MicrobiologyTier 2Medical Sciences concept

Bloodborne virus transmission risk after needlestick injury (HBV, HCV, HIV)

Core concept

Per-exposure risk from a percutaneous injury with a known positive source

Virus	Risk	Memory
Hepatitis B	~30% (up to 30-40% if source HBeAg-positive), ~1-6% if HBeAg-negative	"30, 3, 0.3"
Hepatitis C	~1.8-3%
HIV	~0.3% percutaneous, ~0.09% mucous membrane

Hepatitis B is by far the most transmissible - it survives on surfaces for days and needs a far smaller inoculum
Risk rises with: hollow-bore needle, visible blood on the device, deep injury, needle used in an artery or vein, high source viral load, terminal illness in the source
- An undetectable source HIV viral load makes transmission essentially negligible

Immediate steps

Wash with soap and water (irrigate mucosa/eyes with saline); do not squeeze or use bleach
Risk-assess the device, the fluid and the source; take source serology with consent (HBsAg, anti-HCV + HCV RNA, HIV Ag/Ab)
Baseline serology on the exposed person: HBsAg, anti-HBs, anti-HBc, anti-HCV, HIV
Do not delay PEP while awaiting source results

Hepatitis B - the answer depends on the exposed worker's anti-HBs

Exposed worker	Action
Documented anti-HBs >=10 mIU/mL ever (a known responder)	Nothing required - immune, whatever the source status
Vaccinated non-responder (anti-HBs <10 after 2 full courses)	HBIG within 72 h, and a second dose at 1 month
Unvaccinated or unknown status	HBIG (ideally within 72 h) + start the vaccine course
Vaccinated, response unknown	Urgent anti-HBs - if <10, give HBIG and a booster

Hepatitis C

No vaccine and no post-exposure prophylaxis
Monitor: HCV RNA at 3 and 6 weeks, anti-HCV at 3 and 6 months
If seroconversion occurs, direct-acting antiviral therapy cures >95% - which is why detection matters

HIV

PEP as soon as possible - ideally within 24 h, and not beyond 72 h; 28 days of a 3-drug regimen (tenofovir/emtricitabine + dolutegravir or raltegravir)
Follow-up HIV testing at 4-6 weeks and 3 months (12 weeks after finishing PEP)
Counsel on safe sex and no blood/tissue donation during follow-up

The single highest-yield preventive measure is documenting hepatitis B immunity in every healthcare worker before they start - it converts a complex 72-hour decision into "no action required"
Report every exposure - occupational health, incident form, and follow-up serology; under-reporting is the norm and removes the chance of PEP
Discarded community needlestick (a needle found in a public place) - no reported HIV transmission worldwide; assess and act for hepatitis B, and monitor for HCV
Prevention beats management: safety-engineered devices, never re-sheath a needle, sharps container at point of use, standard precautions for every patient
The source patient cannot be tested without consent; state law and hospital policy govern the process, and a refusal means treating the exposure as high-risk

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