A case-control study of HIV seroconversion in health care workers after percutaneous exposure. Centers for Disease Control and Prevention Needlestick Surveillance Group.

BACKGROUND: The average risk of human immunodeficiency virus (HIV) infection after percutaneous exposure to HIV-infected blood is 0.3 percent, but the factors that influence this risk are not well understood. METHODS: We conducted a case-control study of health care workers with occupational, percutaneous exposure to HIV-infected blood. The case patients were those who became seropositive after exposure to HIV, as reported by national surveillance systems in France, Italy, the United Kingdom, and the United States. The controls were health care workers in a prospective surveillance project who were exposed to HIV but did not seroconvert. RESULTS: Logistic-regression analysis based on 33 case patients and 665 controls showed that significant risk factors for seroconversion were deep injury (odds ratio= 15; 95 percent confidence interval, 6.0 to 41), injury with a device that was visibly contaminated with the source patient's blood (odds ratio= 6.2; 95 percent confidence interval, 2.2 to 21), a procedure involving a needle placed in the source patient's artery or vein (odds ratio=4.3; 95 percent confidence interval, 1.7 to 12), and exposure to a source patient who died of the acquired immunodeficiency syndrome within two months afterward (odds ratio=5.6; 95 percent confidence interval, 2.0 to 16). The case patients were significantly less likely than the controls to have taken zidovudine after the exposure (odds ratio=0.19; 95 percent confidence interval, 0.06 to 0.52). CONCLUSIONS: The risk of HIV infection after percutaneous exposure increases with a larger volume of blood and, probably, a higher titer of HIV in the source patient's blood. Postexposure prophylaxis with zidovudine appears to be protective.

Skin and mucous membrane contacts with blood during surgical procedures: risk and prevention.

OBJECTIVE: To study the epidemiology and preventability of blood contact with skin and mucous membranes during surgical procedures. DESIGN: Observers present at 1,382 surgical procedures recorded information about the procedure, the personnel present, and the contacts that occurred. SETTING: Four US teaching hospitals during 1990. PARTICIPANTS: Operating room personnel in five surgical specialties. MAIN OUTCOME MEASURES: Numbers and circumstances of contact between the patient's blood (or other infective fluids) and surgical personnel's mucous membranes (mucous membrane contacts) or skin (skin contacts, excluding percutaneous injuries). RESULTS: A total of 1,069 skin (including 620 hand, 258 body, and 172 face) and 32 mucous membrane (all affecting eyes) contacts were observed. Surgeons sustained most contacts (19% had > or = 1 skin contact and 0.5% had > or = 1 mucous membrane-eye contact). Hand contacts were 72% lower among surgeons who double gloved, and face contacts were prevented reliably by face shields. Mucous membrane-eye contacts were significantly less frequent in surgeons wearing eyeglasses and were absent in surgeons wearing goggles or face shields. Among surgeons, risk factors for skin contact depended on the area of contact: hand contacts were associated most closely with procedure duration (adjusted odds ratio [OR], 9.4; > or = 4 versus < 1 hour); body contacts (arms, legs, and torso) with estimated blood losses (adjusted OR, 8.4; > or = 1,000 versus < 100 mL); and face contacts, with orthopedic service (adjusted OR, 7.5 compared with general surgery). CONCLUSION: Skin and mucous membrane contacts are preventable by appropriate barrier precautions, yet occur commonly during surgery. Surgeons who perform procedures similar to those included in this study should strongly consider double gloving, changing gloves routinely during surgery, or both.

Percutaneous exposures to HIV-infected blood. Among dental workers enrolled in the CDC Needlestick Study.

The authors found that 19 percutaneous exposures among dental workers occurred both during and after use of instruments such as syringe needles and scalers. Specific information about the device and action associated with an exposure is important for prevention efforts, including safer instruments and work practices. Most of these exposures probably involved smaller, rather than larger, amounts of blood infected with the human immunodeficiency virus. To our knowledge, none of the exposures resulted in HIV transmission to an enrolled dental worker.

Occupational blood contact among prehospital providers.

STUDY OBJECTIVE: To assess the nature and frequency of blood contact (BC) among emergency medical service (EMS) workers. DESIGN: During an 8-month period, we interviewed EMS workers returning from emergency transport calls on a sample of shifts. We simultaneously conducted an HIV seroprevalence survey among EMS-transported patients at receiving hospitals served by these workers. SETTING: Three US cities with high AIDS incidence. PARTICIPANTS: EMS workers. RESULTS: During 165 shifts, 2,472 patients were attended. Sixty-two BCs (1 needlestick and 61 skin contacts) were reported. Individual EMS workers had a mean of 1.25 BCs, including .02 percutaneous exposures, per 100 patients attended. The estimated annual frequency of BC for an EMS worker at the study sites was 12.3, including .2 percutaneous exposures. For 93.5% of the BCs, the HIV serostatus of the source patients was unknown to the EMS worker. HIV seroprevalences among EMS-transported patients at the three receiving hospital emergency departments were 8.3, 7.7, and 4.1 per 100 patients; the highest rates were among male patients 15 to 44 years old who presented with pneumonia. CONCLUSION: EMS personnel regularly experience BCs, most of which are skin contacts. Because the HIV serostatus of the patient is usually unknown, EMS workers should practice universal precautions. Postexposure management should include a mechanism for voluntary HIV counseling and testing of the patient after transport and transmittal of the results to the EMS.

Surveillance of HIV infection and zidovudine use among health care workers after occupational exposure to HIV-infected blood. The CDC Cooperative Needlestick Surveillance Group.

