Occupational exposure: needlestick and splash

6 DOH Abu Dhabi (HAAD) lab licensing practice questions on Occupational exposure: needlestick and splash, part of General Laboratory, Quality and Safety. The first 6 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

1. Question 1 · Easy

   Blood sprays into a technologist's mouth when the cap of a tube pops off. The correct first aid is to:

   1. AGargle with an alcohol-based mouthwash
   2. BRinse the mouth with diluted bleach
   3. CSwallow it and then drink plenty of milk
   4. DSpit it out and rinse the mouth well with water

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   Answer: D · Spit it out and rinse the mouth well with water

   Exposed mucous membranes of the mouth, nose or eyes are flushed at once with plenty of clean water or saline. Antiseptics, alcohol and bleach are not used on mucous membranes, because they irritate and damage the tissue and add no proven protection. The exposure is then reported immediately, so that the risk can be assessed and the source patient tested while post-exposure prophylaxis can still help. The incident is also recorded for occupational health follow-up.

   • A: Alcohol irritates mucous membranes and is not recommended for exposure first aid.
   • B: Bleach damages the lining of the mouth and must never be used on mucous membranes.
   • C: Swallowing does not remove the blood, and milk has no protective effect.

2. Question 2 · Hard

   Four incidents are reported on one shift, and the source patients' HIV status is unknown. Which one should be referred at once for HIV post-exposure prophylaxis assessment?

   1. AClear urine splashed into an eye
   2. BA prick from a clean, unused lancet
   3. CBlood spilled on intact forearm skin
   4. DPleural fluid splashed into an eye

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   Answer: D · Pleural fluid splashed into an eye

   A significant exposure needs both a potentially infectious material and a route of entry: a percutaneous injury, a mucous membrane or non-intact skin. Pleural fluid is treated as potentially infectious, like blood, CSF, synovial, peritoneal, pericardial and amniotic fluid, semen and vaginal secretions, and the eye is a mucous membrane. Urine, feces, saliva and vomit carry negligible HIV risk unless visibly bloody, and intact skin is an effective barrier. All four incidents are still reported and recorded, but only the pleural fluid splash needs urgent assessment for PEP.

   • A: Urine without visible blood is not considered infectious for HIV.
   • B: An unused lancet carries no patient material, so there is no exposure.
   • C: Intact skin is an effective barrier, so the area is simply washed.

3. Question 3 · Easy

   After a needlestick from an infected source patient, which virus carries the highest risk of transmission to a worker who is not immune?

   1. AHuman T-lymphotropic virus 1
   2. BHepatitis C virus
   3. CHepatitis B virus
   4. DHIV

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   Answer: C · Hepatitis B virus

   After a percutaneous exposure, the risk of infection is roughly 6-30% for hepatitis B, depending mainly on whether the source is HBeAg positive. The risk is about 0.2-2% for hepatitis C and about 0.3% for HIV. Hepatitis B virus is present in very high amounts in blood and can survive in dried blood on surfaces for up to a week. This is why every laboratory worker should be vaccinated against hepatitis B and have anti-HBs checked after the series.

   • A: HTLV-1 spreads mainly by breastfeeding, sex and cellular blood components; needlestick cases are rare.
   • B: Hepatitis C transmission after a needlestick is uncommon, about 0.2-2%.
   • D: HIV transmission after a needlestick is about 0.3%.

4. Question 4 · Medium

   The source patient of a technologist's needlestick has hepatitis C, with HCV RNA detected. Under CDC guidance, how is the technologist managed for hepatitis C?

   1. ADirect-acting antivirals started within 72 hours
   2. BHepatitis C immune globulin given the same day
   3. CA course of hepatitis C vaccine started at once
   4. DNo prophylaxis; follow-up HCV RNA and antibody tests

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   Answer: D · No prophylaxis; follow-up HCV RNA and antibody tests

   There is no vaccine or immune globulin for hepatitis C, and CDC does not recommend antiviral drugs as post-exposure prophylaxis. Instead, the worker has baseline anti-HCV testing, HCV RNA testing at 3-6 weeks and a final anti-HCV test at 4-6 months. HCV RNA appears within a few weeks of infection, well before antibody, so early infection is found quickly. If infection is confirmed, it is treated with direct-acting antivirals, which cure most patients.

   • A: CDC does not recommend antivirals as prophylaxis; they are used to treat confirmed infection.
   • B: No hepatitis C immune globulin exists.
   • C: No hepatitis C vaccine is available.

5. Question 5 · Medium

   A phlebotomist has a needlestick from an HBsAg-positive patient. She completed hepatitis B vaccination two years ago, and her anti-HBs one month after the last dose was 85 mIU/mL. What hepatitis B prophylaxis does she need?

   1. AHepatitis B immune globulin alone
   2. BNone, as she is a documented responder
   3. CImmune globulin and a vaccine booster
   4. DA single vaccine booster dose

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   Answer: B · None, as she is a documented responder

   Under CDC guidance, a worker with anti-HBs of at least 10 mIU/mL after a complete vaccine series is protected for the long term, even if antibody levels later fall, because immune memory remains. She needs no immune globulin, no booster and no hepatitis B testing after this exposure. A known non-responder would instead need hepatitis B immune globulin, and a worker whose response is unknown is tested for anti-HBs first. She is still assessed and followed up for HIV and hepatitis C.

   • A: Immune globulin is for workers who are not protected, such as non-responders.
   • C: Neither immune globulin nor a booster adds protection for a documented responder.
   • D: A booster is not needed after a documented response to a full series.

6. Question 6 · Medium

   What should a technologist do first after a needle-stick injury with a used needle?

   1. AIgnore it if there is no visible bleeding
   2. BFinish the shift first, then report it
   3. CSqueeze the wound hard and pour bleach on it
   4. DWash with soap and water, then report it at once

   Answer and explanation in LearnFree account