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PURPOSE To quantify the risk of peritonsillar abscess (PTA) following consultation for respiratory tract infection (RTI) in primary care. METHOD A cohort study was conducted in the UK Clinical Practice Research Datalink including 718 general practices with 65,681,293 patient years of follow-up and 11,007 patients with a first episode of PTA. From a decision tree, Bayes theorem was employed to estimate both the probability of PTA following an RTI consultation if antibiotics were prescribed or not, and the number of patients needed to be treated with antibiotics to prevent 1 PTA. RESULTS There were 11,007 patients with PTA with age-standardized incidence of new episodes of PTA of 17.2 per 100,000 patient years for men and 16.1 for women; 6,996 (64%) consulted their practitioner in the 30 days preceding PTA diagnosis, including 4,243 (39%) consulting for RTI. The probability of PTA following an RTI consultation was greatest in men aged 15 to 24 years with 1 PTA in 565 (95% uncertainty interval 527 to 605) RTI consultations without antibiotics prescribed but 1 in 1,139 consultations (1,044 to 1,242) if antibiotics were prescribed. One PTA might be avoided for every 1,121 (975 to 1,310) additional antibiotic prescriptions for men aged 15 to 24 years and 926 (814 to 1,063) for men aged 25 to 34 years. The risk of PTA following RTI consultation was smaller and the number needed to treat higher at other ages and risks were lower in women than men. CONCLUSIONS The risk of PTA may be lower if antibiotics are prescribed for RTI but even in young men nearly 1,000 antibiotic prescriptions may be required to prevent 1 PTA case. We caution that lack of randomization and data standardization may bias estimates.

Background The threat of antimicrobial resistance has led to intensified efforts to reduce antibiotic utilisation, but serious bacterial infections are increasing in frequency. Objectives To estimate the risks of serious bacterial infections in association with lower antibiotic prescribing and understand stakeholder views with respect to safe antibiotic reduction. Design Mixed-methods research was undertaken, including a qualitative interview study of patient and prescriber views that informed a cohort study and a decision-analytic model, using primary care electronic health records. These three work packages were used to design an application (app) for primary care prescribers. Data sources The Clinical Practice Research Datalink. Setting This took place in UK general practices. Participants A total of 706 general practices with 66.2 million person-years of follow-up from 2002 to 2017 and antibiotic utilisation evaluated for 671,830 registered patients. The qualitative study included 31 patients and 30 health-care professionals from primary care. Main outcome measures Sepsis and localised bacterial infections. Results Patients were concerned about antimicrobial resistance and the side effects, as well as the benefits, of antibiotic treatment. Prescribers viewed the onset of sepsis as the most concerning potential outcome of reduced antibiotic prescribing. More than 40% of antibiotic prescriptions in primary care had no coded indication recorded across both Vision® and EMIS® practice systems. Antibiotic prescribing rates varied widely between general practices, but there was no evidence that serious bacterial infections were less frequent at higher prescribing practices (adjusted rate ratio for 20% increase in prescribing 1.03, 95% confidence interval 1.00 to 1.06; p = 0.074). The probability of sepsis was lower if an antibiotic was prescribed at an infection consultation, and the number of antibiotic prescriptions required to prevent one episode of sepsis (i.e. the number needed to treat) decreased with age. For those aged 0–4 years, the number needed to treat was 29,773 (95% uncertainty interval 18,458 to 71,091) in boys and 27,014 (95% uncertainty interval 16,739 to 65,709) in girls. For those aged > 85 years, the number needed to treat was 262 (95% uncertainty interval 236 to 293) in men and 385 (95% uncertainty interval 352 to 421) in women. Frailty was associated with a greater risk of sepsis and a smaller number needed to treat. For severely frail patients aged 55–64 years, the number needed to treat was 247 (95% uncertainty interval 156 to 459) for men and 343 (95% uncertainty interval 234 to 556) for women. At all ages, the probability of sepsis was greatest for urinary tract infection, followed by skin infection and respiratory tract infection. The numbers needed to treat were generally smaller for the period 2014–17, when sepsis was diagnosed more frequently. The results are available using an app that we developed to provide primary care prescribers with stratified risk estimates during infection consultations. Limitations Analyses were based on non-randomised comparisons. Infection episodes and antibiotic prescribing are poorly documented in primary care. Conclusions Antibiotic treatment is generally associated with lower risks, but the most serious bacterial infections remain infrequent even without antibiotic treatment. This research identifies risk strata in which antibiotic prescribing can be more safely reduced. Future work The software developed from this research may be further developed and investigated for antimicrobial stewardship effect. Funding This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 9, No. 9. See the NIHR Journals Library website for further project information.

