Comment
In The Lancet Infectious Diseases, Robert Aldridge and colleagues1 report the results of a systematic review on pre-entry screening for tuberculosis. They conclude that it should be considered as part of a broad package of activities for tuberculosis care, prevention, and control in migrants. Pre-entry screening refers to screening of people who intend to migrate—ie, before they leave their country of origin. Alternative strategies include upon-entry or post-entry screening. Because in many countries with a low incidence of tuberculosis a high proportion of the burden of tuberculosis is present in foreign-born people with tuberculosis,2 there is a lively debate on whether screening should be implemented and, if so, what approach should be used.3 A recent WHO guideline includes a conditional recommendation (based on very low-quality evidence) for systematic screening for active tuberculosis in subpopulations that have very high tuberculosis rates or very poor access to health care, such as some migrants and refugees residing in, or coming from, settings with a high prevalence of tuberculosis. The guideline stresses the need to prioritise only groups with very high risk.4 With the exception of some refugees, migrants are usually not a risk group in their country of origin, but might be deemed a high-risk group from the perspective of the receiving country. Unsurprisingly, Aldridge and colleagues report that the yield of pre-entry screening for tuberculosis is strongly correlated with the tuberculosis incidence in the country of origin.1 This correlation is the same for post-entry screening.5 Countries use different tuberculosis incidence thresholds to define from which countries of origin migrants should be screened.6 Thus, the quantification of the yield in migrants from different countries of origin provided by Aldridge and colleagues is important to guide prioritisation of countries of origin to focus the screening. Only a few low-incidence countries undertake preentry tuberculosis screening.6 As Aldridge and colleagues report, the cost-effectiveness of pre-entry screening, but also of post-entry screening, is unknown. More importantly, there are few data on the effect of any type of migrant tuberculosis screening on tuberculosis epidemiology.7 Also, the claim that migrant screening is done to protect the health of the autochthonous www.thelancet.com/infection Vol 14 December 2014
population has not been substantiated by proof that there is substantial transmission from migrants to the native population that can be prevented by screening.8 Even though evidence is weak, in view of the aim to eliminate tuberculosis as a public health problem, migrant screening in low-incidence countries might be considered after a careful epidemiological assessment, coupled with detailed monitoring and assessment.9 Pre-entry screening is conventionally financed outof-pocket by visa applicants, whereas treatment is paid either out-of-pocket, by health insurance, or by a national tuberculosis programme. Therefore, cost savings might be associated with pre-entry screening for the receiving country, by reduction of screening and treatment costs after arrival. Shifting costs to the country of origin could reduce overall cost from an international societal perspective because health care costs are normally much higher in the receiving country. However, financial burden, equity, and ethics need to be considered, including the risk of stigma and discrimination. The countries discussed in the report grant visas after completion of tuberculosis treatment. However, some other countries use preentry screening to unconditionally refuse entry even if screen-positive individuals were to be treated before migration—a discriminatory approach without any epidemiological rationale.10,11 When doing pre-entry screening it is important to establish good collaboration and data sharing with the disease control agency in the country of origin. Setting up good laboratory facilities and ensuring high standards of tuberculosis diagnosis and treatment are essential, and can benefit the country of origin. It has also been shown that by helping to improve the overall tuberculosis control approaches in high-incidence countries from which many of their migrants originate, receiving countries can deliver cost savings.12 We agree with Aldridge and colleagues that pre-entry screening is only one potential element of a strategy to improve tuberculosis care and prevention for migrants. Full health care access post-migration is the first priority. Strategies need to cover the full continuum of tuberculosis prevention and care pre-migration and post-migration, including support to global tuberculosis control and addressing underlying determinants of tuberculosis.9
Biophoto Associates/Science Photo Library
Pre-entry, post-entry, or no tuberculosis screening?
Published Online November 7, 2014 http://dx.doi.org/10.1016/ S1473-3099(14)70998-3 See Articles page 1240
1171
Comment
*Marieke J van der Werf, Knut Lönnroth
5
European Centre for Disease Prevention and Control, Stockholm, Sweden (MJvdW); and Global Tuberculosis Programme, World Health Organization, Geneva, Switzerland (KL) [email protected]
6
We declare no competing interests. Both authors contributed equally. Copyright © van der Werf et al. Open Access article distributed under the terms of CC BY. 1
2
3 4
Aldridge RW, Yates TA, Zenner D, White PJ, Abubakar I, Hayward AC. Preentry screening programmes for tuberculosis in migrants to low-incidence countries: a systematic review and meta-analysis. Lancet Infect Dis 2014; published online Nov 7; http://dx.doi.org/10.1016/S1473-3099(14)70966-1 European Centre for Disease Prevention and Control, WHO Regional Office for Europe. Tuberculosis surveillance and monitoring in Europe, 2014. Stockholm: European Centre for Disease Prevention and Control, 2014. Moore-Gillon J, Davies PD, Ormerod LP. Rethinking TB screening: politics, practicalities and the press. Thorax 2010; 65: 663–65. WHO. Systematic screening for active tuberculosis: principles and recommendations. Geneva: World Health Organization, 2013.
