Medical Center

Skip to content. | Skip to navigation

Personal tools

Site Logins
Home > International Healthcare Worker Safety Center > estimates.html


Risk of Infection Following a Single HIV, HBV, or HCV-Contaminated Needlestick or Sharp Instrument Injury


(revised 5/09/01)


HIV 0.25% - 0.4%

HBV 6% - 30%

HCV 0.4% - 1.8%

The CDC estimates that 400 new occupational HBV infections occurred in 1995 among U.S. health care workers, down from 17,000 in 1983. (Arch Intern Med 1997;157:2601-2603)

Assuming that between 1% and 2% of patients are HIV-positive (and therefore that 1% to 2% of needlesticks are HIV-contaminated) between 18 to 35 new occupational HIV infections would occur from percutaneous injuries each year. Infections resulting from blood exposures to non-intact skin or mucuous membranes would add between 2 to 4 cases (based on a transmission rate of .09% for a mucous membrane exposure).

Assuming that between 2% and 10% of patients are HCV-positive (Dr. Richard Garvin, Hepatitis Branch, CDC), between 59 to 1,180 new occupational HCV infections would occur each year. Infections resulting from blood exposures to non-intact skin or mucous membranes would add between 16 to 393 cases (assuming that the transmission rate was between 0.4% and 1.8% per exposure, with lower limit from Dr. Giuseppe Ippolito, Italy, 1999).

The consequences of occupational exposure to bloodborne pathogens are not only infections. Each year, thousands of health care workers are affected by psychological trauma during months of waiting for notification of serological results. Other personal consequences can include postponement of childbearing, altering sexual practices, side effects of prophylactic drugs, infection, chronic disabilities, loss of employment, denial of worker compensation claims, liver transplant, and premature death.

Annual Number of Occupational Percutaneous Injuries and Mucocutaneous Exposures to Blood or Potentially Infective Biological Substances


(revised 6/15/98)

The following figures were calculated based on 1996 EPINet data. We do not know to what degree new HIV treatments have affected health care worker risk of HIV infection. They have probably reduced the risk somewhat since there are now fewer AIDS patients in hospitals.

We estimated percutaneous injuries and blood and body fluid exposures in one year, based on:

  • 30 injuries per 100 occupied hospital beds reported (from our national EPINet data for 1996)

  • 600,000 occupied hospital beds in the U.S.

  • 180,000 injuries in one year reported in hospitals (.3 x 600,000)

  • 39% of incidents not reported (according to surveys conducted in 6 EPINet hospitals in 1996-1997) = 295,082 injuries occurred in hospitals

  • double this figure because 50% of health care workers work outside of hospital settings (total = 590,164 percutaneous injuries)

  • according to EPINet data for 1996, an additional 1/3 of reported exposures (total = 196,721 mucocutaneous exposures) involve skin/non-intact skin or mucous membrane contact with blood or at-risk biological substances with can also transmit HIV, HBV, HCV


Total annual percutaneous and mucocutaneous exposures to blood or at-risk biological substances in the U.S. in 1996 = 786,885