Background: AI-driven digital health tools often rely on estimates of disease incidence or prevalence, but obtaining these estimates is costly and time-consuming. We explored the use of machine learning models that leverage contextual information about diseases from unstructured text, to estimate disease incidence.Methods: We used a class of machine learning models, called language models, to extract contextual information relating to disease incidence. We evaluated three different language models: BioBERT, Global Vectors for Word Representation (GloVe), and the Universal Sentence Encoder (USE), as well as an approach which uses all jointly. The output of these models is a mathematical representation of the underlying data, known as “embeddings.” We used these to train neural network models to predict disease incidence. The neural networks were trained and validated using data from the Global Burden of Disease study, and tested using independent data sourced from the epidemiological literature.Findings: A variety of language models can be used to encode contextual information of diseases. We found that, on average, BioBERT embeddings were the best for disease names across multiple tasks. In particular, BioBERT was the best performing model when predicting specific disease-country pairs, whilst a fusion model combining BioBERT, GloVe, and USE performed best on average when predicting disease incidence in unseen countries. We also found that GloVe embeddings performed better than BioBERT embeddings when applied to country names. However, we also noticed that the models were limited in view of predicting previously unseen diseases. Further limitations were also observed with substantial variations across age groups and notably lower performance for diseases that are highly dependent on location and climate.Interpretation: We demonstrate that context-aware machine learning models can be used for estimating disease incidence. This method is quicker to implement than traditional epidemiological approaches. We therefore suggest it complements existing modeling efforts, where data is required more rapidly or at larger scale. This may particularly benefit AI-driven digital health products where the data will undergo further processing and a validated approximation of the disease incidence is adequate.

BackgroundHuman cytomegalovirus (CMV) is a common herpesvirus which is estimated to infect 83% of the global population. Whilst many infections are asymptomatic, it is an important cause of morbidity and mortality, particularly for immunocompromised people and for infants who are congenitally infected. A vaccine against CMV has been stated as a public health priority, but there are gaps in our understanding of CMV epidemiology. To guide potential future vaccination strategies, our aim was to examine risk factors for CMV seropositivity in young people in England.MethodsThe Health Survey for England (HSE) is an annual, cross-sectional representative survey of households in England during which data are collected through questionnaires, and blood samples are taken. We randomly selected individuals who participated in the HSE 2002, aiming for 25 participants of each sex in each single year age group from 11 to 24 years. Stored samples were tested for CMV antibodies. We undertook descriptive and regression analyses of CMV seroprevalence and risk factors for infection.ResultsDemographic data and serostatus were available for 732 individuals, of whom 175 (23.7%) were CMV-seropositive. CMV seroprevalence was associated with age, with 18.3% seropositive at 11–14 years compared to 28.3% at 22–24 years. CMV serostatus was also higher in people of non-white ethnicity (adjusted odds ratio [aOR] 6.22, 95% confidence interval [CI] 3.47–11.14), and in adults who were seropositive for EBV (aOR 2.08 [1.06–4.09]). There was no evidence that smoking status, occupation, body mass index and region of England were associated with CMV serostatus.ConclusionsCMV seroprevalence is strongly associated with ethnicity, and modestly increases with age in 11–24-year-olds. A greater understanding of the transmission dynamics of CMV, and the impact of this on CMV-associated morbidity and mortality, is necessary to inform effective vaccination strategies when a vaccine for CMV becomes available.

