Building a European database to gather multi-country evidence on active and latent TB screening for migrants

BACKGROUND AND AIM

Screening for active and latent TB among migrants in low TB incidence countries may constitute an important contribution to TB elimination. E-DETECT TB, a European multi-county collaboration, aims to address the present lack of evidence on effectiveness of migrant TB screening by collating data in an international database and perform cross-country pooled and comparative analyses of screening coverage, results and linkage to care.

METHOD

A database was established using migrant TB screening data from participating countries' national screening programs, national screening pilots and local research projects. All partner countries contributed to a common agreed protocol with standardized variables, pooling available numerator and denominator screening data from participating countries and sites.

RESULTS

All collaborating members drafted and agreed upon a data sharing accord as well as a protocol that clearly defined responsibilities and data governance principles. The database has been created and data transfer is ongoing.

CONCLUSION

By persistence and focus the project has overcome considerable administrative, practical and legal challenges. This international collaboration provides greater power of analysis of harmonized data and thereby a unique opportunity to contribute migrant TB screening evidence. E-DETECT TB has started to invite other countries to contribute data to the database.

Million Migrants study of healthcare and mortality outcomes in non-EU migrants and refugees to England: Analysis protocol for a linked population-based cohort study of 1.5 million migrants

Background: In 2017, 15.6% of the people living in England were born abroad, yet we have a limited understanding of their use of health services and subsequent health conditions. This linked population-based cohort study aims to describe the hospital-based healthcare and mortality outcomes of 1.5 million non-European Union (EU) migrants and refugees in England. Methods and analysis: We will link four data sources: first, non-EU migrant tuberculosis pre-entry screening data; second, refugee pre-entry health assessment data; third, national hospital episode statistics; and fourth, Office of National Statistics death records. Using this linked dataset, we will then generate a population-based cohort to examine hospital-based events and mortality outcomes in England between Jan 1, 2006, and Dec 31, 2017. We will compare outcomes across three groups in our analyses: 1) non-EU international migrants, 2) refugees, and 3) general population of England. Ethics and dissemination: We will obtain approval to use unconsented patient identifiable data from the Secretary of State for Health through the Confidentiality Advisory Group and the National Health Service Research Ethics Committee. After data linkage, we will destroy identifying data and undertake all analyses using the pseudonymised dataset. The results will provide policy makers and civil society with detailed information about the health needs of non-EU international migrants and refugees in England.

The UCL-Lancet Commission on Migration and Health: the health of a world on the move

With one billion people on the move or having moved in 2018, migration is a global reality, which has also become a political lightning rod. Although estimates indicate that the majority of global migration occurs within low-income and middle-income countries (LMICs), the most prominent dialogue focuses almost exclusively on migration from LMICs to high-income countries (HICs). Nowadays, populist discourse demonises the very same individuals who uphold economies, bolster social services, and contribute to health services in both origin and destination locations. Those in positions of political and economic power continue to restrict or publicly condemn migration to promote their own interests. Meanwhile nationalist movements assert so-called cultural sovereignty by delineating an us versus them rhetoric, creating a moral emergency.

In response to these issues, the UCL-Lancet Commission on Migration and Health was convened to articulate evidence-based approaches to inform public discourse and policy. The Commission undertook analyses and consulted widely, with diverse international evidence and expertise spanning sociology, politics, public health science, law, humanitarianism, and anthropology. The result of this work is a report that aims to be a call to action for civil society, health leaders, academics, and policy makers to maximise the benefits and reduce the costs of migration on health locally and globally. The outputs of our work relate to five overarching goals that we thread throughout the report.

First, we provide the latest evidence on migration and health outcomes. This evidence challenges common myths and highlights the diversity, dynamics, and benefits of modern migration and how it relates to population and individual health. Migrants generally contribute more to the wealth of host societies than they cost. Our Article shows that international migrants in HICs have, on average, lower mortality than the host country population. However, increased morbidity was found for some conditions and among certain subgroups of migrants, (eg, increased rates of mental illness in victims of trafficking and people fleeing conflict) and in populations left behind in the location of origin. Currently, in 2018, the full range of migrants’ health needs are difficult to assess because of poor quality data. We know very little, for example, about the health of undocumented migrants, people with disabilities, or lesbian, gay, bisexual, transsexual, or intersex (LGBTI) individuals who migrate or who are unable to move.

Second, we examine multisector determinants of health and consider the implication of the current sector-siloed approaches. The health of people who migrate depends greatly on structural and political factors that determine the impetus for migration, the conditions of their journey, and their destination. Discrimination, gender inequalities, and exclusion from health and social services repeatedly emerge as negative health influences for migrants that require cross-sector responses.

Third, we critically review key challenges to healthy migration. Population mobility provides economic, social, and cultural dividends for those who migrate and their host communities. Furthermore, the right to the highest attainable standard of health, regardless of location or migration status, is enshrined in numerous human rights instruments. However, national sovereignty concerns overshadow these benefits and legal norms. Attention to migration focuses largely on security concerns. When there is conjoining of the words health and migration, it is either focused on small subsets of society and policy, or negatively construed. International agreements, such as the UN Global Compact for Migration and the UN Global Compact on Refugees, represent an opportunity to ensure that international solidarity, unity of intent, and our shared humanity triumphs over nationalist and exclusionary policies, leading to concrete actions to protect the health of migrants.

Fourth, we examine equity in access to health and health services and offer evidence-based solutions to improve the health of migrants. Migrants should be explicitly included in universal health coverage commitments. Ultimately, the cost of failing to be health-inclusive could be more expensive to national economies, health security, and global health than the modest investments required.

Finally, we look ahead to outline how our evidence can contribute to synergistic and equitable health, social, and economic policies, and feasible strategies to inform and inspire action by migrants, policy makers, and civil society. We conclude that migration should be treated as a central feature of 21st century health and development. Commitments to the health of migrating populations should be considered across all Sustainable Development Goals (SDGs) and in the implementation of the Global Compact for Migration and Global Compact on Refugees. This Commission offers recommendations that view population mobility as an asset to global health by showing the meaning and reality of good health for all. We present four key messages that provide a focus for future action.