7
8
9 10
11 12
Erkens C, Slump E, Kamphorst M, et al. Coverage and yield of entry and follow-up screening for tuberculosis among new immigrants. Eur Respir J 2008; 32: 153–61. Pareek M, Baussano I, Abubakar I, Dye C, Lalvani A. Evaluation of immigrant tuberculosis screening in industrialized countries. Emerg Infect Dis 2012; 18: 1422–29. Kranzer K, Afnan-Holmes H, Tomlin K, et al. The benefits to communities and individuals of screening for active tuberculosis disease: a systematic review. Int J Tuberc Lung Dis 2013; 17: 432–46. Sandgren A, Schepisi MS, Sotgiu G, et al. Tuberculosis transmission between foreign- and native-born populations in the EU/EEA: a systematic review. Eur Respir J 2014; 43: 1159–71. WHO. Towards tuberculosis elimination: an action framework for lowincidence countries. Geneva: World Health Organization, 2014. Wickramage K, Mosca D. Can migration health assessments become a mechanism for global public health good? Int J Environ Res Public Health 2014; 11: 9954–63. Kronfol NM, Mansour Z. Tuberculosis and migration: a review. East Mediterr Health J 2013; 19: 739–48. Schwartzman K, Oxlade O, Barr RG, et al. Domestic returns from investment in the control of tuberculosis in other countries. New Engl J Med 2005; 353: 1008–20.
Interplay between childhood pneumonia and HIV infection Published Online November 12, 2014 http://dx.doi.org/10.1016/ S1473-3099(14)71006-0 See Articles page 1250
Mortality rate (per 1000 person-years)
15
The old adage “If you want to go there, I wouldn’t start from here” applies to more than a few systematic reviews. However elegantly designed, systematic reviews are at the mercy of what the scientific literature happens to contain on a chosen topic. For comorbidity studies in particular, investigators might have difficulty finding content that systematically makes connections between conditions. In a systematic review and meta-analysis published in
HIV/AIDS-related Pneumonia Other causes Indeterminate
10
5
3 19 94 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10 20 11
19 9
19 9
2
0
Year
Figure: Causes of death of children aged 1–59 months in a rural South African region Causes of 1623 deaths determined by verbal autopsy among children aged 1–59 months at the INDEPTH Network member Agincourt Health and Demographic Surveillance Site in rural South Africa during a major HIV/ AIDS epidemic.2
1172
The Lancet Infectious Diseases, Evropi Theodoratou and colleagues1 try to assess the relation between childhood pneumonia and HIV infection, and then extrapolate to possible global burdens. Inevitably, the review mainly identified studies of hospital admissions, because unambiguous diagnosis of pneumonia and HIV infection is otherwise unlikely. Nevertheless, HIV-infected children had substantially increased risks of hospital admission for pneumonia (odds ratio [OR] 6·5, 95% CI 5·9–7·2) and of dying from pneumonia (5·9, 2·7–12·7). Understanding the Article’s findings in relation to population health is difficult because—especially in sub-Saharan Africa—HIV-infected children with pneumonia might not necessarily be admitted to hospital. A verbal autopsy dataset2,3 collected by the INDEPTH Network (based on interviewing family members following a death4) provides an opportunity to calculate population-based pneumonia and HIV/ AIDS-related cause-specific mortality rates (including deaths in hospital). The dataset contains information for 19 731 deaths over 1·53 million person-years in children aged 1–59 months, across 18 sites in sub-Saharan Africa and southeast Asia. Pneumonia mortality rates ranged from 0·5 (FilaBavi, Vietnam) to 9·7 (Kisumu, Kenya) per 1000 person-years and HIV/AIDS-related mortality rates ranged from 0·01 (Chakaria, Bangladesh) to 6·0 (Kisumu, Kenya) per 1000 person-years. The correlation between the www.thelancet.com/infection Vol 14 December 2014
In The Lancet Infectious Diseases, Robert Aldridge and colleagues1 report the results of a systematic review on pre-entry screening for tuberculosis. They conclude that it should be considered as part of a broad package of activities for tuberculosis care, prevention, and control in migrants. Pre-entry screening refers to screening of people who intend to migrate—ie, before they leave their country of origin. Alternative strategies include upon-entry or post-entry screening. Because in many countries with a low incidence of tuberculosis a high proportion of the burden of tuberculosis is present in foreign-born people with tuberculosis,2 there is a lively debate on whether screening should be implemented and, if so, what approach should be used.3 A recent WHO guideline includes a conditional recommendation (based on very low-quality evidence) for systematic screening for active tuberculosis in subpopulations that have very high tuberculosis rates or very poor access to health care, such as some migrants and refugees residing in, or coming from, settings with a high prevalence of tuberculosis. The guideline stresses the need to