Background Efforts to reduce unnecessary antibiotic prescribing have coincided with increasing awareness of sepsis. We aimed to estimate the probability of sepsis following infection consultations in primary care when antibiotics were or were not prescribed. Methods and findings We conducted a cohort study including all registered patients at 706 general practices in the United Kingdom Clinical Practice Research Datalink, with 66.2 million person-years of follow-up from 2002 to 2017. There were 35,244 first episodes of sepsis (17,886, 51%, female; median age 71 years, interquartile range 57–82 years). Consultations for respiratory tract infection (RTI), skin or urinary tract infection (UTI), and antibiotic prescriptions were exposures. A Bayesian decision tree was used to estimate the probability (95% uncertainty intervals [UIs]) of sepsis following an infection consultation. Age, gender, and frailty were evaluated as association modifiers. The probability of sepsis was lower if an antibiotic was prescribed, but the number of antibiotic prescriptions required to prevent one episode of sepsis (number needed to treat [NNT]) decreased with age. At 0–4 years old, the NNT was 29,773 (95% UI 18,458–71,091) in boys and 27,014 (16,739–65,709) in girls; over 85 years old, NNT was 262 (236–293) in men and 385 (352–421) in women. Frailty was associated with greater risk of sepsis and lower NNT. For severely frail patients aged 55–64 years, the NNT was 247 (156–459) in men and 343 (234–556) in women. At all ages, the probability of sepsis was greatest for UTI, followed by skin infection, followed by RTI. At 65–74 years, the NNT following RTI was 1,257 (1,112–1,434) in men and 2,278 (1,966–2,686) in women; the NNT following skin infection was 503 (398–646) in men and 784 (602–1,051) in women; following UTI, the NNT was 121 (102–145) in men and 284 (241–342) in women. NNT values were generally smaller for the period from 2014 to 2017, when sepsis was diagnosed more frequently. Lack of random allocation to antibiotic therapy might have biased estimates; patients may sometimes experience sepsis or receive antibiotic prescriptions without these being recorded in primary care; recording of sepsis has increased over the study period. Conclusions These stratified estimates of risk help to identify groups in which antibiotic prescribing may be more safely reduced. Risks of sepsis and benefits of antibiotics are more substantial among older adults, persons with more advanced frailty, or following UTIs., In this cohort study, Martin Gulliford and colleagues investigate probability of sepsis in primary care patients with or without prescribed antibiotics., Author summary Why was this study done? Sepsis is a severe reaction to an infection that may lead to life threatening damage to organ systems. Sepsis is an increasingly recognised concern for health professionals and patients in primary care. Inappropriate and unnecessary antibiotic prescribing is a widespread problem in primary care that may be contributing to antimicrobial resistance. This study aimed to estimate the probability of a patient developing sepsis after an infection consultation in primary care if antibiotics are or are not prescribed. What did the researchers do and find? We analysed the electronic health records of all registered patients at 706 general practices, with 66.2 million person-years of follow-up from 2002 to 2017 and 35,244 first episodes of sepsis. We found that the probability of sepsis was lower if an antibiotic was prescribed, but the number of antibiotic prescriptions required to prevent one episode of sepsis (number needed to treat [NNT]) decreased with age. Frailty was associated with greater risk of sepsis and lower NNT. At all ages, the probability of sepsis was greatest for urinary tract infection, followed by skin infection, followed by respiratory tract infection. What do these findings mean? These results show that risks of sepsis and benefits of antibiotics are more substantial among older adults, persons with more advanced frailty, or following urinary tract infections. Antibiotic use may be more safely reduced in groups with lower probability of sepsis. We caution that our results represent averages over diverse localities and years of study, and lack of random allocation to antibiotic therapy might have caused bias.

