The risk of progression from exposure to the tuberculosis bacilli to the development of active disease is a two-stage process governed by both exogenous and endogenous risk factors. Exogenous factors play a key role in accentuating the progression from exposure to infection among which the bacillary load in the sputum and the proximity of an individual to an infectious TB case are key factors. Similarly endogenous factors lead in progression from infection to active TB disease. Along with well-established risk factors (such as human immunodeficiency virus (HIV), malnutrition, and young age), emerging variables such as diabetes, indoor air pollution, alcohol, use of immunosuppressive drugs, and tobacco smoke play a significant role at both the individual and population level. Socioeconomic and behavioral factors are also shown to increase the susceptibility to infection. Specific groups such as health care workers and indigenous population are also at an increased risk of TB infection and disease. This paper summarizes these factors along with health system issues such as the effects of delay in diagnosis of TB in the transmission of the bacilli. 1. Introduction In addition to providing effective treatment and reducing mortality, a primary aim of tuberculosis (TB) control programs in countries of high TB incidence is to reduce the transmission from infectious TB cases. The development of TB in an exposed individual is a two-stage process following infection. In most infected persons, infection is contained by the immune system and bacteria become walled off in caseous granulomas or tubercles. In about 5% of infected cases, rapid progression to tuberculosis will occur within the first two years after infection [1]. About 10% of people with latent infection will reactivate, half within the first year, the remainder over their lifetime [2–7] mostly by reactivation of the dormant tubercle bacilli acquired from primary infection or less frequently by reinfection. Overall, about 10–15% of those infected go on to develop active disease at some stage later in life [2], but the risk of progression is much higher at about 10% per year [8, 9] in HIV-positive and other immunocompromized individuals. The risk of progression to infection and disease is two different aspects and proper understanding of these factors is essential for planning TB control strategies [10]. The risk of infection following TB exposure is primarily governed by exogenous factors and is determined by an intrinsic combination of the infectiousness of the source case, proximity to contact and
References
[1]
I. Sutherland, The Ten-Year Incidence of Clinical Tuberculosis Following “Conversion” in 2550 Individuals Aged 14 To 19 Years, The Hague, Netherlands, 1968.
[2]
D. Maher, “The natural history of Mycobacterium tuberculosis infection in adults,” in Tuberculosis: A Comprehensive Clinical Reference, H. S. Schaaf and A. Zumla, Eds., pp. 129–132, Elsevier Health Sciences, 2009.
[3]
I. Sutherland, “Recent studies in the epidemiology of tuberculosis, based on the risk of being infected with tubercle bacilli,” Advances in Tuberculosis Research, vol. 19, pp. 1–63, 1976.
[4]
E. Vynnycky and P. E. M. Fine, “The natural history of tuberculosis: the implications of age-dependent risks of disease and the role of reinfection,” Epidemiology and Infection, vol. 119, no. 2, pp. 183–201, 1997.
[5]
P. A. Selwyn, D. Hartel, V. A. Lewis et al., “A prospective study of the risk of tuberculosis among intravenous drug users with human immunodeficiency virus infection,” The New England Journal of Medicine, vol. 320, no. 9, pp. 545–550, 1989.
[6]
G. Antonucci, E. Girardi, M. C. Raviglione, and G. Ippolito, “Risk factors for tuberculosis in HIV-infected persons: a prospective cohort study,” Journal of the American Medical Association, vol. 274, no. 2, pp. 143–148, 1995.
[7]
S. Lawn and L. G. Bekker, “Co pathogenesis of Tuberculosis and HIV,” in Tuberculosis: A Comprehensive Clinical Reference, H. S. Schaaf and A. Zumla, Eds., pp. 96–106, Elsevier, 2009.
[8]
E. Girardi, M. C. Raviglione, G. Antonucci, P. Godfrey-Faussett, and G. Ippolito, “Impact of the HIV epidemic on the spread of other diseases: the case of tuberculosis,” AIDS, vol. 14, no. 3, pp. S47–S56, 2000.
[9]
E. L. Corbett, C. J. Watt, N. Walker et al., “The growing burden of tuberculosis: global trends and interactions with the HIV epidemic,” Archives of Internal Medicine, vol. 163, no. 9, pp. 1009–1021, 2003.
[10]
I. Romieu and C. Trenga, “From exposure to disease: the role of environmental factors in susceptibility to and development of tuberculosis,” Epidemiologic Reviews, vol. 23, no. 2, pp. 288–301, 2001.
[11]
F. M. McPhendran and E. L. Opie, “The spread of Tuberculosis in families,” American Journal of Epidemiology, vol. 22, no. 3, pp. 565–643, 1935.
[12]
J. B. Shaw and N. Wynn-Williams, “Infectivity of pulmonary tuberculosis in relation to sputum status,” American Review of Tuberculosis, vol. 69, no. 5, pp. 724–732, 1954.
[13]
N. Ait-Khaled and D. Enarson, Tuberculosis: A manual for medical Students, World Health Organization, 2003.
[14]
M. A. Espinal, E. N. Peréz, J. Baéz et al., “Infectiousness of Mycobacterium tuberculosis in HIV-1-infected patients with tuberculosis: a prospective study,” The Lancet, vol. 355, no. 9200, pp. 275–280, 2000.
