Comment
3
4 5
6
7
8
9
Charlson ES, Bittinger K, Haas AR, et al. Topographical continuity of bacterial populations in the healthy human respiratory tract. Am J Respir Crit Care Med 2011; 184: 957–63. Gleeson K, Eggli DF, Maxwell SL. Quantitative aspiration during sleep in normal subjects. Chest 1997; 111: 1266–72. Lozupone C, Cota-Gomez A, Palmer BE, et al. Widespread colonization of the lung by Tropheryma whipplei in HIV infection. Am J Respir Crit Care Med 2013; 187: 1110–17. Morris A, Beck JM, Schloss PD, et al. Comparison of the respiratory microbiome in healthy nonsmokers and smokers. Am J Respir Crit Care Med 2013; 187: 1067–75. Sloan WT, Lunn M, Woodcock S, Head IM, Nee S, Curtis TP. Quantifying the roles of immigration and chance in shaping prokaryote community structure. Environ Microbiol 2006; 8: 732–40. Charlson ES, Bittinger K, Chen J, et al. Assessing bacterial populations in the lung by replicate analysis of samples from the upper and lower respiratory tracts. PLoS One 2012; 7: e42786. Sze MA, Dimitriu PA, Hayashi S, et al. The lung tissue microbiome in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2012; 185: 1073–80.
10
11
12
13
14 15
Erb-Downward JR, Thompson DL, Han MK, et al. Analysis of the lung microbiome in the “healthy” smoker and in COPD. PLoS One 2011; 6: e16384. Huang YJ, Nelson CE, Brodie EL, et al. Airway microbiota and bronchial hyperresponsiveness in patients with suboptimally controlled asthma. J Allergy Clin Immunol 2011; 127: 372–81. Miller M Twigg HL III, Petrache I. The role of Gram negative bacteria in the susceptibility of mice to an asthmatic phenotype. Am J Respir Crit Care Med 2011; 183: A6207. Shen M, Preston AM, Gillilland MG, et al. Characterization of the lung microbiome of specific pathogen-free mice with and without exposure to cigarette smoke in vivo. Am J Respir Crit Care Med 2011; 183: A6210. Fujimura KE, Slusher NA, Cabana MD, Lynch SV. Role of the gut microbiota in defining human health. Expert Rev Anti Infect Ther 2010; 8: 435–54. Hilty M, Burke C, Pedro H, et al. Disordered microbial communities in asthmatic airways. PLoS One 2010; 5: e8578.
Tuberculosis, HIV, and type 2 diabetes mellitus: a neglected priority
Karin Schermbrucker/AP/Press Association Images
The global burden of type 2 diabetes mellitus is expected to double from 180 million to 366 million people by 2030:1 80% of adult cases are expected to occur in lowincome and middle-income countries. The prevalence of other non-communicable diseases is also rising in such countries—disease and death occurs at younger ages than in high-income countries, resulting in loss of economic output.2 The cumulative economic losses to low-income and middle-income countries from the four most prevalent non-communicable diseases (cardiovascular disease, cancer, chronic respiratory disease, and diabetes) are estimated to surpass
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US$7 trillion between 2011, and 2025: equivalent to 4% of these countries’ GDP.3 Diabetes alone is projected to cost $745 billion worldwide by 2030, $300 billion of which is expected to come from low-income and middle-income countries.3 Tuberculosis is the second highest cause of death from infectious diseases worldwide, with an estimated 9 million new cases in 2011.4 Poor adherence to treatment and an over-reliance on diagnostic tests, a vaccine, and drugs that have not changed for decades are confounding efforts to reduce the number of people with tuberculosis. The emergence of drug-resistant tuberculosis also threatens progress in mitigating the epidemic. Over the next 10 years, tuberculosis will cost an estimated $1–3 trillion globally and the World Bank estimates that it will decrease productivity by 4–7% in many high-burden countries and is predicted to cost the global economy 0·5% of gross national income.5 In 2010 terms, that loss equates to nearly $380 billion. In addition to losses in gross national income, care and control of tuberculosis are expected to cost at least $8 billion per year between 2013, and 2015.5 Furthermore, treatment for multidrugresistant tuberculosis is up to 1000 times costlier than for drug-sensitive disease, requiring 2 years of treatment, with harsh side effects.6 In South Africa alone, treatment of multidrug-resistant tuberculosis takes up to 55% of the $300–400 million national tuberculosis budget, even though it accounts for only 2% of cases.7 www.thelancet.com/respiratory Vol 1 July 2013
Comment
