Tobacco and tuberculosis.
ABSTRACT Smoking is not only the most important source of avoidable disability and death, but a risk factor for TB infection, disease and death. Even passive smoking exposure may increase the risk of infection and disease in adults and children exposed to TB. Considering the increase in tobacco consumption in developing countries, where the prevalence of TB is the highest, smoking may be responsible for a large part of the burden of disease. Therefore, medical advice and counselling in smoking cessation is an important activity for all care providers engaged in management of TB.
- SourceAvailable from: nih.govBritish medical journal 12/1956; 2(5001):1081-6.
- Thorax 08/2005; 60(7):527-8. · 8.38 Impact Factor
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ABSTRACT: Tobacco smoking, passive smoking, and indoor air pollution from biomass fuels have been implicated as risk factors for tuberculosis (TB) infection, disease, and death. Tobacco smoking and indoor air pollution are persistent or growing exposures in regions where TB poses a major health risk. We undertook a systematic review and meta-analysis to quantitatively assess the association between these exposures and the risk of infection, disease, and death from TB. We conducted a systematic review and meta-analysis of observational studies reporting effect estimates and 95% confidence intervals on how tobacco smoking, passive smoke exposure, and indoor air pollution are associated with TB. We identified 33 papers on tobacco smoking and TB, five papers on passive smoking and TB, and five on indoor air pollution and TB. We found substantial evidence that tobacco smoking is positively associated with TB, regardless of the specific TB outcomes. Compared with people who do not smoke, smokers have an increased risk of having a positive tuberculin skin test, of having active TB, and of dying from TB. Although we also found evidence that passive smoking and indoor air pollution increased the risk of TB disease, these associations are less strongly supported by the available evidence. There is consistent evidence that tobacco smoking is associated with an increased risk of TB. The finding that passive smoking and biomass fuel combustion also increase TB risk should be substantiated with larger studies in future. TB control programs might benefit from a focus on interventions aimed at reducing tobacco and indoor air pollution exposures, especially among those at high risk for exposure to TB.PLoS Medicine 02/2007; 4(1):e20. · 15.25 Impact Factor
Monaldi Arch Chest Dis
2008; 69: 2, 83-85
Tobacco and tuberculosis
Human beings are not all equally sensitive to
infection with M. tuberculosis if exposed to a
source of contamination. Among persons exposed
to the contact with an index case with transmissi-
ble tuberculosis, some will develop a latent infec-
tion. Of those with a latent tuberculosis infection,
some will develop a clinical tuberculosis, and
among those suffering from tuberculosis some will
die. Several individual factors modulate these
risks. Many of them, like HIV infection, steroid
treatment or diabetes, are related to the immune
defence mechanisms. Smoking, as one of the most
potent irritants to the airways, also influences the
local immune mechanisms of defence against in-
fection and has long been suspected of influencing
the development and outcome of tuberculosis, but
the evidence were anecdotal . Other factors, fre-
quently associated with tuberculosis and with
smoking, like abuse of alcohol, social deprivation,
homelessness and unemployment were suspected
to confound the relation [2, 3]. Recently, two sys-
tematic reviews of the existing literature have ad-
dressed in details the possible influence of smok-
ing on several aspects of tuberculosis and have
come to remarkably similar conclusions [4, 5]. Si-
multaneously, The International Union against TB
and Lung Disease and the WHO have prepared
documents addressing the relations between tobac-
co and tuberculosis, and a plan for further action
The mechanisms by which tobacco smoke can
influence the mucosal defences responsible for the
control of mycobacterial infection include the in-
crease of the production of bronchial secretions,
the decrease in mucociliary clearance, and the im-
pairment of macrophage function. This leads to a
decrease of bacterial adherence at the surface of
macrophages, a decrease of their phagocytic abili-
ty, a decrease of the release of proinflammatory
cytokines with impaired intracellular killing ca-
pacity and a reduced production of TNF-a and ni-
tric oxide (summary in ).
The influence of tobacco smoke on tuberculo-
sis can be assessed for different types of risk:
a) risk of infection if exposed to tuberculosis
(children exposed to passive smoking and
b) risk of disease if infected, (adults and chil-
c) risk of death from tuberculosis.
Risk of infection (if exposed)
Smokers have an increase in the risk of infec-
tion (usually assessed by the size of the tuberculin
reaction) if exposed to tuberculosis. This increase
has been observed in adult smokers, as well as in
non-smoking adults and children passively ex-
posed to tobacco smoke. The risk for children pas-
sively exposed to tobacco smoke and tuberculosis
was assessed in several studies in US , India
, South Africa  and Spain . The rela-
tive risk was proportional to the intensity and du-
ration of exposure and is evaluated between 1.7
and 3.2. The increased risk of infection for active
smokers was demonstrated in UK among elderly
nursing home residents , in adults in South
Africa , and Vietnam  and in incarcerated
adults in Pakistan . The risk is also proportion-
al to the intensity and duration of smoking. The
OR lies between 1.72 and 3.2 .
