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Journal articleSuel E, Bhatt S, Brauer M, et al., 2021,
Multimodal deep learning from satellite and street-level imagery for measuring income, overcrowding, and environmental deprivation in urban areas
, Remote Sensing of Environment: an interdisciplinary journal, Vol: 257, ISSN: 0034-4257Data collected at large scale and low cost (e.g. satellite and street level imagery) have the potential to substantially improve resolution, spatial coverage, and temporal frequency of measurement of urban inequalities. Multiple types of data from different sources are often available for a given geographic area. Yet, most studies utilize a single type of input data when making measurements due to methodological difficulties in their joint use. We propose two deep learning-based methods for jointly utilizing satellite and street level imagery for measuring urban inequalities. We use London as a case study for three selected outputs, each measured in decile classes: income, overcrowding, and environmental deprivation. We compare the performances of our proposed multimodal models to corresponding unimodal ones using mean absolute error (MAE). First, satellite tiles are appended to street level imagery to enhance predictions at locations where street images are available leading to improvements in accuracy by 20, 10, and 9% in units of decile classes for income, overcrowding, and living environment. The second approach, novel to the best of our knowledge, uses a U-Net architecture to make predictions for all grid cells in a city at high spatial resolution (e.g. for 3 m × 3 m pixels in London in our experiments). It can utilize city wide availability of satellite images as well as more sparse information from street-level images where they are available leading to improvements in accuracy by 6, 10, and 11%. We also show examples of prediction maps from both approaches to visually highlight performance differences.
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Journal articleDolo H, Coulibaly YI, Sow M, et al., 2021,
Serological evaluation of onchocerciasis and lymphatic filariasis elimination in the Bakoye and Falémé Foci, Mali
, Clinical Infectious Diseases, Vol: 72, Pages: 1585-1593, ISSN: 1058-4838BACKGROUND: In Mali, ivermectin-based onchocerciasis elimination from the Bakoye and Falémé foci, reported in 2009-2012, was a beacon leading to policy shifting from morbidity control to elimination of transmission (EOT). These foci are also endemic for lymphatic filariasis (LF). In 2007-2016 mass ivermectin plus albendazole administration was implemented. We report Ov16 (onchocerciasis) and Wb123 (LF) seroprevalence after 24-25 years of treatment to evaluate if onchocerciasis EOT and LF elimination as a public health problem (EPHP) have been achieved. METHODS: The SD Bioline Onchocerciasis/LF IgG4 biplex rapid diagnostic test (RDT) was used in 2,186 children aged 3-10 years in 13 villages (plus two hamlets) in Bakoye, and 2,270 children in 15 villages (plus one hamlet) in Falémé. In Bakoye, all-age serosurveys were conducted in three historically hyperendemic villages, testing 1,867 individuals aged 3-78 years. RESULTS: In Bakoye, IgG4 seropositivity was 0.27% (95%CI=0.13-0.60%) for both Ov16 and Wb123 antigens. In Falémé, Ov16 and Wb123 seroprevalence was, respectively, 0.04% (95%CI=0.01-0.25%) and 0.09% (95%CI=0.02-0.32%). Ov16-seropositive children were from historically meso- and hyperendemic villages. Ov16 positivity was <2% in those ≤14 years, increasing to 16% in those ≥40 years. Wb123 seropositivity was <2% in those ≤39 years, reaching 3% in those ≥40 years. CONCLUSIONS: Notwithstanding uncertainty in the biplex RDT sensitivity, Ov16 and Wb123 seroprevalence among children in Bakoye and Falémé appears consistent with EOT (onchocerciasis) and EPHP (LF) since stopping treatment in 2016. The few Ov16-seropositive children should be skin-snip PCR tested and followed up.
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Journal articleCollin SM, Groves N, O' Sullivan C, et al., 2021,
Uncovering infant group B streptococcal (GBS) disease clusters in the UK and Ireland through genomic analysis: a population-based epidemiological study
, Clinical Infectious Diseases, Vol: 72, Pages: e296-e302, ISSN: 1058-4838BackgroundThe true frequency of hospital outbreaks of invasive group B streptococcal (iGBS; Streptococcus agalactiae) disease in infants is unknown. We used whole genome sequencing (WGS) of iGBS isolates collected during a period of enhanced surveillance of infant iGBS disease in the UK and Ireland to determine the number of clustered cases.MethodsPotentially linked iGBS cases from infants with early (<7 days of life) or late-onset (7–89 days) disease were identified from WGS data (HiSeq 2500 platform, Illumina) from clinical sterile site isolates collected between 04/2014 and 04/2015. We assessed time and place of cases to determine a single-nucleotide polymorphism (SNP) difference threshold for clustered cases. Case details were augmented through linkage to national hospital admission data and hospital record review by local microbiologists.ResultsAnalysis of sequences indicated a cutoff of ≤5 SNP differences to define iGBS clusters. Among 410 infant iGBS isolates, we identified 7 clusters (4 genetically identical pairs with 0 SNP differences, 1 pair with 3 SNP differences, 1 cluster of 4 cases with ≤1 SNP differences) of which 4 clusters were uncovered for the first time. The clusters comprised 16 cases, of which 15 were late-onset (of 192 late-onset cases with sequenced isolates) and 1 an early-onset index case. Serial intervals between cases ranged from 0 to 59 (median 12) days.ConclusionsApproximately 1 in 12 late-onset infant iGBS cases were part of a hospital cluster. Over half of the clusters were previously undetected, emphasizing the importance of routine submission of iGBS isolates to reference laboratories for cluster identification and genomic confirmation.