The link between type 2 diabetes mellitus and tuberculosis has been recognised since the early 20th century, yet more focus on the interaction between communicable and non-communicable diseases—such as type 2 diabetes mellitus and tuberculosis—is still needed. Results of a systematic review8 of 13 observational studies showed that type 2 diabetes mellitus increased the risk of tuberculosis by about a factor of three, with a stronger association in young patients and those from a population with high incidence of tuberculosis. The potential public health importance of this link was underscored by an epidemiological model suggesting that co-prevalent type 2 diabetes mellitus accounts for nearly 15% of cases of pulmonary tuberculosis in India.9 Patients with both tuberculosis and type 2 diabetes mellitus have a poorer outcome than do patients with tuberculosis alone.10 Tuberculosis can also aggravate type 2 diabetes mellitus by worsening glycaemic control, and complicating clinical management.10 A systematic review10 of the effect of type 2 diabetes mellitus on outcome of tuberculosis reported a 69% increase in mortality and risk of treatment failure, in addition to a four-times increase in the risk of relapse after treatment of tuberculosis in patients who also had type 2 diabetes mellitus compared with non-diabetic patients. Rifampicin metabolism could also be affected by type 2 diabetes mellitus, making it less effective and predisposing patients with tuberculosis to acquisition of drug resistance.11 Although evidence also suggests that diabetes alters the clinical presentation of tuberculosis, no evidence exists about whether this effect is associated with a high subclinical prevalence of tuberculosis as reported in people with tuberculosis and HIV-1 coinfection;12 which is important to consider in tuberculosis screening strategies for people with type 2 diabetes mellitus. HIV-1 coinfection—the most important contributor to the tuberculosis epidemic—is high and the availability of antiretroviral treatments has prolonged survival and ageing, with an accompanying increase in comorbidity with non-communicable diseases, including type 2 diabetes mellitus. Treatment of HIV with protease inhibitors and non-nucleoside reverse transcriptase inhibitors has been associated with insulin resistance, dyslipidaemia, and lipodystrophy, resulting in the emergence of complications such as lipid disorders, that increase the risk of cardiovascular disease.13 A study14 of adults with HIV who were www.thelancet.com/respiratory Vol 1 July 2013
taking antiretroviral therapy in Johannesburg, South Africa reported that metabolic syndrome was highly prevalent and positively correlation with CD4 cell count, presumably as a consequence of exposure to antiretroviral therapy. Furthermore, a survey13 in Cape Town, South Africa, of HIV-infected people taking antiretroviral therapy for a median of 17 months reported that the prevalence of new onset dysglycaemia was 21·9% and was significantly associated with use of efavirenz, which could contribute to the type 2 diabetes mellitus epidemic as patients receive antiretroviral therapy for longer periods. However, little is known of the association between type 2 diabetes mellitus and tuberculosis in HIV-infected people from sub-Saharan Africa. South Africa—which has the highest prevalence of HIV-1 and tuberculosis coinfection among countries with a high burden of tuberculosis—also has a high prevalence of overweight and obese people (50% of Panel: Research priorities Priorities in HIV and type 2 diabetes mellitus to improve tuberculosis control • Evaluate the population attributable fraction of tuberculosis caused by type 2 diabetes mellitus in different high tuberculosis burden settings. • Assess the effect on tuberculosis control of tuberculosis prevention strategies in people with type 2 diabetes mellitus and the effect on tuberculosis risk of isoniazid preventive therapy in all patients with type 2 diabetes mellitus, HIV coinfected people only, or tuberculosis contacts only. • Assess the effect of regular tuberculosis screening in people with type 2 diabetes mellitus on tuberculosis case-finding and outcomes. • Investigate the epidemiology of drug-resistant tuberculosis in people with type 2 diabetes mellitus. • Apply health economics research methods to evaluate the additional cost of dual management of tuberculosis and type 2 diabetes mellitus (in addition to HIV in endemic settings) and the cost-benefit ratio of addressing the type 2 diabetes mellitus epidemic in tuberculosis control. Priorities in tuberculosis and type 2 diabetes mellitus in people with HIV • Investigate the strength of the interaction between tuberculosis and type 2 diabetes mellitus in people with HIV. • Assess the potential for active screening for tuberculosis in people with type 2 diabetes mellitus to improve early detection of tuberculosis in people who also have HIV. Priorities in HIV and tuberculosis to improve control of type 2 diabetes mellitus • Investigate the effect on tuberculosis outcomes of interventions to prevent type 2 diabetes mellitus in people with tuberculosis and pre-diabetes or reversible risk factors for diabetes. • Assess the effect of intensified active type 2 diabetes mellitus screening in HIV and tuberculosis clinics on type 2 diabetes mellitus case-finding, management, and outcomes. Health systems research • Explore models of integrated care delivery for tuberculosis, HIV, and type 2 diabetes mellitus, accounting for the feasibility of integrated approaches and the effect on the health system.
