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1.
BMJ Glob Health ; 9(5)2024 May 14.
Article En | MEDLINE | ID: mdl-38749511

INTRODUCTION: There are no published data on the long-term impact of invasive group B Streptococcus disease (iGBS) on economic costs or health-related quality of life (HRQoL) in low-income and middle-income countries. We assessed the impact of iGBS on healthcare utilisation, costs and HRQoL in Argentina, India, Kenya, Mozambique and South Africa. METHODS: Inpatient and outpatient visits, out-of-pocket (OOP) healthcare payments in the 12 months before study enrolment, and health-state utility of children and caregivers (using the EuroQol 5-Dimensions-3-Level) were collected from iGBS survivors and an unexposed cohort matched on site, age at recruitment and sex. We used logistic or Poisson regression for analysing healthcare utilisation and zero-inflated gamma regression models for family and health system costs. For HRQoL, we used a zero-inflated beta model of disutility pooled data. RESULTS: 161 iGBS-exposed and 439 unexposed children and young adults (age 1-20) were included in the analysis. Compared with unexposed participants, iGBS was associated with increased odds of any healthcare utilisation in India (adjusted OR 11.2, 95% CI 2.9 to 43.1) and Mozambique (6.8, 95% CI 2.2 to 21.1) and more frequent healthcare visits (adjusted incidence rate ratio (IRR) for India 1.7 (95% CI 1.4 to 2.2) and for Mozambique 6.0 (95% CI 3.2 to 11.2)). iGBS was also associated with more frequent days in inpatient care in India (adjusted IRR 4.0 (95% CI 2.3 to 6.8) and Kenya 6.4 (95% CI 2.9 to 14.3)). OOP payments were higher in the iGBS cohort in India (adjusted mean: Int$682.22 (95% CI Int$364.28 to Int$1000.16) vs Int$133.95 (95% CI Int$72.83 to Int$195.06)) and Argentina (Int$244.86 (95% CI Int$47.38 to Int$442.33) vs Int$52.38 (95% CI Int$-1.39 to Int$106.1)). For all remaining sites, differences were in the same direction but not statistically significant for almost all outcomes. Health-state disutility was higher in iGBS survivors (0.08, 0.04-0.13 vs 0.06, 0.02-0.10). CONCLUSION: The iGBS health and economic burden may persist for years after acute disease. Larger studies are needed for more robust estimates to inform the cost-effectiveness of iGBS prevention.


Developing Countries , Quality of Life , Streptococcal Infections , Humans , Male , Female , Child , Mozambique , Streptococcal Infections/economics , Child, Preschool , Infant , Adolescent , Kenya , Young Adult , India , Cohort Studies , Streptococcus agalactiae , Patient Acceptance of Health Care/statistics & numerical data , South Africa , Argentina , Health Care Costs/statistics & numerical data
2.
BMC Med ; 22(1): 186, 2024 May 03.
Article En | MEDLINE | ID: mdl-38702767

BACKGROUND: Migrants in the UK and Europe face vulnerability to vaccine-preventable diseases (VPDs) due to missed childhood vaccines and doses and marginalisation from health systems. Ensuring migrants receive catch-up vaccinations, including MMR, Td/IPV, MenACWY, and HPV, is essential to align them with UK and European vaccination schedules and ultimately reduce morbidity and mortality. However, recent evidence highlights poor awareness and implementation of catch-up vaccination guidelines by UK primary care staff, requiring novel approaches to strengthen the primary care pathway. METHODS: The 'Vacc on Track' study (May 2021-September 2022) aimed to measure under-vaccination rates among migrants in UK primary care and establish new referral pathways for catch-up vaccination. Participants included migrants aged 16 or older, born outside of Western Europe, North America, Australia, or New Zealand, in two London boroughs. Quantitative data on vaccination history, referral, uptake, and sociodemographic factors were collected, with practice nurses prompted to deliver catch-up vaccinations following UK guidelines. Focus group discussions and in-depth interviews with staff and migrants explored views on delivering catch-up vaccination, including barriers, facilitators, and opportunities. Data were analysed using STATA12 and NVivo 12. RESULTS: Results from 57 migrants presenting to study sites from 18 countries (mean age 41 [SD 7.2] years; 62% female; mean 11.3 [SD 9.1] years in UK) over a minimum of 6 months of follow-up revealed significant catch-up vaccination needs, particularly for MMR (49 [86%] required catch-up vaccination) and Td/IPV (50 [88%]). Fifty-three (93%) participants were referred for any catch-up vaccination, but completion of courses was low (6 [12%] for Td/IPV and 33 [64%] for MMR), suggesting individual and systemic barriers. Qualitative in-depth interviews (n = 39) with adult migrants highlighted the lack of systems currently in place in the UK to offer catch-up vaccination to migrants on arrival and the need for health-care provider skills and knowledge of catch-up vaccination to be improved. Focus group discussions and interviews with practice staff (n = 32) identified limited appointment/follow-up time, staff knowledge gaps, inadequate engagement routes, and low incentivisation as challenges that will need to be addressed. However, they underscored the potential of staff champions, trust-building mechanisms, and community-based approaches to strengthen catch-up vaccination uptake among migrants. CONCLUSIONS: Given the significant catch-up vaccination needs of migrants in our sample, and the current barriers to driving uptake identified, our findings suggest it will be important to explore this public health issue further, potentially through a larger study or trial. Strengthening existing pathways, staff capacity and knowledge in primary care, alongside implementing new strategies centred on cultural competence and building trust with migrant communities will be important focus areas.


