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

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

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

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

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

Cyanotoxin profiling in the subalpine district lakes

Contains fulltext : 193062.pdf (Publisher’s version ) (Open Access

Examining the epidemiology of tuberculosis in migrants to the UK to inform evidence-based screening policies

Background: In high-income countries an increasing proportion of all tuberculosis cases are detected in migrants. Understanding the epidemiology of tuberculosis in migrants to inform evidence-based screening policies is a priority. Methods: A systematic review and meta-analysis of pre-entry screening for tuberculosis was undertaken (chapter 2). Data from a pilot pre-entry programme in migrants to the UK was described, and risk factors for prevalent cases examined (chapter 3). The accuracy of a novel method for identifying individuals between two datasets was studied (chapter 4). This linkage method was used to combine data from migrants screened pre-entry to the UK tuberculosis register including molecular strain typing data. The linked datasets enabled estimates of the incidence of tuberculosis to be calculated, and risk factors were identified (chapters 5 and 6). Results: The systematic review identified 15 studies and found that culture confirmation increased with WHO prevalence in the country of origin. The crude prevalence of bacteriologically confirmed tuberculosis identified by UK pre-entry screening was 92 per 100,000 population screened. Migrants reporting a history of contact with a case of tuberculosis, and those from higher prevalence countries were at greatest risk. Compared to a gold standard of NHS number, probabilistic linkage identified individuals in two datasets with high sensitivity and specificity. The estimated incidence of tuberculosis notified in the UK in migrants screened pre-entry was 194 per 100,000 person years at risk. Migrants with a chest radiograph classified as suspected tuberculosis and those from higher prevalence countries had a higher risk post- migration. Compared to other non-UK born individuals, migrants screened pre-entry were less likely to be the first case in a cluster of tuberculosis. Conclusions: This thesis generated new knowledge that improves our understanding of the epidemiology of tuberculosis in migrants to the UK. Based on these findings, evidence-based screening recommendations were made

Point-of-care screening for a current Hepatitis C virus infection: influence on uptake of a concomitant offer of HIV screening

Eliminating hepatitis C as a public health threat requires an improved understanding of how to increase testing uptake. We piloted point-of-care testing (POCT) for a current HCV infection in an inner-city Emergency Department (ED) and assessed the influence on uptake of offering concomitant screening for HIV. Over four months, all adults attending ED with minor injuries were first invited to complete an anonymous questionnaire then invited to test in alternating cycles offering HCV POCT or HCV+HIV POCT. Viral RNA was detected in finger-prick blood by GeneXpert. 814/859 (94.8%) questionnaires were returned and 324/814 (39.8%) tests were accepted, comprising 211 HCV tests and 113 HCV+HIV tests. Offering concomitant HIV screening reduced uptake after adjusting for age and previous HCV testing (odds ratio 0.51; 95% confidence interval [CI] 0.38–0.68; p < 0.001). HCV prevalence was 1/324 (0.31%; 95% CI 0.05–1.73); no participant tested positive for HIV. 167/297 (56.2%) POCT participants lived in the most deprived neighbourhoods in England. HCV RNA testing using finger-prick blood was technically feasible. Uptake was moderate and the offer of concomitant HIV screening showed a detrimental impact on acceptability in this low prevalence population. The findings should be confirmed in a variety of other community settings

A rapid review and meta-analysis of the asymptomatic proportion of PCR-confirmed SARS-CoV-2 infections in community settings [version 1; peer review: awaiting peer review]

Background: Cross-sectional studies indicate that up to 80% of active SARS-CoV-2 infections may be asymptomatic. However, accurate estimates of the asymptomatic proportion require systematic detection and follow-up to differentiate between truly asymptomatic and pre-symptomatic cases. We conducted a rapid review and meta-analysis of the asymptomatic proportion of PCR-confirmed SARS-CoV-2 infections based on methodologically appropriate studies in community settings. / Methods: We searched Medline and EMBASE for peer-reviewed articles, and BioRxiv and MedRxiv for pre-prints published before 25/08/2020. We included studies based in community settings that involved systematic PCR testing on participants and follow-up symptom monitoring regardless of symptom status. We extracted data on study characteristics, frequencies of PCR-confirmed infections by symptom status, and (if available) cycle threshold/genome copy number values and/or duration of viral shedding by symptom status, and age of asymptomatic versus (pre)symptomatic cases. We computed estimates of the asymptomatic proportion and 95% confidence intervals for each study and overall using random effect meta-analysis. / Results: We screened 1138 studies and included 21. The pooled asymptomatic proportion of SARS-CoV-2 infections was 23% (95% CI 16%-30%). When stratified by testing context, the asymptomatic proportion ranged from 6% (95% CI 0-17%) for household contacts to 47% (95% CI 21-75%) for non-outbreak point prevalence surveys with follow-up symptom monitoring. Estimates of viral load and duration of viral shedding appeared to be similar for asymptomatic and symptomatic cases based on available data, though detailed reporting of viral load and natural history of viral shedding by symptom status were limited. Evidence into the relationship between age and symptom status was inconclusive. / Conclusion: Asymptomatic viral shedding comprises a substantial minority of SARS-CoV-2 infections when estimated using methodologically appropriate studies. Further investigation into variation in the asymptomatic proportion by testing context, the degree and duration of infectiousness for asymptomatic infections, and demographic predictors of symptom status are warranted

Migration health research in the United Kingdom: A scoping review

Background: One in seven people living in the United Kingdom (UK) is an international migrant, rendering migrants an important population group with diverse and dynamic health and healthcare needs. However, there has been no attempt to map contemporary trends within migration health research conducted in the UK. The aim of this scoping review was to describe trends within migration health research and identify gaps for future research agendas. Methods: PubMed and Embase were systematically searched for empirical research with a primary focus on the concepts “health” and “migrants” published between 2001 and 2019. Findings were analysed using the UCL-Lancet Commission on Migration and Health Conceptual Framework for Migration and Health. Results: In total, 399 studies were included, with almost half (41.1%; 164/399) published in the last five years of the study period between 2015 and 2019 and a third (34.1%; 136/399) conducted in London. Studies included asylum seekers (14.8%; 59/399), refugees (12.3%; 49/399), and undocumented migrants or migrants with insecure status (3.5%; 14/399), but most articles (74.9%; 299/399) did not specify a migrant sub-group. The most studied health topics were specific disease outcomes such as infectious diseases (24.1% of studies) and mental health (19.1%) compared to examining systems or structures that impact health (27.8%), access to healthcare (26.3%), or specific exposures or behaviours (35.3%). Conclusions: There has been a growing interest in migration health. Ensuring a diverse geographic distribution of research conducted in the UK and disaggregation by migrant sub-group is required for a nuanced and region-specific understanding of specific health needs, interventions and appropriate service delivery for different migrant populations. More research is needed to understand how migration policy and legislation intersect with both the social determinants of health and access to healthcare to shape the health of migrants in the UK