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Comment
adult women15) and an epidemic of type 2 diabetes mellitus (age-adjusted prevalence 13·1%), and impaired glucose tolerance (age-adjusted prevalence 11·2%).16 Given the economic losses caused by noncommunicable diseases and the cost of drug-sensitive and drug-resistant tuberculosis, control of these epidemics is crucial. A change in the epidemiology of tuberculosis caused by HIV-1 has necessitated a shift in the focus of tuberculosis research and a reassessment of the best strategies for control, leading to new approaches—for example, intensified case finding, isoniazid preventive therapy, and antiretroviral therapy. Another reassessment is needed as a result of the increase in type 2 diabetes mellitus, since it could affect the accuracy of diagnostic instruments and the effectiveness of tuberculosis control strategies. Improved prevention and early diagnosis of tuberculosis in people with type 2 diabetes mellitus are crucial to control tuberculosis in this group. The panel summarises some priorities for research and funding. The rising prevalence of type 2 diabetes mellitus might counteract gains in tuberculosis control by adding to the disease burden in low-income and middle-income countries. This threat means that prevention of type 2 diabetes mellitus should be prioritised by addressing modifiable risk factors caused by rapid urbanisation and socioeconomic development. Furthermore, a greater focus is needed on the effect of rapid urban and epidemiological development on health systems and economics as well as on the epidemiology of the association between type 2 diabetes mellitus and tuberculosis.
We declare that we have no conflicts of interest. RJW is supported by the Wellcome Trust and by the Medical Research Council. 1
2 3
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9
10 11 12
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Wild S, Roglic G, Green A, Sicree R, King H. Global prevalence of diabetes: estimates for the year 2000 and projections for 2030. Diabetes Care 2004; 27: 1047–53. WHO. Global status report on non-communicable diseases. Geneva: World Health Organisation, 2011. World Economic Forum and the Harvard School of Public Health. The Global Economic Burden of Non-communicable Disease. 2011. http://www.weforum.org/EconomicsOfNCD. (accessed Jan 17, 2013). WHO. Global tuberculosis report 2012. Geneva: World Health Organization. 2012. Laxminarayan R, Klein E, Dye C, Floyd K, Darley S, Adeyi O. Economic Benefit of TB Control. 2007. http://www-wds.worldbank.org/external/ default/WDSContentServer/IW3P/IB/2007/08/01/000158349_20070801 103922/Rendered/PDF/wps4295.pdf (accessed Jan 17, 2013). WHO. Multidrug and extensively drug-resistant TB (M/XDR-TB). 2010 global report on surveillance and response. Geneva: World Health Organization. 2010. Schnippel K, Rosen S, Shearer K, et al. Costs of inpatient treatment for multi-drug-resistant tuberculosis in South Africa. Trop Med Int Health 2012; 18: 109–16. Jeon CY, Murray MB. Diabetes mellitus increases the risk of active tuberculosis: a systematic review of 13 observational studies. PLoS Med 2008; 5: e152. Stevenson CR, Forouhi NG, Roglic G, et al. Diabetes and tuberculosis: the impact of the diabetes epidemic on tuberculosis incidence. BMC Public Health 2007; 7: 234. Baker MA, Harries AD, Jeon CY, et al. The impact of diabetes on tuberculosis treatment outcomes: a systematic review. BMC Medicine 2011; 9: 81. Restrepo BI. Convergence of the tuberculosis and diabetes epidemics: renewal of old acquaintances. Clin Infect Dis 2007; 45: 436–38. Oni T, Burke R, Tsekela R, et al. High prevalence of subclinical tuberculosis in HIV-1-infected persons without advanced immunodeficiency: implications for TB screening. Thorax 2011; 66: 669. Dave JA, Lambert EV, Badri M, West S, Maartens G, Levitt NS. Effect of non-nucleoside reverse transcriptase inhibitor-based antiretroviral therapy on dysglycemia and insulin sensitivity in South African HIV-infected patients. J Acquir Immune Defic Syndr 2011; 57: 284–89. Julius H, Basu D, Ricci E, et al. The burden of metabolic diseases amongst HIV positive patients on HAART attending the Johannesburg Hospital. Curr HIV Res 2011; 9: 247–52. Thorogood M, Connor M, Tollman S, Lewando Hundt G, Fowkes G, Marsh J. A cross-sectional study of vascular risk factors in a rural South African population: data from the Southern African Stroke Prevention Initiative (SASPI). BMC Public Health 2007; 7: 326. Peer N, Steyn K, Lombard C, Lambert EV, Vythilingum B, Levitt NS. Rising diabetes prevalence among urban-dwelling black South Africans. PLoS One 2012; 7: e43336.