prioritise only groups with very high risk.4 With the exception of some refugees, migrants are usually not a risk group in their country of origin, but might be deemed a high-risk group from the perspective of the receiving country. Unsurprisingly, Aldridge and colleagues report that the yield of pre-entry screening for tuberculosis is strongly correlated with the tuberculosis incidence in the country of origin.1 This correlation is the same for post-entry screening.5 Countries use different tuberculosis incidence thresholds to define from which countries of origin migrants should be screened.6 Thus, the quantification of the yield in migrants from different countries of origin provided by Aldridge and colleagues is important to guide prioritisation of countries of origin to focus the screening. Only a few low-incidence countries undertake preentry tuberculosis screening.6 As Aldridge and colleagues report, the cost-effectiveness of pre-entry screening, but also of post-entry screening, is unknown. More importantly, there are few data on the effect of any type of migrant tuberculosis screening on tuberculosis epidemiology.7 Also, the claim that migrant screening is done to protect the health of the autochthonous www.thelancet.com/infection Vol 14 December 2014
population has not been substantiated by proof that there is substantial transmission from migrants to the native population that can be prevented by screening.8 Even though evidence is weak, in view of the aim to eliminate tuberculosis as a public health problem, migrant screening in low-incidence countries might be considered after a careful epidemiological assessment, coupled with detailed monitoring and assessment.9 Pre-entry screening is conventionally financed outof-pocket by visa applicants, whereas treatment is paid either out-of-pocket, by health insurance, or by a national tuberculosis programme. Therefore, cost savings might be associated with pre-entry screening for the receiving country, by reduction of screening and treatment costs after arrival. Shifting costs to the country of origin could reduce overall cost from an international societal perspective because health care costs are normally much higher in the receiving country. However, financial burden, equity, and ethics need to be considered, including the risk of stigma and discrimination. The countries discussed in the report grant visas after completion of tuberculosis treatment. However, some other countries use preentry screening to unconditionally refuse entry even if screen-positive individuals were to be treated before migration—a discriminatory approach without any epidemiological rationale.10,11 When doing pre-entry screening it is important to establish good collaboration and data sharing with the disease control agency in the country of origin. Setting up good laboratory facilities and ensuring high standards of tuberculosis diagnosis and treatment are essential, and can benefit the country of origin. It has also been shown that by helping to improve the overall tuberculosis control approaches in high-incidence countries from which many of their migrants originate, receiving countries can deliver cost savings.12 We agree with Aldridge and colleagues that pre-entry screening is only one potential element of a strategy to improve tuberculosis care and prevention for migrants. Full health care access post-migration is the first priority. Strategies need to cover the full continuum of tuberculosis prevention and care pre-migration and post-migration, including support to global tuberculosis control and addressing underlying determinants of tuberculosis.9
Biophoto Associates/Science Photo Library
Pre-entry, post-entry, or no tuberculosis screening?
Published Online November 7, 2014 http://dx.doi.org/10.1016/ S1473-3099(14)70998-3 See Articles page 1240
1171
Comment
*Marieke J van der Werf, Knut Lönnroth
5
European Centre for Disease Prevention and Control, Stockholm, Sweden (MJvdW); and Global Tuberculosis Programme, World Health Organization, Geneva, Switzerland (KL) [email protected]
6
We declare no competing interests. Both authors contributed equally. Copyright © van der Werf et al. Open Access article distributed under the terms of CC BY. 1
2
3 4
Aldridge RW, Yates TA, Zenner D, White PJ, Abubakar I, Hayward AC. Preentry screening programmes for tuberculosis in migrants to low-incidence countries: a systematic review and meta-analysis. Lancet Infect Dis 2014; published online Nov 7; http://dx.doi.org/10.1016/S1473-3099(14)70966-1 European Centre for Disease Prevention and Control, WHO Regional Office for Europe. Tuberculosis surveillance and monitoring in Europe, 2014. Stockholm: European Centre for Disease Prevention and Control, 2014. Moore-Gillon J, Davies PD, Ormerod LP. Rethinking TB screening: politics, practicalities and the press. Thorax 2010; 65: 663–65. WHO. Systematic screening for active tuberculosis: principles and recommendations. Geneva: World Health Organization, 2013.