Global patterns of mortality in international migrants: a systematic review and meta-analysis

BACKGROUND

258 million people reside outside their country of birth; however, to date no global systematic reviews or meta-analyses of mortality data for these international migrants have been done. We aimed to review and synthesise available mortality data on international migrants.

METHODS

In this systematic review and meta-analysis, we searched MEDLINE, Embase, the Cochrane Library, and Google Scholar databases for observational studies, systematic reviews, and randomised controlled trials published between Jan 1, 2001, and March 31, 2017, without language restrictions. We included studies reporting mortality outcomes for international migrants of any age residing outside their country of birth. Studies that recruited participants exclusively from intensive care or high dependency hospital units, with an existing health condition or status, or a particular health exposure were excluded. We also excluded studies limited to maternal or perinatal outcomes. We screened studies using systematic review software and extracted data from published reports. The main outcomes were all-cause and International Classification of Diseases, tenth revision (ICD-10) cause-specific standardised mortality ratios (SMRs) and absolute mortality rates. We calculated summary estimates using random-effects models. This study is registered with PROSPERO, number CRD42017073608.

FINDINGS

Of the 12 480 articles identified by our search, 96 studies were eligible for inclusion. The studies were geographically diverse and included data from all global regions and for 92 countries. 5464 mortality estimates for more than 15·2 million migrants were included, of which 5327 (97%) were from high-income countries, 115 (2%) were from middle-income countries, and 22 (<1%) were from low-income countries. Few studies included mortality estimates for refugees (110 estimates), asylum seekers (144 estimates), or labour migrants (six estimates). The summary estimate of all-cause SMR for international migrants was lower than one when compared with the general population in destination countries (0·70 [95% CI 0·65-0·76]; I2=99·8%). All-cause SMR was lower in both male migrants (0·72 [0·63-0·81]; I2=99·8%) and female migrants (0·75 [0·67-0·84]; I2=99·8%) compared with the general population. A mortality advantage was evident for refugees (SMR 0·50 [0·46-0·54]; I2=89·8%), but not for asylum seekers (1·05 [0·89-1·24]; I2=54·4%), although limited data was available on these groups. SMRs for all causes of death were lower in migrants compared with the general populations in the destination country across all 13 ICD-10 categories analysed, with the exception of infectious diseases and external causes. Heterogeneity was high across the majority of analyses. Point estimates of all-cause age-standardised mortality in migrants ranged from 420 to 874 per 100 000 population.

INTERPRETATION

Our study showed that international migrants have a mortality advantage compared with general populations, and that this advantage persisted across the majority of ICD-10 disease categories. The mortality advantage identified will be representative of international migrants in high-income countries who are studying, working, or have joined family members in these countries. However, our results might not reflect the health outcomes of more marginalised groups in low-income and middle-income countries because little data were available for these groups, highlighting an important gap in existing research. Our results present an opportunity to reframe the public discourse on international migration and health in high-income countries.

FUNDING

Wellcome Trust, National Institute for Health Research, Medical Research Council, Alliance for Health Policy and Systems Research, Department for International Development, Fogarty International Center, Grand Challenges Canada, International Development Research Centre Canada, Inter-American Institute for Global Change Research, National Cancer Institute, National Heart, Lung and Blood Institute, National Institute of Mental Health, Swiss National Science Foundation, World Diabetes Foundation, UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, and European Society for Clinical Microbiology and Infectious Diseases (ESCMID) Study Group Research Funding for the ESCMID Study Group for Infections in Travellers and Migrants.

Changes in health in the countries of the UK and 150 English Local Authority areas 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016

BACKGROUND

Previous studies have reported national and regional Global Burden of Disease (GBD) estimates for the UK. Because of substantial variation in health within the UK, action to improve it requires comparable estimates of disease burden and risks at country and local levels. The slowdown in the rate of improvement in life expectancy requires further investigation. We use GBD 2016 data on mortality, causes of death, and disability to analyse the burden of disease in the countries of the UK and within local authorities in England by deprivation quintile.

METHODS

We extracted data from the GBD 2016 to estimate years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life-years (DALYs), and attributable risks from 1990 to 2016 for England, Scotland, Wales, Northern Ireland, the UK, and 150 English Upper-Tier Local Authorities. We estimated the burden of disease by cause of death, condition, year, and sex. We analysed the association between burden of disease and socioeconomic deprivation using the Index of Multiple Deprivation. We present results for all 264 GBD causes of death combined and the leading 20 specific causes, and all 84 GBD risks or risk clusters combined and 17 specific risks or risk clusters.

FINDINGS

The leading causes of age-adjusted YLLs in all UK countries in 2016 were ischaemic heart disease, lung cancers, cerebrovascular disease, and chronic obstructive pulmonary disease. Age-standardised rates of YLLs for all causes varied by two times between local areas in England according to levels of socioeconomic deprivation (from 14 274 per 100 000 population [95% uncertainty interval 12 791-15 875] in Blackpool to 6888 [6145-7739] in Wokingham). Some Upper-Tier Local Authorities, particularly those in London, did better than expected for their level of deprivation. Allowing for differences in age structure, more deprived Upper-Tier Local Authorities had higher attributable YLLs for most major risk factors in the GBD. The population attributable fractions for all-cause YLLs for individual major risk factors varied across Upper-Tier Local Authorities. Life expectancy and YLLs have improved more slowly since 2010 in all UK countries compared with 1990-2010. In nine of 150 Upper-Tier Local Authorities, YLLs increased after 2010. For attributable YLLs, the rate of improvement slowed most substantially for cardiovascular disease and breast, colorectal, and lung cancers, and showed little change for Alzheimer's disease and other dementias. Morbidity makes an increasing contribution to overall burden in the UK compared with mortality. The age-standardised UK DALY rate for low back and neck pain (1795 [1258-2356]) was higher than for ischaemic heart disease (1200 [1155-1246]) or lung cancer (660 [642-679]). The leading causes of ill health (measured through YLDs) in the UK in 2016 were low back and neck pain, skin and subcutaneous diseases, migraine, depressive disorders, and sense organ disease. Age-standardised YLD rates varied much less than equivalent YLL rates across the UK, which reflects the relative scarcity of local data on causes of ill health.