Background Epstein Barr Virus (EBV) infects 90%-95% of all adults globally and causes ~ 1% of all cancers. Differing proportions of Burkitt's lymphoma (BL), gastric carcinoma (GC), Hodgkin's lymphoma (HL) and nasopharyngeal carcinoma (NPC) are associated with EBV. We sought to systematically review the global epidemiological evidence for risk factors that (in addition to EBV) contribute to the development of the EBV-associated forms of these cancers, assess the quality of the evidence, and compare and contrast the cancers. Methods MEDLINE, Embase and Web of Science were searched for studies of risk factors for EBV-associated BL, GC, HL and NPC without language or temporal restrictions. Studies were excluded if there was no cancer-free comparator group or where analyses of risk factors were inadequately documented. After screening and reference list searching, data were extracted into standardised spreadsheets and quality assessed. Due to heterogeneity, a narrative synthesis was undertaken. Results 9916 hits were retrieved. 271 papers were retained: two BL, 24 HL, one GC and 244 NPC. The majority of studies were from China, North America and Western Europe. Risk factors were categorised as dietary, environmental/non-dietary, human genetic, and infection and clinical. Anti-EBV antibody load was associated with EBV-associated GC and BL. Although the evidence could be inconsistent, HLA-A alleles, smoking, infectious mononucleosis and potentially other infections were risk factors for EBV-associated HL. Rancid dairy products; anti-EBV antibody and EBV DNA load; history of chronic ear, nose and/or throat conditions; herbal medicine use; family history; and human genetics were risk factors for NPC. Fresh fruit and vegetable and tea consumption may be protective against NPC. Conclusions Many epidemiological studies of risk factors in addition to EBV for the EBV-associated forms of BL, GC, HL and NPC have been undertaken, but there is a dearth of evidence for GC and BL. Available evidence is of variable quality. The aetiology of EBV-associated cancers likely results from a complex intersection of genetic, clinical, environmental and dietary factors, which is difficult to assess with observational studies. Large, carefully designed, studies need to be strategically undertaken to harmonise and clarify the evidence. Registration PROSPERO CRD42017059806.

Clinical trials have demonstrated that sheep with footrot treated with parenteral and topical antibiotics without foot trimming (treatment A), cure faster than sheep treated with foot trimming and topical antibiotics (treatment B). We investigated how key players in the UK sheep industry recommended treating footrot, and tested whether reviewing the evidence surrounding treatment of footrot changed their beliefs. Eight key players attended a workshop to investigate their current practices, and their perceived efficacy of treatments, using probabilistic elicitation. At the start of the study, all participants recommended use of antibiotic injection but only four recommended not foot trimming feet with footrot. Initial beliefs in the difference in cure rate within five days of treatment ranged from 30 to 97% in favour of treatment A (true difference 60%); this heterogeneity reduced after reviewing the evidence. Participants who believed the cure rate differed by60% over-estimated the cure rate of treatment A whilst participants who believed the difference was60% over-estimated the efficacy of treatment B. During discussions, participants stated that parenteral antibiotics had always been recommended as a treatment for footrot but that the new research clarified when to use them. In contrast, it was highly novel to hear that foot trimming was detrimental to recovery, and key players and farmers are taking longer to accept this evidence. Three months after the workshop, two participants stated that they now placed greater emphasis on rapid individual antibiotic treatment of lame sheep and one was no longer recommending trimming feet.

ObjectiveThis study evaluated whether serious bacterial infections are more frequent at family practices with lower antibiotic prescribing rates.DesignCohort study.Setting706 UK family practices in the Clinical Practice Research Datalink from 2002 to 2017.Participants10.1 million registered patients with 69.3 million patient-years’ follow-up.ExposuresAll antibiotic prescriptions, subgroups of acute and repeat antibiotic prescriptions, and proportion of antibiotic prescriptions associated with specific-coded indications.Main outcome measuresFirst episodes of serious bacterial infections. Poisson models were fitted adjusting for age group, gender, comorbidity, deprivation, region and calendar year, with random intercepts representing family practice-specific estimates.ResultsThe age-standardised antibiotic prescribing rate per 1000 patient-years increased from 2002 (male 423; female 621) to 2012 (male 530; female 842) before declining to 2017 (male 449; female 753). The median family practice had an antibiotic prescribing rate of 648 per 1000 patient-years with 95% range for different practices of 430–1038 antibiotic prescriptions per 1000 patient-years. Specific coded indications were recorded for 58% of antibiotic prescriptions at the median family practice, the 95% range at different family practices was from 10% to 75%. There were 139 759 first episodes of serious bacterial infection. After adjusting for covariates and the proportion of coded consultations, there was no evidence that serious bacterial infections were lower at family practices with higher total antibiotic prescribing. The adjusted rate ratio for 20% higher total antibiotic prescribing was 1.03, (95% CI 1.00 to 1.06, p=0.074).ConclusionsWe did not find population-level evidence that family practices with lower total antibiotic prescribing might have more frequent occurrence of serious bacterial infections overall. Improving the recording of infection episodes has potential to inform better antimicrobial stewardship in primary care.

