1103
21. Lord CF, Gebhardt MC, Tomford WW, Mankin HJ. Infection in bone allografts: incidence, nature and treatment. J Bone Joint Surg 1988; 70A: 369-76. 22. Berrey BH, Lord CF, Gebhardt MC, Mankin HJ. Fractures of allografts: frequency, treatment and end-results. J Bone Joint Surg 1990; 72A: 825-33.
OCCUPATIONAL INFECTION AMONG ANAESTHETISTS Anaesthetists are regularly exposed to blood and body fluids that may carry infectious organisms, of which hepatitis B virus (HBV) and human immunodeficiency virus (HIV) HBV is
highly infectious; minute of blood entering through cuts, mucous membranes, or accidental inoculation are sufficient for disease transmission. The overall risk of contracting hepatitis B from a single needlestick injury contaminated with blood from an infected patient has been estimated to be 5%.’ The fact that anaesthetists have more HBV markers than the general population suggests that occupational infection does occur.2 Immunisation against hepatitis B gives a high level of protection, although the existence of a vaccine-induced escape mutant of the virus has been reported.3 Hepatitis B immune globulin given to nonimmunised subjects after needlestick injury is only partly effective in preventing infection 4 The frequency of HIV infection in the population is not uniform, and people in high-risk groups may have higher than normal hospital attendance rates.5 Although there have been no fully documented cases of accidental HIV infection
cause most concern.
amounts
anaesthetists, such incidents have been reported in other health care workers.5 Infection appears to require the transfer of larger volumes of blood than is the case with HBV,6so one might expect hollow instruments such as the needles used mainly by anaesthetists to be more dangerous than surgical scalpel blades or sewing needles. Most documented occupational HIV transmissions result from needlestick injuries involving blood, but transmission via other body fluids and routes has been reported.5 There is little information about the frequency of seroconversion after occupational exposure to HIV; a figure of 0-4% is widely cited.’ Although the risk of contracting HIV as a result of occupational exposure may be low compared with HBV, the consequences of infection are far more serious: whereas only 2% of people infected with HBV die of the infection6 50% of those infected with HIV will have AIDS within six years.8 There is no protective vaccine against HIV and prompt treatment with zidovudine after needlestick injury has proved ineffective in two cases.9 In the UK, 0-1-0-5% of the population are said to be carriers of HBV, although many more have serological evidence of past infection." For HIV, in 1988 it was reported that 0.1-0-3% of the population were infected;"aa later study12 suggested that the lower figure may be more accurate. Because polymerase chain reaction techniques may pick up those without antibodies, these figures may slightly underestimate the true level of HIV infection.13 Up-to-date information on the extent of exposure of anaesthetists to blood and body fluids is available from independent surveys conducted in two hospitals. The first showed that during the course of 270 anaesthetics, blood from 14% of patients caused skin contamination of 65 people during 46 incidents.14 8% of staff had skin cuts at the time of the events and one needlestick injury occurred among
the survey. In the second survey of 7000 anaesthetics15 the frequency of needlestick injury was 013%, of which two-thirds were with contaminated needles. 20% of the anaesthetists received a needlestick injury during the three-month study. The Association of Anaesthetists10 and the Expert Advisory Group on AIDS’ both advise anaesthetists to wear gloves as a minimum protective measure when there is likely to be contact with blood. The first survey14 showed that glove-wearing varied with procedure from 8% for peripheral venous cannulation to 90% for central venous cannulation. Failure to wear gloves led to many avoidable contamination incidents. Although gloves did not prevent needlestick injury in these surveys, double-gloving has been shown to reduce the frequency of skin contamination from needle punctures.16
during
Only 71 %14 and 74%ls of anaesthetists in these were immunised against HBV, despite the
surveys proven
