COVID-19-related mortality and hospital admissions in the VIVALDI study cohort: October 2020 to March 2023

BACKGROUND

Long-term-care facilities (LTCFs) were heavily affected by COVID-19 early in the pandemic, but the impact of the virus has reduced over time with vaccination campaigns and build-up of immunity from prior infection.

OBJECTIVES

To evaluate the mortality and hospital admissions associated with SARS-CoV-2 in LTCFs in England over the course of the VIVALDI study, from October 2020 to March 2023.

METHODS

We included residents aged ≥65 years from participating LTCFs who had available follow-up time within the analysis period. We calculated incidence rates (IRs) of COVID-19-linked mortality and hospital admissions per calendar quarter, along with infection fatality ratios (IFRs, within 28 days) and infection hospitalization ratios (IHRs, within 14 days) following positive SARS-CoV-2 test.

RESULTS

A total of 26,286 residents were included, with at least one positive test for SARS-CoV-2 in 8513 (32.4%). The IR of COVID-19-related mortality peaked in the first quarter (Q1) of 2021 at 0.47 per 1000 person-days (1 kpd) (around a third of all deaths), in comparison with 0.10 per 1 kpd for Q1 2023 which had a similar IR of SARS-CoV-2 infections. There was a fall in observed IFR for SARS-CoV-2 infections from 24.9% to 6.7% between these periods, with a fall in IHR from 12.1% to 8.8%. The population had high overall IRs for mortality for each quarter evaluated, corresponding to annual mortality probability of 28.8-41.3%.

CONCLUSIONS

Standardized real-time monitoring of hospitalization and mortality following infection in LTCFs could inform policy on the need for non-pharmaceutical interventions to prevent transmission.

Antagonism between co-infecting gastrointestinal nematodes: A meta-analysis of experimental infections in Sheep

Gastrointestinal nematodes (GIN) have enormous global impacts in humans, wildlife and grazing livestock. Within grazing livestock, sheep are of particular global importance and the economics and sustainability of sheep production are greatly constrained by GIN infections. Natural infections are composed of co-infections with multiple species, and while some past work suggests species can interact negatively with one another within the same host, there is wide variation in reported patterns. Here, we undertook a systematic literature search and meta-analysis of experimental GIN co-infections of sheep to determine whether these experimental studies support the hypothesis of antagonistic interactions between different co-infecting GIN, and test whether aspects of parasite biology or experimental design influence the observed effects. A systematic search of the literature yielded 4848 studies, within which, we identified 19 experimental sheep studies comparing post-mortem worm counts across two co-infecting GIN species. Meta-analysis of 67 effects obtained from these studies provides strong evidence for interactions between GIN species. There was wide variation in the strength and direction of these interactions, but the global effect was significantly antagonistic. On average, there was a decrease in the number of worms of one species when a co-infecting species was also present, relative to a mono-infection with that species alone. This effect was dependent on the infectious dose and was rapidly lost after anthelmintic treatment, suggesting that live worms are required for the effect to occur. Individual parasite species varied in the extent to which they both exerted, and were subject to, these interspecies interactions, and these differences are more complex than simply co-localisation within the gastrointestinal tract. Antagonistic interactions between co-infecting GIN may feedback into their epidemiology as well as potentially affecting the clinical impacts of infection. Furthermore, the consequences of these interactions may be heightened when clinical interventions affect only one species within the co-infecting network. Whilst it was not possible to identify the causes of variation between GIN species in the impact of co-infection, these findings point to new avenues for epidemiological, clinical and mechanistic research on GIN co-infections.

Sub-1.4 cm3 capsule for detecting labile inflammatory biomarkers in situ

Transient molecules in the gastrointestinal tract such as nitric oxide and hydrogen sulfide are key signals and mediators of inflammation. Owing to their highly reactive nature and extremely short lifetime in the body, these molecules are difficult to detect. Here we develop a miniaturized device that integrates genetically engineered probiotic biosensors with a custom-designed photodetector and readout chip to track these molecules in the gastrointestinal tract. Leveraging the molecular specificity of living sensors1, we genetically encoded bacteria to respond to inflammation-associated molecules by producing luminescence. Low-power electronic readout circuits2 integrated into the device convert the light emitted by the encapsulated bacteria to a wireless signal. We demonstrate in vivo biosensor monitoring in the gastrointestinal tract of small and large animal models and the integration of all components into a sub-1.4 cm3 form factor that is compatible with ingestion and capable of supporting wireless communication. With this device, diseases such as inflammatory bowel disease could be diagnosed earlier than is currently possible, and disease progression could be more accurately tracked. The wireless detection of short-lived, disease-associated molecules with our device could also support timely communication between patients and caregivers, as well as remote personalized care.