Background Epstein-Barr virus (EBV) is an important human pathogen; it in-fects >90% people globally and is linked to infectious mononucleosis and sev-eral types of cancer. Vaccines against EBV are in development. In this study we present the first systematic review of the literature on risk factors for EBV infection, and discuss how they differ between settings, in order to improve our understanding of EBV epidemiology and aid the design of effective vacci-nation strategies. Methods MEDLINE, Embase, and Web of Science were searched on 6th March 2017 for observational studies of risk factors for EBV infection. Studies were excluded if they were published before 2008 to ensure relevance to the modern day, given the importance of influencing future vaccination policies. There were no language restrictions. After title, abstract and full text screening, followed by checking the reference lists of included studies to identify further studies, data were extracted into standardised spreadsheets and quality assessed. A narrative synthesis was undertaken. Results Seventy-seven papers met our inclusion criteria, including data from 31 countries. There was consistent evidence that EBV seroprevalence was associat-ed with age, increasing throughout childhood and adolescence and remaining constant thereafter. EBV was generally acquired at younger ages in Asia than Europe/North America. There was also compelling evidence for an association between cytomegalovirus infection and EBV. Additional factors associated with EBV seroprevalence, albeit with less consistent evidence, included ethnicity, so-cioeconomic status, other chronic viral infections, and genetic variants of HLA and immune response genes. Conclusions Our study is the first systematic review to draw together the global literature on the risk factors for EBV infection and includes an evaluation of the quality of the published evidence. Across the literature, the factors examined are diverse. In Asia, early vaccination of infants would be required to prevent EBV infection. In contrast, in Western countries a vaccine could be deployed later, particularly if it has only a short duration of protection and the intention was to protect against infectious mononucleosis. There is a lack of high-qual-ity data on the prevalence and age of EBV infection outside of Europe, North America and South-East Asia, which are essential for informing effective vacci-nation policies in these settings

In countries with low tuberculosis (TB) incidence, TB is concentrated in vulnerable populations, including people living with the human immunodeficiency virus (PLHIV), who have a substantially greater risk of TB than people without HIV. We searched PubMed, EMBASE and Web of Science for studies evaluating the risk factors for latent tuberculous infection (LTBI) or active TB in PLHIV in countries with TB incidence 10 per 100 000 population. Due to the number of risk factors evaluated and heterogeneity in study designs, we present summary data and a narrative synthesis. We included 45 studies: 17 reported data on the risk factors for LTBI and 32 on active TB. Black, Asian or Hispanic ethnicity, birth or long-term residence in a country with high TB incidence, and HIV acquisition via injecting drug use (IDU) or heterosexual sex were strong predictors of both LTBI and active TB. History of contact, a greater degree of immunosuppression at diagnosis or higher viral load increased the TB risk. Early HIV diagnosis to allow timely initiation of antiretroviral therapy is essential for the prevention of TB in PLHIV. Screening and treating PLHIV for LTBI to reduce the risk of progression to active TB disease should also be considered to further reduce the burden of active TB in low TB incidence settings. Research to support the expansion of TB and HIV prevention and treatment globally is essential to eliminate TB in low-incidence settings.

