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Canada Communicable Disease Report

 

 

Canada Communicable Disease Report
Volume 28 • ACS-7
15 December 2002

An Advisory Committee Statement (ACS)
The Canadian Tuberculosis Committee*†

RECOMMENDATIONS FOR THE SCREENING AND PREVENTION OF TUBERCULOSIS IN PATIENTS WITH HIV AND THE SCREENING FOR HIV IN TUBERCULOSIS PATIENTS AND THEIR CONTACTS

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Preamble

The Canadian Tuberculosis Committee (CTC) provides Health Canada with ongoing, timely and scientifically based advice on national strategies and priorities with respect to tuberculosis prevention and control in Canada. Health Canada acknowledges that the advice and recommendations set out in this statement are based upon the best current available scientific knowledge and medical practice.
It is disseminating this document for information purposes to the medical community involved in the care of individuals with tuberculosis and/or HIV/AIDS.

Screening and Prevention of Tuberculosis in Patients with HIV

The HIV epidemic has had a dramatic impact on tuberculosis (TB) rates and tuberculosis control in populations in which both infections are prevalent(1). HIV, in particular advanced HIV (AIDS), is the most potent risk factor ever identified for the progression to disease of recent or remotely acquired infection with Mycobacterium tuberculosis(2). It operates by destroying the two types of immune cell most important to the containment of tubercle bacilli (macrophages and CD4 receptor bearing lymphocytes)(3). Among people infected with M. tuberculosis who are not receiving highly active antiretroviral therapy (HAART), the estimated risk of active tuberculosis relative to patients with no known risk factor is 170.0 for AIDS and 113.0 for HIV infection without AIDS(2). Cases of TB thus produced increase the risk of transmission of M. tuberculosis within the community, thereby constituting a second, indirect mechanism by which HIV increases TB morbidity(4).

In Canada, dormant or latent tuberculosis infection (LTBI) is most commonly found in four groups: those born in countries where TB is endemic, Aboriginal people, the inner city poor and homeless, and elderly people(5). Co-infection with HIV is not uncommon among inner city people with a history of injection drug use(6).
Recent data suggest that the incidence of HIV/AIDS is increasing among Aboriginal people(6-8) and those born in tuberculosis endemic countries(9). Treatment of LTBI has been shown to reduce the risk of progression to active disease in HIV-TB co-infected individuals(10,11). The following recommendations are made:

  1. Every patient with newly diagnosed HIV infection should be assessed for the presence of active TB at the time of diagnosis of HIV. An inquiry about symptoms that would suggest active TB (cough, especially if productive or associated with hemoptysis, fever, night sweats, weight loss) should be made and any history of TB or known/likely exposure to it ascertained. For patients who report that they have received treatment of active TB or LTBI in the past, the adequacy of that treatment must be assessed. As well, a physical examination that includes examination of extrapulmonary sites of disease, such as lymph nodes(12), and chest radiography should be performed, and features of current or past TB sought. The examiner should be aware that the clinical presentation of TB may be altered in the presence of HIV infection and that radiographic features may be altered or absent in approximate proportion to the individual's degree of immunosuppression(3). People with suspected active TB should have sputum or other appropriate specimens submitted for acid-fast bacilli (AFB) smear and culture.

  2. Health care workers caring for patients with HIV infection should maintain a high level of suspicion for TB.

  3. Except in those with a history of active TB or a well documented previous, positive tuberculin skin test (TST), every HIV-infected person should be given a TST with intermediate strength (5-TU) purified protein derivative by the Mantoux method, which should be read 48 to 72 hours later by a health care worker experienced in reading TSTs.

  4. TB screening with TST should be performed as soon as possible after HIV infection is diagnosed, because the reliability of the TST can diminish as the CD4 lymphocyte count declines.

  5. For those in whom annual testing is felt to be justified by high infection rates, a baseline two step TST should be considered(2).

  6. Induration of >= 5 mm on the TST should be considered indicative of TB infection(2,3).

  7. Routine anergy testing is not recommended(13,14). Administration of TB preventive therapy to anergic, HIV-infected individuals has not been found to be useful or cost-effective if none of the other indications is present (see below)(15-17).

  8. TST negative patients with evidence of old, healed TB on the chest radiograph, especially those with a history of TB exposure, should be considered for TB preventive therapy once active tuberculosis has been excluded. Repeat TST may be considered after institution of antiretroviral therapy and evidence of immune reconstitution(3).

  9. Unless specifically contraindicated, HIV-positive patients who a) have a positive TST ( >= 5 mm of induration), b) have not already been treated for TB infection, and c) have test results excluding active TB should be strongly encouraged to take preventive therapy(1,18-20). This preventive therapy is indicated even if the date of TST conversion cannot be determined. Because of the very high risk of development of active TB in HIV-TB co-infected individuals, creative means of enhancing adherence, such as directly observed preventive therapy, should be considered, particularly if there are concerns about the patient's adherence. Preventive therapy regimens and monitoring are outlined in the 5th edition of the Canadian Tuberculosis Standards, Web site: www.lung.ca/tb/TBStandards_Eng.pdf

  10. HIV-infected close contacts of patients with infectious TB should receive treatment for presumptive LTBI, even when repeat TST after contact is not indicative of latent infection(20). Because re-infection can occur, this may, at times, imply re-treatment of a person who has already undergone treatment in the past.

