Needlestick Exposure: CDC Recommends Three-Drug Regimen

On June 7 the U.S. Centers for Disease Control and Prevention (CDC) published revised guidelines for antiviral treatment to reduce the risk of HIV transmission due to occupational exposure, such as needlestick injury with HIV-positive blood in a hospital or laboratory. The new guidelines are provisional, as little data is available.

Because the risk of transmission is low -- only about 3 HIV infections per one thousand percutaneous exposures to HIV-infected blood, and because the antiviral drugs can have side effects, treatment is not recommended in very low risk situations (such as exposure to urine or saliva from HIV-positive persons). When treatment is recommended, it should be started very rapidly, preferably within one to two hours of exposure. The treatment suggested is indinavir (Crixivan(R)) plus AZT plus 3TC for four weeks; however, this regimen should be changed in certain cases, such as with a patient likely to be intolerant to one of those drugs or who is taking incompatible medications.

The previous recommendation for occupational exposure to HIV called for treatment with AZT. A case-control study found that this use of AZT alone was associated with a 79% reduced risk of seroconversion. There is no human data on the effectiveness of combination treatment in preventing infection due to occupational exposure to HIV (since it takes a long time to get such data, because cases of seroconversion are rare). But all that is known suggests that combination treatment will probably be more effective than AZT alone.

The complete guidelines were published in the June 7 MMWR (MORTALITY AND MORBIDITY WEEKLY REPORT, of the CDC). According to this publication, updated information about prevention of infection due to occupational exposure to HIV will be available in early 1997 from the CDC's Internet home page (http://www.cdc.gov), and also by fax and telephone.