Association of Patient Belief About Success of Antibiotics for Appendicitis and Outcomes: A Secondary Analysis of the CODA Randomized Clinical Trial

Importance

A patient's belief in the likely success of a treatment may influence outcomes, but this has been understudied in surgical trials.

Objective

To examine the association between patients' baseline beliefs about the likelihood of treatment success with outcomes of antibiotics for appendicitis in the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial.

Design, Setting, and Participants

This was a secondary analysis of the CODA randomized clinical trial. Participants from 25 US medical centers were enrolled between May 3, 2016, and February 5, 2020. Included in the analysis were participants with appendicitis who were randomly assigned to receive antibiotics in the CODA trial. After informed consent but before randomization, participants who were assigned to receive antibiotics responded to a baseline survey including a question about how successful they believed antibiotics could be in treating their appendicitis.

Interventions

Participants were categorized based on baseline survey responses into 1 of 3 belief groups: unsuccessful/unsure, intermediate, and completely successful.

Main Outcomes and Measures

Three outcomes were assigned at 30 days: (1) appendectomy, (2) high decisional regret or dissatisfaction with treatment, and (3) persistent signs and symptoms (abdominal pain, tenderness, fever, or chills). Outcomes were compared across groups using adjusted risk differences (aRDs), with propensity score adjustment for sociodemographic and clinical factors.

Results

Of the 776 study participants who were assigned antibiotic treatment in CODA, a total of 425 (mean [SD] age, 38.5 [13.6] years; 277 male [65%]) completed the baseline belief survey before knowing their treatment assignment. Baseline beliefs were as follows: 22% of participants (92 of 415) had an unsuccessful/unsure response, 51% (212 of 415) had an intermediate response, and 27% (111 of 415) had a completely successful response. Compared with the unsuccessful/unsure group, those who believed antibiotics could be completely successful had a 13-percentage point lower risk of appendectomy (aRD, -13.49; 95% CI, -24.57 to -2.40). The aRD between those with intermediate vs unsuccessful/unsure beliefs was -5.68 (95% CI, -16.57 to 5.20). Compared with the unsuccessful/unsure group, those with intermediate beliefs had a lower risk of persistent signs and symptoms (aRD, -15.72; 95% CI, -29.71 to -1.72), with directionally similar results for the completely successful group (aRD, -15.14; 95% CI, -30.56 to 0.28).

Conclusions and Relevance

Positive patient beliefs about the likely success of antibiotics for appendicitis were associated with a lower risk of appendectomy and with resolution of signs and symptoms by 30 days. Pathways relating beliefs to outcomes and the potential modifiability of beliefs to improve outcomes merit further investigation.

Trial Registration

ClinicalTrials.gov Identifier: NCT02800785.

Outcomes of a residential respite service for homeless people with tuberculosis in London, UK: a cross-sectional study

BACKGROUND

Many countries are seeking to eliminate tuberculosis (TB), but incidence remains high in socially excluded groups such as people experiencing homelessness. There is limited research into the effectiveness of residential respite services (RRS), which provide accomodation and social and clinical support for homeless people with active TB.

METHODS

We used a register of all cases of TB diagnosed in London between 1 January 2010 and 3 October 2019 to compare characteristics and outcomes of patients treated in an RRS with patients receiving standard care. The primary outcome was successful treatment completion. We used logistic regression to compare likelihood of completing treatment, and simulation to estimate the absolute change in treatment completion resulting from this service.

RESULTS

A total of 78 homeless patients finished an episode of TB treatment at the RRS. Patients treated in the RRS were more likely than patients treated in standard care to have clinical and social risk factors including drug resistance, history of homelessness, drug or alcohol use, and need for directly observed therapy. After adjusting for these factors, patients treated in the RRS had 2.97 times the odds of completing treatment (95% CI = 1.44-6.96). Treatment ended in failure for 8/78 patients treated in the RRS (10%, 95% CI = 5%-20%). We estimated that in the absence of the RRS, treatment would have ended in failure for 17/78 patients (95% CI = 11-25).

CONCLUSION

The residential respite service for homeless TB patients with complex social needs was associated with better treatment outcomes.

Feasibility study of hospital antimicrobial stewardship analytics using electronic health records

BACKGROUND

Hospital antimicrobial stewardship (AMS) programmes are multidisciplinary initiatives to optimize antimicrobial use. Most hospitals depend on time-consuming manual audits to monitor clinicians' prescribing. But much of the information needed could be sourced from electronic health records (EHRs).