*Tolu Oni, Kari Stoever, Robert J Wilkinson Clinical Infectious Disease Research Initiative, Institute of Infectious Disease and Molecular Medicine (TO, RJW), Center for Infectious Disease Epidemiology Research, School of Public Health (TO), University of Cape Town, Observatory 7925, South Africa; Aeras, Rockville, MD, USA (KS); Division of Medicine, Imperial College London, London, UK (RJW); and Medical Research Council National Institute for Medical Research, London, UK (RJW) [email protected]
Corrections Wong GWK, Brunekreef B, Ellwood P, et al. Cooking fuels and prevalence of asthma: a global analysis of phase three of the International Study of Asthma and Allergies in Childhood (ISAAC). Lancet Respir Med 2013; 1: 386–94—The third sentence in the second paragraph in the Introduction of this Article (published online May 31) should have read “In resource-poor countries, cooking with…”. The correction has been made to the online version as of July 8, 2013, and the printed Article is correct.
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3
4 5
6
7
8
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Charlson ES, Bittinger K, Haas AR, et al. Topographical continuity of bacterial populations in the healthy human respiratory tract. Am J Respir Crit Care Med 2011; 184: 957–63. Gleeson K, Eggli DF, Maxwell SL. Quantitative aspiration during sleep in normal subjects. Chest 1997; 111: 1266–72. Lozupone C, Cota-Gomez A, Palmer BE, et al. Widespread colonization of the lung by Tropheryma whipplei in HIV infection. Am J Respir Crit Care Med 2013; 187: 1110–17. Morris A, Beck JM, Schloss PD, et al. Comparison of the respiratory microbiome in healthy nonsmokers and smokers. Am J Respir Crit Care Med 2013; 187: 1067–75. Sloan WT, Lunn M, Woodcock S, Head IM, Nee S, Curtis TP. Quantifying the roles of immigration and chance in shaping prokaryote community structure. Environ Microbiol 2006; 8: 732–40. Charlson ES, Bittinger K, Chen J, et al. Assessing bacterial populations in the lung by replicate analysis of samples from the upper and lower respiratory tracts. PLoS One 2012; 7: e42786. Sze MA, Dimitriu PA, Hayashi S, et al. The lung tissue microbiome in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2012; 185: 1073–80.
10
11
12
13
14 15
Erb-Downward JR, Thompson DL, Han MK, et al. Analysis of the lung microbiome in the “healthy” smoker and in COPD. PLoS One 2011; 6: e16384. Huang YJ, Nelson CE, Brodie EL, et al. Airway microbiota and bronchial hyperresponsiveness in patients with suboptimally controlled asthma. J Allergy Clin Immunol 2011; 127: 372–81. Miller M Twigg HL III, Petrache I. The role of Gram negative bacteria in the susceptibility of mice to an asthmatic phenotype. Am J Respir Crit Care Med 2011; 183: A6207. Shen M, Preston AM, Gillilland MG, et al. Characterization of the lung microbiome of specific pathogen-free mice with and without exposure to cigarette smoke in vivo. Am J Respir Crit Care Med 2011; 183: A6210. Fujimura KE, Slusher NA, Cabana MD, Lynch SV. Role of the gut microbiota in defining human health. Expert Rev Anti Infect Ther 2010; 8: 435–54. Hilty M, Burke C, Pedro H, et al. Disordered microbial communities in asthmatic airways. PLoS One 2010; 5: e8578.
