UK Health Protection Agency Research Articles

An appraisal of the UK Health Protection Agency's document "The Impact on Health of Emissions to Air from Municipal Waste Incinerators"

An appraisal of the UK Health Protection Agency's document "The Impact on Health of Emissions to Air from Municipal Waste Incinerators"

PCV35 - Budget Impact Analysis of Routine Gentamicin-Collagen Implants for the Prevention of Surgical Site Infection (SSI) in High Risk Cardiothoracic Surgery Patients

The SSI rate after cardiothoracic surgery is estimated at 7.3% by the UK Health Protection Agency (HPA) for high risk patients. This represents a burden on resources, through greater risk of in-hospital mortality and increased length of hospital stay (mean 22.1 extra days for deep SSI). Treatment guidelines recommend IV antibiotic prophylaxis before surgery; however a challenge in high-BMI and diabetic patients (high risk) is the inability of systemic antibiotics to sufficiently penetrate target tissue. It is however estimated that 40%-60% of SSIs are avoidable, with clinical data supporting additional use of local gentamicin-collagen for SSI prevention. The purpose of this study was to examine the budget impact case from a UK NHS perspective of routinely administering gentamicin-collagen local prophylaxis against SSI in high risk patients undergoing cardiothoracic surgery. A literature review was undertaken regarding gentamicin-collagen efficacy in reducing SSI in cardiothoracic patients, NHS costs of SSI, and annual UK cardiothoracic patient numbers. The SSI rate in cardiothoracic surgery was obtained from HPA data. Findings were incorporated into a decision tree budget impact model to analyse potential savings from routine use of gentamicin-collagen in high risk cardiothoracic patients. Considering a cohort of 3710 high-risk cardiothoracic patients, annual NHS costs of SSI are £2,164,316. Administration of two gentamicin-collagen implants to each high risk patient would cost £200 per patient. Assuming a 59% reduction in SSI; this would prevent 197 sternal wound infections, with direct savings of £1,590,882 per year, a net saving of £229 per cardiothoracic surgery patient. Significant NHS and hospital trust savings may be achievable through routine use of gentamicin-collagen implants in high risk cardiothoracic surgery patients. A conservative estimate of high-risk patient numbers was used in the analysis, suggesting the scope for budgetary savings could exceed reported findings.

347 Do changes in the incidence of occupationally-acquired food-borne zoonotic infections precede changes in the wider population?

ObjectivesRecently the WHO estimated that up to 75% of emerging pathogens may be of zoonotic origin. Occupationally acquired zoonoses are of particular concern in food producing sectors because of the...

Type testing of a head band dosemeter for measuring eye lens dose in terms of HP(3)

A new head band dosemeter, for the measurement of eye lens dose in terms of Hp(3), has been type tested by Public Health England's Centre for Radiation, Environmental and Chemical Hazards [formerly part of the UK Health Protection Agency (HPA)]. The type tests were based on the International Standard ISO 12794, drawing also upon earlier work at HPA. The results show that, unlike many existing dosemeters, the new head band dosemeter correctly measures Hp(3) for beta radiations as well as photons.

PTH-026 Predictors for all Cause Mortality following Clostridium Difficile Associated Diarrhoea

IntroductionSevere Clostridium difficile associated diarrhoea (CDAD) is an important nosocomial infection, often resulting in severe morbidity or death. The rates of CDAD have increased significantly in the last 2 decades,...

