The trusted source for
healthcare information and
Risk drops of HIV from needlesticks
No new occupational cases since 1999
The risk of acquiring HIV infection from occupational exposures may be even lower than the three in 1,000 rate that is commonly cited. No new documented cases of occupationally acquired HIV have occurred among health care workers since 1999, according to the Centers for Disease Control and Prevention (CDC).
The use of post-exposure prophylaxis (PEP), safer needle devices, and treatments that lower the viral load of HIV patients all may play a part in the reduction in seroconversions, says Ronald H. Goldschmidt, MD, director of the family practice inpatient service at San Francisco General Hospital and director of the National Clinicians’ Post-Exposure Prophylaxis Hotline (PEPline). "There clearly is a risk. But the risk does appear to be less as long as all of those things are in place," he says.
Since 1985, 57 health care workers have had documented cases of occupationally acquired HIV infection. Most of the cases occurred in the 1980s and early 1990s. Another 138 health care workers had possible cases of occupationally acquired HIV.
"Even though we don’t have denominator data [of how many health care workers had HIV-positive blood exposures], I think it’s still reassuring that numbers of cases are small, taking into account underreporting," says Adelisa Panlilio, MD, MPH, medical epidemiologist with CDC’s Division of Healthcare Quality Promotion.
"These are fortunately relatively rare events. The way to keep them rare is to be really vigilant, particularly with handling of sharps, and to have prompt reporting so that if post-exposure prophylaxis is warranted it is initiated promptly," she says.
An analysis of the documented cases provides insight into the risk from needlesticks and other exposures. For example, eight of the 57 documented cases occurred despite the use of PEP. (In one of those eight, the health care worker received only one dose of zidovudine and then refused further treatment.)1 The other health care workers did not receive the multidrug therapies that are currently recommended and may be more effective, Goldschmidt notes.
Nonetheless, PEP is not foolproof, and health care workers who receive it still may become infected, he says. CDC research indicates that zidovudine alone reduces the risk of infection from occupational exposure by about 81%.2
The magnitude of the exposure also appears to play a role. Forty-five of 51 percutaneous exposures (88%) involved hollow-bore needles.
Twenty-nine of 47 health care workers with percutaneous exposure reported that blood was visible on the needle at the time of injury. Most of the injuries occurred after a procedure (41%) or during "unexpected circumstances" such as the sudden movement of the patient (20%).
"We don’t think all exposures pose the same risk," Panlilio adds. "Some are of lesser severity than others."
Yet even seemingly minor exposures can lead to serious consequences. Eight health care workers acquired HIV from mucocutaneous exposures, including contact with a patient’s blood on chapped hands. One had a splatter from a blood collection tube in the face and mouth.
Those cases underscore the importance of glove use and of wearing face shields when performing a procedure that could result in a splash of body fluids, he says.
Of the 57 infected health care workers, 24 (42%) are nurses and 16 (28%) are lab technicians. Seventy-nine percent of them are women. Almost half (46%) have developed AIDS.
Post-exposure treatment has become more complex with the advent of new retroviral therapies. If an exposure occurs, Panlilio recommends contacting a local HIV expert or the PEPline. "We would strongly recommend that you get expert consultation," she says. "When you’re dealing with concerns about resistance [to antiretroviral therapies], selection of the regimen may not be one of the standard drug regimens."
[Editor’s note: For more information on PEP, contact the PEPline at (888) 448-4911, or visit the web site of the National Clinicians’ Consultation Center at www.ucsf.edu/hivcntr.]
1. Do AN, Ciesielski CA, Metler RP, et al. Occupationally acquired human immunodeficiency virus (HIV) infection: National case surveillance data during 20 years of the HIV epidemic in the United States. Infect Control Hosp Epidemiol 2003; 24:86-96.
2. Cardo DM, Culver DH, Ciesielski CA, et al. A case-control study of HIV seroconversion in health care workers after percutaneous exposure. N Engl J Med 1997; 337:1,485-1,490.