effectiveness of the vaccine. If these levels of immunisation apply throughout the UK, about 1500 anaesthetists are putting themselves at unnecessary risk of infection. These surveys suggest that many UK anaesthetists are not adopting simple measures to reduce the risk of occupationally acquired infections. Perhaps they are complacent because the risk of a single incident leading to infection is very small. However, the average anaesthetist will treat many thousands of patients during his or her working life, so the cumulative risk of occupationally acquired HIV infection may be as high as 1 in 25. 1. Guidance for Clinical Health Care Workers: protection against infection with HIV and hepatitis viruses. Recommendations of the Expert Advisory Group on AIDS. London: HM Stationery Office, 1990. 2. Berry AJ, Isaacson IJ, Kane MA, et al. A multicentre study of the prevalence of hepatitis B viral serologic markers in anesthesia personnel. Anesth Analg 1984; 63: 738-42. 3. Carman WF, Zanetti AR, Karayiannis P, et al. Vaccine-induced escape mutant of hepatitis B virus. Lancet 1990; 336: 325-29. 4. Seeff LB, Wright EC, Zimmerman HJ, et al. Type B hepatitis after needle-stick exposure: prevention with hepatitis B immune globulin. Ann Intern Med 1978; 88: 285-87. 5. Kelen GD. Human immunodeficiency virus and the emergency department: risks and risk protection for health care providers. Ann Emerg Med 1990; 19: 242-48. 6. Morgan DR. HIV and needlestick injuries. Lancet 1990; 335: 1280. 7. Ruthane M, and the CDC Cooperative Needlestick Surveillance Group. Surveillance of health care workers exposed to blood from patients infected with the human immunodeficiency virus. N Engl J Med 1988; 319: 1118-23. 8. Moss AR, Bacchetti P, Osmond D, et al. Seropositivity for HIV and the development of AIDS or AIDS related condition: three year follow up of the San Francisco General Hospital cohort. Br Med J 1988; 296: 745-50. 9. Anon. Zidovudine and needlestick exposure. Lancet 1990; 335: 1271. 10. AIDS and Hepatitis B Guidelines for Anaesthetists. London: Association of Anaesthetists, April, 1989. 11. Wilkie AD. Forecasting AIDS using an actuarial model. In: Cox D. Short-term prediction of HIV infection and AIDS in England and Wales. Report of the working group. London: HM Stationery Office, 1988. 12. Acquired Immune Deficiency Syndrome in England and Wales to end 1993: projections using data to end September 1989. Report of a working group convened by the Director of the Public Health Laboratory Service. London: Public Health Laboratory Service, 1990. 13. Soriano V, Hewlett I, Tor J, Clotet B, Epstein J, Foz M. Silent HIV infection in heterosexual partners of seropositive drug abusers in Spain. Lancet 1990; 335: 860. 14. Harrison CA, Rogers DW, Rosen M. Blood contamination of anaesthetic and related staff. Anaesthesia 1990; 45: 831-33. 15. Maz S, Lyons G. Needlestick injuries in anaesthetists. Anaesthesia 1990; 45: 677-78. 16. Matta H, Thompson AM, Rainey JB. Does wearing two pairs of gloves protect operating theatre staff from skin contamination? Br Med J 1988; 297: 597-98. 17. Jones ME. A thing about AIDS. Anaesth Intens Care 1989; 17: 253-63.
21. Lord CF, Gebhardt MC, Tomford WW, Mankin HJ. Infection in bone allografts: incidence, nature and treatment. J Bone Joint Surg 1988; 70A: 369-76. 22. Berrey BH, Lord CF, Gebhardt MC, Mankin HJ. Fractures of allografts: frequency, treatment and end-results. J Bone Joint Surg 1990; 72A: 825-33.
OCCUPATIONAL INFECTION AMONG ANAESTHETISTS Anaesthetists are regularly exposed to blood and body fluids that may carry infectious organisms, of which hepatitis B virus (HBV) and human immunodeficiency virus (HIV) HBV is
highly infectious; minute of blood entering through cuts, mucous membranes, or accidental inoculation are sufficient for disease transmission. The overall risk of contracting hepatitis B from a single needlestick injury contaminated with blood from an infected patient has been estimated to be 5%.’ The fact that anaesthetists have more HBV markers than the general population suggests that occupational infection does occur.2 Immunisation against hepatitis B gives a high level of protection, although the existence of a vaccine-induced escape mutant of the virus has been reported.3 Hepatitis B immune globulin given to nonimmunised subjects after needlestick injury is only partly effective in preventing infection 4 The frequency of HIV infection in the population is not uniform, and people in high-risk groups may have higher than normal hospital attendance rates.5 Although there have been no fully documented cases of accidental HIV infection
cause most concern.