General Practice , Transients and Migrants , Vaccination , Humans , Pilot Projects , Male , Adolescent , Female , Adult , United Kingdom , Young Adult , Vaccination/statistics & numerical data , General Practice/statistics & numerical data , Middle Aged
3.
Vaccine ; 42(13): 3206-3214, 2024 May 10.
Article En | MEDLINE | ID: mdl-38631950

BACKGROUND: The World Health Organization's (WHO) Immunization Agenda 2030 emphasises ensuring equitable access to vaccination across the life course. This includes placing an emphasis on migrant populations who may have missed key childhood vaccines, doses, and boosters due to disrupted healthcare systems and the migration process, or differing vaccination schedules in home countries. Guidelines exist in the UK for offering catch-up vaccinations to adolscent and adult migrants with incomplete or uncertain vaccination status (including MMR, Td-IPV, MenACWY, HPV), but emerging evidence suggests awareness and implementation in primary care is poor. It is unclear whether patient-level barriers to uptake of catch-up vaccinations also exist. We explored experiences and views around catch-up vaccination among adult migrants from a range of backgrounds, to define strategies for improving catch-up vaccination policy and practice. METHODS: In-depth semi-structured interviews were carried out in two phases with adult migrant populations (refugees, asylum seekers, undocumented migrants, those with no recourse to public funds) on views and experiences around vaccination, involving a team of peer researchers from specific migrant communities trained through the study. In Phase 1, we conducted remote interviews with migrants resident in the UK for < 10 years, from diverse backgrounds. In Phase 2, we engaged specifically Congolese and Angolan migrants as part of a community-based participatory study. Topic guides were developed iteratively and piloted. Participants were recruited using purposive, opportunistic and snowball sampling methods. Interviews were conducted in English (interpreters offered), Lingala or French and were audio-recorded, transcribed and analysed using a thematic framework approach in NVivo 12. RESULTS: 71 participants (39 in Phase 1, 32 in Phase 2) were interviewed (Mean age 43.6 [SD:12.4] years, 69% female, mean 9.5 [SD:7] years in the UK). Aside from COVID-19 vaccines, most participants reported never having been offered vaccinations or asked about their vaccination history since arriving in the UK as adults. Few participants mentioned being offered specific catch-up vaccines (e.g. MMR/Td-IPV) when attending a healthcare facility on arrival in the UK. Vaccines such as flu vaccines, pregnancy-related or pre-travel vaccination were more commonly mentioned. In general, participants were not aware of adult catch-up vaccination but regarded it positively when it was explained. A few participants expressed concerns about side-effects, risks/inconveniences associated with access (e.g. links to immigration authorities, travel costs), preference for natural remedies, and hesitancy to engage in further vaccination campaigns due to the intensity of COVID-19 vaccination campaigns. Trust was a major factor in vaccination decisions, with distinctions noted within and between groups; some held a healthcare professional's recommendation in high regard, while others were less trusting towards the healthcare system because of negative experiences of the NHS and past experiences of discrimination, injustice and marginalisation by wider authorities. CONCLUSIONS: The major barrier to adult catch-up vaccination for missed routine immunisations and doses in migrant communities in the UK is the limited opportunities, recommendations or tailored vaccination information presented to migrants by health services. This could be improved with financial incentives for provision of catch-up vaccination in UK primary care, alongside training of healthcare professionals to support catch-up immunisation and raise awareness of existing guidelines. It will also be essential to address root causes of mistrust around vaccination, where it exists among migrants, by working closely with communities to understand their needs and meaningfully involving migrant populations in co-producing tailored information campaigns and culturally relevant interventions to improve coverage.


