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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:
-
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.
-
Health care workers caring for patients with HIV
infection should maintain a high level of
suspicion for TB.
-
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.
-
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.
-
For those in whom annual testing is felt to be
justified by high infection rates, a baseline two
step TST should be considered(2).
-
Induration of >= 5 mm on the TST should be
considered indicative of TB
infection(2,3).
-
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).
-
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).
-
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: http://www.lung.ca/cts-sct/pdf/tbstand07_e.pdf
-
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.
-
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.
-
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.
-
The administration of BCG vaccine to HIV-infected
patients is contraindicated because of its
potential to cause disseminated disease.
-
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:
-
All patients with newly diagnosed TB should be
strongly encouraged to undergo HIV serologic
testing according to established
guidelines(25,26).
-
HIV-testing of contacts of infectious TB cases
should be considered if they are at risk for
HIV(27,28).
-
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
-
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.
-
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.
-
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.
-
Narain JP, Raviglione MC, Kochi A.
HIV-associated tuberculosis in developing
countries: epidemiology and strategies for
prevention. Tubercle Lung Dis 1992;73:311-21.
-
Long R, Njoo H, Hershfield E. Tuberculosis:
3. The epidemiology of the disease in
Canada. Can Med Assoc J 1999;160:1185-90.
-
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.
-
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.
-
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.
-
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.
-
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.
-
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.
-
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.
-
CDC. Anergy skin testing and tuberculosis
preventive therapy for HIV-infected persons:
revised recommendations. MMWR
1997;46(RR-15):1-10.
-
Slovis BS, Plitman JD, Haas DW. The case
against anergy testing as routine adjunct to
tuberculin skin testing. JAMA
2000;283:2003-2007.
-
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.
-
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.
-
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.
-
CDC. USPHS/IDSA guidelines for the prevention
of opportunistic infections in persons infected
with human immunodeficiency virus. MMWR
1997;46(RR-12):1-46.
-
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.
-
American Thoracic Society. Targeted tuberculin
testing and treatment of latent tuberculosis
infection. Am J Respir Crit Care Med
2000;161(supplement):S221-S247.
-
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.
-
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.
-
Cantwell MF, Snider DE, Cauthen GM et al.
Epidemiology of tuberculosis in the United
States, 1985 through 1992. JAMA
1994;272:535-39.
-
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.
-
Canadian Medical Association. Counselling
guidelines for HIV
testing. Ottawa: CMA, 1995.
-
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.
-
CDC. Missed opportunities for prevention of
tuberculosis among persons with HIV infection -
selected locations, United States, 1996-1997.
MMWR 2000;49 (30):685-87.
-
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]
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