OBJECTIVE: To study the risk for human immunodeficiency virus (HIV) infection and the patterns of use and associated toxicity of zidovudine among health care workers after an occupational exposure to HIV. DESIGN: An ongoing, prospective surveillance project conducted by the Centers for Disease Control and Prevention. PARTICIPANTS: Exposed workers voluntarily reported by 312 U.S. health care facilities from August 1983 to June 1992. RESULTS: Four of 1103 enrolled workers with percutaneous exposure to HIV-infected blood seroconverted (HIV seroconversion rate, 0.36%; upper limit of the 95% Cl, 0.83%); no enrolled workers with mucous membrane (n = 75) or skin (n = 67) contact seroconverted. During October 1988 to June 1992, 31% of 848 enrolled workers used zidovudine after exposure; this proportion increased from 5% during October through December 1988 to 43% during January through June 1992. Despite using zidovudine after exposure, one worker became infected with a strain of HIV that was apparently sensitive to zidovudine. Adverse symptoms, most commonly nausea, malaise or fatigue, and headache, were reported by 75% of workers using zidovudine; 31% of workers did not complete planned courses of zidovudine because of adverse events. CONCLUSIONS: The risk for HIV seroconversion after percutaneous exposure to HIV-infected blood is 0.36%, which is similar to previous estimates. Zidovudine is used after exposure by a sizable proportion of health care workers enrolled in the project despite frequent, minor, associated symptoms. Documented failures of postexposure zidovudine prophylaxis, including in one worker enrolled in this study, indicate that if zidovudine is protective, any protection afforded is not absolute. Postexposure zidovudine, if used, requires careful consideration of possible risks and benefits.

A survey of occupational blood contact and HIV infection among orthopedic surgeons. The American Academy of Orthopaedic Surgeons Serosurvey Study Committee.

OBJECTIVE: To study the seroprevalence of human immunodeficiency virus (HIV) among orthopedic surgeons, and correlate the results with occupational and nonoccupational risk factors. Orthopedic surgeons are one of several groups of health care workers at risk for occupationally acquired HIV infection; however, few HIV seroprevalence studies in health care workers, and none in surgeons, have been performed to assist in estimating the extent of occupational risk. DESIGN: A voluntary, anonymous HIV serosurvey at an annual meeting. To assess the representativeness of participants, a mail survey of orthopedic surgeons was conducted 5 months prior to the annual meeting. SETTING: The 1991 annual meeting of the American Academy of Orthopaedic Surgeons held in Anaheim, Calif. PARTICIPANTS: United States or Canadian orthopedic surgeons in training, in practice, or retired from practice who attended the annual meeting. MAIN OUTCOME MEASURES: Participants' HIV serostatus and reporting of occupational and nonoccupational risk factors for HIV infection. RESULTS: Of 7147 eligible orthopedists at the annual meeting, 3420 (47.9%) participated. Compared with the 10,411 orthopedic surgeons responding to the mail survey, serosurvey participants had at least as many opportunities for occupational contact with blood and with HIV-infected patients. Among participants, 87.4% reported a blood-skin contact and 39.2% reported a percutaneous blood contact in the previous month. Among 3267 participants without reported nonoccupational risk factors for HIV infection, none was positive for HIV antibody (0%; upper limit of the 95% confidence interval [CI] = 0.09%); among 108 participants with reported nonoccupational HIV risk factors, two were positive for HIV antibody (1.9%; upper limit of the 95% CI = 5.7%). CONCLUSION: Although these findings may not be generalizable to all orthopedic surgeons, we found no evidence of HIV infection among serosurvey participants without nonoccupational risk factors. The high rates of self-reported blood contact underscore the importance of compliance with infection control precautions and of development of new techniques and equipment to minimize the risk of exposures to blood during surgical procedures.

Percutaneous injuries during surgical procedures.

OBJECTIVE: To study the numbers and circumstances of percutaneous injuries (eg, needle sticks, cuts) that occur during surgical procedures. Surgical personnel risk infection with blood-borne pathogens from percutaneous injuries; some injuries might also place patients at risk by exposing them to a health care worker's blood. DESIGN: Observers present at 1382 surgical procedures recorded information about the procedure, the personnel present, and percutaneous injuries that occurred. SETTING: Four US teaching hospitals during 1990. PARTICIPANTS: Operating room personnel in five surgical specialties. MAIN OUTCOME MEASURES: Numbers and circumstances of percutaneous injuries among surgical personnel and instances in which surgical instruments that had injured a worker recontacted the patient's surgical wound. RESULTS: Ninety-nine injuries occurred during 95 (6.9%) of the 1382 procedures. Seventy-six injuries (77%) were caused by suture needles and affected the nondominant hand (62 injuries [63%]), especially the distal forefinger. The risk of injury adjusted for confounding variables by logistic regression was higher during vaginal hysterectomy (odds ratio [OR], 3.5; 95% confidence interval [CI], 1.6 to 7.5) and lower during certain orthopedic procedures (OR, 0.2; CI, 0.1 to 0.7) than during 11 other types of procedures (reference group; OR, 1.0). Use of fingers rather than an instrument to hold the tissue being sutured was associated with 35 injuries (35%). Eighty-eight injuries (89%) were sustained by resident or attending surgeons; in 28 (32%) of the 88 injuries in surgeons, the sharp object that caused the injury recontacted the patient. CONCLUSION: Percutaneous injuries occur regularly during surgery, placing surgical personnel and, to a lesser extent, patients at risk for infection with blood-borne pathogens. Many such injuries may be preventable with changes in devices, techniques, or protective equipment; all such measures require careful evaluation to determine their efficacy in reducing injury and their effect on patient care.