Transients and Migrants , Vaccination Coverage , Vaccination , Humans , United Kingdom , Adult , Female , Male , Vaccination/psychology , Vaccination Coverage/statistics & numerical data , Middle Aged , Interviews as Topic , Young Adult , Refugees , COVID-19/prevention & control
4.
J Travel Med ; 2024 Feb 29.
Article En | MEDLINE | ID: mdl-38423523

BACKGROUND: Ensuring vaccination coverage reaches established herd immunity thresholds (HIT) is the cornerstone of any vaccination programme. Diverse migrant populations in European countries have been associated with cases of vaccine-preventable diseases (VPD) and outbreaks, yet it is not clear to what extent they are an under-immunised group. METHODS: We did a systematic review and meta-analysis to synthesise peer-reviewed published primary research reporting data on the immune status of migrants in EU/EEA countries, the UK and Switzerland, calculating their pooled immunity coverage for measles, mumps, rubella, and diphtheria using random-effects models. We searched on Web of Science, Embase, Global Health and MEDLINE (January 1st 2000 to June 10th 2022), with no language restrictions. The protocol is registered with PROSPERO (CRD42018103666). FINDINGS: Of 1103 abstracts screened, 62 met eligibility criteria, of which 39 were included in the meta-analysis. The meta-analysis included 75 089 migrants, predominantly from outside Europe. Pooled immunity coverage among migrant populations was well below the recommended HIT for diphtheria (n = 7, 57.4% [95% CI: 43.1-71.7%] I2 = 99% vs HIT 83-86%), measles (n = 21, 83.7% [95% CI: 79.2-88.2] I2 = 99% vs HIT 93-95%), and mumps (n = 8, 67.1% [95% CI: 50.6-83.6] I2 = 99% vs HIT 88-93%), and midway for rubella (n = 29, 85.6% [95% CI: 83.1-88.1%] I2 = 99% vs HIT 83-94%), with high heterogeneity across studies. INTERPRETATION: Migrants in Europe are an under-immunised group for a range of important VPDs, with this study reinforcing the importance of engaging children, adolescents, and adults in 'catch-up' vaccination initiatives on arrival for vaccines, doses, and boosters they may have missed in their home countries. Co-designing strategies to strengthen catch-up vaccination across the life-course in under-immunised groups is an important next step if we are to meet European and global targets for VPD elimination and control and ensure vaccine equity.

5.
J Migr Health ; 9: 100203, 2024.
Article En | MEDLINE | ID: mdl-38059072

Background: Migrants in Europe face a disproportionate burden of undiagnosed infection, including tuberculosis, blood-borne viruses, and parasitic infections and many belong to an under-immunised group. The European Centre for Disease Control (ECDC) has called for innovative strategies to deliver integrated multi-disease screening to migrants within primary care, yet this is poorly implemented in the UK. We did an in-depth qualitative study to understand current practice, barriers and solutions to infectious disease screening in primary care, and to seek feedback on a collaboratively developed digitalised integrated clinical decision-making tool called Health Catch UP!, which supports multi-infection screening for migrant patients. Methods: Two-phase qualitative study of UK primary healthcare professionals, in-depth semi-structured telephone-interviews were conducted. In Phase A, we conducted interviews with clinical staff (general practitioners (GPs), nurses, health-care-assistants (HCAs)); these informed data collection and analysis for phase B (administrative staff). Data were analysed iteratively, using thematic analysis. Results: In phase A, 48 clinicians were recruited (25 GPs, 15 nurses, seven HCAs, one pharmacist) and 16 administrative staff (11 Practice-Managers, five receptionists) in phase B. Respondents were positive about primary care's ability to effectively deliver infectious disease screening. However, we found current infectious disease screening lacks a standardised approach and many practices have no system for screening meaning migrant patients are not always receiving evidence-based care (i.e., NICE/ECDC/UKHSA screening guidelines). Barriers to screening were reported at patient, staff, and system-levels. Respondents reported poor implementation of existing screening initiatives (e.g., regional latent TB screening) citing overly complex pathways that required extensive administrative/clinical time and lacked financial/expert support. Solutions included patient/staff infectious disease champions, targeted training and specialist support, simplified care pathways for screening and management of positive results, and financial incentivisation. Participants responded positively to Health Catch-UP!, stating it would systematically integrate data and support clinical decision-making, increase knowledge, reduce missed screening opportunities, and normalisation of primary care-based infectious disease screening for migrants. Conclusions: Our results suggest that implementation of infectious disease screening in migrant populations is not comprehensively done in UK primary care. Primary health care professionals support the concept of innovative digital tools like Health Catch-UP! and that they could significantly improve disease detection and effective implementation of screening guidance but that they require robust testing and resourcing.

6.
Lancet Reg Health Eur ; 33: 100714, 2023 Oct.
Article En | MEDLINE | ID: mdl-37954001

Newborn bloodspot screening (NBS) policy is a contentious area in Europe. Variation in the screening panels on offer, in the approach to evidence assessment and in the use of health economic modelling are some of the issues which are debated on the topic. In this paper we focus on a set of patient-driven principles for newborn screening published by EURORDIS and use these as a reference point for exploration and comparison with NBS policy development and screening practice in the UK. In doing so, we share UK practice; we note the UK is generally well aligned with many of the recommended principles, but we also discuss areas of controversy and challenges. Some of these, like 'actionability', will undoubtedly continue to be debated and may never reach consensus. For others, such as patient and public voice participation in newborn screening systems, there are opportunities to continue improving existing processes and developing new mechanisms for stakeholder participation. Screening bodies in other European countries should also compare their policy-making and implementation practices with the EURORDIS principles to stimulate further discussion on the challenges and opportunities of newborn screening and provide a cross-European baseline.