7
8
9 10
11 12
Erkens C, Slump E, Kamphorst M, et al. Coverage and yield of entry and follow-up screening for tuberculosis among new immigrants. Eur Respir J 2008; 32: 153–61. Pareek M, Baussano I, Abubakar I, Dye C, Lalvani A. Evaluation of immigrant tuberculosis screening in industrialized countries. Emerg Infect Dis 2012; 18: 1422–29. Kranzer K, Afnan-Holmes H, Tomlin K, et al. The benefits to communities and individuals of screening for active tuberculosis disease: a systematic review. Int J Tuberc Lung Dis 2013; 17: 432–46. Sandgren A, Schepisi MS, Sotgiu G, et al. Tuberculosis transmission between foreign- and native-born populations in the EU/EEA: a systematic review. Eur Respir J 2014; 43: 1159–71. WHO. Towards tuberculosis elimination: an action framework for lowincidence countries. Geneva: World Health Organization, 2014. Wickramage K, Mosca D. Can migration health assessments become a mechanism for global public health good? Int J Environ Res Public Health 2014; 11: 9954–63. Kronfol NM, Mansour Z. Tuberculosis and migration: a review. East Mediterr Health J 2013; 19: 739–48. Schwartzman K, Oxlade O, Barr RG, et al. Domestic returns from investment in the control of tuberculosis in other countries. New Engl J Med 2005; 353: 1008–20.
Interplay between childhood pneumonia and HIV infection Published Online November 12, 2014 http://dx.doi.org/10.1016/ S1473-3099(14)71006-0 See Articles page 1250
Mortality rate (per 1000 person-years)
15
The old adage “If you want to go there, I wouldn’t start from here” applies to more than a few systematic reviews. However elegantly designed, systematic reviews are at the mercy of what the scientific literature happens to contain on a chosen topic. For comorbidity studies in particular, investigators might have difficulty finding content that systematically makes connections between conditions. In a systematic review and meta-analysis published in
HIV/AIDS-related Pneumonia Other causes Indeterminate
10
5
3 19 94 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10 20 11
19 9
19 9
2
0
Year
Figure: Causes of death of children aged 1–59 months in a rural South African region Causes of 1623 deaths determined by verbal autopsy among children aged 1–59 months at the INDEPTH Network member Agincourt Health and Demographic Surveillance Site in rural South Africa during a major HIV/ AIDS epidemic.2
1172
The Lancet Infectious Diseases, Evropi Theodoratou and colleagues1 try to assess the relation between childhood pneumonia and HIV infection, and then extrapolate to possible global burdens. Inevitably, the review mainly identified studies of hospital admissions, because unambiguous diagnosis of pneumonia and HIV infection is otherwise unlikely. Nevertheless, HIV-infected children had substantially increased risks of hospital admission for pneumonia (odds ratio [OR] 6·5, 95% CI 5·9–7·2) and of dying from pneumonia (5·9, 2·7–12·7). Understanding the Article’s findings in relation to population health is difficult because—especially in sub-Saharan Africa—HIV-infected children with pneumonia might not necessarily be admitted to hospital. A verbal autopsy dataset2,3 collected by the INDEPTH Network (based on interviewing family members following a death4) provides an opportunity to calculate population-based pneumonia and HIV/ AIDS-related cause-specific mortality rates (including deaths in hospital). The dataset contains information for 19 731 deaths over 1·53 million person-years in children aged 1–59 months, across 18 sites in sub-Saharan Africa and southeast Asia. Pneumonia mortality rates ranged from 0·5 (FilaBavi, Vietnam) to 9·7 (Kisumu, Kenya) per 1000 person-years and HIV/AIDS-related mortality rates ranged from 0·01 (Chakaria, Bangladesh) to 6·0 (Kisumu, Kenya) per 1000 person-years. The correlation between the www.thelancet.com/infection Vol 14 December 2014