Background HIV co-infection of tuberculosis (TB) patients is associated with TB disease progression, treatment complications, and higher mortality. Over the last decade, national guidelines have encouraged earlier diagnosis of HIV infection and greater use of anti-retroviral therapy (ART). We investigated the relationship between HIV and TB diagnoses at a national level. Methods TB patients aged ≥15 years notified to Public Health England from 2000–2014 were linked to national HIV surveillance data. Amongst co-infected patients, we examined the order of TB and HIV diagnoses. Diagnoses were classed as ‘simultaneous’ if TB and HIV were diagnosed within 91 days of each other. Results 106,829 TB cases aged ≥15 years were notified to PHE between 2000 and 2014, of which 5792 (5.4%) were co-infected with HIV. The absolute number of HIV-TB diagnoses rose between 2000–2004, and then decreased from 543 (8.0%) in 2004 to 205 (3.2%) in 2014. Overall, 2,787/5,792 (49%) were diagnosed with TB and HIV simultaneously, whilst 549 (9%) were diagnosed with TB before and 2456 (42%) after HIV diagnosis. The relationship between TB and HIV diagnosis changed over time (figure 1). The absolute number of TB cases in people with known HIV rose from 75/224 (33%) in 2000 to 210/454 (46%) in 2007, then fell to 117/205 (57%) by 2014, but increased as a proportion of all HIV-TB cases from 2000 to 2014. There were corresponding declines in the proportion diagnosed simultaneously with TB and HIV from 298/543 (55%) in 2004 to 79/205 (39%) in 2014 and those first diagnosed with TB (51/224 (23%) in 2000 to 9/205 (4%) in 2014). Conclusions Within an overall decline in HIV-TB co-infection there has been a change in the pattern of co-infection. A greater proportion of cases now occur in people with known HIV infection, and fewer HIV infections are diagnosed after TB diagnosis. This may be explained by more HIV testing, including in TB clinics, resulting in earlier HIV diagnosis. However, as the number of people with HIV in the UK increases, sustained success requires better management of latent TB infection to prevent the occurrence of TB disease in people diagnosed with HIV.

OBJECTIVES: Tuberculosis (TB) is common in people living with HIV, leading to worse clinical outcomes including increased mortality. We investigated risk factors for developing TB following HIV diagnosis.DESIGN: Adults aged at least 15 years first presenting to health services for HIV care in England, Wales or Northern Ireland from 2000 to 2014 were identified from national HIV surveillance data and linked to TB surveillance data.METHODS: We calculated incidence rates for TB occurring more than 91 days after HIV diagnosis and investigated risk factors using multivariable Poisson regression.RESULTS: A total of 95 003 adults diagnosed with HIV were followed for 635 591 person-years; overall incidence of TB was 344 per 100 000 person-years (95% confidence interval 330-359). TB incidence was high for people who acquired HIV through injecting drugs [PWID; men 876 (696-1104), women 605 (365-945)] and black Africans born in high TB incidence countries [644 (612-677)]. The adjusted incidence rate ratio for TB amongst PWID was 4.79 (3.35-6.85) for men and 6.18 (3.49-10.93) for women, compared with MSM. The adjusted incidence rate ratio for TB in black Africans from high-TB countries was 4.27 (3.42-5.33), compared with white UK-born individuals. Lower time-updated CD4 cell count was associated with increased rates of TB.CONCLUSION: PWID had the greatest risk of TB; incidence rates were comparable with those in black Africans from high TB incidence countries. Most TB cases in PWID were UK-born, and likely acquired TB through transmission within the United Kingdom. Earlier HIV diagnosis and quicker initiation of antiretroviral therapy should reduce TB incidence in these populations.