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Journal articleGiguere K, Eaton J, Marsh K, et al., 2021,
Trends in knowledge of HIV status and efficiency of HIV testing services in sub-Saharan Africa, 2000-20: a modelling study using survey and HIV testing programme data
, The Lancet HIV, Vol: 8, Pages: 284-293, ISSN: 2405-4704Background: Monitoring knowledge of HIV status (KOS) among people living with HIV (PLHIV) is essential for an effective national HIV response. This study estimates progress and gaps in reaching the UNAIDS 2020 target of 90% KOS, and the efficiency of HIV testing services (HTS) in sub-Saharan Africa (SSA), where two thirds of all PLHIV live. Methods: We used data from 183 population-based surveys (N=2·7 million participants) and national HTS programs (N=315 country-years) from 40 countries as inputs into a mathematical model to examine trends in KOS among PLHIV, median time from HIV infection to diagnosis, HIV testing positivity, and proportion of new diagnoses among all positive tests, adjusting for retesting.Findings: Across SSA, KOS steadily increased from 6% (95% credible interval [95%CrI]: 5% to 7%) in 2000 to 84% (95%CrI: 82% to 86%) in 2020. Twelve countries and one region, Southern Africa, reached the 90% target. In 2020, KOS was lower among men (79%) than women (87%) across SSA. PLHIV aged 15-24 years were the least likely to know their status (65%), but the largest gap in terms of absolute numbers was among men aged 35-49 years, with over 700,000 left undiagnosed. As KOS increased from 2000 to 2020, the median time to diagnosis decreased from 10 to 3 years, HIV testing positivity declined from 9% to 3%, and the proportion of first-time diagnoses among all positive tests dropped from 89% to 42%.Interpretation: On the path towards the next UNAIDS target of 95% diagnostic coverage by 2030, and in a context of declining positivity and yield of first-time diagnoses, we need to focus on addressing disparities in KOS. Increasing KOS and treatment coverage among older men could be critical to reduce HIV incidence among women in SSA, and by extension, reducing mother-to-child transmission.
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Journal articleThomas R, Probert W, Sauter R, et al., 2021,
Cost and cost-effectiveness of a universal HIV testing and treatment intervention in Zambia and South Africa: evidence and projections from the HPTN 071 (PopART) trial
, The Lancet Global Health, Vol: 9, Pages: e668-e680, ISSN: 2214-109XBackgroundThe HPTN 071 (PopART) trial showed that a combination HIV prevention package including universal HIV testing and treatment (UTT) reduced population-level incidence of HIV compared with standard care. However, evidence is scarce on the costs and cost-effectiveness of such an intervention.MethodsUsing an individual-based model, we simulated the PopART intervention and standard care with antiretroviral therapy (ART) provided according to national guidelines for the 21 trial communities in Zambia and South Africa (for all individuals aged >14 years), with model parameters and primary cost data collected during the PopART trial and from published sources. Two intervention scenarios were modelled: annual rounds of PopART from 2014 to 2030 (PopART 2014–30; as the UNAIDS Fast-Track target year) and three rounds of PopART throughout the trial intervention period (PopART 2014–17). For each country, we calculated incremental cost-effectiveness ratios (ICERs) as the cost per disability-adjusted life-year (DALY) and cost per HIV infection averted. Cost-effectiveness acceptability curves were used to indicate the probability of PopART being cost-effective compared with standard care at different thresholds of cost per DALY averted. We also assessed budget impact by projecting undiscounted costs of the intervention compared with standard care up to 2030.FindingsDuring 2014–17, the mean cost per person per year of delivering home-based HIV counselling and testing, linkage to care, promotion of ART adherence, and voluntary medical male circumcision via community HIV care providers for the simulated population was US$6·53 (SD 0·29) in Zambia and US$7·93 (0·16) in South Africa. In the PopART 2014–30 scenario, median ICERs for PopART delivered annually until 2030 were $2111 (95% credible interval [CrI] 1827–2462) per HIV infection averted in Zambia and $3248 (2472–3963) per HIV infection averted in South Afric
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Journal articleChristen P, D'Aeth J, Lochen A, et al., 2021,
The J-IDEA pandemic planner: a framework for implementing hospital provision interventions during the COVID-19 pandemic