[15]
E. Hernández-Gardu？o, V. Cook, D. Kunimoto, R. K. Elwood, W. A. Black, and J. M. FitzGerald, “Transmission of tuberculosis from smear negative patients: a molecular epidemiology study,” Thorax, vol. 59, no. 4, pp. 286–290, 2004.
[16]
G. L. Hobby, A. P. Holman, M. D. Iseman, and J. M. Jones, “Enumeration of tubercle bacilli in sputum of patients with pulmonary tuberculosis,” Antimicrobial Agents and Chemotherapy, vol. 4, no. 2, pp. 94–104, 1973.
[17]
A. S. Dharmadhikari and E. Nardell, “Transmission of Mycobacterium tuberculosis,” in Tuberculosis: A Comprehensive Clinical Reference, H. S. Schaaf and A. Zumla, Eds., pp. 8–17, Elsevier Health Sciences, 2009.
[18]
D. Menzies, “Issues in the management of contacts of patients with active pulmonary tuberculosis,” Canadian Journal of Public Health, vol. 88, no. 3, pp. 197–201, 1997.
[19]
S. Andersen and A. Geser, “The distribution of tuberculous infection among households in African communities,” Bulletin of the World Health Organization, vol. 22, pp. 39–60, 1960.
[20]
R. Narain, S. S. Nair, G. R. Rao, and P. Chandrasekhar, “Distribution of tuberculous infection and disease among households in a rural community,” Bulletin of the World Health Organization, vol. 34, no. 4, pp. 639–654, 1966.
[21]
A. Rouillon, S. Perdrizet, and R. Parrot, “Transmission of tubercle bacilli: the effects of chemotherapy,” Tubercle, vol. 57, no. 4, pp. 275–299, 1976.
[22]
W. Schilling, “Epidemiology and surveillance of tuberculosis in the German Democratic Republic,” Bulletin of the International Union Against Tuberculosis and Lung Disease, vol. 65, no. 2-3, pp. 40–42, 1990.
[23]
D. A. Enarson, E. A. Fanning, and E. A. Allen, “Case-finding in the elimination phase of tuberculosis: high risk groups in epidemiology and clinical practice,” Bulletin of the International Union Against Tuberculosis and Lung Disease, vol. 65, no. 2-3, pp. 73–74, 1990.
[24]
S. Etkind, “Contact tracing,” in Tuberculosis: A Comprehensive International Approach, L. B. Reichman and E. S. Hershfield, Eds., vol. 144, pp. 275–289, Marcel Dekker, New York, NY, USA, 1993.
[25]
V. K. Dhingra, S. Rajpal, N. Aggarwal, and D. K. Taneja, “Tuberculosis trend among household contacts of TB patients,” Indian Journal of Community Medicine, vol. 29, no. 1, pp. 1–3, 2004.
[26]
S. Radhakrishna, T. R. Frieden, R. Subramani, T. Santha, P. R. Narayanan, and T. R. Frieden, “Additional risk of developing TB for household members with a TB case at home at intake: a 15-year study,” The International Journal of Tuberculosis and Lung Disease, vol. 11, no. 3, pp. 282–288, 2007.
[27]
M. Singh, M. L. Mynak, L. Kumar, J. L. Mathew, and S. K. Jindal, “Prevalence and risk factors for transmission of infection among children in household contact with adults having pulmonary tuberculosis,” Archives of Disease in Childhood, vol. 90, no. 6, pp. 624–628, 2005.
[28]
H. A. van Geuns, J. Meijer, and K. Styblo, “Results of contact examination in Rotterdam, 1967–1969,” Bulletin of the International Union against Tuberculosis, vol. 50, no. 1, pp. 107–121, 1975.
[29]
M. A. Behr, S. A. Warren, H. Salamon et al., “Transmission of Mycobacterium tuberculosis from patients smear-negative for acid-fast bacilli,” The Lancet, vol. 353, no. 9151, pp. 444–449, 1999.
[30]
R. K. Elwood, V. J. Cook, and E. Hernández-Gardu？o, “Risk of tuberculosis in children from smear-negative source cases,” International Journal of Tuberculosis and Lung Disease, vol. 9, no. 1, pp. 49–55, 2005.
[31]
A. Tostmann, S. V. Kik, N. A. Kalisvaart et al., “Tuberculosis transmission by patients with smear-negative pulmonary tuberculosis in a large cohort in the Netherlands,” Clinical Infectious Diseases, vol. 47, no. 9, pp. 1135–1142, 2008.
[32]
S. Grzybowski, G. D. Barnett, and K. Styblo, “Contacts of cases of active pulmonary tuberculosis,” Bulletin of the International Union against Tuberculosis, vol. 50, no. 1, pp. 90–106, 1975.
[33]
R. Joshi, A. L. Reingold, D. Menzies, and M. Pai, “Tuberculosis among health-care workers in low- and middle-income countries: a systematic review,” PLoS Medicine, vol. 3, no. 12, article e494, 2006.