OBJECTIVES

To develop an informatics methodology to analyse characteristics of hospital AMS practice using routine electronic prescribing and laboratory records.

METHODS

Feasibility study using electronic prescribing, laboratory and clinical coding records from adult patients admitted to six specialities at Queen Elizabeth Hospital, Birmingham, UK (September 2017-August 2018). The study involved: (i) a review of AMS standards of care; (ii) their translation into concepts measurable from commonly available EHRs; and (iii) a pilot application in an EHR cohort study (n = 61679 admissions).

RESULTS

We developed data modelling methods to characterize antimicrobial use (antimicrobial therapy episode linkage methods, therapy table, therapy changes). Prescriptions were linked into antimicrobial therapy episodes (mean 2.4 prescriptions/episode; mean length of therapy 5.8 days), enabling several actionable findings. For example, 22% of therapy episodes for low-severity community-acquired pneumonia were congruent with prescribing guidelines, with a tendency to use broader-spectrum antibiotics. Analysis of therapy changes revealed IV to oral therapy switching was delayed by an average 3.6 days (95% CI: 3.4-3.7). Microbial cultures were performed prior to treatment initiation in just 22% of antibacterial prescriptions. The proposed methods enabled fine-grained monitoring of AMS practice down to specialities, wards and individual clinical teams by case mix, enabling more meaningful peer comparison.

CONCLUSIONS

It is feasible to use hospital EHRs to construct rapid, meaningful measures of prescribing quality with potential to support quality improvement interventions (audit/feedback to prescribers), engagement with front-line clinicians on optimizing prescribing, and AMS impact evaluation studies.

Precision worm control in grazing lambs by targeting group treatment based on performance of sentinels

Given the economic impact of gastrointestinal nematode infection on livestock farming worldwide, and increasing anthelmintic resistance, it is imperative to develop practical, efficient and sustainable control strategies. Targeted selective treatment (TST), whereby anthelmintic treatments are administered to animals individually, based on selection criteria such as weight gain, has been shown to successfully maintain animal productivity whilst reducing the selection pressure for anthelmintic resistance and the economic cost of treatment in experimental and commercial settings. Despite the benefits of the TST approach, the equipment and time required to monitor animals individually make this strategy unsuitable for some farming enterprises. The sentinel group approach aims to maintain the benefits observed using TST whilst reducing these requirements. The study involved two experiments, each following a group of 80 lambs through their first grazing season. Anthelmintic treatment of the whole group was determined by monitoring the weight gain of identified sentinel lambs within it every 2 weeks: when 40% of the sentinel lambs failed to reach their weight gain targets, the whole group was treated. The sentinel lambs consisted of 45% of the group (n = 36) in experiment one and 20% (n = 16) in experiment two. A control group of 20 lambs was co-grazed with the main group during both experiments; in experiment one, the sentinel approach was compared with a TST approach, in which control lambs were treated on an individual basis in response to weight gain. In experiment two, the sentinel approach was compared with conventional prophylaxis, where all lambs in the control group were treated at strategic time points throughout the season (= strategic prophylactic treatment). The sentinel lambs were found to be representative of overall group performance regardless of the proportion of sentinels within the group: they recorded similar growth rates and reached weight gain targets simultaneously at each time point and overall. Live-weight gain was also similar between sentinel and control animals in both experiments. The findings of the current study suggest that monitoring sentinel lambs comprising 20% of a group of grazing lambs is sufficient to determine the need for anthelmintic treatment within the whole group, and that this approach maintains production in line with conventional or TST treatment regimes.

Does the NHS Diabetes Prevention Programme prevent diabetes? A population-based matched cohort study

Background

To reduce the incidence of type 2 diabetes (T2DM) in England, the National Health Service piloted the Diabetes Prevention Programme (DPP). The DPP aims to prevent T2DM by providing high-risk adults with access to 13 face-to-face sessions over nine months that focus on diet and weight management. The DPP has been shown to improve intermediate outcomes for T2DM prevention (weight loss and glycated haemoglobin (HbA1c) reduction). However, there is a lack of evidence examining incident T2DM as the outcome.

Methods

We conducted a retrospective observational cohort study using linked electronic health records from primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care for June 2016 to January 2019. We compared rates of new T2DM diagnoses among eligible adults who were referred to the DPP with rates for propensity score-matched (ratio of 1:4) controls who were eligible for the DPP but were not invited. DPP eligibility was defined as having HbA1c levels of 42-47 mmol/mol or fasting plasma glucose (FPG) levels of 5.5-6.9 mmol/L. Adults with pre-existing T2DM were excluded. Time to the first record of T2DM was modelled using Cox regression with age, alcohol intake, body mass index, ethnicity, sex, HbA1c, index of multiple deprivation and smoking status included as covariates.