INTERPRETATION

These estimates at local, regional, and national level will allow policy makers to match resources and priorities to levels of burden and risk factors. Improvement in YLLs and life expectancy slowed notably after 2010, particularly in cardiovascular disease and cancer, and targeted actions are needed if the rate of improvement is to recover. A targeted policy response is also required to address the increasing proportion of burden due to morbidity, such as musculoskeletal problems and depression. Improving the quality and completeness of available data on these causes is an essential component of this response.

FUNDING

Bill & Melinda Gates Foundation and Public Health England.

Hepatitis C among vulnerable populations: A seroprevalence study of homeless, people who inject drugs and prisoners in London

Injecting drugs substantially increases the risk of hepatitis C virus (HCV) infection and is common in the homeless and prisoners. Capturing accurate data on disease prevalence within these groups is challenging but is essential to inform strategies to reduce HCV transmission. The aim of this study was to estimate the prevalence of HCV in these populations. We conducted a cross-sectional study between May 2011 and June 2013 in London and, using convenience sampling, recruited participants from hostels for the homeless, drug treatment services and a prison. A questionnaire was administered and blood samples were tested for hepatitis C. We recruited 491 individuals who were homeless (40.7%), 205 drug users (17%) and 511 prisoners (42.3%). Eight per cent of patients (98/1207, 95% CI: 6.7%-9.8%) had active HCV infection and 3% (38/1207, 95% CI: 2.3%-4.3%) past HCV infection. Overall, one quarter (51/205) of people recruited in drug treatment services, 13% (65/491) of people from homeless residential sites and 4% (20/511) prisoners in this study were anti-HCV positive. Seventy-seven of the 136 (56.6%, 95% CI: 47.9%-65%) of HCV infected participants identified had a history of all three risk factors (homelessness, imprisonment and drug use), 27.3% (95% CI: 20.1%-35.6%) had 2 overlapping risk factors, and 15.4% (95% CI: 10.6%-23.7%) one risk factor. Drug treatment services, prisons and homelessness services provide good opportunities for identifying hepatitis C-infected individuals. Effective models need to be developed to ensure case identification in these settings that can lead to an effective treatment and an efficient HCV prevention.

High prevalence of latent tuberculosis and bloodborne virus infection in a homeless population

Introduction

Urban homeless populations in the UK have been shown to have high rates of active tuberculosis, but less is known about the prevalence of latent tuberculosis infection (LTBI). This study aimed to estimate the prevalence of LTBI among individuals using homeless hostels in London.

Methods

We performed a cross-sectional survey with outcome follow-up in homeless hostels in London. Our primary outcome was prevalence of LTBI. Recruitment for the study took place between May 2011 and June 2013. To estimate an LTBI prevalence of 10% with 95% CIs between 8% and 13%, we required 500 participants.

Results

491/804 (61.1%) individuals agreed to be screened. The prevalence of LTBI was 16.5% (81/491; 95% CI 13.2 to 19.8). In UK-born individuals, a history of incarceration was associated with increased risk of LTBI (OR 3.49; 95% CI 1.10 to 11.04; P=0.018) after adjusting for age, length of time spent homeless and illicit drug use. Of the three subjects who met English treatment guidelines for LTBI at the time of the study, none engaged with services after referral for treatment. Prevalence of past hepatitis B infection was 10.4% (51/489; 95% CI 7.7 to 13.1), and 59.5% (291/489; 95% CI 55.1 to 63.9) of individuals were non-immune. Prevalence of current hepatitis C infection was 10.4% (51/489; 95% CI 7.8 to 13.1).

Conclusions

This study demonstrates the high prevalence of LTBI in homeless people in London and the associated poor engagement with care. There is a large unmet need for LTBI and hepatitis C infection treatment, and hepatitis B vaccination, in this group.

What works in inclusion health: overview of effective interventions for marginalised and excluded populations

Inclusion health is a service, research, and policy agenda that aims to prevent and redress health and social inequities among the most vulnerable and excluded populations. We did an evidence synthesis of health and social interventions for inclusion health target populations, including people with experiences of homelessness, drug use, imprisonment, and sex work. These populations often have multiple overlapping risk factors and extreme levels of morbidity and mortality. We identified numerous interventions to improve physical and mental health, and substance use; however, evidence is scarce for structural interventions, including housing, employment, and legal support that can prevent exclusion and promote recovery. Dedicated resources and better collaboration with the affected populations are needed to realise the benefits of existing interventions. Research must inform the benefits of early intervention and implementation of policies to address the upstream causes of exclusion, such as adverse childhood experiences and poverty.

Morbidity and mortality in homeless individuals, prisoners, sex workers, and individuals with substance use disorders in high-income countries: a systematic review and meta-analysis

BACKGROUND

Inclusion health focuses on people in extremely poor health due to poverty, marginalisation, and multimorbidity. We aimed to review morbidity and mortality data on four overlapping populations who experience considerable social exclusion: homeless populations, individuals with substance use disorders, sex workers, and imprisoned individuals.

METHODS

For this systematic review and meta-analysis, we searched MEDLINE, Embase, and the Cochrane Library for studies published between Jan 1, 2005, and Oct 1, 2015. We included only systematic reviews, meta-analyses, interventional studies, and observational studies that had morbidity and mortality outcomes, were published in English, from high-income countries, and were done in populations with a history of homelessness, imprisonment, sex work, or substance use disorder (excluding cannabis and alcohol use). Studies with only perinatal outcomes and studies of individuals with a specific health condition or those recruited from intensive care or high dependency hospital units were excluded. We screened studies using systematic review software and extracted data from published reports. Primary outcomes were measures of morbidity (prevalence or incidence) and mortality (standardised mortality ratios [SMRs] and mortality rates). Summary estimates were calculated using a random effects model.