7.
PLoS Med ; 20(3): e1004068, 2023 03.
Article En | MEDLINE | ID: mdl-36917564

BACKGROUND: Group B Streptococcus (GBS) can cause invasive disease (iGBS) in young infants, typically presenting as sepsis or meningitis, and is also associated with stillbirth and preterm birth. GBS vaccines are under development, but their potential health impact and cost-effectiveness have not been assessed globally. METHODS AND FINDINGS: We assessed the health impact and value (using net monetary benefit (NMB), which measures both health and economic effects of vaccination into monetary units) of GBS maternal vaccination in an annual cohort of 140 million pregnant women across 183 countries in 2020. Our analysis uses a decision tree model, incorporating risks of GBS-related health outcomes from an existing Bayesian disease burden model. We extrapolated country-specific GBS-related healthcare costs using data from a previous systematic review and calculated quality-adjusted life years (QALYs) lost due to infant mortality and long-term disability. We assumed 80% vaccine efficacy against iGBS and stillbirth, following the WHO Preferred Product Characteristics, and coverage based on the proportion of pregnant women receiving at least 4 antenatal visits. One dose was assumed to cost $50 in high-income countries, $15 in upper-middle income countries, and $3.50 in low-/lower-middle-income countries. We estimated NMB using alternative normative assumptions that may be adopted by policymakers. Vaccinating pregnant women could avert 127,000 (95% uncertainty range 63,300 to 248,000) early-onset and 87,300 (38,100 to 209,000) late-onset infant iGBS cases, 31,100 deaths (14,400 to 66,400), 17,900 (6,380 to 49,900) cases of moderate and severe neurodevelopmental impairment, and 23,000 (10,000 to 56,400) stillbirths. A vaccine effective against GBS-associated prematurity might also avert 185,000 (13,500 to 407,000) preterm births. Globally, a 1-dose vaccine programme could cost $1.7 billion but save $385 million in healthcare costs. Estimated global NMB ranged from $1.1 billion ($-0.2 to 3.8 billion) under the least favourable normative assumptions to $17 billion ($9.1 to 31 billion) under the most favourable normative assumptions. The main limitation of our analysis was the scarcity of data to inform some of the model parameters such as those governing health-related quality of life and long-term costs from disability, and how these parameters may vary across country contexts. CONCLUSIONS: In this study, we found that maternal GBS vaccination could have a large impact on infant morbidity and mortality. Globally, a GBS maternal vaccine at reasonable prices is likely to be a cost-effective intervention.


Premature Birth , Streptococcal Infections , Vaccines , Infant , Female , Infant, Newborn , Pregnancy , Humans , Cost-Benefit Analysis , Stillbirth , Streptococcal Infections/epidemiology , Streptococcal Infections/prevention & control , Quality of Life , Bayes Theorem , Vaccination/methods , Immunization , Streptococcus agalactiae
8.
J Med Screen ; 30(3): 97-112, 2023 09.
Article En | MEDLINE | ID: mdl-36617971

OBJECTIVES: To systematically review the accuracy of artificial intelligence (AI)-based systems for grading of fundus images in diabetic retinopathy (DR) screening. METHODS: We searched MEDLINE, EMBASE, the Cochrane Library and the ClinicalTrials.gov from 1st January 2000 to 27th August 2021. Accuracy studies published in English were included if they met the pre-specified inclusion criteria. Selection of studies for inclusion, data extraction and quality assessment were conducted by one author with a second reviewer independently screening and checking 20% of titles. Results were analysed narratively. RESULTS: Forty-three studies evaluating 15 deep learning (DL) and 4 machine learning (ML) systems were included. Nine systems were evaluated in a single study each. Most studies were judged to be at high or unclear risk of bias in at least one QUADAS-2 domain. Sensitivity for referable DR and higher grades was ≥85% while specificity varied and was <80% for all ML systems and in 6/31 studies evaluating DL systems. Studies reported high accuracy for detection of ungradable images, but the latter were analysed and reported inconsistently. Seven studies reported that AI was more sensitive but less specific than human graders. CONCLUSIONS: AI-based systems are more sensitive than human graders and could be safe to use in clinical practice but have variable specificity. However, for many systems evidence is limited, at high risk of bias and may not generalise across settings. Therefore, pre-implementation assessment in the target clinical pathway is essential to obtain reliable and applicable accuracy estimates.


