- Email: [email protected]
Control of TB back on track
samples are not available or when tests are of such a nature that standard analytes cannot be developed for proficiency test purposes. These situations include tests for unusual or rare analytes, labile analytes, relatively new tests, tests that are hard to standardize, or tests that have low sensitivity or specificity. Several alternative approaches may be used to satisfy the validation requirement. These include (i) splitting the patient sample and sending a portion to a reference laboratory to compare the results, (ii) testing split samples as unknowns in the user's laboratory by >2 testing personnel, (iii) saving known positive and negative samples to prepare inhouse QC and/or PT samples, or (iv) obtaining the analyte from an outside source for use as a reference standard.
Frequency of Test Validation Individual laboratories are responsible for assuring that test validation occurs frequently enough to ensure the continued performance of a laboratory test. In most cases, following the manufacturer's guidelines, and/or the requirements of the regulatory or accrediting agencies will provide this assurance. In this regard, CLIA '88 regulations recommend 6 months. Conclusion Ensuring good laboratory practice, which includes complying with regulations from various agencies, can be a
challenge. The availability of clear and useful guidelines for performing verification and validation that specifically address clinical microbiology should make the accomplishment of this aspect of good laboratory practice easier to achieve. The contributions of the following individuals in the preparation of the Cumitech (2) on which this summary is based is gratefully acknowledged: B. W. McCurdy, S. A. Hansen, J. A. Kellogg, E J. Marsik, and R. J. Zabransky.
References 1. Health Care Financing Administration, 1992. Medicare, Medicaid, and CLIA programs. Regulations implementing the Clinical Laboratory Improvement Amendments of 1988 (CLIA). Fed Register 57:7002-7186. 2. Elder, B.L. et al. 1997. Verification and validation of procedures in the clinical microbiology laboratory. Cumitech 31. B.W. McCurdy. coordinating ed., American Society for Microbiology, Washington, D.C. 3. Sewell, D.L. and R.B. Schifman. 1995. Quality assurance: quality improvement, quality control, and test validation, p. 55-66, In: P.R. Murray et al. (ed.) Manual of Clinical Microbiology, 6th ed. American Society for Microbiology, Washington, D.C. 4. Jorgensen, J.H. 1993. Selection criteria for an antimicrobial susceptibility test-
ing system. J. Clin. Microbiol. 31:28412844. 5. Murray, ER., A.C. Niles, and R.L. Heeren. 1987. Comparison of a highly automated 5-h susceptibility testing system, the Cobas-Bact, with two reference methods: Kirby-Bauer disk diffusion and broth microdilution. J. Clin. Microbiol. 25:2372-2377. 6. Ferraro, M.J. and J.H. Jorgensen. Instrument-based antibacterial susceptibility testing, p. 1379-1384, In: ER. Murray et al. (ed.), Manual of Clinical Microbiology 6th ed., ASM Press, Washington, D.C. 7. National Committee for Clinical Laboratory Standards. 1994. Specifications for immunological testing for infectious diseases. Approved Guideline I/LA 18-A. National Committee for Clinical Laboratory Standards, Wayne, PA. 8. Miller, J.M. 1991. Evaluating biochemical identification systems. J. Clin. Microbiol. 29:1559-1561. 9. Miller, J.M. and C.M. O'Hara. 1995. Substrate utilization systems for the identification of bacteria and yeasts, p.103 - 109. In ER. Murray et al. (ed.), Manual of clinical microbiology 6th ed., ASM Press, Washington, D.C. 10. Wilson, Michael L. 1994. Blood Cultures - Introduction. Clin. Lab. Med. 14:1-7.
Editorial
Control of TB Back on Track Ronald J. Zabransky, Ph.D. VA Medical Center Cleveland, Ohio 44106 The Centers for Disease Control and Prevention (CDC) recently announced that the number of tuberculosis (TB) cases in the United States has declined for the fourth straight year (1). This observation suggests that the nation is recovering from the resurgence of TB that followed the surge of AIDS in the mid-1980s. The World Health Organization has also indicated that progress is occurring worldwide against TB (2).