FINDINGS

Our search identified 7946 articles, of which 337 studies were included for analysis. All-cause standardised mortality ratios were significantly increased in 91 (99%) of 92 extracted datapoints and were 11·86 (95% CI 10·42-13·30; I2=94·1%) in female individuals and 7·88 (7·03-8·74; I2=99·1%) in men. Summary SMR estimates for the International Classification of Diseases disease categories with two or more included datapoints were highest for deaths due to injury, poisoning, and other external causes, in both men (7·89; 95% CI 6·40-9·37; I2=98·1%) and women (18·72; 13·73-23·71; I2=91·5%). Disease prevalence was consistently raised across the following categories: infections (eg, highest reported was 90% for hepatitis C, 67 [65%] of 103 individuals for hepatitis B, and 133 [51%] of 263 individuals for latent tuberculosis infection), mental health (eg, highest reported was 9 [4%] of 227 individuals for schizophrenia), cardiovascular conditions (eg, highest reported was 32 [13%] of 247 individuals for coronary heart disease), and respiratory conditions (eg, highest reported was 9 [26%] of 35 individuals for asthma).

INTERPRETATION

Our study shows that homeless populations, individuals with substance use disorders, sex workers, and imprisoned individuals experience extreme health inequities across a wide range of health conditions, with the relative effect of exclusion being greater in female individuals than male individuals. The high heterogeneity between studies should be explored further using improved data collection in population subgroups. The extreme health inequity identified demands intensive cross-sectoral policy and service action to prevent exclusion and improve health outcomes in individuals who are already marginalised.

FUNDING

Wellcome Trust, National Institute for Health Research, NHS England, NHS Research Scotland Scottish Senior Clinical Fellowship, Medical Research Council, Chief Scientist Office, and the Central and North West London NHS Trust.

Outcomes of specialist discharge coordination and intermediate care schemes for patients who are homeless: analysis protocol for a population-based historical cohort

INTRODUCTION

People who are homeless often experience poor hospital discharge arrangements, reflecting ongoing care and housing needs. Specialist integrated homeless health and care provision (SIHHC) schemes have been developed and implemented to facilitate the safe and timely discharge of homeless patients from hospital. Our study aims to investigate the health outcomes of patients who were homeless and seen by a selection of SIHHC services.

METHODS AND ANALYSIS

Our study will employ a historical population-based cohort in England. We will examine health outcomes among three groups of adults: (1) homeless patients seen by specialist discharge schemes during their hospital admission; (2) homeless patients not seen by a specialist scheme and (3) admitted patients who live in deprived neighbourhoods and were not recorded as being homeless. Primary outcomes will be: time from discharge to next hospital inpatient admission; time from discharge to next accident and emergency attendance and 28-day emergency readmission. Outcome data will be generated through linkage to hospital admissions data (Hospital Episode Statistics) and mortality data for November 2013 to November 2016. Multivariable regression will be used to model the relationship between the study comparison groups and each of the outcomes.

ETHICS AND DISSEMINATION

Approval has been obtained from the National Health Service (NHS) Confidentiality Advisory Group (reference 16/CAG/0021) to undertake this work using unconsented identifiable data. Health Research Authority Research Ethics approval (REC 16/EE/0018) has been obtained in addition to local research and development approvals for data collection at NHS sites. We will feedback the results of our study to our advisory group of people who have lived experience of homelessness and seek their suggestions on ways to improve or take this work further for their benefit. We will disseminate our findings to SIHHC schemes through a series of regional workshops.

Tuberculosis in migrants moving from high-incidence to low-incidence countries: a population-based cohort study of 519 955 migrants screened before entry to England, Wales, and Northern Ireland

BACKGROUND

Tuberculosis elimination in countries with a low incidence of the disease necessitates multiple interventions, including innovations in migrant screening. We examined a cohort of migrants screened for tuberculosis before entry to England, Wales, and Northern Ireland and tracked the development of disease in this group after arrival.

METHODS

As part of a pilot pre-entry screening programme for tuberculosis in 15 countries with a high incidence of the disease, the International Organization for Migration screened all applicants for UK visas aged 11 years or older who intended to stay for more than 6 months. Applicants underwent a chest radiograph, and any with results suggestive of tuberculosis underwent sputum testing and culture testing (when available). We tracked the development of tuberculosis in those who tested negative for the disease and subsequently migrated to England, Wales, and Northern Ireland with the Enhanced Tuberculosis Surveillance system. Primary outcomes were cases of all forms of tuberculosis (including clinically diagnosed cases), and bacteriologically confirmed pulmonary tuberculosis.

FINDINGS

Our study cohort was 519 955 migrants who were screened for tuberculosis before entry to the UK between Jan 1, 2006, and Dec 31, 2012. Cases notified on the Enhanced Tuberculosis Surveillance system between Jan 1, 2006, and Dec 31, 2013, were included. 1873 incident cases of all forms of tuberculosis were identified, and, on the basis of data for England, Wales, and Northern Ireland, the estimated incidence of all forms of tuberculosis in migrants screened before entry was 147 per 100 000 person-years (95% CI 140-154). The estimated incidence of bacteriologically confirmed pulmonary tuberculosis in migrants screened before entry was 49 per 100 000 person-years (95% CI 45-53). Migrants whose chest radiographs were compatible with active tuberculosis but with negative pre-entry microbiological results were at increased risk of tuberculosis compared with those with no radiographic abnormalities (incidence rate ratio 3·2, 95% CI 2·8-3·7; p<0·0001). Incidence of tuberculosis after migration increased significantly with increasing WHO-estimated prevalence of tuberculosis in migrants' countries of origin. 35 of 318 983 pre-entry screened migrants included in a secondary analysis with typing data were assumed index cases. Estimates of the rate of assumed reactivation tuberculosis ranged from 46 (95% CI 42-52) to 91 (82-102) per 100 000 population.