Results

We identified 2205 individuals who participated in the DPP and 8820 matched controls with a similar breakdown in age, sex, HbA1c and FPG. During the 2.5-year study period, 4.13% of DPP individuals developed T2DM vs 6.42% of controls. Our results indicate that DPP referrals were associated with a 59% reduction T2DM incidence rates [adjusted hazard ratio=0.41;95%CI=0.38-0.44].

Conclusions

This is the first study to investigate the impact of the DPP on T2DM, relative to usual care. Our results provide support for the effectiveness of DPP in preventing T2DM onset and are compatible with findings for similar interventions in other settings.

Key messages

The evidence suggests that providing consistent face-to-face sessions which concentrate on diet and weight management can reduce short-term T2DM incidences in high-risk adults. With a 59% reduction in T2DM rates in DPP referees relative to eligible adults who were not referred, the DPP is effective in reducing short-term T2DM incidences in high-risk adults.

Validity of UK electronic health records to study migrant health: a population-based cohort study

Background

An estimated 14.3% (9.4 million people) of people living in the UK in 2019 were international migrants. Despite this, little is known about how migrants access and use healthcare services. To use electronic healthcare records (EHRs) to study migration health, a valid migration phenotype is necessary: a transparent reproducible algorithm using clinical terminology codes to determine migration status. We have previously described the validity of a migration phenotype in CALIBER data using the Clinical Practice Research Datalink (CPRD), the largest UK primary care EHR. This study further evaluates the phenotype by examining certainty of migration status.

Methods

This is a population-based cohort study of individuals in CPRD Gold (1997-2018) with a Read term indicating migration to the UK. We describe completeness of recording of migration over time: percentage of individuals recorded as migrants. We also describe cohort size based on certainty of migration status: “definite” (country of birth or visa status terms), “probable” (non-English first/main language terms), and “possible” (non-UK origin terms).

Results

Overall, 2.5% (403,768/16,071,111) of CPRD had ≥1 of 434 terms indicating migration to the UK. The percentage of recorded migrants per year increased from 0.2% (4,417/2,210,551) in 1997 to 3.64% (100,626/2,761,397) in 2018, following a similar trend to national migration data. 44.27% (178,749/403,768) were “definite” migrants and 53.68% (216,731/403,768) were “probable” migrants. Only 2.05%(8,288/16,071,111) were “possible” migrants.

Conclusions

We have created a large cohort of international migrants in the UK and certainty of migration status is high. This cohort can be used to study migration health in UK primary care EHR. The large contribution of language terms make this phenotype particularly suitable for understanding healthcare access and use by non-English speaking migrants who may face additional barriers to care.

Key messages

We have developed a way to study migration health in UK primary care electronic health records. Our method is particularly useful to study healthcare for non-English speaking migrants who may face additional barriers to care.

Active case finding and treatment adherence in risk groups in the tuberculosis pre-elimination era

Vulnerable populations, including homeless persons, high-risk drug and alcohol users, prison inmates and other marginalised populations, contribute a disproportionate burden of tuberculosis (TB) cases in low-incidence settings. Drivers of this disease burden include an increased risk of both TB transmission in congregate settings, and progression from infection to active disease. Late diagnosis and poor treatment completion further propagate the epidemic and fuel the acquisition of drug resistance. These groups are therefore a major priority for TB control programmes in low-incidence settings. Targeted strategies include active case finding (ACF) initiatives and interventions to improve treatment completion, both of which should be tailored to local populations. ACF usually deploys mobile X-ray unit screening, which allows sensitive, high-throughput screening with immediate availability of results. Such initiatives have been found to be effective and cost-effective, and associated with reductions in proxy measures of transmission in hard-to-reach groups. The addition of point-of-care molecular diagnostics and automated X-ray readers may further streamline the screening pathway. There is little evidence to support interventions to improve adherence among these risk groups. Such approaches include enhanced case management and directly observed treatment, while video-observed therapy (currently under evaluation) appears to be a promising tool for the future. Integrating outreach services to include both case detection and case-management interventions that share a resource infrastructure may allow cost-effectiveness to be maximised. Integrating screening and treatment for other diseases that are prevalent among targeted risk groups into TB outreach interventions may further improve cost-effectiveness. This article reviews the existing literature, and highlights priorities for further research.