HIV increases the progression of latent tuberculosis (TB) infection to active disease and contributed to increased TB in the UK until 2004. We describe temporal trends in HIV infection amongst patients with TB and identify factors associated with HIV infection.We used national surveillance data of all TB cases reported in England, Wales and Northern Ireland from 2000 to 2014 and determined HIV status through record linkage to national HIV surveillance. We used logistic regression to identify associations between HIV and demographic, clinical and social factors.There were 106,829 cases of TB in adults (≥ 15 years) reported from 2000 to 2014. The number and proportion of TB patients infected with HIV decreased from 543/6782 (8.0%) in 2004 to 205/6461 (3.2%) in 2014. The proportion of patients diagnosed with HIV 91 days prior to their TB diagnosis increased from 33.5% in 2000 to 60.2% in 2013. HIV infection was highest in people of black African ethnicity from countries with high HIV prevalence (32.3%), patients who misused drugs (8.1%) and patients with miliary or meningeal TB (17.2%).There has been an overall decrease in TB-HIV co-infection and a decline in the proportion of patients diagnosed simultaneously with both infections. However, high rates of HIV remain in some sub-populations of patients with TB, particularly black Africans born in countries with high HIV prevalence and people with a history of drug misuse. Whilst the current policy of testing all patients diagnosed with TB for HIV infection is important in ensuring appropriate management of TB patients, many of these TB cases would be preventable if HIV could be diagnosed before TB develops. Improving screening for both latent TB and HIV and ensuring early treatment of HIV in these populations could help prevent these TB cases. British HIV Association guidelines on latent TB testing for people with HIV from sub-Saharan Africa remain relevant, and latent TB screening for people with HIV with a history of drug misuse, homelessness or imprisonment should also be considered.

The aim of this study was to investigate the cost-benefit of different strategies to treat and control ovine footrot. In November 2006, 162 sheep farmers in England responded to a survey on prevalence and management of lameness. The costs of lameness per ewe per year (PEPY) were calculated for 116 flocks. Linear regression was used to model the overall cost of lameness PEPY by management method. Associations between farmer satisfaction and time and money spent managing lameness were investigated. The median prevalence of lameness was 5% (inter-quartile range, IQR, 4-10%). The overall cost of lameness PEPY in flocks with ≥10% lameness was UK £6.35 versus £3.90 for flocks with

The aims of this study were to update the prevalence of lameness in sheep in England and identify novel risk factors. A total of 1260 sheep farmers responded to a postal survey. The survey captured detailed information on the period prevalence of lameness from May 2012–April 2013 and the prevalence and farmer naming of lesions attributable to interdigital dermatitis (ID), severe footrot (SFR), contagious ovine digital dermatitis (CODD) and shelly hoof (SH), management and treatment of lameness, and farm and flock details.\ud \ud The global mean period prevalence of lameness fell between 2004 and 2013 from 10.6% to 4.9% and the geometric mean period prevalence of lameness fell from 5.4% (95% CL: 4.7%–6.0%) to 3.5% (95% CI: 3.3%–3.7%). In 2013, more farmers were using vaccination and antibiotic treatment for ID and SFR and fewer farmers were using foot trimming as a routine or therapeutic treatment than in 2004.\ud \ud Two over-dispersed Poisson regression models were developed with the outcome the period prevalence of lameness, one investigated associations with farmer estimates of prevalence of the four foot lesions and one investigated associations with management practices to control and treat lameness and footrot. A prevalence of ID > 10%, SFR > 2.5% and CODD > 2.5% were associated with a higher prevalence of lameness compared with those lesions being absent, however, the prevalence of SH was not associated with a change in risk of lameness.\ud \ud A key novel management risk associated with higher prevalence of lameness was the rate of feet bleeding/100 ewes trimmed/year. In addition, vaccination of ewes once per year and selecting breeding replacements from never-lame ewes were associated with a decreased risk of lameness. Other factors associated with a lower risk of lameness for the first time in a random sample of farmers and a full risk model were: recognising lameness in sheep at locomotion score 1 compared with higher scores, treatment of the first lame sheep in a group compared with waiting until >5 were lame, treatment of lame sheep within 3 days, ease of catching lame sheep and quarantine for > 21 days. A previously known factor associated with a lower risk of lameness was footbathing to prevent ID. We conclude that the prevalence of lameness in sheep in England has fallen and that this might be in part because of increased uptake of managements recently reported as beneficial to control lameness. Routine foot trimming should be avoided.