Diabetes Mellitus , Diabetic Retinopathy , Humans , Artificial Intelligence , Diabetic Retinopathy/diagnostic imaging , Early Detection of Cancer , Mass Screening/methods
9.
Lancet Digit Health ; 4(12): e899-e905, 2022 12.
Article En | MEDLINE | ID: mdl-36427951

Rigorous evaluation of artificial intelligence (AI) systems for image classification is essential before deployment into health-care settings, such as screening programmes, so that adoption is effective and safe. A key step in the evaluation process is the external validation of diagnostic performance using a test set of images. We conducted a rapid literature review on methods to develop test sets, published from 2012 to 2020, in English. Using thematic analysis, we mapped themes and coded the principles using the Population, Intervention, and Comparator or Reference standard, Outcome, and Study design framework. A group of screening and AI experts assessed the evidence-based principles for completeness and provided further considerations. From the final 15 principles recommended here, five affect population, one intervention, two comparator, one reference standard, and one both reference standard and comparator. Finally, four are appliable to outcome and one to study design. Principles from the literature were useful to address biases from AI; however, they did not account for screening specific biases, which we now incorporate. The principles set out here should be used to support the development and use of test sets for studies that assess the accuracy of AI within screening programmes, to ensure they are fit for purpose and minimise bias.


Artificial Intelligence , Diagnostic Imaging , Mass Screening
10.
EClinicalMedicine ; 47: 101358, 2022 May.
Article En | MEDLINE | ID: mdl-35747160

Background: Data are limited regarding long-term consequences of invasive GBS (iGBS) disease in early infancy, especially from low- and middle-income countries (LMIC) where most cases occur. We aimed to estimate risk of neurodevelopmental impairment (NDI) in children with a history of iGBS disease. Methods: A multi-country matched cohort study was undertaken in South Africa, India, Mozambique, Kenya, and Argentina from October 2019 to April 2021. The exposure of interest was defined as a history of iGBS disease (sepsis or meningitis) before 90 days of age, amongst children now aged 1·5-18 years. Age and sex-matched, children without history of GBS were also recruited. Age-appropriate, culturally-adapted assessments were used to define NDI across multiple domains (cognitive, motor, hearing, vision, emotional-behaviour, growth). Pooled NDI risk was meta-analysed across sites. Association of iGBS exposure and NDI outcome was estimated using modified Poisson regression with robust variance estimator. Findings: Amongst 138 iGBS survivors and 390 non-iGBS children, 38·1% (95% confidence interval [CI]: 30·0% - 46·6%) of iGBS children had any NDI, compared to 21·7% (95% CI: 17·7% - 26·0%) of non- iGBS children, with notable between-site heterogeneity. Risk of moderate/severe NDI was 15·0% (95% CI: 3·4% - 30·8%) among GBS-meningitis, 5·6% (95% CI: 1·5% - 13·7%) for GBS-sepsis survivors. The adjusted risk ratio (aRR) for moderate/severe NDI among iGBS survivors was 1.27 (95% CI: 0.65, 2.45), when compared to non-GBS children. Mild impairment was more frequent in iGBS (27.6% (95% CI: 20.3 - 35.5%)) compared to non-GBS children (12.9% (95% CI: 9.7% - 16.4%)). The risk of emotional-behavioural problems was similar irrespective of iGBS exposure (aRR=0.98 (95% CI: 0.55, 1.77)). Interpretation: Our findings suggest that iGBS disease is on average associated with a higher risk of moderate/severe NDI, however substantial variation in risk was observed between sites and data are consistent with a wide range of values. Our study underlines the importance of long-term follow-up for at-risk neonates and more feasible, standardised assessments to facilitate diagnosis in research and clinical practice. Funding: This work was supported by a grant (INV-009018) from the Bill & Melinda Gates Foundation to the London School of Hygiene &Tropical Medicine.

11.
Lancet Digit Health ; 4(7): e558-e565, 2022 07.
Article En | MEDLINE | ID: mdl-35750402

Artificial intelligence (AI) could have the potential to accurately classify mammograms according to the presence or absence of radiological signs of breast cancer, replacing or supplementing human readers (radiologists). The UK National Screening Committee's assessments of the use of AI systems to examine screening mammograms continues to focus on maximising benefits and minimising harms to women screened, when deciding whether to recommend the implementation of AI into the Breast Screening Programme in the UK. Maintaining or improving programme specificity is important to minimise anxiety from false positive results. When considering cancer detection, AI test sensitivity alone is not sufficiently informative, and additional information on the spectrum of disease detected and interval cancers is crucial to better understand the benefits and harms of screening. Although large retrospective studies might provide useful evidence by directly comparing test accuracy and spectrum of disease detected between different AI systems and by population subgroup, most retrospective studies are biased due to differential verification (ie, the use of different reference standards to verify the target condition among study participants). Enriched, multiple-reader, multiple-case, test set laboratory studies are also biased due to the laboratory effect (ie, radiologists' performance in retrospective, laboratory, observer studies is substantially different to their performance in a clinical environment). Therefore, assessment of the effect of incorporating any AI system into the breast screening pathway in prospective studies is required as it will provide key evidence for the effect of the interaction of medical staff with AI, and the impact on women's outcomes.