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

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

Assessing hepatitis C spontaneous clearance and understanding associated factors-A systematic review and meta-analysis

New advances in the treatment of hepatitis C provide high levels of sustained viral response but their expense limits availability in publicly funded health systems. The aim of this review was to estimate the proportion of patients who will spontaneously clear HCV, to identify factors that are associated with clearance and to support better targeting of directly acting antivirals. We searched Ovid EMBASE, Ovid MEDLINE and PubMed from 1 January 1994 to 30 June 2015 for studies reporting hepatitis C spontaneous clearance and/or demographic, clinical and behavioural factors associated with clearance. We undertook meta-analyses to estimate the odds of clearance for each predictor. Forty-three studies met the inclusion criteria, representing 20 110 individuals, and 6 of these studies included sufficient data to estimate spontaneous clearance. The proportion achieving clearance within 3, 6, 12 and 24 months following infection were, respectively, 19.8% (95% CI: 2.6%-47.5%), 27.9% (95% CI: 17.2%-41.8%), 36.1% (95% CI: 23.5%-50.9%) and 37.1% (95% CI: 23.7%-52.8%). Individuals who had not spontaneously cleared by 12 months were unlikely to do so. The likelihood of spontaneous clearance was lower in males and individuals with HIV co-infection, the absence of HBV co-infection, asymptomatic infection, black or nonindigenous race, nongenotype 1 infection, older age and alcohol or drug problems. This study suggests that patients continue to spontaneously clear HCV for at least 12 months following initial infection. However, injecting drug users are comparatively less likely to achieve clearance; thus, they should be considered a priority for early treatment given the continuing risks that these individuals pose for onwards transmission.

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

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

Fitness to fly testing in term and ex-preterm babies without bronchopulmonary dysplasia

BACKGROUND

During air flight, cabin pressurisation produces an effective fraction of inspired oxygen (FiO(2)) of 0.15. This can cause hypoxia in predisposed individuals, including infants with bronchopulmonary dysplasia (BPD), but the effect on ex-preterm babies without BPD was uncertain. The consequences of feeding a baby during the hypoxia challenge were also unknown.

METHODS

Ex-preterm (without BPD) and term infants had fitness to fly tests (including a period of feeding) at 3 or 6 months corrected gestational age (CGA) in a body plethysmograph with an FiO(2) of 0.15 for 20 min. A 'failed' test was defined as oxygen saturation (SpO(2)) <90% for at least 2 min.

RESULTS

41 term and 30 ex-preterm babies (mean gestational age 39.8 and 33.1 weeks, respectively) exhibited a significant median drop in SpO(2) (median -6%, p<0.0001); there was no difference between term versus ex-preterm babies, or 3 versus 6 months. Two term (5%) and two ex-preterm (7%) babies failed the challenge. The SpO(2) dropped further during feeding (median -4% in term and -2% in ex-preterm, p<0.0001), with transient desaturation (up to 30 s) <90% seen in 8/36 (22%) term and 9/28 (32%) ex-preterm infants; the ex-preterm babies desaturated more quickly (median 1 vs 3 min, p=0.002).

CONCLUSIONS

Ex-preterm babies without BPD and who are at least 3 months CGA do not appear to be a particularly at-risk group for air travel, and routine preflight testing is not indicated. Feeding babies in an FiO(2) of 0.15 leads to a further fall in SpO(2), which is significant but transient.

Genomic advances will herald new insights into the Brassica: Leptosphaeria maculans pathosystem

The study of the relationship between plants and phytopathogenic fungi is one of the most rapidly moving fields in the plant sciences, the findings of which have contributed to the development of new strategies and technologies to protect crops. Plants employ sophisticated mechanisms to perceive and appropriately defend themselves against pathogens. A good example of plant and pathogen evolution is the gene-for-gene interaction between the fungal pathogen Leptosphaeria maculans, the causal agent of blackleg disease, and Brassica crops. This interaction has been studied at the genetic and physiological level due to its agro-economic importance. The newly available genome sequence for Brassica spp. and L. maculans will provide the resources to study the co-evolution of this plant and pathogen. Particularly, an understanding of the co-evolution of genes responsible for virulence and resistance will lead to improved plant protection strategies for Brassica canola and provide a model to understand plant-pathogen interactions in other major crops. This review summarises the research-to-date in the study of the Brassica-L. maculans gene-for-gene interaction, with a focus on the genetics of resistance in Brassica and the wealth of information to be gained from genome sequencing efforts.