INTERPRETATION

Migrants from countries with a high incidence of tuberculosis screened before being granted entry to low-incidence countries pose a negligible risk of onward transmission but are at increased risk of tuberculosis, which could potentially be prevented through identification and treatment of latent infection in close collaboration with a pre-entry screening programme.

FUNDING

Wellcome Trust, UK National Institute for Health Research, UK Medical Research Council, Public Health England, and Department of Health Policy Research Programme.

Prevalence of and risk factors for active tuberculosis in migrants screened before entry to the UK: a population-based cross-sectional study

BACKGROUND

An increasing number of countries with low incidence of tuberculosis have pre-entry screening programmes for migrants. We present the first estimates of the prevalence of and risk factors for tuberculosis in migrants from 15 high-incidence countries screened before entry to the UK.

METHODS

We did a population-based cross-sectional study of applicants for long-term visas who were screened for tuberculosis before entry to the UK in a pilot programme between Oct 1, 2005, and Dec 31, 2013. The primary outcome was prevalence of bacteriologically confirmed tuberculosis. We used Poisson regression to estimate crude prevalence and created a multivariable logistic regression model to identify risk factors for the primary outcome.

FINDINGS

476 455 visa applicants were screened, and the crude prevalence of bacteriologically confirmed tuberculosis was 92 (95% CI 84-101) per 100 000 individuals. After adjustment for age and sex, factors that were strongly associated with an increased risk of bacteriologically confirmed disease at pre-entry screening were self-report of close or household contact with an individual with tuberculosis (odds ratio 11·6, 95% CI 7·0-19·3; p<0·0001) and being an applicant for settlement and dependant visas (1·3, 1·0-1·6; p=0·0203).

INTERPRETATION

Migrants reporting contact with an individual with tuberculosis had the highest risk of tuberculosis at pre-entry screening. To tackle this disease burden in migrants, a comprehensive and collaborative approach is needed between countries with pre-entry screening programmes, health services in the countries of origin and migration, national tuberculosis control programmes, and international public health bodies.

FUNDING

Wellcome Trust, Medical Research Council, and UK National Institute for Health Research.

Are School Absences Correlated with Influenza Surveillance Data in England? Results from Decipher My Data-A Research Project Conducted through Scientific Engagement with Schools

BACKGROUND

School aged children are a key link in the transmission of influenza. Most cases have little or no interaction with health services and are therefore missed by the majority of existing surveillance systems. As part of a public engagement with science project, this study aimed to establish a web-based system for the collection of routine school absence data and determine if school absence prevalence was correlated with established surveillance measures for circulating influenza.

METHODS

We collected data for two influenza seasons (2011/12 and 2012/13). The primary outcome was daily school absence prevalence (weighted to make it nationally representative) for children aged 11 to 16. School absence prevalence was triangulated graphically and through univariable linear regression to Royal College of General Practitioners (RCGP) influenza like illness (ILI) episode incidence rate, national microbiological surveillance data on the proportion of samples positive for influenza (A+B) and with Rhinovirus, RSV and laboratory confirmed cases of Norovirus.

RESULTS

27 schools submitted data over two respiratory seasons. During the first season, levels of influenza measured by school absence prevalence and established surveillance were low. In the 2012/13 season, a peak of school absence prevalence occurred in week 51, and week 1 in RCGP ILI surveillance data. Linear regression showed a strong association between the school absence prevalence and RCGP ILI (All ages, and 5-14 year olds), laboratory confirmed cases of influenza A & B, and weak evidence for a linear association with Rhinovirus and Norovirus.

INTERPRETATION

This study provides initial evidence for using routine school illness absence prevalence as a novel tool for influenza surveillance. The network of web-based data collection platforms we established through active engagement provides an innovative model of conducting scientific research and could be used for a wide range of infectious disease studies in the future.

Effectiveness of peer educators on the uptake of mobile X-ray tuberculosis screening at homeless hostels: a cluster randomised controlled trial

TRIAL DESIGN

Cluster randomised controlled trial.

OBJECTIVE

To compare current practice for encouraging homeless people to be screened for tuberculosis on a mobile digital X-ray unit in London, UK, with the additional use of volunteer peer educators who have direct experience of tuberculosis, homelessness or both.

PARTICIPANTS

46 hostels took part in the study, with a total of 2342 residents eligible for screening. The study took place between February 2012 and October 2013 at homeless hostels in London, UK.

INTERVENTION

At intervention sites, volunteer peer educators agreed to a work plan that involved moving around the hostel in conjunction with the hostel staff, and speaking to residents in order to encourage them to attend the screening.

RANDOMISATION

Cluster randomisation (by hostel) was performed using an internet-based service to ensure allocation concealment, with minimisation by hostel size and historical screening uptake.

BLINDING

Only the study statistician was blinded to the allocation of intervention or control arms.

PRIMARY OUTCOME

The primary outcome was the number of eligible clients at a hostel venue screened for active pulmonary tuberculosis by the mobile X-ray unit.

RESULTS

A total of 59 hostels were considered for eligibility and 46 were randomised. Control sites had a total of 1192 residents, with a median uptake of 45% (IQR 33-55). Intervention sites had 1150 eligible residents with a median uptake of 40% (IQR 25-61). Using Poisson regression to account for the clustered study design, hostel size and historical screening levels, there was no evidence that peer educators increased uptake (adjusted risk ratio 0.98; 95% CIs 0.80 to 1.20). The study team noted no adverse events.

CONCLUSIONS

This study found no evidence that volunteer peer educators increased client uptake of mobile X-ray unit screening for tuberculosis. Further qualitative work should be undertaken to explore the possible ancillary benefits to peer volunteers.

TRIAL REGISTRATION NUMBER

ISRCTN17270334.

