare personnel. These are cases in which a worker is infected with HIV and has a history of occupational exposure, but did not have a test immediately before and after the possible exposure. As no other risk factors are reported, it is most likely that the infection has occurred as a result of that occupational exposure.¹²⁴

It should be noted that because of the voluntary nature of the reporting system, there might be some under-reporting of cases. In addition, the U.S. Centers for Disease Control and Prevention emphasise that over 90 percent of health care workers infected with HIV also have non-occupational risk factors for acquiring their infection. ¹²⁵

In the UK, as of November 2008, the Health Protection Agency (HPA) has reported that there have been five documented cases of HIV infection after occupational exposure in the healthcare setting, the last being in 1999. ¹²⁶

What are Universal Precautions?

Universal precautions protect healthcare workers, patients and the environment.

In a healthcare setting workers should take precautions with everybody to eliminate the need to make assumptions about people's lifestyles and how much of a risk they present. Health care workers should have the right to be able to protect themselves against infection, whether it is HIV, Hepatitis or other TTIs.

The following universal infection control precautions are advised by the World Health Organization¹²⁷ to help protect health care workers from blood-borne infections including HIV:

• Hand washing after direct contact with patients.
• Use of protective barriers such as gloves, gowns aprons, masks, goggles for direct contact with blood and other body fluids.
• Safe collection and disposal of needles and sharps, with required puncture- and liquid- proof boxes in each patient care area.
• Preventing two-handed recapping of needles.
• Covering all cuts and abrasions with a waterproof dressing.
• Promptly and carefully cleaning up spills of blood and other body fluids.
• Using a safe system for health care waste management and disposal.

Appropriate waste disposal is essential to prevent used and potentially contaminated medical equipment being recycled. However, this is reliant on the necessary disposal facilities being in place. ¹²⁸ The use of sharps boxes for used needles prevents health workers from injuring themselves or re-using them. It also protects members of the public from exposure to needles, which can easily occur if medical waste is disposed of alongside normal refuse.

Post-exposure Prophylaxis

Research has shown that the use of antiretroviral drugs if given soon after an injury may reduce the risk of transmission. Such treatment is referred to as Post-exposure Prophylaxis (PEP). PEP is recommended for health care workers if they have had a significant occupational exposure to blood or another high-risk body fluid that is likely to be infected with HIV.¹²⁹

Although exposure through needlestick injuries can usually be avoided by following good working practices, health care workers should consider the implications of taking PEP. This will help them to make a swift decision in the event of an accident where an injury occurs.