  11. Preventive therapy is recommended during pregnancy for HIV- infected patients who have either a positive TST or a recent history of exposure to active TB, after active tuberculosis has been excluded.

  12. HIV-infected people who are candidates for, but who do not receive, TB preventive therapy should be assessed periodically for symptoms of active TB as part of their ongoing management of HIV infection. Clinicians should educate them about the symptoms of TB and advise them to seek medical attention promptly should such symptoms develop.

  13. The administration of BCG vaccine to HIV-infected patients is contraindicated because of its potential to cause disseminated disease.

  14. HIV-infected patients should be advised that certain activities and occupations may increase the likelihood of exposure to TB. These include volunteer work or employment in health care facilities, correctional institutions, and shelters for the homeless, as well as travel to TB endemic countries.

TB disease in an HIV-infected person is an AIDS defining illness. Both TB and AIDS should be reported to the Public Health Department(21).

Screening for HIV in TB Patients and Their Contacts

Patients with TB constitute an important “sentinel“ population for HIV screening. In some African countries with high TB prevalence, HIV prevalence exceeds 50% among TB patients(22). Between 1985 and 1992, TB patients in the United States were 204-fold more likely to have AIDS than the general population(23). The benefits of identifying previously unrecognized HIV infection are substantial in
terms of both the opportunities for preventing future HIV transmission and the large potential benefits to the patient of antiretroviral therapy(3). Knowledge of the HIV serostatus of TB patients may also influence the treatment of their TB(17). Even in those not receiving antiretroviral drugs there may be an increased risk of adverse reactions from antituberculosis drugs(24). Because HIV-infected people are at risk of peripheral neuropathy, co-administration of pyridoxine with isoniazid may be prudent. For some HIV-infected TB patients malabsorption of their anti-
tuberculosis drugs has been reported, so that measurement of serum drug levels may be necessary if there is a poor response to treatment(3). The following recommendations are made:

  1. All patients with newly diagnosed TB should be strongly encouraged to undergo HIV serologic testing according to established guidelines(25,26).

  2. HIV-testing of contacts of infectious TB cases should be considered if they are at risk for HIV(27,28).

  3. Additional information resources concerning HIV should be available to patients for whom HIV testing is recommended as well as to other patients seen by TB programs.

Health care providers, administrators, and TB controllers should strive to promote coordinated care for patients with TB and HIV, and to improve information sharing between TB control programs and HIV/AIDS programs.

Acknowledgements

The authors would like to thank members of the Centre for Infectious Disease Prevention and Control, Public Health Agency of Canada, Health Canada, the Canadian Thoracic Society, and the Canadian Infectious Disease Society for their critical review and ultimate approval of these recommendations. They would also like to thank Susan Falconer for her secretarial assistance.

References

  1. Cantwell MF, Binkin NJ. Tuberculosis in sub-Saharan Africa: a regional assessment of the impact of the human immunodeficiency virus and National Tuberculosis Control Program quality. Tubercle Lung Dis 1996;77:220-25.

  2. Menzies D, Pourier L. Diagnosis of tuberculosis infection and disease. In: Long R, ed. The Canadian tuberculosis standards, 5th ed. Ottawa: Health Canada and Canadian Lung Association, 2000:45-65.

  3. Houston S, Schwartzman K, Brassard P et al. Tuberculosis and human immunodeficiency virus. In Long R, ed. The Canadian Tuberculosis Standards, 5th ed. Ottawa: Health Canada and the Canadian Lung Association, 2000:141-51.

  4. Narain JP, Raviglione MC, Kochi A. HIV-associated tuberculosis in developing countries: epidemiology and strategies for prevention. Tubercle Lung Dis 1992;73:311-21.

  5. Long R, Njoo H, Hershfield E. Tuberculosis: 3. The epidemiology of the disease in Canada. Can Med Assoc J 1999;160:1185-90.

  6. Blenkush MF, Korzeniewska-Kozela M, Elwood RK et al. HIV-related tuberculosis in British Columbia: indications of a rise in prevalence and a change in risk groups. Clin Invest Med 1996;19:271-78.

  7. Calzavara LM, Bullock S, Myers T et al. Sexual partnering and risk of HIV/STD among Aboriginals. Can J Public Health 1999;90:186-91.

  8. Health Canada. HIV/AIDS Epi Update. HIV/AIDS among Aboriginal persons in Canada remains a pressing issue. Division of HIV/AIDS, Centre for Infectious Disease Prevention and Control, Health Canada, May 2001.