Accuracy of Probabilistic Linkage Using the Enhanced Matching System for Public Health and Epidemiological Studies

Background

The Enhanced Matching System (EMS) is a probabilistic record linkage program developed by the tuberculosis section at Public Health England to match data for individuals across two datasets. This paper outlines how EMS works and investigates its accuracy for linkage across public health datasets.

Methods

EMS is a configurable Microsoft SQL Server database program. To examine the accuracy of EMS, two public health databases were matched using National Health Service (NHS) numbers as a gold standard unique identifier. Probabilistic linkage was then performed on the same two datasets without inclusion of NHS number. Sensitivity analyses were carried out to examine the effect of varying matching process parameters.

Results

Exact matching using NHS number between two datasets (containing 5931 and 1759 records) identified 1071 matched pairs. EMS probabilistic linkage identified 1068 record pairs. The sensitivity of probabilistic linkage was calculated as 99.5% (95%CI: 98.9, 99.8), specificity 100.0% (95%CI: 99.9, 100.0), positive predictive value 99.8% (95%CI: 99.3, 100.0), and negative predictive value 99.9% (95%CI: 99.8, 100.0). Probabilistic matching was most accurate when including address variables and using the automatically generated threshold for determining links with manual review.

Conclusion

With the establishment of national electronic datasets across health and social care, EMS enables previously unanswerable research questions to be tackled with confidence in the accuracy of the linkage process. In scenarios where a small sample is being matched into a very large database (such as national records of hospital attendance) then, compared to results presented in this analysis, the positive predictive value or sensitivity may drop according to the prevalence of matches between databases. Despite this possible limitation, probabilistic linkage has great potential to be used where exact matching using a common identifier is not possible, including in low-income settings, and for vulnerable groups such as homeless populations, where the absence of unique identifiers and lower data quality has historically hindered the ability to identify individuals across datasets.

Effects of donor/recipient human leukocyte antigen mismatch on human cytomegalovirus replication following liver transplantation

Background

Natural immunity against cytomegalovirus (CMV) can control virus replication after solid organ transplantation; however, it is not known which components of the adaptive immune system mediate this protection. We investigated whether this protection requires human leukocyte antigen (HLA) matching between donor and recipient by exploiting the fact that, unlike transplantation of other solid organs, liver transplantation does not require HLA matching, but some donor and recipient pairs may nevertheless be matched by chance.

Methods

To further investigate this immune control, we determined whether chance HLA matching between donor (D) and recipient (R) in liver transplants affected a range of viral replication parameters.

Results

In total, 274 liver transplant recipients were stratified according to matches at the HLA A, HLA B, and HLA DR loci. The incidence of CMV viremia, kinetics of replication, and peak viral load were similar between the HLA matched and mismatched patients in the D+/R+ and D−/R+ transplant groups. D+/R− transplants with 1 or 2 mismatches at the HLA DR locus had a higher incidence of CMV viremia >3000 genomes/mL blood compared to patients matched at this locus (78% vs. 17%; P = 0.01). Evidence was seen that matching at the HLA A locus had a small effect on peak viral loads in D+/R− patients, with median peak loads of 3540 and 14,706 genomes/mL in the 0 and combined (1 and 2) mismatch groups, respectively (P = 0.03).

Conclusion

Overall, our data indicate that, in the setting of liver transplantation, prevention of CMV infection and control of CMV replication by adaptive immunity is minimally influenced by HLA matching of the donor and recipient. Our data raise questions about immune control of CMV in the liver and also about the cells in which the virus is amplified to give rise to CMV viremia.

Epidemiology of tuberculosis in big cities of the European Union and European Economic Area countries

This cross-sectional survey aimed to examine the epidemiology of tuberculosis (TB) in European Union (EU) and European Economic Area (EEA) cities with populations greater than 500,000. National TB programme managers were asked to provide data on big city population size, total number of notified TB cases in big cities and national notification rate for 2009. A rate ratio was calculated using the big city TB notification rate as a numerator and country TB notification rate, excluding big city TB cases and population, as a denominator. Twenty of the 30 EU/EEA countries had at least one big city. Pooled rate ratios were 2.5, 1.0, and 0.7 in low-, intermediate- and high-incidence countries respectively. In 15 big cities, all in low-incidence countries, rate ratios were twice the national notification rate. These data illustrate the TB epidemiology transition, a situation whereby TB disease concentrates in big cities as national incidence falls, most likely as a result of the higher concentration of risk groups found there. This situation requires targeted interventions and we recommend that big city TB data, including information about patients' risk factors, are collected and analysed systematically, and that successful interventions are shared.

Tuberculosis control in big cities and urban risk groups in the European Union: a consensus statement

In low-incidence countries in the European Union (EU), tuberculosis (TB) is concentrated in big cities, especially among certain urban high-risk groups including immigrants from TB high-incidence countries, homeless people, and those with a history of drug and alcohol misuse. Elimination of TB in European big cities requires control measures focused on multiple layers of the urban population. The particular complexities of major EU metropolises, for example high population density and social structure, create specific opportunities for transmission, but also enable targeted TB control interventions, not efficient in the general population, to be effective or cost effective. Lessons can be learnt from across the EU and this consensus statement on TB control in big cities and urban risk groups was prepared by a working group representing various EU big cities, brought together on the initiative of the European Centre for Disease Prevention and Control. The consensus statement describes general and specific social, educational, operational, organisational, legal and monitoring TB control interventions in EU big cities, as well as providing recommendations for big city TB control, based upon a conceptual TB transmission and control model.

Influenza vaccination, inverse care and homelessness: cross-sectional survey of eligibility and uptake during the 2011/12 season in London

Background

Influenza vaccination eligibility and uptake among homeless adults has not been previously assessed in the UK. This cross-sectional survey aimed to measure the proportion of homeless people visited by an NHS outreach service (Find and Treat) who were eligible for and had received vaccination during 2011/12.

Methods

A cross-sectional survey was carried out in 27 separate homeless hostels, day centres and drug services in London between July and August in 2012. Eligibility for the survey was by virtue of being in attendance at one of 27 venues visited by Find and Treat. No specific exclusion criteria were used.