Virus shedding and environmental deposition of novel A (H1N1) pandemic influenza virus: interim findings

BACKGROUND

The relative importance of different routes of influenza transmission, including the role of bioaerosols, and ability of masks and/or hand hygiene to prevent transmission, remains poorly understood. Current evidence suggests that infectious virus is not typically released from adults after 5 days of illness, however, little is known about the extent to which virus is deposited by infected individuals into the environment and whether deposited virus has the ability to infect new hosts. Further information about the deposition of viable influenza virus in the immediate vicinity of patients with pandemic influenza is fundamental to our understanding of the routes and mechanisms of transmission.

OBJECTIVES

To collect data on patients infected with pandemic H1N1 2009 (swine flu). Primary objectives were to correlate the amount of virus detected in a patient's nose with that recovered from his/her immediate environment, and with symptom duration and severity. Secondary objectives were to describe virus shedding and duration according to major patient characteristics: adults versus children, and those with mild illness (community patients) versus those with more severe disease (hospitalised patients).

METHODS

Adults and children, both in hospital and from the community, who had symptoms of pandemic H1N1 infection, were enrolled and visited every day during follow-up for a maximum of 12 days. Symptom data was collected and samples were taken, including nose swabs and swabs from surfaces and objects around patients. Samples of air were obtained using validated sampling equipment. The samples were tested for the presence of pandemic H1N1 virus, using polymerase chain reaction (PCR) to detect virus genome and an immunofluorescence technique to detect viable virus.

RESULTS

Forty-three subjects were followed up, and 19 of them were subsequently proven to be infected with pandemic H1N1 virus. The median duration of virus shedding from the 19 infected cases was 6 days when detection was performed by PCR, and 3 days when detection was performed by a culture technique. Over 30% of cases remained potentially infectious for at least 5 days. Only 0.5% of all community and none of the hospital swabs taken revealed virus on surfaces. Five subjects had samples of the air around them collected and virus was detected by PCR from four; some of the air particles in which virus was detected were small enough to be inhaled and deposited deep in the lungs.

LIMITATION

Small number of subjects recruited.

CONCLUSIONS

The finding that over 30% of infected individuals have infectious virus in their noses for 5 days or more has infection control implications. The data suggest that contact transmission of pandemic influenza via fomites may be less important than previously thought, but transmission via bioaerosols at short range may be possible, meaning that high-level personal protective equipment may be needed by health-care workers when attending patients with pandemic influenza. Further work is being undertaken to consolidate these findings, as they have important potential implications for the protection of health-care workers and the formulation of advice to households, nationally and internationally.

HIV prevalence and testing practices among tuberculosis cases in London: a missed opportunity for HIV diagnosis?

BACKGROUND

Universal testing for HIV in patients with tuberculosis (TB) has been advocated for over a decade. The aim of this study was to describe the prevalence and testing practices of HIV in TB centres in London.

METHODS

A cohort study was undertaken of all patients with TB in Greater London in 2003-4 (n = 1941). Logistic regression was used to assess factors affecting being offered and accepting testing and having a positive HIV result.

RESULTS

The overall known prevalence of HIV was 9.9% (193/1941). In those with a test result (including those diagnosed previously) it was 25.6%. Overall, 50.8% of patients aged > or =20 years without previous testing were offered HIV testing and, of these, 73% accepted. In multivariable analysis, factors associated with being HIV positive were age 20-49 years, black ethnicity and being born overseas. Those with smear-negative disease and with a poor understanding of English were significantly less likely to be offered HIV testing. Factors associated with refusal of an offered test were female gender or age >49 years. HIV status was not associated with smear status, drug resistance or death, but was associated with CNS disease (OR 1.8, 95% CI 1.0 to 3.0, p = 0.003).

CONCLUSIONS

Nearly half the patients with TB in London in 2003-4 were not offered HIV testing. In those offered testing, uptake was high. Patients in higher risk groups were more likely to be offered testing but, even within the highest risk groups, testing was not universally offered. This represents a missed opportunity for diagnosing HIV in patients with TB in London.

Tuberculosis in the United Kingdom and Republic of Ireland

AIMS

To describe the clinical features, diagnosis and management of children with tuberculosis in the United Kingdom and Republic of Ireland.

METHODS

Cases of culture-confirmed and clinically diagnosed tuberculosis were reported to the British Paediatric Surveillance Unit from December 2003 to January 2005.