amounts
anaesthetists, such incidents have been reported in other health care workers.5 Infection appears to require the transfer of larger volumes of blood than is the case with HBV,6so one might expect hollow instruments such as the needles used mainly by anaesthetists to be more dangerous than surgical scalpel blades or sewing needles. Most documented occupational HIV transmissions result from needlestick injuries involving blood, but transmission via other body fluids and routes has been reported.5 There is little information about the frequency of seroconversion after occupational exposure to HIV; a figure of 0-4% is widely cited.’ Although the risk of contracting HIV as a result of occupational exposure may be low compared with HBV, the consequences of infection are far more serious: whereas only 2% of people infected with HBV die of the infection6 50% of those infected with HIV will have AIDS within six years.8 There is no protective vaccine against HIV and prompt treatment with zidovudine after needlestick injury has proved ineffective in two cases.9 In the UK, 0-1-0-5% of the population are said to be carriers of HBV, although many more have serological evidence of past infection." For HIV, in 1988 it was reported that 0.1-0-3% of the population were infected;"aa later study12 suggested that the lower figure may be more accurate. Because polymerase chain reaction techniques may pick up those without antibodies, these figures may slightly underestimate the true level of HIV infection.13 Up-to-date information on the extent of exposure of anaesthetists to blood and body fluids is available from independent surveys conducted in two hospitals. The first showed that during the course of 270 anaesthetics, blood from 14% of patients caused skin contamination of 65 people during 46 incidents.14 8% of staff had skin cuts at the time of the events and one needlestick injury occurred among
the survey. In the second survey of 7000 anaesthetics15 the frequency of needlestick injury was 013%, of which two-thirds were with contaminated needles. 20% of the anaesthetists received a needlestick injury during the three-month study. The Association of Anaesthetists10 and the Expert Advisory Group on AIDS’ both advise anaesthetists to wear gloves as a minimum protective measure when there is likely to be contact with blood. The first survey14 showed that glove-wearing varied with procedure from 8% for peripheral venous cannulation to 90% for central venous cannulation. Failure to wear gloves led to many avoidable contamination incidents. Although gloves did not prevent needlestick injury in these surveys, double-gloving has been shown to reduce the frequency of skin contamination from needle punctures.16
during
Only 71 %14 and 74%ls of anaesthetists in these were immunised against HBV, despite the
surveys proven
effectiveness of the vaccine. If these levels of immunisation apply throughout the UK, about 1500 anaesthetists are putting themselves at unnecessary risk of infection. These surveys suggest that many UK anaesthetists are not adopting simple measures to reduce the risk of occupationally acquired infections. Perhaps they are complacent because the risk of a single incident leading to infection is very small. However, the average anaesthetist will treat many thousands of patients during his or her working life, so the cumulative risk of occupationally acquired HIV infection may be as high as 1 in 25. 1. Guidance for Clinical Health Care Workers: protection against infection with HIV and hepatitis viruses. Recommendations of the Expert Advisory Group on AIDS. London: HM Stationery Office, 1990. 2. Berry AJ, Isaacson IJ, Kane MA, et al. A multicentre study of the prevalence of hepatitis B viral serologic markers in anesthesia personnel. Anesth Analg 1984; 63: 738-42. 3. Carman WF, Zanetti AR, Karayiannis P, et al. Vaccine-induced escape mutant of hepatitis B virus. Lancet 1990; 336: 325-29. 4. Seeff LB, Wright EC, Zimmerman HJ, et al. Type B hepatitis after needle-stick exposure: prevention with hepatitis B immune globulin. Ann Intern Med 1978; 88: 285-87. 5. Kelen GD. Human immunodeficiency virus and the emergency department: risks and risk protection for health care providers. Ann Emerg Med 1990; 19: 242-48. 6. Morgan DR. HIV and needlestick injuries. Lancet 1990; 335: 1280. 7. Ruthane M, and the CDC Cooperative Needlestick Surveillance Group. Surveillance of health care workers exposed to blood from patients infected with the human immunodeficiency virus. N Engl J Med 1988; 319: 1118-23. 8. Moss AR, Bacchetti P, Osmond D, et al. Seropositivity for HIV and the development of AIDS or AIDS related condition: three year follow up of the San Francisco General Hospital cohort. Br Med J 1988; 296: 745-50. 9. Anon. Zidovudine and needlestick exposure. Lancet 1990; 335: 1271. 10. AIDS and Hepatitis B Guidelines for Anaesthetists. London: Association of Anaesthetists, April, 1989. 11. Wilkie AD. Forecasting AIDS using an actuarial model. In: Cox D. Short-term prediction of HIV infection and AIDS in England and Wales. Report of the working group. London: HM Stationery Office, 1988. 12. Acquired Immune Deficiency Syndrome in England and Wales to end 1993: projections using data to end September 1989. Report of a working group convened by the Director of the Public Health Laboratory Service. London: Public Health Laboratory Service, 1990. 13. Soriano V, Hewlett I, Tor J, Clotet B, Epstein J, Foz M. Silent HIV infection in heterosexual partners of seropositive drug abusers in Spain. Lancet 1990; 335: 860. 14. Harrison CA, Rogers DW, Rosen M. Blood contamination of anaesthetic and related staff. Anaesthesia 1990; 45: 831-33. 15. Maz S, Lyons G. Needlestick injuries in anaesthetists. Anaesthesia 1990; 45: 677-78. 16. Matta H, Thompson AM, Rainey JB. Does wearing two pairs of gloves protect operating theatre staff from skin contamination? Br Med J 1988; 297: 597-98. 17. Jones ME. A thing about AIDS. Anaesth Intens Care 1989; 17: 253-63.