Results

455 clients took part in the survey out of 592 approached (76.9%). A total of 190 homeless people (41.8%; 95% CI: 34.5,50.5) were eligible for influenza vaccination. In those aged 16–64, eligibility due to clinical risk factors was 38.9% (95% CI: 31.5,48.2). Uptake of vaccination in homeless 16–64 year olds with a clinical risk factor during the 2011/12 influenza season was 23.7% (95% CI: 19.8,28.3) compared to national levels of 53.2% (excluding pregnant women). In those aged over 65, uptake was 42.9% (95% CI: 16.7,100.0) compared with 74.0% nationally.

Conclusions

This study demonstrates that the homeless population have high levels of chronic health problems predisposing them to severe complications of influenza, but vaccine uptake levels that are less than half those seen among eligible GP patient groups in England. It provides a clear example of the health inequalities and inverse care law that impact this population. The results of this study provide strong justification for intensifying efforts to ensure homeless people have access to influenza vaccination.

Effects of ascent to high altitude on human antimycobacterial immunity

BACKGROUND

Tuberculosis infection, disease and mortality are all less common at high than low altitude and ascent to high altitude was historically recommended for treatment. The immunological and mycobacterial mechanisms underlying the association between altitude and tuberculosis are unclear. We studied the effects of altitude on mycobacteria and antimycobacterial immunity.

METHODS

Antimycobacterial immunity was assayed in 15 healthy adults residing at low altitude before and after they ascended to 3400 meters; and in 47 long-term high-altitude residents. Antimycobacterial immunity was assessed as the extent to which participants' whole blood supported or restricted growth of genetically modified luminescent Bacille Calmette-Guérin (BCG) mycobacteria during 96 hours incubation. We developed a simplified whole blood assay that could be used by a technician in a low-technology setting. We used this to compare mycobacterial growth in participants' whole blood versus positive-control culture broth and versus negative-control plasma.

RESULTS

Measurements of mycobacterial luminescence predicted the number of mycobacterial colonies cultured six weeks later. At low altitude, mycobacteria grew in blood at similar rates to positive-control culture broth whereas ascent to high altitude was associated with restriction (p ≤ 0.002) of mycobacterial growth to be 4-times less than in culture broth. At low altitude, mycobacteria grew in blood 25-times more than negative-control plasma whereas ascent to high altitude was associated with restriction (p ≤ 0.01) of mycobacterial growth to be only 6-times more than in plasma. There was no evidence of differences in antimycobacterial immunity at high altitude between people who had recently ascended to high altitude versus long-term high-altitude residents.

CONCLUSIONS

An assay of luminescent mycobacterial growth in whole blood was adapted and found to be feasible in low-resource settings. This demonstrated that ascent to or residence at high altitude was associated with decreased mycobacterial growth in whole blood relative to controls, consistent with altitude-related augmentation of antimycobacterial cellular immunity.

Cost-effectiveness analysis of 3-D computerized tomography colonography versus optical colonoscopy for imaging symptomatic gastroenterology patients

BACKGROUND

When symptomatic gastroenterology patients have an indication for colonic imaging, clinicians have a choice between optical colonoscopy (OC) and computerized tomography colonography with three-dimensional reconstruction (3-D CTC). 3-D CTC provides a minimally invasive and rapid evaluation of the entire colon, and it can be an efficient modality for diagnosing symptoms. It allows for a more targeted use of OC, which is associated with a higher risk of major adverse events and higher procedural costs. A case can be made for 3-D CTC as a primary test for colonic imaging followed if necessary by targeted therapeutic OC; however, the relative long-term costs and benefits of introducing 3-D CTC as a first-line investigation are unknown.

AIM

The aim of this study was to assess the cost effectiveness of 3-D CTC versus OC for colonic imaging of symptomatic gastroenterology patients in the UK NHS.

METHODS

We used a Markov model to follow a cohort of 100,000 symptomatic gastroenterology patients, aged 50 years or older, and estimate the expected lifetime outcomes, life years (LYs) and quality-adjusted life years (QALYs), and costs (£, 2010-2011) associated with 3-D CTC and OC. Sensitivity analyses were performed to assess the robustness of the base-case cost-effectiveness results to variation in input parameters and methodological assumptions.

RESULTS

3D-CTC provided a similar number of LYs (7.737 vs 7.739) and QALYs (7.013 vs 7.018) per individual compared with OC, and it was associated with substantially lower mean costs per patient (£467 vs £583), leading to a positive incremental net benefit. After accounting for the overall uncertainty, the probability of 3-D CTC being cost effective was around 60 %, at typical willingness-to-pay values of £20,000-£30,000 per QALY gained.

CONCLUSION

3-D CTC is a cost-saving and cost-effective option for colonic imaging of symptomatic gastroenterology patients compared with OC.

Active case finding for pulmonary tuberculosis using mobile digital chest radiography: an observational study

BACKGROUND

Mobile digital chest radiography (CXR) is used routinely to screen for pulmonary tuberculosis (PTB) in London among homeless populations, persons accessing drug treatment services and prisoners.

OBJECTIVE

1) To establish the sensitivity and specificity of mobile digital CXR, and 2) to test the hypothesis that actively identified cases have reduced odds of sputum smear positivity vs. those presenting passively to health care services from the same populations.

METHODS

Sensitivity and specificity were calculated using a gold standard comparator of culture-confirmed cases of PTB reported to the national surveillance system within 90 days of screening. Logistic regression was used to determine whether actively detected cases had reduced odds of smear positivity compared to passively detected cases after adjustment for confounding.

RESULTS

The intervention had a sensitivity of 81.8% (95%CI 64.5-93.0) and a specificity of 99.2% (95%CI 99.1-99.3). After adjusting for confounding, there was evidence that cases identified through screening were less likely to be smear-positive than passively identified cases (OR 0.34, 95%CI 0.14-0.85; likelihood ratio test P = 0.022).