[34]
W. H. Frost, “Risk of persons in familial contact with pulmonary tuberculosis,” American Journal of Public Health, vol. 23, no. 5, pp. 426–432, 1933.
[35]
E. L. Opie and F. M. McPhendran, “Spread of tuberculosis within families,” The Journal of the American Medical Association, vol. 87, no. 19, pp. 1549–1551, 1926.
[36]
S. Devadatta, J. J. Dawson, W. Fox et al., “Attack rate of tuberculosis in a 5-year period among close family contacts of tuberculous patients under domiciliary treatment with isoniazid plus PAS or isoniazid alone,” Bulletin of the World Health Organization, vol. 42, no. 3, pp. 337–351, 1970.
[37]
R. H. Andrews, W. Fox, S. Devadatta, and S. Radhakrishna, “Prevalence of tuberculosis among close family contacts of tuberculous patients in South India, and influence of segregation of the patient on the early attack rate,” Bulletin of the World Health Organization, vol. 23, pp. 463–510, 1960.
[38]
S. R. Kamat, J. J. Dawson, S. Devadatta et al., “A controlled study of the influence of segregation of tuberculous patients for one year on the attack rate of tuberculosis in a 5-year period in close family contacts in South India,” Bulletin of the World Health Organization, vol. 34, no. 4, pp. 517–532, 1966.
[39]
J. Morrison, M. Pai, and P. C. Hopewell, “Tuberculosis and latent tuberculosis infection in close contacts of people with pulmonary tuberculosis in low-income and middle-income countries: a systematic review and meta-analysis,” The Lancet Infectious Diseases, vol. 8, no. 6, pp. 359–368, 2008.
[40]
D. Menzies, K. Schwartzman, and M. Pai, “Immune-based tests for tuberculosis,” in Tuberculosis: A Comprehensive Clinical Reference, H. S. Schaaf and A. Zumla, Eds., pp. 179–196, Elsevier Health Sciences, 2009.
[41]
S. Ferebee, “Controlled chemoprophylaxis trials in tuberculosis. A general review,” Advances in Tuberculosis Research, vol. 17, pp. 28–106, 1970.
[42]
T. A. Kenyon, S. E. Valway, W. W. Ihle, I. M. Onorato, and K. G. Castro, “Transmission of multidrug-resistant Mycobacterium tuberculosis during a long airplane flight,” The New England Journal of Medicine, vol. 334, no. 15, pp. 933–938, 1996.
[43]
J. Veen, “Microepidemics of tuberculosis: the stone-in-the-pond principle,” Tubercle and Lung Disease, vol. 73, no. 2, pp. 73–76, 1992.
[44]
E. T. Blomquist, “Tuberculosis casefinding, 1961,” Public Health Reports, vol. 76, no. 10, pp. 871–876, 1961.
[45]
G. Rose, “Sick individuals and sick populations,” International Journal of Epidemiology, vol. 30, no. 3, pp. 427–432, 2001.
[46]
T. M. Daniel, “The history of tuberculosis: past, present, and challenges for the future,” in Tuberculosis: A Comprehensive Clinical Reference, H. S. Schaaf and A. Zumla, Eds., pp. 1–8, Elsevier Saunders, London, UK, 1st edition, 2009.
[47]
A. S. Pope, P. E. Sartwell, and D. Zacks, “Development of tuberculosis in infected children,” American Journal of Public Health, vol. 29, no. 12, pp. 1318–1325, 1939.
[48]
M. Brailey, “A study of tuberculous infection and mortality in the children of tuberculous households,” American Journal of Epidemiology, vol. 31, no. 1, pp. 1–43, 1940.
[49]
F. J. W. Miller, R. M. E. Seal, and M. D. Taylor, Tuberculosis in Children: Evolution, Control, Treatment, J. & A. Churchill, 1963.
[50]
S. S. Nair, G. R. Rao, and P. Chandrasekhar, “Distribution of tuberculous infection and disease in clusters of rural households,” Indian Journal of Tuberculosis, vol. 28, no. 1, pp. 3–9, 1971.
[51]
W. R. Bishai, N. M. H. Graham, S. Harrington et al., “Molecular and geographic patterns of tuberculosis transmission after 15 years of directly observed therapy,” Journal of the American Medical Association, vol. 280, no. 19, pp. 1679–1684, 1998.
[52]
D. P. Chin, C. M. Crane, M. Y. Diul et al., “Spread of Mycobacterium tuberculosis in a community implementing recommended elements of tuberculosis control,” Journal of the American Medical Association, vol. 283, no. 22, pp. 2968–2974, 2000.
[53]
W. Z. Bradford, J. Koehler, H. El-Hajj et al., “Dissemination of Mycobacterium tuberculosis across the San Francisco Bay Area,” Journal of Infectious Diseases, vol. 177, no. 4, pp. 1104–1107, 1998.
[54]
J. Cacho Calvo, J. Astray Mochales, A. Pérez Meixeira, A. Ramos Martos, M. Hernando García, M. Sánchez Concheiro, et al., “Ten-year population-based molecular epidemiological study of tuberculosis transmission in the metropolitan area of Madrid, Spain,” The International Journal of Tuberculosis and Lung Disease, vol. 9, no. 11, pp. 1236–1241, 2005.