Breast Neoplasms , Early Detection of Cancer , Artificial Intelligence , Breast Neoplasms/diagnosis , Early Detection of Cancer/methods , Female , Humans , Retrospective Studies , United Kingdom
12.
Lancet Glob Health ; 10(6): e807-e819, 2022 06.
Article En | MEDLINE | ID: mdl-35490693

BACKGROUND: Group B streptococcus (GBS) colonisation during pregnancy can lead to invasive GBS disease (iGBS) in infants, including meningitis or sepsis, with a high mortality risk. Other outcomes include stillbirths, maternal infections, and prematurity. There are data gaps, notably regarding neurodevelopmental impairment (NDI), especially after iGBS sepsis, which have limited previous global estimates. In this study, we aimed to address this gap using newly available multicountry datasets. METHODS: We collated and meta-analysed summary data, primarily identified in a series of systematic reviews published in 2017 but also from recent studies on NDI and stillbirths, using Bayesian hierarchical models, and estimated the burden for 183 countries in 2020 regarding: maternal GBS colonisation, iGBS cases and deaths in infants younger than 3 months, children surviving iGBS affected by NDI, and maternal iGBS cases. We analysed the proportion of stillbirths with GBS and applied this to the UN-estimated stillbirth risk per country. Excess preterm births associated with maternal GBS colonisation were calculated using meta-analysis and national preterm birth rates. FINDINGS: Data from the seven systematic reviews, published in 2017, that informed the previous burden estimation (a total of 515 data points) were combined with new data (17 data points) from large multicountry studies on neurodevelopmental impairment (two studies) and stillbirths (one study). A posterior median of 19·7 million (95% posterior interval 17·9-21·9) pregnant women were estimated to have rectovaginal colonisation with GBS in 2020. 231 800 (114 100-455 000) early-onset and 162 200 (70 200-394 400) late-onset infant iGBS cases were estimated to have occurred. In an analysis assuming a higher case fatality rate in the absence of a skilled birth attendant, 91 900 (44 800-187 800) iGBS infant deaths were estimated; in an analysis without this assumption, 58 300 (26 500-125 800) infant deaths from iGBS were estimated. 37 100 children who recovered from iGBS (14 600-96 200) were predicted to develop moderate or severe NDI. 40 500 (21 500-66 200) maternal iGBS cases and 46 200 (20 300-111 300) GBS stillbirths were predicted in 2020. GBS colonisation was also estimated to be potentially associated with considerable numbers of preterm births. INTERPRETATION: Our analysis provides a comprehensive assessment of the pregnancy-related GBS burden. The Bayesian approach enabled coherent propagation of uncertainty, which is considerable, notably regarding GBS-associated preterm births. Our findings on both the acute and long-term consequences of iGBS have public health implications for understanding the value of investment in maternal GBS immunisation and other preventive strategies. FUNDING: Bill & Melinda Gates Foundation.


Premature Birth , Sepsis , Streptococcal Infections , Bayes Theorem , Child , Female , Global Health , Humans , Infant , Infant Death , Infant, Newborn , Pregnancy , Premature Birth/epidemiology , Stillbirth/epidemiology , Streptococcal Infections/complications , Streptococcal Infections/epidemiology , Streptococcal Infections/prevention & control , Streptococcus agalactiae , Systematic Reviews as Topic
13.
Lancet Reg Health Eur ; 16: 100353, 2022 May.
Article En | MEDLINE | ID: mdl-35492962

A recent report on screening in the UK proposed that the responsibility for recommendations on population and targeted screening programmes should be held by one new integrated advisory body. There is no wide international consensus on the definition of targeted screening. Our review identified and compared the defining components of screening terms: targeted, population, selective, and cascade screening, and case finding. Definitions of targeted screening and population screening were clearly demarcated by the eligible population; targeted and selective screening were found to be conceptually interchangeable; cascade screening, whilst conceptually similar to targeted screening across several components, was only used within the context of genetic diseases. There was little consensus between different definitions of case finding. These comparisons contributed to an updated definition of targeted screening. Considerable overlap between definition components across terms implies that a broad range of disease areas may fall into the remit of the new advisory body.

14.
Br J Cancer ; 126(9): 1355-1361, 2022 05.
Article En | MEDLINE | ID: mdl-35110696

BACKGROUND: Population breast screening services in England were suspended in March 2020 due to the COVID-19 pandemic. Here, we estimate the number of breast cancers whose detection may be delayed because of the suspension, and the potential impact on cancer deaths over 10 years. METHODS: We estimated the number and length of screening delays from observed NHS Breast Screening System data. We then estimated additional breast cancer deaths from three routes: asymptomatic tumours progressing to symptomatically diagnosed disease, invasive tumours which remain screen-detected but at a later date, and ductal carcinoma in situ (DCIS) progressing to invasive disease by detection. We took progression rates, prognostic characteristics, and survival rates from published sources. RESULTS: We estimated that 1,489,237 women had screening delayed by around 2-7 months between July 2020 and June 2021, leaving 745,277 outstanding screens. Depending on how quickly this backlog is cleared, around 2500-4100 cancers would shift from screen-detected to symptomatic cancers, resulting in 148-452 additional breast cancer deaths. There would be an additional 164-222 screen-detected tumour deaths, and 71-97 deaths from DCIS that progresses to invasive cancer. CONCLUSIONS: An estimated 148-687 additional breast cancer deaths may occur as a result of the pandemic-related disruptions. The impact depends on how quickly screening services catch up with delays.


