Needlestick and Sharps Injury

A needlestick or sharps injury is a contaminated needle, blade, wire, drill bit or bone fragment piercing the skin of a member of the surgical team. It is one of the most common occupational hazards in surgery and a favourite exam topic because it links microbiology (which viruses), risk assessment (how likely is transmission) and practical management (what you actually do at 2am when you are stuck).

Why it matters. A single percutaneous injury can transmit hepatitis B virus, hepatitis C virus or HIV from an infected source patient into the injured worker. The chance of transmission from any one injury is generally low, but it is not zero, and it depends on how the injury happened and on who the source was.

Why orthopaedics. We routinely handle sharp Kirschner wires, drill bits, oscillating saws, sharp-tipped suture needles and jagged bone ends, often with reduced tactile feedback through gloves and in awkward positions, so we have more sharps exposures than many other fields. The whole topic reduces to two threads the examiner will test: prevent the injury, and respond correctly when it happens.

Three blood-borne viruses dominate the risk assessment after a sharps injury, and the order of transmission risk per injury is the single most testable fact: hepatitis B is the most transmissible, then hepatitis C, then HIV is the least transmissible per stick.

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Why the risk varies so much between viruses. It comes down to how much circulating virus there usually is and how the body defends against it. Hepatitis B is present in very high concentrations in infected blood and is highly infectious, which is why an unprotected worker is at greatest risk, and why vaccination, which gives most people lasting protection, is so powerful. HIV circulates at far lower levels and is less hardy, so the average per-injury risk is low, but because untreated infection is so serious we still act urgently with drug prophylaxis.

What makes a single injury more dangerous. Not every stick carries the same risk. These factors come straight from the landmark case-control work on HIV transmission and are used everywhere to decide whether the exposure is "significant" and whether PEP is offered. Transmission is more likely with:

• A deeper injury (more inoculum transferred)
• A hollow, blood-filled needle rather than a solid suture needle
• Visible blood on the device
• A needle that had just been in the source patient's artery or vein
• A source with advanced disease or a high viral load

Alongside those five, single gloving and a longer contact time both mean more blood is transferred, so an ungloved, deep, bloody stick from a hollow needle that had been in a vessel, in an ill source, is the high-transmission injury.

This is the most heavily tested practical sequence, and it is answered in a fixed order: first aid, report, risk-assess the source and the injury, then treat and follow up.

First aid. For a skin injury, encourage the wound to bleed gently and wash it with soap under running water. Do not suck it, scrub it or apply caustic agents; there is no evidence these help and they may worsen tissue damage. For a splash to the eye, mouth or nose, irrigate generously with water or saline, remove contact lenses and irrigate again.

Stop and report. Step away from the field safely, a colleague taking over if you are scrubbed, and report promptly to occupational health or the emergency department per local policy. Prompt reporting is what unlocks timely risk assessment and PEP.

Assess the source and the injury. Establish the source patient's blood-borne virus status, seeking consent for testing if it is unknown, and grade the injury against the factors above. Together these decide whether the exposure is significant.

Treat and follow up. Offer HIV PEP if indicated, manage hepatitis B according to the worker's vaccination status and the source, take baseline bloods from the worker and arrange follow-up testing. There is no PEP for hepatitis C.

Managing each virus

Hepatitis B. Management depends on the worker's vaccination and immune status. A documented vaccine responder is well protected and may need only a check or a booster; a non-responder or unvaccinated worker exposed to a hepatitis B source may need hepatitis B immunoglobulin plus an accelerated vaccine course.

Hepatitis C. There is no vaccine and no post-exposure drug prophylaxis, so management is baseline testing and then follow-up testing. If the worker seroconverts, modern direct-acting antivirals are highly effective, which is why the emphasis is on detection and early treatment.

HIV. A significant exposure from a positive or high-risk source gets a 4-week (28-day) course of combination antiretroviral PEP, started as early as possible, with counselling that PEP reduces but does not eliminate the risk, and with follow-up HIV testing. The regimen is typically a two-drug nucleoside backbone (tenofovir disoproxil plus emtricitabine) with a third agent, the modern preference being an integrase inhibitor (raltegravir or dolutegravir) for tolerability and few interactions.