[55]
R. Diel, S. Schneider, K. Meywald-Walter, C. M. Ruf, S. Rüsch-Gerdes, and S. Niemann, “Epidemiology of tuberculosis in Hamburg, Germany: long-term population-based analysis applying classical and molecular epidemiological techniques,” Journal of Clinical Microbiology, vol. 40, no. 2, pp. 532–539, 2002.
[56]
M. Ruiz Garcia, J. C. Rodríguez, J. F. Navarro, S. Samper, C. Martín, and G. Royo, “Molecular epidemiology of tuberculosis in Elche, Spain: a 7-year study,” Journal of Medical Microbiology, vol. 51, no. 3, pp. 273–277, 2002.
[57]
S. Narayanan, S. Das, R. Garg et al., “Molecular epidemiology of tuberculosis in a rural area of high prevalence in South India: implications for disease control and prevention,” Journal of Clinical Microbiology, vol. 40, no. 12, pp. 4785–4788, 2002.
[58]
C. N. Classen, R. Warren, M. Richardson et al., “Impact of social interactions in the community on the transmission of tuberculosis in a high incidence area,” Thorax, vol. 54, no. 2, pp. 136–140, 1999.
[59]
S. Verver, R. M. Warren, Z. Munch et al., “Proportion of tuberculosis transmission that takes place in households in a high-incidence area,” The Lancet, vol. 363, no. 9404, pp. 212–214, 2004.
[60]
J. E. Golub, W. A. Cronin, O. O. Obasanjo et al., “Transmission of Mycobacterium tuberculosis through casual contact with an infectious case,” Archives of Internal Medicine, vol. 161, no. 18, pp. 2254–2258, 2001.
[61]
B. J. Marais, C. C. Obihara, R. M. Warren, H. S. Schaaf, R. P. Gie, and P. R. Donald, “The burden of childhood tuberculosis: a public health perspective,” International Journal of Tuberculosis and Lung Disease, vol. 9, no. 12, pp. 1305–1313, 2005.
[62]
J. P. Aparicio, A. F. Capurro, and C. Castillo-Chavez, “Transmission and dynamics of tuberculosis on generalized households,” Journal of Theoretical Biology, vol. 206, no. 3, pp. 327–341, 2000.
[63]
E. L. Corbett, B. Marston, G. J. Churchyard, and K. M. De Cock, “Tuberculosis in sub-Saharan Africa: opportunities, challenges, and change in the era of antiretroviral treatment,” The Lancet, vol. 367, no. 9514, pp. 926–937, 2006.
[64]
H. C. Bucher, L. E. Griffith, G. H. Guyatt et al., “Isoniazid prophylaxis for tuberculosis in HIV infection: a meta-analysis of randomized controlled trials,” AIDS, vol. 13, no. 4, pp. 501–507, 1999.
[65]
M. Miles Braun, N. Badi, R. W. Ryder et al., “A retrospective cohort study of the risk of tuberculosis among women of childbearing age with HIV infection in Zaire,” American Review of Respiratory Disease, vol. 143, no. 3 I, pp. 501–504, 1991.
[66]
C. L. Daley, P. M. Small, G. F. Schecter et al., “An outbreak of tuberculosis with accelerated progression among persons infected with the human immunodeficiency virus: an analysis using restriction-fragment-length polymorphisms,” The New England Journal of Medicine, vol. 326, no. 4, pp. 231–235, 1991.
[67]
R. W. Shafer, S. P. Singh, C. Larkin, and P. M. Small, “Exogenous reinfection with multidrug-resistant Mycobacterium tuberculosis in an immunocompetent patient,” Tubercle and Lung Disease, vol. 76, no. 6, pp. 575–577, 1995.
[68]
S. D. Lawn, L. G. Bekker, K. Middelkoop, L. Myer, and R. Wood, “Impact of HIV infection on the epidemiology of tuberculosis in a peri-urban community in South Africa: the need for age-specific interventions,” Clinical Infectious Diseases, vol. 42, no. 7, pp. 1040–1047, 2006.
[69]
K. DeRiemer, L. M. Kawamura, P. C. Hopewell, and C. L. Daley, “Quantitative impact of human immunodeficiency virus infection on tuberculosis dynamics,” American Journal of Respiratory and Critical Care Medicine, vol. 176, no. 9, pp. 936–944, 2007.
[70]
K. R. Collins, M. E. Qui？ones-Mateu, Z. Toossi, and E. J. Arts, “Impact of tuberculosis on HIV-1 replication, diversity, and disease progression,” AIDS Reviews, vol. 4, no. 3, pp. 165–176, 2002.
[71]
S. K. Sharma, A. Mohan, and T. Kadhiravan, “HIV-TB co-infection: Epidemiology, diagnosis & management,” Indian Journal of Medical Research, vol. 121, no. 4, pp. 550–567, 2005.
[72]
M. Badri, R. Ehrlich, R. Wood, T. Pulerwitz, and G. Maartens, “Association between tuberculosis and HIV disease progression in a high tuberculosis prevalence area,” International Journal of Tuberculosis and Lung Disease, vol. 5, no. 3, pp. 225–232, 2001.