Breast Neoplasms , COVID-19 , Carcinoma, Intraductal, Noninfiltrating , Breast Neoplasms/pathology , Carcinoma, Intraductal, Noninfiltrating/pathology , Communicable Disease Control , Early Detection of Cancer , England/epidemiology , Female , Humans , Male , Mammography , Mass Screening , Pandemics
15.
Clin Infect Dis ; 74(Suppl_1): S14-S23, 2022 01 20.
Article En | MEDLINE | ID: mdl-34725690

BACKGROUND: Invasive group B Streptococcus disease (iGBS) in infancy, including meningitis or sepsis, carries a high risk of mortality and neurodevelopmental impairment (NDI). We present data on iGBS from 2 decades of surveillance in Manhiça, Mozambique, with a focus on NDI. METHODS: Morbidity surveillance databases in a rural Mozambican district hospital were screened for iGBS cases. From February 2020 to March 2021, surviving iGBS patients (n = 39) plus age- and sex-matched children without iGBS (n = 119) were assessed for neurocognitive development, vision, and hearing. The role of GBS in stillbirths and infant deaths was investigated using minimally invasive tissue sampling (MITS). RESULTS: Ninety iGBS cases were included, with most children being <3 months of age (85/90). The in-hospital case fatality rate was 14.4% (13/90), increasing to 17.8% (3 additional deaths) when considering mortality during the 6 months postdiagnosis. Fifty percent of the iGBS exposed infants and 10% of those unexposed showed any NDI. Surviving GBS conferred a 11-fold increased adjusted odds of moderate/severe NDI (odds ratio, 2.8 [95% confidence interval, .92-129.74]; P = .06) in children aged 0-5 years. For older children (6-18 years), no differences in NDI were found between exposed and unexposed. Motor domain was the most affected among young GBS survivors. Three stillbirths and 4 early neonatal deaths (of the 179 MITS performed) were attributed to iGBS. CONCLUSIONS: In absence of preventive strategies, such as intrapartum antibiotics, iGBS remains a significant cause of perinatal and infant disease and death. GBS also causes major longer-term neurodevelopmental sequelae, altogether justifying the need for maternal GBS vaccination strategies to increase perinatal and infant survival.


Streptococcal Infections , Vaccines , Adolescent , Child , Child, Preschool , Cohort Studies , Female , Humans , Infant , Infant, Newborn , Pregnancy , Retrospective Studies , Streptococcal Infections/complications , Streptococcus agalactiae
16.
J Migr Health ; 3: 100041, 2021.
Article En | MEDLINE | ID: mdl-33903857

BACKGROUND: Migrants in high-income countries may be at increased risk of COVID-19 due to their health and social circumstances, yet the extent to which they are affected and their predisposing risk factors are not clearly understood. We did a systematic review to assess clinical outcomes of COVID-19 in migrant populations, indirect health and social impacts, and to determine key risk factors. METHODS: We did a systematic review following PRISMA guidelines (PROSPERO CRD42020222135). We searched multiple databases to 18/11/2020 for peer-reviewed and grey literature on migrants (foreign-born) and COVID-19 in 82 high-income countries. We used our international networks to source national datasets and grey literature. Data were extracted on primary outcomes (cases, hospitalisations, deaths) and we evaluated secondary outcomes on indirect health and social impacts and risk factors using narrative synthesis. RESULTS: 3016 data sources were screened with 158 from 15 countries included in the analysis (35 data sources for primary outcomes: cases [21], hospitalisations [4]; deaths [15]; 123 for secondary outcomes). We found that migrants are at increased risk of infection and are disproportionately represented among COVID-19 cases. Available datasets suggest a similarly disproportionate representation of migrants in reported COVID-19 deaths, as well as increased all-cause mortality in migrants in some countries in 2020. Undocumented migrants, migrant health and care workers, and migrants housed in camps have been especially affected. Migrants experience risk factors including high-risk occupations, overcrowded accommodation, and barriers to healthcare including inadequate information, language barriers, and reduced entitlement. CONCLUSIONS: Migrants in high-income countries are at high risk of exposure to, and infection with, COVID-19. These data are of immediate relevance to national public health and policy responses to the pandemic. Robust data on testing uptake and clinical outcomes in migrants, and barriers and facilitators to COVID-19 vaccination, are urgently needed, alongside strengthening engagement with diverse migrant groups.