156
0196-4399/97/$0.00 + 17.00
Both these announcements, although relieving our anxieties, underscore the need for continued vigilance in the fight to eliminate TB. When TB returned in a form more deadly than before, we had let our guard down. But it was Pasteur who said that those who ignore history are doomed to repeat it. History did indeed show us that when systems to control TB are not maintained, TB returns. In the U.S. at the turn of the century, the death rate per 100,000 was 195; it was 85 in 1925, 22 in 1950, and only 6 in 1960 (3)! These declining rates led to the belief that TB
© 1997 Elsevier Science Inc.
was a disease of the past and it was targeted for eradication by the year 2000. During the 1970s and 1980s, TB control funds were redirected to other activities; the trend toward elimination of the disease ended and drug-resistant st~ins emerged. This was complicated by the appearance of multi-drug resistant strains and increasing numbers of HIV-positive individuals susceptible to TB. By 1996, 47 states have reported an 8% overall resistance rate to one drug (isoniazid) and 1.5% multiply resistance rate (isoniazid plus rifampin) (1). In the early 1990s additional funding
Clinical Microbiology Newsletter 19:20,1997
to bring TB back under control was provided by the U.S. Department of Health and Human Services. The public health infrastructure was reestablished and local and state health departments improved their detection and treatment programs. CDC spending on prevention and control of TB tripled to $145 million from 1992 to 1997. Programs involving international collaboration, improved diagnostic tools, and directly observed therapy have become critical components to eliminate TB in the U.S. The recent drop by almost 7% of cases between 1995 and 1996 is noteworthy (1). It represents the fourth consecutive year that the number of reported cases has decreased, resulting in the lowest number and rate since national reporting began in 1953. Still, the number of cases of TB reported in 1996 exceeds the revised national goal for TB elimination (<1 case per million) by 2010 (4). The highest priority of TB prevention and control programs must be to ensure that all persons are promptly identified and treated (5). This program also recommends that intensified efforts be directed at foreign-born persons emigrating to the U.S. from areas with high TB rates. The CDC has recently recommended a number of changes in the nature of laboratory facilities that process specimens for the isolation of MTB, notably increasing their biosafety level to BSL3 (6). The proposed changes, while reflecting the importance of controlling TB among health care workers, especially laboratorians, appear to be made with-
out adequate data to indicate that there is indeed a problem (7). Conversion rates are apparently very low among personnel working in mycobacteriology laboratories that are following the current CDC/NIH guidelines (8) which recommend the use of at least BSL2 facilities. In a letter of response to the proposed changes, Gilchrist and fellow American Society for Microbiology officers (7) suggest that the cost of upgrading many clinical and public health laboratories may be an unwarranted expense and that other laboratory safety practices should be examined. This is further supported by studies among other health care workers. Using a mathematical model, Gammaitoni and Nucci (9) recently evaluated the efficacy of TB control measures in four previously reported case studies. They concluded that the efficacy of environmental control efforts depend on the duration of exposure and the infection rate and that the only measures that will significantly reduce infection rates are administrative. HEPA-filter air handling systems, UV lights, and masks are important, but not as critical as proper personnel practices. Nevertheless, we must remain committed to the elimination of TB or the disease will again be on the rise and the next battle will be much more costly.
3.
4.
5.
6.
7.
8.
References 1. Centers for Disease Control and Prevention.1997. Tuberculosis Morbidity--United States, 1996. MMWR 46:695-700. 2. Global Tuberculosis Programme, World Health Organization. 1997. Treatment of tuberculosis: guidelines
9.
