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757 Laboratory Safety
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The Standard

The Centers for Disease Control and Prevention (CDC) notes that although more than 200 different diseases can be transmitted from exposure to blood, the most serious infections are:

  • hepatitis B virus (HBV)
  • hepatitis C virus (HCV)
  • human immunodeficiency virus (HIV)

Fortunately, the risk of acquiring any of these infections is low. HBV is the most infectious virus of the three viruses listed above. For an unvaccinated healthcare worker, the risk of developing an infection from a single needlestick or a cut exposed to HBV-infected blood ranges from 6-30%. The risk for infection from HCV- and HIV-infected blood under the same circumstances is 1.8 and 0.3 percent, respectively.

Many factors influence the risk of becoming infected after a needlestick or cut exposure to HBV-, HCV- or HIV-contaminated blood. These factors include:

  • the health status of the individual
  • the volume of the blood exchanged
  • the concentration of the virus in the blood
  • the extent of the cut or the depth of penetration of the needlestick

Knowledge Check Choose the best answer for the question.

6-2. Which of the viruses below is most infectious for an unvaccinated healthcare worker?