Risk of disease (if infected)
Once infected, only a minority of patients will
develop tuberculosis, estimates being between
10% for adults and 50% for infants under the age
of 1 year . Individual factors influence this
rate, the most important being immune deficiency
due to HIV, immunosuppressive therapy or dia-
Keywords: Tobacco smoke, Tuberculosis, Infection, Passive smoking, Developing countries.
Department of ambulatory care and community medicine, University of Lausanne, Switzerland.
Correspondence: Jean-Pierre Zellweger, MD, Department of ambulatory care and community medicine, University of Lausanne,
Switzerland; e-mail: firstname.lastname@example.org
ABSTRACT: Tobacco and tuberculosis. J.P. Zellweger.
Smoking is not only the most important source of avoid-
able disability and death, but a risk factor for TB infection,
disease and death. Even passive smoking exposure may in-
crease the risk of infection and disease in adults and children
exposed to TB. Considering the increase in tobacco con-
sumption in developing countries, where the prevalence of
TB is the highest, smoking may be responsible for a large
part of the burden of disease. Therefore, medical advice and
counselling in smoking cessation is an important activity for
all care providers engaged in management of TB.
Monaldi Arch Chest Dis 2008; 69: 2, 83-85.
betes. The increase in risk for smokers compared
to non smokers is evaluated up to 4.6 for the de-
velopment of disease. Furthermore, passive smok-
ing exposure also increases the risk of developing
tuberculosis if infected, particularly among chil-
dren, where the relative risk is between 5 and 9.3
One of the reviews also addressed the relation
between exposure to indoor air pollution (mainly
wood smoke from cooking, a general problem in
many developing countries) and demonstrated that
this was also associated with a higher risk of TB
Death from tuberculosis
Once tuberculosis has developed, most pa-
tients will be cured by an adequate treatment but in
some settings the death rate may still be elevated.
This is particularly the case among elderly patients
with diverse comorbidities, patients with lung de-
struction and chronic obstructive pulmonary dis-
eases. The OR for death from tuberculosis associ-
ated with active smoking is estimated to be 2.2 .
In India, a large survey has concluded that up to
half of all TB deaths can be attributed to smoking
. These date were confirmed by a prospective
Some studies have also concluded that the
severity of disease, the speed of bacteriological
conversion and the rate of failure and relapse may
be negatively influenced by smoking .
Public Health impact of smoking
among TB patients
Smoking has a large impact on public health,
due to the increase in risk of several severe and po-
tentially lethal diseases. It appears therefore that
the increase in smoking habit is not only the cause
of an increase in the prevalence of COPD [23, 24]
but also of tuberculosis. Considering the large and
increasing number of smokers in many developing
countries which also experience a high burden of
tuberculosis, the population attributable risk is
now considered to be significant . A recent
evaluation by WHO has come to the conclusions
that up to 16% of cases of tuberculosis in low-in-
come countries and 28% in high-burden countries
could be attributed to smoking . The associa-
tion between smoking and tuberculosis may be
even higher in populations with a large proportion
of HIV infection .
One of the intriguing questions is to know why
it has taken so long to realize the interaction be-
tween smoking and tuberculosis. One of the rea-
sons may be the fact that smoking was considered
a health problem mainly in developed countries
with a low burden of tuberculosis, whereas devel-
oping countries with a high burden of tuberculosis
had until recently a low or moderate prevalence of
smoking. One notable exception is Eastern Europe,
where the prevalence of both smoking and tubercu-
losis is high. Considering the increase in smoking
habits of the countries with the highest burden of
TB, this interaction can no more be ignored.
The practical consequence for all health care
workers active in the management of tuberculosis
is the clear obligation to address the problem of
smoking with all patients under treatment for tu-
berculosis and to advise the smokers to stop smok-
ing. In order to achieve this, training of health care
workers has to be provided. A study has demon-
strated the impact of minimal advice in such set-
tings . Patients treated by trained health care
workers have a greater chance of stopping smok-
ing at the end of the treatment of tuberculosis than
patients treated by untrained health care profes-
sionals. Tobacco cessation has to be included in
standard practice for all caregivers engaged in the
management of tuberculosis .
1. Lowe CR. An association between smoking and respi-
ratory tuberculosis. Br Med J 1956; 2: 1081-1086.
Bothamley GH. Smoking and tuberculosis: a chance or
causal association? Thorax 2005; 60: 527-528.
Lin HH, Ezzati M, Murray M. Tobacco Smoke, Indoor
Air Pollution and Tuberculosis: A Systematic Review
and Meta-Analysis. PLoS Med 2007; 4: e20.