[73]
C. Whalen, C. R. Horsburgh, D. Hom, C. Lahart, M. Simberkoff, and J. Ellner, “Accelerated course of human immunodeficiency virus infection after tuberculosis,” American Journal of Respiratory and Critical Care Medicine, vol. 151, no. 1, pp. 129–135, 1995.
[74]
R. Smith, A. Cattamanchi, K. R. Steingart, C. Denkinger, K. Dheda, K. L. Winthrop, et al., “Interferon-gamma release assays for diagnosis of latent tuberculosis infection: evidence in immune-mediated inflammatory disorders,” Current Opinion in Rheumatology, vol. 23, no. 4, pp. 377–384, 2011.
[75]
K. L. Winthrop, “Risk and prevention of tuberculosis and other serious opportunistic infections associated with the inhibition of tumor necrosis factor,” Nature Clinical Practice Rheumatology, vol. 2, no. 11, pp. 602–610, 2006.
[76]
K. L. Winthrop and T. Chiller, “Preventing and treating biologic-associated opportunistic infections,” Nature reviews. Rheumatology, vol. 5, no. 7, pp. 405–410, 2009.
[77]
D. P. De Leon, E. Acevedo-Vasquez, S. Alvizuri et al., “Comparison of an interferon-γ assay with tuberculin skin testing for detection of tuberculosis (TB) infection in patients with rheumatoid arthritis in a TB-endemic population,” Journal of Rheumatology, vol. 35, no. 5, pp. 776–781, 2008.
[78]
M. Pai, “Spectrum of latent tuberculosis existing tests cannot resolve the underlying phenotypes,” Nature Reviews Microbiology, vol. 8, no. 3, p. 242, 2010.
[79]
J. P. Cegielski and D. N. McMurray, “The relationship between malnutrition and tuberculosis: evidence from studies in humans and experimental animals,” International Journal of Tuberculosis and Lung Disease, vol. 8, no. 3, pp. 286–298, 2004.
[80]
K. L？nnroth, B. G. Williams, P. Cegielski, and C. Dye, “A consistent log-linear relationship between tuberculosis incidence and body mass index,” International Journal of Epidemiology, vol. 39, no. 1, Article ID dyp308, pp. 149–155, 2010.
[81]
R. K. Chandra, “Nutrition and the immune system: an introduction,” The American Journal of Clinical Nutrition, vol. 66, no. 2, pp. 460S–463S, 1997.
[82]
R. K. Chandra and S. Kumari, “Nutrition and immunity: an overview,” Journal of Nutrition, vol. 124, supplement 8, pp. 1433S–1435S, 1994.
[83]
K. Abba, T. D. Sudarsanam, L. Grobler, and J. Volmink, “Nutritional supplements for people being treated for active tuberculosis,” Cochrane Database of Systematic Reviews, no. 4, Article ID CD006086, 2008.
[84]
G. W. Comstock and C. E. Palmer, “Long-term results of BCG vaccination in the southern United States,” American Review of Respiratory Disease, vol. 93, no. 2, pp. 171–183, 1966.
[85]
J. P. Cegielski, L. Kohlmeier, and J. Cornoni-Huntley, “Malnutrition and tuberculosis in a nationally representative cohort of adults in the United States, 1971–1987,” in Proceedings of the 44th Annual Meeting, American Society of Tropical Medicine and Hygiene, p. 152, American Society of Tropical Medicine and Hygiene, San Antonio, Tex, USA, 1995.
[86]
P. Davies, “The natural history of tuberculosis in children,” Tubercle, vol. 42, pp. 1–40, 1961.
[87]
L. D. Zeidberg, R. S. Gass, A. Dillon, and R. H. Hutcheson, “The Williamson County Tuberculosis Study. A twenty-four-year epidemiologic study,” The American Review of Respiratory Disease, vol. 87, article 1, 1963.
[88]
B. J. Marais, R. P. Gie, H. S. Schaaf et al., “The clinical epidemiology of childhood pulmonary tuberculosis: a critical review of literature from the pre-chemotherapy era,” International Journal of Tuberculosis and Lung Disease, vol. 8, no. 3, pp. 278–285, 2004.
[89]
F. J. Bentley, S. Grzybowski, and B. Benjamin, Tuberculosis in Childhood and Adolescence, 1954, National Association for the Prevention of Tuberculosis, London, UK, 1954.
[90]
B. J. Marais and P. R. Donald, “The natural history of tuberculosis infection and disease in children,” in Tuberculosis: A Comprehensive Clinical Reference, H. S. Schaaf and A. Zumla, Eds., Elsevier Health Sciences, 2009.
[91]
B. Alisjahbana, R. Van Crevel, E. Sahiratmadja, M. den Heijer, A. Maya, E. Istriana, et al., “Diabetes mellitus is strongly associated with tuberculosis in Indonesia,” The International Journal of Tuberculosis and Lung Disease, vol. 10, no. 6, pp. 696–700, 2006.
[92]
S. J. Kim, Y. P. Hong, W. J. Lew, S. C. Yang, and E. G. Lee, “Incidence of pulmonary tuberculosis among diabetics,” Tubercle and Lung Disease, vol. 76, no. 6, pp. 529–533, 1995.