CONCLUSION

Digital CXR achieves a high level of sensitivity and specificity in an operational setting; targeted mobile radiographic screening can reduce the risk of onward transmission by identifying cases before they become infectious.

Cytomegalovirus replication kinetics in solid organ transplant recipients managed by preemptive therapy

After allotransplantation, cytomegalovirus (CMV) may be transmitted from the donor organ, giving rise to primary infection in a CMV negative recipient or reinfection in one who is CMV positive. In addition, latent CMV may reactivate in a CMV positive recipient. In this study, serial blood samples from 689 kidney or liver transplant recipients were tested for CMV DNA by quantitative PCR. CMV was managed using preemptive antiviral therapy and no patient received antiviral prophylaxis. Dynamic and quantitative measures of viremia and treatment were assessed. Median peak viral load, duration of viremia and duration of treatment were highest during primary infection, followed by reinfection then reactivation. In patients who experienced a second episode of viremia, the viral replication rate was significantly slower than in the first episode. Our data provide a clear demonstration of the immune control of CMV in immunosuppressed patients and emphasize the effectiveness of the preemptive approach for prevention of CMV syndrome and end organ disease. Overall, our findings provide quantitative biomarkers which can be used in pharmacodynamic assessments of the ability of novel CMV vaccines or antiviral drugs to reduce or even interrupt such transmission.

Dedicated outreach service for hard to reach patients with tuberculosis in London: observational study and economic evaluation

OBJECTIVE

To assess the cost effectiveness of the Find and Treat service for diagnosing and managing hard to reach individuals with active tuberculosis.

DESIGN

Economic evaluation using a discrete, multiple age cohort, compartmental model of treated and untreated cases of active tuberculosis.

SETTING

London, United Kingdom. Population Hard to reach individuals with active pulmonary tuberculosis screened or managed by the Find and Treat service (48 mobile screening unit cases, 188 cases referred for case management support, and 180 cases referred for loss to follow-up), and 252 passively presenting controls from London's enhanced tuberculosis surveillance system.

MAIN OUTCOME MEASURES

Incremental costs, quality adjusted life years (QALYs), and cost effectiveness ratios for the Find and Treat service.

RESULTS

The model estimated that, on average, the Find and Treat service identifies 16 and manages 123 active cases of tuberculosis each year in hard to reach groups in London. The service has a net cost of £1.4 million/year and, under conservative assumptions, gains 220 QALYs. The incremental cost effectiveness ratio was £6400-£10,000/QALY gained (about €7300-€11,000 or $10,000-$16 000 in September 2011). The two Find and Treat components were also cost effective, even in unfavourable scenarios (mobile screening unit (for undiagnosed cases), £18,000-£26,000/QALY gained; case management support team, £4100-£6800/QALY gained).

CONCLUSIONS

Both the screening and case management components of the Find and Treat service are likely to be cost effective in London. The cost effectiveness of the mobile screening unit in particular could be even greater than estimated, in view of the secondary effects of infection transmission and development of antibiotic resistance.

Panton-Valentine leukocidin associated staphylococcal disease: a cross-sectional study at a London hospital, England

Recently, there has been international concern at the rapid emergence of highly pathogenic strains of Staphylococcus aureus associated with a toxin called Panton-Valentine leukocidin (PVL). In the UK, these strains are considered to be rare and mainly severe. We estimate the proportion of staphylococcal infections that are caused by strains containing the PVL genes, and describe risk factors for these infections. Three hundred and ninety consecutive S. aureus clinical isolates, submitted for routine diagnostic purposes were screened for PVL genes. Risk factors for infection were identified from the patient medical record. 9.7% (95% CI 7.0-13.1%) of clinical isolates and 20.8% of skin and soft tissue specimens contained the genes for PVL. Methicillin-resistant S. aureus with PVL was rare (0.8% of all isolates) but PVL with methicillin-sensitive S. aureus was common (9.0% of all specimens). PVL infection was more frequent in males (OR 3.0, 95% CI 1.3-7.0), and in young adults aged 20-39 years (OR 3.7, 95% CI 1.3-10.4). Over half of PVL positive S. aureus infections originated in patients based in the community. Community-onset PVL-associated disease is common in the UK and mainly causes skin and soft tissue infections that do not require admission to hospital. Consideration should be given to current infection control strategy, which advocates household contact screening and decolonization on the assumption that PVL-associated disease is rare.

Determining a cost effective intervention response to HIV/AIDS in Peru

Background

The HIV epidemic in Peru is still regarded as concentrated - sentinel surveillance data shows greatest rates of infection in men who have sex with men, while much lower rates are found in female sex workers and still lower in the general population. Without an appropriate set of preventive interventions, continuing infections could present a challenge to the sustainability of the present programme of universal access to treatment. Determining how specific prevention and care strategies would impact on the health of Peruvians should be key in reshaping the national response.

Methods

HIV/AIDS prevalence levels for risk groups with sufficient sentinel survey data were estimated. Unit costs were calculated for a series of interventions against HIV/AIDS which were subsequently inputted into a model to assess their ability to reduce infection transmission rates. Interventions included: mass media, voluntary counselling and testing; peer counselling for female sex workers; peer counselling for men who have sex with men; peer education of youth in-school; condom provision; STI treatment; prevention of mother to child transmission; and highly active antiretroviral therapy. Impact was assessed by the ability to reduce rates of transmission and quantified in terms of cost per DALY averted.

Results

Results of the analysis show that in Peru, the highest levels of HIV prevalence are found in men who have sex with men. Cost effectiveness varied greatly between interventions ranging from peer education of female commercial sex workers at $US 55 up to $US 5,928 (per DALY averted) for prevention of mother to child transmission.

Conclusion

The results of this work add evidence-based clarity as to which interventions warrant greatest consideration when planning an intervention response to HIV in Peru. Cost effectiveness analysis provides a necessary element of transparency when facing choices about priority setting, particularly when the country plans to amplify its response through new interventions partly funded by the GFATM.