Tuberculosis, HIV, and type 2 diabetes mellitus: a neglected priority
Karin Schermbrucker/AP/Press Association Images
The global burden of type 2 diabetes mellitus is expected to double from 180 million to 366 million people by 2030:1 80% of adult cases are expected to occur in lowincome and middle-income countries. The prevalence of other non-communicable diseases is also rising in such countries—disease and death occurs at younger ages than in high-income countries, resulting in loss of economic output.2 The cumulative economic losses to low-income and middle-income countries from the four most prevalent non-communicable diseases (cardiovascular disease, cancer, chronic respiratory disease, and diabetes) are estimated to surpass
356
US$7 trillion between 2011, and 2025: equivalent to 4% of these countries’ GDP.3 Diabetes alone is projected to cost $745 billion worldwide by 2030, $300 billion of which is expected to come from low-income and middle-income countries.3 Tuberculosis is the second highest cause of death from infectious diseases worldwide, with an estimated 9 million new cases in 2011.4 Poor adherence to treatment and an over-reliance on diagnostic tests, a vaccine, and drugs that have not changed for decades are confounding efforts to reduce the number of people with tuberculosis. The emergence of drug-resistant tuberculosis also threatens progress in mitigating the epidemic. Over the next 10 years, tuberculosis will cost an estimated $1–3 trillion globally and the World Bank estimates that it will decrease productivity by 4–7% in many high-burden countries and is predicted to cost the global economy 0·5% of gross national income.5 In 2010 terms, that loss equates to nearly $380 billion. In addition to losses in gross national income, care and control of tuberculosis are expected to cost at least $8 billion per year between 2013, and 2015.5 Furthermore, treatment for multidrugresistant tuberculosis is up to 1000 times costlier than for drug-sensitive disease, requiring 2 years of treatment, with harsh side effects.6 In South Africa alone, treatment of multidrug-resistant tuberculosis takes up to 55% of the $300–400 million national tuberculosis budget, even though it accounts for only 2% of cases.7 www.thelancet.com/respiratory Vol 1 July 2013
Comment
The link between type 2 diabetes mellitus and tuberculosis has been recognised since the early 20th century, yet more focus on the interaction between communicable and non-communicable diseases—such as type 2 diabetes mellitus and tuberculosis—is still needed. Results of a systematic review8 of 13 observational studies showed that type 2 diabetes mellitus increased the risk of tuberculosis by about a factor of three, with a stronger association in young patients and those from a population with high incidence of tuberculosis. The potential public health importance of this link was underscored by an epidemiological model suggesting that co-prevalent type 2 diabetes mellitus accounts for nearly 15% of cases of pulmonary tuberculosis in India.9 Patients with both tuberculosis and type 2 diabetes mellitus have a poorer outcome than do patients with tuberculosis alone.10 Tuberculosis can also aggravate type 2 diabetes mellitus by worsening glycaemic control, and complicating clinical management.10 A systematic review10 of the effect of type 2 diabetes mellitus on outcome of tuberculosis reported a 69% increase in mortality and risk of treatment failure, in addition to a four-times increase in the risk of relapse after treatment of tuberculosis in patients who also had type 2 diabetes mellitus compared with non-diabetic patients. Rifampicin metabolism could also be affected by type 2 diabetes mellitus, making it less effective and predisposing patients with tuberculosis to acquisition of drug resistance.11 Although evidence also suggests that diabetes alters the clinical presentation of tuberculosis, no evidence exists about whether this effect is associated with a high subclinical prevalence of tuberculosis as reported in people with tuberculosis and HIV-1 coinfection;12 which is important to consider in tuberculosis screening strategies for people with type 2 diabetes mellitus. HIV-1 coinfection—the most important contributor to the tuberculosis epidemic—is high and the availability of antiretroviral treatments has prolonged survival and ageing, with an accompanying increase in comorbidity with non-communicable diseases, including type 2 diabetes mellitus. Treatment of HIV with protease inhibitors and non-nucleoside reverse transcriptase inhibitors has been associated with insulin resistance, dyslipidaemia, and lipodystrophy, resulting in the emergence of complications such as lipid disorders, that increase the risk of cardiovascular disease.13 A study14 of adults with HIV who were www.thelancet.com/respiratory Vol 1 July 2013