[93]
World Health Organization, “Equity, Social Determinants and Public Health Programmes,” Geneva: World Health Organization, http://books.google.co.in/books?id=7JxutqCmctUC, 2010.
[94]
W. Rathmann, G. Giani, S. H. Wild et al., “Global prevalence of diabetes: estimates for the year 2000 and projections for 2030,” Diabetes Care, vol. 27, no. 10, pp. 2568–2569, 2004.
[95]
C. Y. Jeon and M. B. Murray, “Diabetes mellitus increases the risk of active tuberculosis: a systematic review of 13 observational studies,” PLoS Med, vol. 5, no. 7, article e152, 2008.
[96]
B. Alisjahbana, E. Sahiratmadja, E. J. Nelwan, A. M. Purwa, Y. Ahmad, T. H. M. Ottenhoff, et al., “The effect of type 2 diabetes mellitus on the presentation and treatment response of pulmonary tuberculosis,” Clinical Infectious Diseases, vol. 45, no. 4, pp. 428–435, 2007.
[97]
M. Baker, A. Harries, C. Jeon, J. Hart, A. Kapur, K. Lonnroth, et al., “The impact of diabetes on tuberculosis treatment outcomes: a systematic review,” BMC Medicine, vol. 9, article 81, 2011.
[98]
G. W. Martens, M. C. Arikan, J. Lee, F. Ren, D. Greiner, and H. Kornfeld, “Tuberculosis susceptibility of diabetic mice,” American Journal of Respiratory Cell and Molecular Biology, vol. 37, no. 5, pp. 518–524, 2007.
[99]
J. E. Stalenhoef, B. Alisjahbana, E. J. Nelwan et al., “The role of interferon-gamma in the increased tuberculosis risk in type 2 diabetes mellitus,” European Journal of Clinical Microbiology and Infectious Diseases, vol. 27, no. 2, pp. 97–103, 2008.
[100]
M. Delamaire, D. Maugendre, M. Moreno, M. C. Le Goff, H. Allannic, and B. Genetet, “Impaired leucocyte functions in diabetic patients,” Diabetic Medicine, vol. 14, no. 1, pp. 29–34, 1997.
[101]
K. E. Dooley and R. E. Chaisson, “Tuberculosis and diabetes mellitus: convergence of two epidemics,” The Lancet Infectious Diseases, vol. 9, no. 12, pp. 737–746, 2009.
[102]
R. M. Anjana, R. Pradeepa, M. Deepa, M. Datta, V. Sudha, R. Unnikrishnan, et al., “ICMR-INDIAB Collaborative Study Group: prevalence of diabetes and prediabetes (impaired fasting glucose and/or impaired glucose tolerance) in urban and rural India: phase I results of the Indian Council of Medical Research-INdia DIABetes (ICMR-INDIAB) study,” Diabetologia, vol. 54, pp. 3022–3027, 2011.
[103]
R. Ruslami, R. E. Aarnoutse, B. Alisjahbana, A. van der ven, and R. van Crevel, “Implications of the global increase of diabetes for tuberculosis control and patient care,” Tropical Medicine & International Health, vol. 15, no. 11, pp. 1289–1299, 2010.
[104]
A. Seidler, A. Nienhaus, and R. Diel, “Review of epidemiological studies on the occupational risk of tuberculosis in low-incidence areas,” Respiration, vol. 72, no. 4, pp. 431–446, 2005.
[105]
J. N. S. Eisenberg, M. A. Desai, K. Levy et al., “Environmental determinants of infectious disease: a framework for tracking causal links and guiding public health research,” Environmental Health Perspectives, vol. 115, no. 8, pp. 1216–1223, 2007.
[106]
C. Dye and B. G. Williams, “The population dynamics and control of tuberculosis,” Science, vol. 328, no. 5980, pp. 856–861, 2010.
[107]
K. L？nnroth, E. Jaramillo, B. G. Williams, C. Dye, and M. Raviglione, “Drivers of tuberculosis epidemics: the role of risk factors and social determinants,” Social Science and Medicine, vol. 68, no. 12, pp. 2240–2246, 2009.
[108]
M. Muniyandi, R. Ramachandran, P. G. Gopi et al., “The prevalence of tuberculosis in different economic strata: a community survey from South India,” International Journal of Tuberculosis and Lung Disease, vol. 11, no. 9, pp. 1042–1045, 2007.
[109]
O. 'Grady J, M. Maeurer, R. Atun, I. Abubakar, P. Mwaba, M. Bates, et al., “Tuberculosis in prisons: anatomy of global neglect,” European Respiratory Journal, vol. 38, no. 4, pp. 752–754, 2011.
[110]
C. Raina MacIntyre, N. Kendig, L. Kummer, S. Birago, and N. M. H. Graham, “Impact of tuberculosis control measures and crowding on the incidence of tuberculous infection in Maryland prisons,” Clinical Infectious Diseases, vol. 24, no. 6, pp. 1060–1067, 1997.
[111]
V. Maurya, V. K. Vijayan, and A. Shah, “Smoking and tuberculosis: an association overlooked,” International Journal of Tuberculosis and Lung Disease, vol. 6, no. 11, pp. 942–951, 2002.