Baseline and follow-up testing. Before starting, take baseline HIV (a fourth-generation antigen/antibody test), hepatitis B and C, plus renal and liver function and a pregnancy test. Follow-up HIV testing runs to around 12 weeks after exposure, the shorter window the fourth-generation tests allow, with hepatitis C antibody/RNA follow-up; counsel on barrier precautions and not donating blood during the follow-up period.

The exposure route. The average per-exposure HIV risk falls with the route: percutaneous (around 0.3%) is higher than a mucous-membrane splash (around 0.09%), which is higher than non-intact skin, and intact skin carries no meaningful risk.

Source unknown or untraceable. Make an individual risk assessment from the clinical setting and local prevalence rather than reflexively giving or withholding PEP.

Prevention is the part examiners reward most, because the best management of a needlestick is never to have one. The measures stack: no single step is perfect, but together they substantially cut exposures.

Double gloving. The single most reliable measure, and strongly advised in orthopaedics. Two glove layers dramatically reduce the rate at which the inner glove, and therefore the skin, is breached, and a coloured indicator under-glove makes a perforation immediately visible so the gloves can be changed.

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Blunt suture needles. Blunt-tipped needles pass through fascia and muscle but are far less likely to puncture skin, and they markedly reduce sharps injuries during closure of the deep layers where a sharp tip is not needed.

No-touch, hands-free technique. Sharps are never passed hand to hand. A neutral zone, a kidney dish or a designated tray, receives the instrument; the person using it picks it up and puts it back, so no two people hold it at once.

Safe disposal and no resheathing. Sharps go immediately into a puncture-proof container kept close to the point of use. Never resheath a needle by hand and never overfill the container; both are classic causes of injury.

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Vaccination. Hepatitis B vaccination of all staff, with confirmation of an antibody response, converts the most transmissible virus into a largely preventable one and is the strongest single argument for a vaccinated workforce.

A blame-free reporting culture and training. Underreporting of sticks is common among surgeons. A clear, fast, non-judgemental reporting pathway is what makes timely risk assessment and PEP actually happen.

Needlestick injury sits at the meeting point of personal safety, patient care and medico-legal responsibility, which is why it appears so often in basic-science and clinical vivas. Every orthopaedic surgeon will be exposed at some point, so the examiner expects you to be calm and systematic, to understand the risk in proportion, and to show professionalism: do you protect your team, and do you report honestly so the system can protect you?

The other direction: the infected surgeon and exposure-prone procedures. The professional duties are to know your status, not to self-diagnose or self-treat, and to disclose to occupational health. Whether an infected worker may perform exposure-prone procedures (EPPs) depends on the virus:

• Hepatitis B - an e-antigen-positive worker must not perform EPPs; an e-antigen-negative worker may, provided the HBV DNA viral load stays below a set threshold (around 200 IU/mL, or maintained low on antiviral treatment with monitoring)
• Hepatitis C - an HCV-RNA-positive worker must not perform EPPs until successfully treated and RNA-negative (cured), after which they may return
• HIV - historically barred, but modern guidance permits EPPs if the worker is on effective antiretroviral therapy with an undetectable plasma viral load (below about 200 copies/mL) and is regularly monitored by occupational health

• A consistent global message runs through occupational-health guidance (for example US CDC/US Public Health Service guidance, UK guidance from UKHSA/Public Health bodies and the Royal College of Surgeons, and WHO occupational-safety standards): treat every sharps injury as a potential blood-borne virus exposure, give immediate first aid, report promptly, risk-assess the source, and offer time-critical HIV PEP for significant exposures.
• Hepatitis B vaccination of all healthcare workers with confirmation of an antibody response is recommended worldwide and is the cornerstone of protecting against the most transmissible of the three viruses.
• Engineering and practice controls are emphasised everywhere: double gloving (with an indicator glove), blunt suture needles, safety-engineered devices, hands-free transfer/neutral zones, and puncture-proof sharps containers with no resheathing.
• Underreporting is a recognised global problem, especially among surgeons. Guidance stresses a fast, blame-free reporting pathway, because timely reporting is what makes risk assessment and prophylaxis possible.
• Practice varies by setting: source HIV testing, PEP drug availability, and hepatitis B immunoglobulin access differ between high- and low-resource environments, but the assess-and-act framework is the same everywhere.

The evidence base is built on a small number of influential studies: a case-control study that defined HIV transmission risk and the value of prophylaxis, and randomised trials showing that extra glove layers protect the surgeon.