for national programmes. 2nd ed. World health Organization Report No. WHO/TB/97:220. Centers for Disease Control and Prevention. 1996. Tuberculosis Morbidity--United States, 1995. MMWR 45:365-370. Centers for Disease Control and Prevention. 1989. A strategic plan for the elimination of tuberculosis in the United States. MMWR 38(S-3). Centers for Disease Control and Prevention. 1995. Essential components of a tuberculosis prevention and control program: recommendations of the Advisory Council for the Elimination of Tuberculosis. MMWR 44 (RR-11). Centers for Disease Control and Prevention. 1997. Goals for working safely with Mycobacterium tuberculosis in clinical, public health, and research laboratories; notice. Federal Register Part V, 62(81). Gilchrist, M.J.R., G. Cassell, and S. Falkow. 1997. Comments on: Federal Register, Part V, Department of Health and Human Services, Centers for Disease Control and prevention. 62(81), April 28, 1997, Goals for working safely with Mycobacterium tuberculosis in clinical, public health and research laboratories; notice. Amer. Soc. Microbiology, letter to CDC. Centers for Disease Control and Prevention and National Institutes of Health. 1993. Biosafety in microbiological and biomedical laboratories. 3d ed.; HHS Publ. No. (CDC) 93-8395. U.S. Govemm. Print. Office, Washington, D.C. Gammaitoni, L., and M.C. Nucci. 1997. Using a mathematical model to evaluate the efficacy of TB control measures. Emerging Inf. Dis. 3:335-342.
Case Report
Heficobacter cinaedi Bacteremia in a Patient with HIV Infection Athina Kansoozidou, M.D. V.G. Kiosses, M.D. B.D. Danielides, M.D.
Department of Bacteriology Infectious Diseases Hospital Thessaloniki, Greece Souzy Tsoulfa, M.D. Lina Kondodimou, M.D.
Department of Bacteriology "'G. Papanikolaou" Hospital Thessaloniki, Greece Clinical Microbiology Newsletter 19:20,1997
Patients with HIV infection can be infected with a variety of organisms, including "Campylobacter-like organisms" (CLO), two of the more common species were first described by Fennell et al. in 1984 (1). They were initially characterized as members of the genus Campylobacter ( C. cinaedi and C. fennelliae) (2), but later were reclassified into the genus Helicobacter; they are now called Helicobacter cinaedi © 1997 Elsevier Science Inc.
and H. fennelliae respectively (3). These organisms cause proctitis, proctocolitis, and enteritis in homosexual men, especially those with HIV infection. They also cause, although rarely, bacteremic illness in homosexual men who are immunosuppressed or have HIV infection (4). H. cinaedi bacteremia has been reported in homosexual males with or without intestinal symptoms (5). Successive episodes of 0196-4399/97/$0.00 + 17.00
157
Frequency of Test Validation Individual laboratories are responsible for assuring that test validation occurs frequently enough to ensure the continued performance of a laboratory test. In most cases, following the manufacturer's guidelines, and/or the requirements of the regulatory or accrediting agencies will provide this assurance. In this regard, CLIA '88 regulations recommend 6 months. Conclusion Ensuring good laboratory practice, which includes complying with regulations from various agencies, can be a
challenge. The availability of clear and useful guidelines for performing verification and validation that specifically address clinical microbiology should make the accomplishment of this aspect of good laboratory practice easier to achieve. The contributions of the following individuals in the preparation of the Cumitech (2) on which this summary is based is gratefully acknowledged: B. W. McCurdy, S. A. Hansen, J. A. Kellogg, E J. Marsik, and R. J. Zabransky.