[112]
L. Arcavi and N. L. Benowitz, “Cigarette smoking and infection,” Archives of Internal Medicine, vol. 164, no. 20, pp. 2206–2216, 2004.
[113]
D. G. Yanbaeva, M. A. Dentener, E. C. Creutzberg, G. Wesseling, and E. F. M. Wouters, “Systemic effects of smoking,” Chest, vol. 131, no. 5, pp. 1557–1566, 2007.
[114]
M. N. Bates, A. Khalakdina, M. Pai, L. Chang, F. Lessa, and K. R. Smith, “Risk of tuberculosis from exposure to tobacco smoke: a systematic review and meta-analysis,” Archives of Internal Medicine, vol. 167, no. 4, pp. 335–342, 2007.
[115]
K. Slama, C. Y. Chiang, D. A. Enarson et al., “Tobacco and tuberculosis: a qualitative systematic review and meta-analysis,” International Journal of Tuberculosis and Lung Disease, vol. 11, no. 10, pp. 1049–1061, 2007.
[116]
M. Pai, A. Mohan, K. Dheda et al., “Lethal interaction: the colliding epidemics of tobacco and tuberculosis,” Expert Review of Anti-Infective Therapy, vol. 5, no. 3, pp. 385–391, 2007.
[117]
H. H. Lin, M. Ezzati, and M. Murray, “Tobacco smoke, indoor air pollution and tuberculosis: a systematic review and meta-analysis,” PLoS Medicine, vol. 4, no. 1, article e20, 2007.
[118]
E. Houtmeyers, R. Gosselink, G. Gayan-Ramirez, and M. Decramer, “Regulation of mucociliary clearance in health and disease,” European Respiratory Journal, vol. 13, no. 5, pp. 1177–1188, 1999.
[119]
M. Sopori, “Effects of cigarette smoke on the immune system,” Nature Reviews Immunology, vol. 2, no. 5, pp. 372–377, 2002.
[120]
H. Wang, M. Yu, M. Ochani et al., “Nicotinic acetylcholine receptor α7 subunit is an essential regulator of inflammation,” Nature, vol. 421, no. 6921, pp. 384–388, 2003.
[121]
S. Shang, D. Ordway, M. Henao-Tamayo et al., “Cigarette smoke increases susceptibility to tuberculosis-evidence from in vivo and in vitro models,” Journal of Infectious Diseases, vol. 203, no. 9, pp. 1240–1248, 2011.
[122]
K. L？nnroth, B. G. Williams, S. Stadlin, E. Jaramillo, and C. Dye, “Alcohol use as a risk factor for tuberculosis-a systematic review,” BMC Public Health, vol. 8, article 289, 2008.
[123]
A. Fok, Y. Numata, M. Schulzer, and M. J. FitzGerald, “Risk factors for clustering of tuberculosis cases: a systematic review of population-based molecular epidemiology studies,” International Journal of Tuberculosis and Lung Disease, vol. 12, no. 5, pp. 480–492, 2008.
[124]
G. Szabo, “Alcohol's contribution to compromised immunity,” Alcohol Research and Health, vol. 21, no. 1, pp. 30–38, 1997.
[125]
K. R. Smith, “Indoor air pollution in developing countries: recommendations for research,” Indoor Air, vol. 12, no. 3, pp. 198–207, 2002.
[126]
V. K. Mishra, R. D. Retherford, and K. R. Smith, “Biomass cooking fuels and prevalence of tuberculosis in India,” International Journal of Infectious Diseases, vol. 3, no. 3, pp. 119–129, 1999.
[127]
R. Perez-Padilla, C. Perez-Guzman, R. Baez-Saldana, and A. Torres-Cruz, “Cooking with biomass stoves and tuberculosis: a case control study,” The International Journal of Tuberculosis and Lung Disease, vol. 5, no. 5, pp. 441–447, 2001.
[128]
C. Kolappan and R. Subramani, “Association between biomass fuel and pulmonary tuberculosis: a nested case-control study,” Thorax, vol. 64, no. 8, pp. 705–708, 2009.
[129]
A. K. Pokhrel, M. N. Bates, S. C. Verma, H. S. Joshi, C. T. Sreeramareddy, and K. R. Smith, “Tuberculosis and indoor biomass and kerosene use in Nepal: a case-control study,” Environmental Health Perspectives, vol. 118, no. 4, pp. 558–564, 2010.
[130]
J. V. Diaz, J. Koff, M. B. Gotway, S. Nishimura, and J. R. Balmes, “Case report: a case of wood-smoke-related pulmonary disease,” Environmental Health Perspectives, vol. 114, no. 5, pp. 759–762, 2006.
[131]
R. B. Fick Jr., E. S. Paul, and W. W. Merrill, “Alterations n the antibacterial properties of rabbit pulmonary macrophages exposed to wood smoke,” American Review of Respiratory Disease, vol. 129, no. 1, pp. 76–81, 1984.
