After stepping on a 20‑gauge needle at the beach, should I be tested for hepatitis B surface antigen, hepatitis C antibody, and HIV antibody/antigen?

Testing After Stepping on a Beach Needle

You should undergo baseline testing for HIV antibody/antigen, hepatitis B serology, and hepatitis C antibody, with follow-up testing at specified intervals over 6 months. 1, 2

Immediate First Aid (Already Completed)

• Wash the puncture site thoroughly with soap and water—do not squeeze or apply pressure to increase bleeding 3
• Report to a healthcare provider within 1 hour if possible, as timing is critical for post-exposure prophylaxis eligibility 3

Why Testing Is Recommended Despite Unknown Source

The CDC explicitly advises against testing discarded needles or syringes for virus contamination because results are unreliable. 1, 3 Since the source patient cannot be identified in your beach needle scenario, management must proceed based on the assumption of potential exposure to bloodborne pathogens. 4, 1

Baseline Testing (Perform Immediately)

You should undergo the following baseline tests before any prophylaxis is started:

• HIV antibody or antigen/antibody combination test 1, 2
• Hepatitis B serology: HBsAg (surface antigen), anti-HBs (surface antibody), and anti-HBc (core antibody) 1, 3
• Hepatitis C antibody (anti-HCV) 1, 2
• Alanine aminotransferase (ALT) for liver function 4, 1
• Document your hepatitis B vaccination history and prior vaccine response 4, 1

Post-Exposure Prophylaxis Considerations

Hepatitis B

• If you are unvaccinated or incompletely vaccinated against hepatitis B, you should receive hepatitis B immune globulin (HBIG) 0.06 mL/kg intramuscularly as soon as possible (ideally within 24 hours) and begin the hepatitis B vaccine series simultaneously. 4, 2, 3
• If you were previously vaccinated and have documented immunity (anti-HBs positive), no treatment is necessary 4, 2

HIV

• HIV post-exposure prophylaxis (PEP) should be considered for unknown-source needlestick injuries, particularly if the needle was visibly contaminated with blood or found in a high-risk setting. 4, 3 The decision to start PEP must be made within 72 hours, as effectiveness drops dramatically after this window 3
• The basic regimen consists of Zidovudine (ZDV) 600 mg/day in 2-3 divided doses plus Lamivudine (3TC) 150 mg twice daily for 28 days 4, 2
• If PEP is started, you should be evaluated within 72 hours and monitored for drug toxicity every 2 weeks 4, 2

Hepatitis C

• No post-exposure prophylaxis exists for hepatitis C—early identification through testing is the primary approach. 4, 2, 3

Follow-Up Testing Schedule

HIV Testing

• Perform HIV antibody testing at baseline, 6 weeks, 3 months, and 6 months post-exposure 4, 1
• Additional testing if you develop symptoms compatible with acute retroviral syndrome (fever, rash, lymphadenopathy) 4, 1

Hepatitis C Testing

• Baseline anti-HCV and ALT, then repeat at 4-6 months post-exposure 4, 1
• If earlier diagnosis is desired, HCV RNA testing can be performed at 4-6 weeks 4, 1, 2
• Confirm any repeatedly reactive anti-HCV enzyme immunoassay with supplemental testing 4, 1

Hepatitis B Testing

• If you receive hepatitis B vaccine after this exposure, test for anti-HBs 1-2 months after the final vaccine dose to confirm protective immunity 4, 1, 2
• Note that anti-HBs response cannot be accurately determined if HBIG was received in the previous 3-4 months 4, 1

Understanding Your Risk

The actual transmission risk from a beach needle is likely lower than occupational healthcare exposures because:

• The risk of HIV transmission after percutaneous exposure to HIV-infected blood is approximately 0.3% 4
• The risk of hepatitis C transmission averages 1.8% (range 0-7%) per percutaneous exposure to infected blood 1
• The risk of hepatitis B transmission may exceed 30% without prophylaxis if exposed to HBeAg-positive blood 1

However, these risks assume fresh blood from a known infected source. Environmental exposure on a beach likely reduces viral viability, though this cannot be quantified reliably. 3

Precautions During Follow-Up Period

• Use barrier protection during sexual activity for 6 months 3
• Do not donate blood, plasma, organs, tissue, or semen during the follow-up period 3
• Seek medical evaluation immediately if you develop any acute illness during follow-up, including fever, rash, fatigue, or jaundice 4, 1

Common Pitfalls to Avoid

• Delaying baseline testing—this should be done immediately to establish your pre-exposure status 1, 3
• Failing to complete the full 6-month follow-up testing schedule, particularly for HIV 4, 1
• If HIV PEP is started, stopping the medication early eliminates protection—the full 28-day course must be completed 3
• Assuming no risk because the source is unknown—proceed with testing as if exposure occurred 4, 1