taking antiretroviral therapy in Johannesburg, South Africa reported that metabolic syndrome was highly prevalent and positively correlation with CD4 cell count, presumably as a consequence of exposure to antiretroviral therapy. Furthermore, a survey13 in Cape Town, South Africa, of HIV-infected people taking antiretroviral therapy for a median of 17 months reported that the prevalence of new onset dysglycaemia was 21·9% and was significantly associated with use of efavirenz, which could contribute to the type 2 diabetes mellitus epidemic as patients receive antiretroviral therapy for longer periods. However, little is known of the association between type 2 diabetes mellitus and tuberculosis in HIV-infected people from sub-Saharan Africa. South Africa—which has the highest prevalence of HIV-1 and tuberculosis coinfection among countries with a high burden of tuberculosis—also has a high prevalence of overweight and obese people (50% of Panel: Research priorities Priorities in HIV and type 2 diabetes mellitus to improve tuberculosis control • Evaluate the population attributable fraction of tuberculosis caused by type 2 diabetes mellitus in different high tuberculosis burden settings. • Assess the effect on tuberculosis control of tuberculosis prevention strategies in people with type 2 diabetes mellitus and the effect on tuberculosis risk of isoniazid preventive therapy in all patients with type 2 diabetes mellitus, HIV coinfected people only, or tuberculosis contacts only. • Assess the effect of regular tuberculosis screening in people with type 2 diabetes mellitus on tuberculosis case-finding and outcomes. • Investigate the epidemiology of drug-resistant tuberculosis in people with type 2 diabetes mellitus. • Apply health economics research methods to evaluate the additional cost of dual management of tuberculosis and type 2 diabetes mellitus (in addition to HIV in endemic settings) and the cost-benefit ratio of addressing the type 2 diabetes mellitus epidemic in tuberculosis control. Priorities in tuberculosis and type 2 diabetes mellitus in people with HIV • Investigate the strength of the interaction between tuberculosis and type 2 diabetes mellitus in people with HIV. • Assess the potential for active screening for tuberculosis in people with type 2 diabetes mellitus to improve early detection of tuberculosis in people who also have HIV. Priorities in HIV and tuberculosis to improve control of type 2 diabetes mellitus • Investigate the effect on tuberculosis outcomes of interventions to prevent type 2 diabetes mellitus in people with tuberculosis and pre-diabetes or reversible risk factors for diabetes. • Assess the effect of intensified active type 2 diabetes mellitus screening in HIV and tuberculosis clinics on type 2 diabetes mellitus case-finding, management, and outcomes. Health systems research • Explore models of integrated care delivery for tuberculosis, HIV, and type 2 diabetes mellitus, accounting for the feasibility of integrated approaches and the effect on the health system.
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Comment
adult women15) and an epidemic of type 2 diabetes mellitus (age-adjusted prevalence 13·1%), and impaired glucose tolerance (age-adjusted prevalence 11·2%).16 Given the economic losses caused by noncommunicable diseases and the cost of drug-sensitive and drug-resistant tuberculosis, control of these epidemics is crucial. A change in the epidemiology of tuberculosis caused by HIV-1 has necessitated a shift in the focus of tuberculosis research and a reassessment of the best strategies for control, leading to new approaches—for example, intensified case finding, isoniazid preventive therapy, and antiretroviral therapy. Another reassessment is needed as a result of the increase in type 2 diabetes mellitus, since it could affect the accuracy of diagnostic instruments and the effectiveness of tuberculosis control strategies. Improved prevention and early diagnosis of tuberculosis in people with type 2 diabetes mellitus are crucial to control tuberculosis in this group. The panel summarises some priorities for research and funding. The rising prevalence of type 2 diabetes mellitus might counteract gains in tuberculosis control by adding to the disease burden in low-income and middle-income countries. This threat means that prevention of type 2 diabetes mellitus should be prioritised by addressing modifiable risk factors caused by rapid urbanisation and socioeconomic development. Furthermore, a greater focus is needed on the effect of rapid urban and epidemiological development on health systems and economics as well as on the epidemiology of the association between type 2 diabetes mellitus and tuberculosis.