RESULTS

385 eligible cases were reported. Pulmonary disease was present in 154 (40%) children. Just over half (197, 51%) of children presented clinically and most of the remainder (166, 43%) at contact tracing. A probable source case was identified for 73/197 (36%) of the children presenting clinically. The majority (253, 66%) of children had a microbiological and/or histological investigation, and culture results were available for 240 (62%), of whom 102 (26%) were culture positive. Drug resistance was reported in 15 (0.4%) cases. 44% (128/292) of non-white children did not receive the recommended quadruple drug therapy. Seven children died. Only 57% (217) of children were managed by a paediatric subspecialist in respiratory or infectious diseases or a general paediatrician with a special interest in one of these areas. Fewer than five cases were reported from 119/143 (83%) respondents and 72 of 96 (75%) centres.

CONCLUSIONS

Many paediatricians and centres see few children with tuberculosis. This may affect adherence to national guidelines. Managed clinical networks for children with tuberculosis may improve management and should be the standard of care.

An evaluation of the completeness of reporting of childhood tuberculosis

The sensitivity of the Enhanced Tuberculosis Surveillance (ETS) scheme for monitoring tuberculosis in children is unknown. We used the British Paediatric Surveillance Unit (BPSU) reporting scheme to conduct a prospective observational study of tuberculosis in children aged <16 yrs in the UK. Reported cases were then matched with records from the ETS database. A total of 320 cases were reported to the BPSU between January and December 2004. We estimated that there were 557 paediatric cases in England, Wales and Northern Ireland in 2004: 222 (40%) cases reported to both BPSU and ETS, 98 (18%) reported to BPSU but not ETS and 237 (42%) reported to ETS but not BPSU. Children aged <5 yrs were significantly less likely to be reported to ETS compared with older children (p<0.01). There is substantial under-reporting of childhood tuberculosis, especially of children aged <5 yrs. ETS provides a representative picture of the demographics but may miss approximately 20% of cases. This should be taken into account when planning training and resource requirements for tuberculosis. Increased efforts are needed to ensure that all paediatric cases are reported to ETS.

Tuberculosis screening of asylum seekers: 1 years' experience at the Dover Induction Centres

OBJECTIVES

To describe the uptake and outcomes of a service for tuberculosis screening of asylum seekers.

STUDY DESIGN

Descriptive study.

METHODS

A tuberculosis screening service was established at the Dover Induction Centres for all asylum seekers entering the UK through ports in Kent. This study describes the uptake and completion of tuberculosis screening, the results of tuberculin skin testing and follow-up, and the cost of the service during its first year.

RESULTS

In 1 year, 8258 asylum seekers were screened: 94% of 8799 who were eligible. A total of 2.2% of those with completed screens were positive (on the basis of symptoms requiring further investigation or positive Heaf reaction). Eleven cases of active respiratory disease were diagnosed on the basis of symptoms, Heaf reaction plus chest X-ray, or both; three were confirmed microbiologically. One-quarter of Heaf tests were not read because of the rapid dispersal of asylum seekers. The follow-up of those requiring further investigations at their destinations was largely unknown. The service cost was 350,000 pounds.

CONCLUSIONS

Induction centre tuberculosis screening services for asylum seekers can achieve a high uptake, but their cost-effectiveness is questionable, particularly where the yield of active disease is low. Tuberculin skin testing is not an ideal screening procedure in this setting because it may be uncompleted and the benefit of detecting latent infections is uncertain.

The impact of social factors on tuberculosis management

AIM

This paper is a report of a study to examine the impact of social factors on the management of tuberculosis including engagement with services, hospitalization and extended treatment.

BACKGROUND

Rates of tuberculosis in major European cities have increased greatly in the last 10 years. The changing epidemiology of the disease, concentrated in marginalized groups, presents new challenges to the control of tuberculosis.

METHODS

A prospective cohort study of 250 newly diagnosed tuberculosis patients was conducted in London between January 2003 and January 2005. Data were collected by means of a risk assessment tool and from medical records. Outcome measures included missed appointments, frequency and duration of hospitalization and length of treatment.

RESULTS

The median age of the study sample was 33.82 (range 16.4-92.5) and 56.8% were male. Thirty-two per cent were hostel/street homeless or temporarily sharing accommodation with friends or relatives. Thirty-nine per cent were in receipt of welfare benefits and 13.2% had no income. Over a third anticipated difficulties taking their medicines and 30.3% had noone to remind them of this. Increased hospitalization was associated with hostel/street homelessness, drug or alcohol use and having noone to remind them to take their medicines (all P <or= 0.01). Missed appointments were associated with drug/alcohol use and previous tuberculosis treatment. Extended treatment was also associated with drug/alcohol use; previous tuberculosis treatment, drug resistance and those anticipating difficulties taking medication (all P <or= 0.001).

CONCLUSIONS

The development of a social outreach model of care with an emphasis on prevention and support is an essential aspect of modern, international tuberculosis care.