Bates MN, Khalakdina A, Pai M, Chang L, Lessa F,
Smith KR. Risk of tuberculosis from exposure to to-
bacco smoke: a systematic review and meta-analysis.
Arch Intern Med 2007; 167: 335-342.
Fig. 1. - Impact of smoking on the airways (after ref 8).Fig. 2. - Interactions between smoking and tuberculosis.
TOBACCO AND TUBERCULOSIS
5. Chiang CY, Slama K, Enarson DA. Associations be-
tween tobacco and tuberculosis. Int J Tuberc Lung Dis
2007; 11: 258-262.
Chiang CY, Slama K, Enarson DA. Tobacco use and to-
bacco control. Int J Tuberc Lung Dis 2007; 11: 381-385.
Slama K, Chiang CY, Enarson DA. Tobacco cessation
and brief advice. Int J Tuberc Lung Dis 2007; 11: 612-
Pai M, Mohan A, Dheda K et al. Lethal interaction: the
colliding epidemics of tobacco and tuberculosis. Expert
Rev Anti Infect Ther 2007; 5: 385-391.
Kuemmerer JM, Comstock GW. Sociologic concomi-
tants of tuberculin sensitivity. Am Rev Respir Dis 1967;
Singh M, Mynak ML, Kumar L, Mathew JL, Jindal SK.
Prevalence and risk factors for transmission of infection
among children in household contact with adults having
pulmonary tuberculosis. Arch Dis Child2005; 90: 624-628.
den Boon S, Verver S, Marais BJ et al. Association be-
tween passive smoking and infection with Mycobac-
terium tuberculosis in children. Pediatrics 2007; 119:
Altet N, Alcaide J, Lozano P, Plans P, Parron I, Salleras
LI. Smoking as risk factor of tuberculosis in children
and youth. Tubercle. Lung Dis 1994; 75: 68.
Nisar M, Williams CSD, Ashby D, Davies PDO. Tu-
berculin testing in residential homes for the elderly.
Thorax 1993; 48: 1257-1260.
den Boon S, van Lill SW, Borgdorff MW, et al. Asso-
ciation between smoking and tuberculosis infection: a
population survey in a high tuberculosis incidence area.
Thorax 2005; 60: 555-557.
Plant AJ, Watkins RE, Gushulak B, et al. Predictors of
tuberculin reactivity among prospective Vietnamese
migrants: the effect of smoking. Epidemiol Infect 2002;
Hussain H, Akhtar S, Nanan D. Prevalence of and risk
factors associated with Mycobacterium tuberculosis in-
fection in prisoners, North West Frontier Province, Pak-
istan. Int J Epidemiol 2003; 32: 794-799.
17. Marais BJ, Gie RP, Schaaf HS, et al. The natural histo-
ry of childhood intra-thoracic tuberculosis: a critical re-
view of literature from the pre-chemotherapy era. Int J
Tuberc Lung Dis 2004; 8: 392-402.
Altet MN, Alcaide J, Plans P, et al. Passive smoking
and risk of pulmonary tuberculosis in children immedi-
ately following infection. A case-control study. Tuber
Lung Dis 1996; 77: 537-544.
den BS, Verver S, Marais BJ, et al. Association be-
tween passive smoking and infection with Mycobac-
terium tuberculosis in children. Pediatrics 2007; 119:
Gajalakshmi V, Peto R, Kanaka TS, Jha P. Smoking
and mortality from tuberculosis and other diseases in
India: retrospective study of 43000 adult male deaths
and 35000 controls. Lancet 2003; 362: 507-515.
Pednekar MS, Gupta PC. Prospective study of smoking
and tuberculosis in India. Prev Med 2007; 44: 496-498.
Leung CC, Li T, Lam TH, et al. Smoking and tubercu-
losis among the elderly in Hong Kong. Am J Respir Crit
Care Med 2004; 170: 1027-1033.
Ezzati M, Lopez AD. Estimates of global mortality at-
tributable to smoking in 2000. Lancet 2003; 362: 847-
Chan-Yeung M, Ait-Khaled N, White N, Ip MS, Tan
WC. The burden and impact of COPD in Asia and
Africa. Int J Tuberc Lung Dis 2004; 8 (1): 2-14.
Dagli E. Are low income countries targets of the tobac-
co industry? Int J Tuberc Lung Dis 1999; 3 (2): 113-
Brands A, Ottmani SE, Lonnroth K, et al. Reply to ‘Ad-
dressing smoking cessation in tuberculosis control’.
Bull World Health Organ 2007; 85 (8): 647-648.
El SA, Slama K, Salieh M, et al. Feasibility of brief to-
bacco cessation advice for tuberculosis patients: a study
from Sudan. Int J Tuberc Lung Dis 2007; 11 (2): 150-
Slama K, Chiang CY, Enarson DA. Introducing brief
advice in tuberculosis services. Int J Tuberc Lung Dis
2007; 11 (5): 496-499.
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