References 1. Health Care Financing Administration, 1992. Medicare, Medicaid, and CLIA programs. Regulations implementing the Clinical Laboratory Improvement Amendments of 1988 (CLIA). Fed Register 57:7002-7186. 2. Elder, B.L. et al. 1997. Verification and validation of procedures in the clinical microbiology laboratory. Cumitech 31. B.W. McCurdy. coordinating ed., American Society for Microbiology, Washington, D.C. 3. Sewell, D.L. and R.B. Schifman. 1995. Quality assurance: quality improvement, quality control, and test validation, p. 55-66, In: P.R. Murray et al. (ed.) Manual of Clinical Microbiology, 6th ed. American Society for Microbiology, Washington, D.C. 4. Jorgensen, J.H. 1993. Selection criteria for an antimicrobial susceptibility test-
ing system. J. Clin. Microbiol. 31:28412844. 5. Murray, ER., A.C. Niles, and R.L. Heeren. 1987. Comparison of a highly automated 5-h susceptibility testing system, the Cobas-Bact, with two reference methods: Kirby-Bauer disk diffusion and broth microdilution. J. Clin. Microbiol. 25:2372-2377. 6. Ferraro, M.J. and J.H. Jorgensen. Instrument-based antibacterial susceptibility testing, p. 1379-1384, In: ER. Murray et al. (ed.), Manual of Clinical Microbiology 6th ed., ASM Press, Washington, D.C. 7. National Committee for Clinical Laboratory Standards. 1994. Specifications for immunological testing for infectious diseases. Approved Guideline I/LA 18-A. National Committee for Clinical Laboratory Standards, Wayne, PA. 8. Miller, J.M. 1991. Evaluating biochemical identification systems. J. Clin. Microbiol. 29:1559-1561. 9. Miller, J.M. and C.M. O'Hara. 1995. Substrate utilization systems for the identification of bacteria and yeasts, p.103 - 109. In ER. Murray et al. (ed.), Manual of clinical microbiology 6th ed., ASM Press, Washington, D.C. 10. Wilson, Michael L. 1994. Blood Cultures - Introduction. Clin. Lab. Med. 14:1-7.
Editorial
Control of TB Back on Track Ronald J. Zabransky, Ph.D. VA Medical Center Cleveland, Ohio 44106 The Centers for Disease Control and Prevention (CDC) recently announced that the number of tuberculosis (TB) cases in the United States has declined for the fourth straight year (1). This observation suggests that the nation is recovering from the resurgence of TB that followed the surge of AIDS in the mid-1980s. The World Health Organization has also indicated that progress is occurring worldwide against TB (2).
156
0196-4399/97/$0.00 + 17.00
Both these announcements, although relieving our anxieties, underscore the need for continued vigilance in the fight to eliminate TB. When TB returned in a form more deadly than before, we had let our guard down. But it was Pasteur who said that those who ignore history are doomed to repeat it. History did indeed show us that when systems to control TB are not maintained, TB returns. In the U.S. at the turn of the century, the death rate per 100,000 was 195; it was 85 in 1925, 22 in 1950, and only 6 in 1960 (3)! These declining rates led to the belief that TB
© 1997 Elsevier Science Inc.
was a disease of the past and it was targeted for eradication by the year 2000. During the 1970s and 1980s, TB control funds were redirected to other activities; the trend toward elimination of the disease ended and drug-resistant st~ins emerged. This was complicated by the appearance of multi-drug resistant strains and increasing numbers of HIV-positive individuals susceptible to TB. By 1996, 47 states have reported an 8% overall resistance rate to one drug (isoniazid) and 1.5% multiply resistance rate (isoniazid plus rifampin) (1). In the early 1990s additional funding
Clinical Microbiology Newsletter 19:20,1997
to bring TB back under control was provided by the U.S. Department of Health and Human Services. The public health infrastructure was reestablished and local and state health departments improved their detection and treatment programs. CDC spending on prevention and control of TB tripled to $145 million from 1992 to 1997. Programs involving international collaboration, improved diagnostic tools, and directly observed therapy have become critical components to eliminate TB in the U.S. The recent drop by almost 7% of cases between 1995 and 1996 is noteworthy (1). It represents the fourth consecutive year that the number of reported cases has decreased, resulting in the lowest number and rate since national reporting began in 1953. Still, the number of cases of TB reported in 1996 exceeds the revised national goal for TB elimination (<1 case per million) by 2010 (4). The highest priority of TB prevention and control programs must be to ensure that all persons are promptly identified and treated (5). This program also recommends that intensified efforts be directed at foreign-born persons emigrating to the U.S. from areas with high TB rates. The CDC has recently recommended a number of changes in the nature of laboratory facilities that process specimens for the isolation of MTB, notably increasing their biosafety level to BSL3 (6). The proposed changes, while reflecting the importance of controlling TB among health care workers, especially laboratorians, appear to be made with-
out adequate data to indicate that there is indeed a problem (7). Conversion rates are apparently very low among personnel working in mycobacteriology laboratories that are following the current CDC/NIH guidelines (8) which recommend the use of at least BSL2 facilities. In a letter of response to the proposed changes, Gilchrist and fellow American Society for Microbiology officers (7) suggest that the cost of upgrading many clinical and public health laboratories may be an unwarranted expense and that other laboratory safety practices should be examined. This is further supported by studies among other health care workers. Using a mathematical model, Gammaitoni and Nucci (9) recently evaluated the efficacy of TB control measures in four previously reported case studies. They concluded that the efficacy of environmental control efforts depend on the duration of exposure and the infection rate and that the only measures that will significantly reduce infection rates are administrative. HEPA-filter air handling systems, UV lights, and masks are important, but not as critical as proper personnel practices. Nevertheless, we must remain committed to the elimination of TB or the disease will again be on the rise and the next battle will be much more costly.