  9. Health Canada. HIV/AIDS Epi Update. AIDS/HIV ethnicity in Canada. Division of HIV/AIDS, Centre for Infectious Disease Prevention and Control, Health Canada, May 2001.

  10. Wilkinson D, Squire SB, Garner P. Effect of preventive treatment for tuberculosis in adults infected with HIV: a systematic review of randomized placebo controlled trials. BMJ 1998;317:625-28.

  11. Bucher HC, Griffith LE, Guyatt GH et al. Isoniazid prophylaxis for tuberculosis in HIV infection: a meta-analysis of randomized controlled trials. AIDS 1999;13:501-508.

  12. Korzeniewska-Kosela M, FitzGerald MJ, Vedal S et al. Spectrum of tuberculosis in patients with HIV infection in British Columbia: report of 40 cases. Can Med Assoc J 1992;146:1927-34.

  13. CDC. Anergy skin testing and tuberculosis preventive therapy for HIV-infected persons: revised recommendations. MMWR 1997;46(RR-15):1-10.

  14. Slovis BS, Plitman JD, Haas DW. The case against anergy testing as routine adjunct to tuberculin skin testing. JAMA 2000;283:2003-2007.

  15. Whalen CC, Johnson JL, Okwera A et al. A trial of three regimens to prevent tuberculosis in Ugandan adults infected with human immunodeficiency virus. N Engl J Med 1997;337:801-808.

  16. Gordin FM, Matts JP, Miller C et al. A controlled trial of isoniazid in persons with anergy and human immunodeficiency virus infection who are at high risk for tuberculosis. N Engl J Med 1997;337:315-20.

  17. CDC. Prevention and treatment of tuberculosis among patients infected with human immunodeficiency virus: principles of therapy and revised recommendations. MMWR 1998;47(RR-20):1-51.

  18. CDC. USPHS/IDSA guidelines for the prevention of opportunistic infections in persons infected with human immunodeficiency virus. MMWR 1997;46(RR-12):1-46.

  19. DeRiemer K, Daley CL, Reingold AL. Preventing tuberculosis among HIV-infected persons: a survey of physicians' knowledge and practices. Prev Med 1999;28:437-44.

  20. American Thoracic Society. Targeted tuberculin testing and treatment of latent tuberculosis infection. Am J Respir Crit Care Med 2000;161(supplement):S221-S247.

  21. Brassard P, Remis RS. Incidence of tuberculosis among reported AIDS cases in Quebec from 1979 to 1996. Can Med Assoc J 1999;160:1838-42.

  22. Dye C, Scheele S, Dolin P et al. for the WHO Global Surveillance and Monitoring Project. Global burden of tuberculosis: estimated incidence, prevalence and mortality by country. JAMA 1999;282:677-86.

  23. Cantwell MF, Snider DE, Cauthen GM et al. Epidemiology of tuberculosis in the United States, 1985 through 1992. JAMA 1994;272:535-39.

  24. Ungo JR, Jones D, Ashkin D et al. Antituberculosis drug induced hepatotoxicity: the role of hepatitis C and the human immunodeficiency virus. Am J Respir Crit Care Med 1998;157:1871-76.

  25. Canadian Medical Association. Counselling guidelines for HIV
    testing    . Ottawa: CMA, 1995.

  26. Rowan MS, Toombs M, Bally G et al. Qualitative evaluation of the Canadian Medical Association's counselling guidelines for HIV serologic testing. Can Med Assoc J 1996;154:665-71.

  27. CDC. Missed opportunities for prevention of tuberculosis among persons with HIV infection - selected locations, United States, 1996-1997. MMWR 2000;49 (30):685-87.

  28. Marks SM, Taylor Z, Qualls NL et al. Outcomes of contact investigations of infectious tuberculosis patients. Am J Respir Crit Care Med 2000;162:2033-38.

* Members: Dr. V. Hoeppner (Chair); Dr. M Baikie; Dr. C Balram; Ms. P. Bleackley; Ms. C. Case; Dr. E. Ellis (Executive Secretary); R.K. Elwood (Past Chair); Ms. P. Gaba;, Dr. B. Graham; Dr. B. Gushulak; Ms. C. Helmsley; Dr. E.S. Hershfield; Ms. R. Hickey; Dr. A. Kabani; Dr. B. Kawa; Dr. R. Long; Dr. F. Stratton; Ms. N. Sutton; Dr. L. Sweet; Dr. T.N. Tannenbaum.

† This statement was prepared by Dr. R. Long, Dr. S. Houston, and Dr. E.S. Hershfield. It has been approved by the Canadian Tuberculosis Committee, Canadian Thoracic Society of the Canadian Lung Association, Canadian Infectious Disease Society, and Centre for Infectious Disease Prevention and Control, Public Health Agency of Canada, Health Canada.

[Canada Communicable Disease Report]
Last Updated: 2002-12-15 Top
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