We declare that we have no conflicts of interest. RJW is supported by the Wellcome Trust and by the Medical Research Council. 1
2 3
4 5
6
7
8
9
10 11 12
13
14
15
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Wild S, Roglic G, Green A, Sicree R, King H. Global prevalence of diabetes: estimates for the year 2000 and projections for 2030. Diabetes Care 2004; 27: 1047–53. WHO. Global status report on non-communicable diseases. Geneva: World Health Organisation, 2011. World Economic Forum and the Harvard School of Public Health. The Global Economic Burden of Non-communicable Disease. 2011. http://www.weforum.org/EconomicsOfNCD. (accessed Jan 17, 2013). WHO. Global tuberculosis report 2012. Geneva: World Health Organization. 2012. Laxminarayan R, Klein E, Dye C, Floyd K, Darley S, Adeyi O. Economic Benefit of TB Control. 2007. http://www-wds.worldbank.org/external/ default/WDSContentServer/IW3P/IB/2007/08/01/000158349_20070801 103922/Rendered/PDF/wps4295.pdf (accessed Jan 17, 2013). WHO. Multidrug and extensively drug-resistant TB (M/XDR-TB). 2010 global report on surveillance and response. Geneva: World Health Organization. 2010. Schnippel K, Rosen S, Shearer K, et al. Costs of inpatient treatment for multi-drug-resistant tuberculosis in South Africa. Trop Med Int Health 2012; 18: 109–16. Jeon CY, Murray MB. Diabetes mellitus increases the risk of active tuberculosis: a systematic review of 13 observational studies. PLoS Med 2008; 5: e152. Stevenson CR, Forouhi NG, Roglic G, et al. Diabetes and tuberculosis: the impact of the diabetes epidemic on tuberculosis incidence. BMC Public Health 2007; 7: 234. Baker MA, Harries AD, Jeon CY, et al. The impact of diabetes on tuberculosis treatment outcomes: a systematic review. BMC Medicine 2011; 9: 81. Restrepo BI. Convergence of the tuberculosis and diabetes epidemics: renewal of old acquaintances. Clin Infect Dis 2007; 45: 436–38. Oni T, Burke R, Tsekela R, et al. High prevalence of subclinical tuberculosis in HIV-1-infected persons without advanced immunodeficiency: implications for TB screening. Thorax 2011; 66: 669. Dave JA, Lambert EV, Badri M, West S, Maartens G, Levitt NS. Effect of non-nucleoside reverse transcriptase inhibitor-based antiretroviral therapy on dysglycemia and insulin sensitivity in South African HIV-infected patients. J Acquir Immune Defic Syndr 2011; 57: 284–89. Julius H, Basu D, Ricci E, et al. The burden of metabolic diseases amongst HIV positive patients on HAART attending the Johannesburg Hospital. Curr HIV Res 2011; 9: 247–52. Thorogood M, Connor M, Tollman S, Lewando Hundt G, Fowkes G, Marsh J. A cross-sectional study of vascular risk factors in a rural South African population: data from the Southern African Stroke Prevention Initiative (SASPI). BMC Public Health 2007; 7: 326. Peer N, Steyn K, Lombard C, Lambert EV, Vythilingum B, Levitt NS. Rising diabetes prevalence among urban-dwelling black South Africans. PLoS One 2012; 7: e43336.
*Tolu Oni, Kari Stoever, Robert J Wilkinson Clinical Infectious Disease Research Initiative, Institute of Infectious Disease and Molecular Medicine (TO, RJW), Center for Infectious Disease Epidemiology Research, School of Public Health (TO), University of Cape Town, Observatory 7925, South Africa; Aeras, Rockville, MD, USA (KS); Division of Medicine, Imperial College London, London, UK (RJW); and Medical Research Council National Institute for Medical Research, London, UK (RJW) [email protected]
Corrections Wong GWK, Brunekreef B, Ellwood P, et al. Cooking fuels and prevalence of asthma: a global analysis of phase three of the International Study of Asthma and Allergies in Childhood (ISAAC). Lancet Respir Med 2013; 1: 386–94—The third sentence in the second paragraph in the Introduction of this Article (published online May 31) should have read “In resource-poor countries, cooking with…”. The correction has been made to the online version as of July 8, 2013, and the printed Article is correct.
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