3.
4.
5.
6.
7.
8.
References 1. Centers for Disease Control and Prevention.1997. Tuberculosis Morbidity--United States, 1996. MMWR 46:695-700. 2. Global Tuberculosis Programme, World Health Organization. 1997. Treatment of tuberculosis: guidelines
9.
for national programmes. 2nd ed. World health Organization Report No. WHO/TB/97:220. Centers for Disease Control and Prevention. 1996. Tuberculosis Morbidity--United States, 1995. MMWR 45:365-370. Centers for Disease Control and Prevention. 1989. A strategic plan for the elimination of tuberculosis in the United States. MMWR 38(S-3). Centers for Disease Control and Prevention. 1995. Essential components of a tuberculosis prevention and control program: recommendations of the Advisory Council for the Elimination of Tuberculosis. MMWR 44 (RR-11). Centers for Disease Control and Prevention. 1997. Goals for working safely with Mycobacterium tuberculosis in clinical, public health, and research laboratories; notice. Federal Register Part V, 62(81). Gilchrist, M.J.R., G. Cassell, and S. Falkow. 1997. Comments on: Federal Register, Part V, Department of Health and Human Services, Centers for Disease Control and prevention. 62(81), April 28, 1997, Goals for working safely with Mycobacterium tuberculosis in clinical, public health and research laboratories; notice. Amer. Soc. Microbiology, letter to CDC. Centers for Disease Control and Prevention and National Institutes of Health. 1993. Biosafety in microbiological and biomedical laboratories. 3d ed.; HHS Publ. No. (CDC) 93-8395. U.S. Govemm. Print. Office, Washington, D.C. Gammaitoni, L., and M.C. Nucci. 1997. Using a mathematical model to evaluate the efficacy of TB control measures. Emerging Inf. Dis. 3:335-342.
Case Report
Heficobacter cinaedi Bacteremia in a Patient with HIV Infection Athina Kansoozidou, M.D. V.G. Kiosses, M.D. B.D. Danielides, M.D.
Department of Bacteriology Infectious Diseases Hospital Thessaloniki, Greece Souzy Tsoulfa, M.D. Lina Kondodimou, M.D.
Department of Bacteriology "'G. Papanikolaou" Hospital Thessaloniki, Greece Clinical Microbiology Newsletter 19:20,1997
Patients with HIV infection can be infected with a variety of organisms, including "Campylobacter-like organisms" (CLO), two of the more common species were first described by Fennell et al. in 1984 (1). They were initially characterized as members of the genus Campylobacter ( C. cinaedi and C. fennelliae) (2), but later were reclassified into the genus Helicobacter; they are now called Helicobacter cinaedi © 1997 Elsevier Science Inc.
and H. fennelliae respectively (3). These organisms cause proctitis, proctocolitis, and enteritis in homosexual men, especially those with HIV infection. They also cause, although rarely, bacteremic illness in homosexual men who are immunosuppressed or have HIV infection (4). H. cinaedi bacteremia has been reported in homosexual males with or without intestinal symptoms (5). Successive episodes of 0196-4399/97/$0.00 + 17.00
157