, Medical Care, Vol: 59, Pages: 371-378, ISSN: 0025-7079Background : Planning for extreme surges in demand for hospital care of patientsrequiring urgent life-saving treatment for COVID-19, whilst retaining capacity for otheremergency conditions, is one of the most challenging tasks faced by healthcareproviders and policymakers during the pandemic. Health systems must be wellpreparedto cope with large and sudden changes in demand by implementinginterventions to ensure adequate access to care. We developed the first planning toolfor the COVID-19 pandemic to account for how hospital provision interventions (suchas cancelling elective surgery, setting up field hospitals, or hiring retired staff) will affectthe capacity of hospitals to provide life-saving care.Methods : We conducted a review of interventions implemented or considered in 12 European countries in March-April 2020, an evaluation of their impact on capacity, anda review of key parameters in the care of COVID-19 patients. This information wasused to develop a planner capable of estimating the impact of specific interventions ondoctors, nurses, beds and respiratory support equipment. We applied this to ascenario-based case study of one intervention, the set-up of field hospitals in England,under varying levels of COVID-19 patients.Results : The J-IDEA pandemic planner is a hospital planning tool that allows hospitaladministrators, policymakers and other decision-makers to calculate the amount ofcapacity in terms of beds, staff and crucial medical equipment obtained byimplementing the interventions. Flexible assumptions on baseline capacity, the numberof hospitalisations, staff-to-beds ratios, and staff absences due to COVID-19 make theplanner adaptable to multiple settings. The results of the case study show that whilefield hospitals alleviate the burden on the number of beds available, this intervention isfutile unless the deficit of critical care nurses is addressed first.Discussion : The tool supports decision-makers in delivering a fast and effectiveresponse to
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Journal articleWard H, Cooke GS, Atchison C, et al., 2021,
Prevalence of antibody positivity to SARS-CoV-2 following the first peak of infection in England: Serial cross-sectional studies of 365,000 adults
, The Lancet Regional Health - Europe, Vol: 4, Pages: 1-7, ISSN: 2666-7762BackgroundThe time-concentrated nature of the first wave of the COVID-19 epidemic in England in March and April 2020 provides a natural experiment to measure changes in antibody positivity at the population level before onset of the second wave and initiation of the vaccination programme.MethodsThree cross-sectional national surveys with non-overlapping random samples of the population in England undertaken between late June and September 2020 (REACT-2 study). 365,104 adults completed questionnaires and self-administered lateral flow immunoassay (LFIA) tests for IgG against SARS-CoV-2.FindingsOverall, 17,576 people had detectable antibodies, a prevalence of 4.9% (95% confidence intervals 4.9, 5.0) when adjusted for test characteristics and weighted to the adult population of England. The prevalence declined from 6.0% (5.8, 6.1), to 4.8% (4.7, 5.0) and 4.4% (4.3, 4.5), over the three rounds of the study a difference of -26.5% (-29.0, -23.8). The highest prevalence and smallest overall decline in positivity was in the youngest age group (18-24 years) at -14.9% (-21.6, -8.1), and lowest prevalence and largest decline in the oldest group (>74 years) at -39.0% (-50.8, -27.2). The decline from June to September 2020 was largest in those who did not report a history of COVID-19 at -64.0% (-75.6, -52.3), compared to -22.3% (-27.0, -17.7) in those with SARS-CoV-2 infection confirmed on PCR.InterpretationA large proportion of the population remained susceptible to SARS-CoV-2 infection in England based on naturally acquired immunity from the first wave. Widespread vaccination is needed to confer immunity and control the epidemic at population level.FundingThis work was funded by the Department of Health and Social Care in England.
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Journal articleMcCarthy CV, Sandmann FG, Jit M, 2021,
Global and national estimates of the number of healthcare workers at high risk of SARS-CoV-2 infection
, JOURNAL OF HOSPITAL INFECTION, Vol: 111, Pages: 205-207, ISSN: 0195-6701- Cite
- Citations: 1
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Journal articleMacLennan JM, Rodrigues CMC, Bratcher HB, et al., 2021,
Meningococcal carriage in periods of high and low invasive meningococcal disease incidence in the UK: comparison of UKMenCar1-4 cross-sectional survey results
, LANCET INFECTIOUS DISEASES, Vol: 21, Pages: 677-687, ISSN: 1473-3099- Cite
- Citations: 28
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Journal articleFerguson NM, Laydon D, Nedjati-Gilani G, et al., 2021,
COVID-19 and potential global mortality - Revisited (Retraction of Vol 144, art no 105054, 2020)
, EARLY HUMAN DEVELOPMENT, Vol: 156, ISSN: 0378-3782
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