The estimated risk of HIV transmission from doctor to patient
during an invasive radiologic procedure is quite low, slightly
less than the risk during surgery, according to a study from the
University of Texas Southwestern Medical Center at Dallas.
An invasive radiologic procedure is any technique that involves
use of a needle or scalpel and some type of imaging guidance,
such as ultrasound, CT, or fluoroscopy, said Dr. Margaret Hansen,
of the university's Department of Radiology, who presented the
study's findings at the 95th Annual Meeting of the American Roentgen
Ray Society in Washington, D.C. Common invasive procedures include
arteriograms, angioplasty, and imaging-guided biopsies and drainages.
The risk of becoming infected with HIV after exposure to infected
blood is 1 in 250, according to previous studies. For a patient
to become infected with HIV during a radiologic procedure, the
radiologist must be infected and injured in a manner that causes
bleeding. Then the radiologist's blood must contact the patient
in a way that can transmit the virus. It is estimated that 0.4%
to 0.7% of the US population is HIV positive.
Injuries occur less often during radiologic procedures than during
surgery, according to studies by Dr. Hansen and others. A study
of five surgical specialties by the Centers for Disease Control
found the rate of recontact (reuse of a contaminated instrument)
during surgery to be 29%. The rate of recontact during an invasive
radiologic procedure is 0.2%, according to a survey of members
of the Society of Cardiovascular and Interventional Radiology
(SCVIR) conducted by Dr. Hansen.
The current study found that the estimated risk of HIV transmission
from doctor to patient during an invasive radiologic procedure
is only 0.03 per million procedures, if the radiologist's HIV
status is unknown. The estimated risk of transmission during surgery,
according to previous reports, is 0.01 to 0.9 per million procedures.
If the radiologist is known to be HIV-positive, the risk is 7.4
per million procedures. The estimated risk during during surgery
is 2.4 to 24 per million procedures, if the physician's HIV status
On average, an SCVIR member performs 665 invasive radiologic procedures
annually, and this number is rising. However, the estimated risk
of HIV transmission from physician to patient is so low that global
practice restrictions for interventional radiologists are not
warranted, said Dr. Hansen.
Occupational Safety and Health Administration regulations implemented
in 1992 make universal precautions, including the use of protective
clothing and equipment and prohibitions against recapping sharp
instruments, mandatory. "Despite the low risk of HIV transmission,
radiologists need to be vigilant about taking all necessary precautions
to enhance procedure safety for everyone," said Dr. Hansen.