[132]
J. T. Zelikoff, C. C. Lung, M. D. Cohen, and R. B. Schlesinger, “The toxicology of inhaled woodsmoke,” Journal of Toxicology and Environmental Health—part B: critical Reviews, vol. 5, no. 3, pp. 269–282, 2002.
[133]
B. C. Boman, A. B. Forsberg, and B. G. J？rvholm, “Adverse health effects from ambient air pollution in relation to residential wood combustion in modern society,” Scandinavian Journal of Work, Environment and Health, vol. 29, no. 4, pp. 251–260, 2003.
[134]
N. Bruce, R. Perez-Padilla, and R. Albalak, “Indoor air pollution in developing countries: a major environmental and public health challenge,” Bulletin of the World Health Organization, vol. 78, no. 9, pp. 1078–1092, 2000.
[135]
M. Ezzati and D. M. Kammen, “The health impacts of exposure to indoor air pollution from solid fuels in developing countries: knowledge, gaps, and data needs,” Environmental Health Perspectives, vol. 110, no. 11, pp. 1057–1068, 2002.
[136]
L. Wang, “Tuberculosis among aboriginal and nonaboriginal persons in British Columbia,” Canadian Respiratory Journal, vol. 7, no. 2, pp. 151–157, 2000.
[137]
A. J. Plant, V. L. Krause, J. R. Condon, and C. Kerr, “Aborigines and tuberculosis: why they are at risk,” Australian Journal of Public Health, vol. 19, no. 5, pp. 487–491, 1995.
[138]
M. Clark and E. Vynnycky, “The use of maximum likelihood methods to estimate the risk of tuberculous infection and disease in a Canadian First Nations population,” International Journal of Epidemiology, vol. 33, no. 3, pp. 477–484, 2004.
[139]
M. Clark, P. Riben, and E. Nowgesic, “The association of housing density, isolation and tuberculosis in Canadian First Nations communities,” International Journal of Epidemiology, vol. 31, no. 5, pp. 940–945, 2002.
[140]
C. M. T. Greenwood, T. M. Fujiwara, L. J. Boothroyd et al., “Linkage of tuberculosis to chromosome 2q35 loci, including NRAMP1, in a large Aboriginal Canadian family,” American Journal of Human Genetics, vol. 67, no. 2, pp. 405–416, 2000.
[141]
World Health Organization, “Global Tuberculosis Control,” http://www.who.int/tb/country/en/index.html, 2010.
[142]
J. Golub, S. Bur, W. A. Cronin et al., “Delayed tuberculosis diagnosis and tuberculosis transmission,” International Journal of Tuberculosis and Lung Disease, vol. 10, no. 1, pp. 24–30, 2006.
[143]
H. H. Lin, M. Murray, T. Cohen, C. Colijn, and M. Ezzati, “Effects of smoking and solid-fuel use on COPD, lung cancer, and tuberculosis in China: a time-based, multiple risk factor, modelling study,” The Lancet, vol. 372, no. 9648, pp. 1473–1483, 2008.
[144]
M. Demissie, B. Lindtjorn, and Y. Berhane, “Patient and health service delay in the diagnosis of pulmonary tuberculosis in Ethiopia,” BMC Public Health, vol. 2, no. 1, article 23, 2002.
[145]
C. Lienhardt, J. Rowley, K. Manneh et al., “Factors affecting time delay to treatment in a tuberculosis control programme in a sub-Saharan African country: the experience of The Gambia,” International Journal of Tuberculosis and Lung Disease, vol. 5, no. 3, pp. 233–239, 2001.
[146]
M. Pai, A. Zwerling, and D. Menzies, “Systematic review: T-cell-based assays for the diagnosis of latent tuberculosis infection: an update,” Annals of Internal Medicine, vol. 149, no. 3, pp. 177–184, 2008.
[147]
E. L. Corbett, T. Bandason, T. Duong et al., “Comparison of two active case-finding strategies for community-based diagnosis of symptomatic smear-positive tuberculosis and control of infectious tuberculosis in Harare, Zimbabwe (DETECTB): a cluster-randomised trial,” The Lancet, vol. 376, no. 9748, pp. 1244–1253, 2010.
[148]
S. Satyanarayana, S. A. Nair, S. S. Chadha, R. Shivashankar, G. Sharma, S. Yadav, et al., “From where are tuberculosis patients accessing treatment in India? Results from a cross-sectional community based survey of 30 districts,” PLoS ONE, vol. 6, no. 9, Article ID e24160, 2011.
[149]
V. Gajalakshmi, R. Peto, T. S. Kanaka, and P. Jha, “Smoking and mortality from tuberculosis and other diseases in India: retrospective study of 43 000 adult male deaths and 35000 controls,” The Lancet, vol. 362, no. 9383, pp. 507–515, 2003.
[150]
C. P. Wen, T. C. Chan, H. T. Chan, M. K. Tsai, T. Y. Cheng, and S. P. Tsai, “The reduction of tuberculosis risks by smoking cessation,” BMC Infectious Diseases, vol. 10, article 156, 2010.
[151]
K. L？nnroth and M. C. Raviglione, “Global epidemiology of tuberculosis: prospects for control,” Seminars in Respiratory and Critical Care Medicine, vol. 29, no. 5, pp. 481–491, 2008.