18.
BMJ Open ; 10(11): e038505, 2020 11 19.
Article En | MEDLINE | ID: mdl-33444184

OBJECTIVES: To assess the cost-effectiveness of universal repeat screening for syphilis in late pregnancy, compared with the current strategy of single screening in early pregnancy with repeat screening offered only to high-risk women. DESIGN: A decision tree model was developed to assess the incremental costs and health benefits of the two screening strategies. The base case analysis considered short-term costs during the pregnancy and the initial weeks after delivery. Deterministic and probabilistic sensitivity analyses and scenario analyses were conducted to assess the robustness of the results. SETTING: UK antenatal screening programme. POPULATION: Hypothetical cohort of pregnant women who access antenatal care and receive a syphilis screen in 1 year. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the cost to avoid one case of congenital syphilis (CS). Secondary outcomes were the cost to avoid one case of intrauterine fetal demise (IUFD) or neonatal death and the number of women needing to be screened/treated to avoid one case of CS, IUFD or neonatal death. The cost per quality-adjusted life year gained was assessed in scenario analyses. RESULTS: Base case results indicated that for pregnant women in the UK (n=725 891), the repeat screening strategy would result in 5.5 fewer cases of CS (from 8.8 to 3.3), 0.1 fewer cases of neonatal death and 0.3 fewer cases of IUFD annually compared with the single screening strategy. This equates to an additional £1.8 million per case of CS prevented. When lifetime horizon was considered, the incremental cost-effectiveness ratio for the repeat screening strategy was £120 494. CONCLUSIONS: Universal repeat screening for syphilis in pregnancy is unlikely to be cost-effective in the current UK setting where syphilis prevalence is low. Repeat screening may be cost-effective in countries with a higher syphilis incidence in pregnancy, particularly if the cost per screen is low.


Pregnancy Complications, Infectious , Syphilis , Cost-Benefit Analysis , Female , Humans , Mass Screening , Pregnancy , Pregnancy Complications, Infectious/diagnosis , Syphilis/diagnosis , Syphilis/epidemiology , United Kingdom/epidemiology
20.
Lancet Infect Dis ; 18(9): e259-e271, 2018 09.
Article En | MEDLINE | ID: mdl-29778396

Rates of migration to Europe, and within Europe, have increased in recent years, with considerable implications for health systems. Migrants in Europe face a disproportionate burden of tuberculosis, HIV, and hepatitis B and C, yet experience a large number of barriers to accessing statutory health care on arrival. A better understanding of how to deliver effective and cost-effective screening, vaccination, and health services to this group is now crucial. We did a systematic review to document and assess the effectiveness and cost-effectiveness of approaches used for infectious diseases screening, and to explore facilitators and barriers experienced by migrants to accessing screening programmes. Following PRISMA guidelines, we searched Embase, PubMed, PsychINFO, the Cochrane Library, and Web of Science (1989 to July 1, 2015, updated on Jan 1, 2018), with no language restrictions, and systematically approached experts across the European Union (EU) for grey literature. Inclusion criteria were primary research studies assessing screening interventions for any infectious disease in the migrant (foreign-born) population residing in EU or European Economic Area (EEA) countries. Primary outcomes were the following effectiveness indicators: uptake of screening, coverage, infections detected, and treatment outcomes. Of 4112 unique records, 47 studies met our inclusion criteria, from ten European countries (Belgium, Denmark, France, Italy, the Netherlands, Norway, Spain, Sweden, Switzerland, and the UK) encompassing 248 402 migrants. We found that most European countries screening migrants focus on single diseases only-predominantly active or latent tuberculosis infection-and specifically target asylum seekers and refugees, with 22 studies reporting on other infections (including HIV and hepatitis B and C). An infection was detected in 3·74% (range 0·00-95·16) of migrants. Latent tuberculosis had the highest prevalence across all infections (median 15·02% [0·35-31·81]). Uptake of screening by migrants was high (median 79·50% [18·62-100·00]), particularly in primary health-care settings (uptake 96·77% [76·00-100·00]). However, in 24·62% (0·12-78·99) of migrants screening was not completed and a final diagnosis was not made. Pooled data highlight high treatment completion in migrants (83·79%, range 0·00-100·00), yet data were highly heterogeneous for this outcome, masking important disparities between studies and infections, with only 54·45% (35·71-72·27) of migrants with latent tuberculosis ultimately completing treatment after screening. Coverage of the migrant population in Europe is low (39·29% [14·53-92·50]). Data on cost-effectiveness were scarce, but suggest moderate to high cost-effectiveness of migrant screening programmes depending on migrant group and disease targeted. European countries have adopted a variety of approaches to screening migrants for infections; however, these are limited in scope to single diseases and a narrow subset of migrants, with low coverage. More emphasis must be placed on developing innovative and sustainable strategies to facilitate screening and treatment completion and improve health outcomes, encompassing multiple key infections with consideration given to a wider group of high-risk migrants. Policy makers and researchers involved with global migration need to ensure a longer-term view on improving health outcomes in migrant populations as they integrate into health systems in host countries.


Communicable Disease Control/methods , Communicable Diseases/diagnosis , Mass Screening/methods , Refugees/statistics & numerical data , Transients and Migrants/statistics & numerical data , Europe , Humans
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