Tuberculosis screening in migrants in selected European countries shows wide disparities

Well-established tuberculosis screening units in Western Europe were selectively sampled. Three screening units in Norway, two in the UK, one in the Netherlands and one in Switzerland were evaluated. The aim of this study was to describe a range of service models used at a number of individual tuberculosis units for the screening of new entrants into Europe. Semi-structured interviews were conducted with clinicians, nurses and administrators from a selected sample of European tuberculosis screening units. An outline of key themes to be addressed was forwarded to units ahead of scheduled interviews. Themes included the history of the unit, structure, processes and outputs involved in screening new entrants for tuberculosis. Considerable variation in screening services exists in the approaches studied. Units are sited in transit camps or as units within hospital facilities. Staff capacity and administration varies from one clinic per week with few dedicated staff to fully dedicated units. Only one site recorded symptoms; tuberculin testing was universal in children, but varied in adults; chest radiograph screening was universal except at one site where a positive tuberculin skin test or symptoms were required in those <35 yrs of age before ordering a radiograph. Few output data are routinely and systematically collected, which hinders comparison and determination of effectiveness and efficiency. Service models for screening new immigrants for tuberculosis appear to vary in Western Europe. The systematic collection of data would make international comparisons between units easier and help draw conclusions that might usefully inform service development.

Joint hypermobility: the use of a new assessment tool to measure lower limb hypermobility

OBJECTIVES

The aim of the study was to compare the use of a new assessment tool for diagnosis of hypermobility in the lower limb to the Beighton score for generalised hypermobility.

METHODS

Three groups of children were compared (n = 225) and included a "normal" population of 116 school children, a "possible hypermobile" group of 88 children attending afoot and gait clinic and a "known hypermobile" group of 21 children referred from a paediatrician or rheumatologist. The Beighton score was used to measure generalised hypermobility. The Lower Limb Assessment Score was used to measure hypermobility in the lower limbs.

RESULTS

The Lower Limb Assessment Score was able to distinguish between the three groups of children better than the Beighton score. At a threshold of 5/9 indicating hypermobility, the Beighton score identified hypermobility in 34% of school children; the lower limb score identified hypermobility in 21% of school children after a threshold was identified. There was disagreement between the scores in school children where 26.7% of children appeared to have a positive Beighton score that was not accompanied by a positive lower limb score. In the "known hypermobile" group the Beighton score was positive in only 10% of children when the lower limb score was negative for hypermobility.

CONCLUSION

In this group of school children, the Beighton score appeared to over-diagnose hypermobility at the threshold of 5/9. Specific thresholds for diagnosis need to be set dependant on the age and ethnic group of the population being studied. The Lower Limb Assessment Score may be a useful score for health professionals specifically interested in lower limb hypermobility.

Screening programmes for tuberculosis in new entrants across Europe

Screening foreign-born groups with high rates of tuberculosis may help to ensure that they can benefit from early treatment and minimise onward transmission. In January 2003, we surveyed new entrant screening programmes in Europe. Of the 26 countries from whom a response was received, 13 (50%) conducted no specific tuberculosis screening. Of 13 countries with programmes, none conducted pre-entry screening, three conducted screening at ports of entry, and nine screened in other centres. All 13 principally screened refugees. All programmes used chest X-rays as a screening tool, but no two countries took the same specific clinical approach.

Patient and health service delays in initiating treatment for patients with pulmonary tuberculosis: retrospective cohort study

SETTING

Catchment population of the North Middlesex University Hospital (NMUH), London, UK.

OBJECTIVE

To measure patient and health care delays in treatment of pulmonary tuberculosis.

DESIGN

Retrospective cohort study of patients notified with pulmonary tuberculosis between 1 April 2001 and 1 March 2002.

RESULTS

The median case finding delays were between 78 and 99 days. Median patient-related delay was between 34.5 and 54 days. Median health care-related delay was 29.5 days. Shorter case finding delays were found in patients born in a high prevalence country, patients presenting first to Accident and Emergency department (A&E), younger patients, and those with sputum smear-positive disease. In those presenting first to A&E, those born in a high prevalence country, and those with sputum-positive disease, this effect was predominantly due to shorter health care delays. Limitations of TB service capacity and organisational factors appeared responsible for up to half of the difference in delay between those presenting to A&E or general practitioners (GPs).

CONCLUSION

Patient and health service delays contribute substantially to delays in patients accessing treatment. Considerable reduction in case finding delays may be achieved through changes in the capacity of tuberculosis services, and coordination of associated health services.