Sa1242 Predictors for All-Cause Mortality Following Clostridium Diffcile Associated Diarrhoea

Introduction Severe Clostridium difficile associated diarrhoea (CDAD) is an important nosocomial infection, often resulting in severe morbidity or death. The rates of CDAD have increased significantly in the last 2 decades, but predictors of outcome are poorly understood. Methods A retrospective cohort study was performed in patients with a diagnosis of CDAD hospitalised at Leeds Teaching Hospitals NHS Trust (LTHT) between January 2011 and December 2011. The data on these cases was collected from electronic patient records and medical notes. Data collected included general demographics, underlying medical conditions, Horn Index, Charlson co-morbidity score, clinical and laboratory data, and the medical treatment given. Death due to any cause either during that hospital stay or within 30 days of discharge from hospital was the primary outcome. Severe CDAD was defined according to the UK Health Protection Agency (HPA) guidelines as WCC > 15 X 109/L, or an acute rising serum creatinine (i.e. > 50% increase above baseline), or a temperature of > 38.5°C, or evidence of severe colitis (abdominal or radiological signs). Logistic Regression analysis was used to identify parameters associated with mortality. SPSS version 17 (IBM Corp, NY) was used to perform the statistical analysis. Results There were 247 patients with a diagnosis of CDAD made in 2011 at LTHT of which 16 were wrongly coded, 5 were treated in the community, 12 had insufficient information in the notes and in 68 patients the medical notes could not be traced. A total of 170 episodes in 146 patients were finally analysed. There were 36 deaths in this group. Patients who were dead were older (mean age 78±12.9 vs 76.6±17.6). Independent predictors of mortality on multivariate analysis included age (OR 1.051, 95% CI 1.009–1.095), Charlson co-morbidity score of ≥3 (OR 3.036, 95% CI 1.209–7.622), Horn Index (Major or Extreme) (OR 4.725, 95% CI 1.818–12.283), Severe CDAD (OR 3.454, 95% CI 1.222–9.760) and in-appropriate treatment of severe CDAD with metronidazole as first line therapy (OR 4.642, 95% CI 1.213–19.193). Factors not found significant included gender, prior use of antibiotics, PPI use, opioid use, prior episodes of CDAD and treatment with vancomycin. Conclusion Predictors of all-cause mortality in patients with CDAD include older age, Charlson score≥3, Horn index ≥3, severe CDAD as defined by the UK HPA and in-appropriate use of metronidazole in severe CDAD. Patients with severe CDAD should not be treated with Metronidazole as first line therapy. Further prospective validation of these results is needed in a multicenter setting. Disclosure of Interest None Declared.

Diversity of Canadian meningococcal serogroup B isolates and estimated coverage by an investigational meningococcal serogroup B vaccine (4CMenB)

BackgroundIn collaboration with the Canadian Immunization Monitoring Program Active (IMPACT), the National Microbiology Laboratory, the UK Health Protection Agency and Novartis Vaccines, we tested the potential of an investigational 4-component meningococcal B vaccine (4CMenB) to cover Canadian strains circulating from 2006 to 2009. MethodsIMPACT meningococcal surveillance is population based and includes over 50% of Canadian adults and children. All isolates were characterized by Meningococcal Antigen Typing System (MATS) and sequencing for factor H-binding protein (fHbp), Neisseria Heparin Binding Antigen (NHBA) and Neisserial adhesin A (NadA). ResultsIn total, 157 isolates were tested. Overall, 4CMenB MATS predicted strain coverage was 66% (95% CI: 46–78%), with 26%, 29% and 11% of strains covered by one, two and three vaccine antigens, respectively. The coverage of each antigen was as follows: 13% PorA, 1% NadA, 52% fHbp and 51% NHBA. The majority of strains for clonal complex (cc) 41/44 and cc60 were covered by NHBA; the majority of strains for cc269 and cc32 were covered by fHbp and NHBA.Coverage for two prevalent strains (sequence type (ST)-269 and ST-154) was 95% and 100%, respectively. Conclusions4CMenB has the potential to protect against a significant proportion of Canadian invasive MenB strains.

Whole-genome sequencing to identify transmission of Mycobacterium abscessus between patients with cystic fibrosis: a retrospective cohort study

SummaryBackgroundIncreasing numbers of individuals with cystic fibrosis are becoming infected with the multidrug-resistant non-tuberculous mycobacterium (NTM) Mycobacterium abscessus, which causes progressive lung damage and is extremely challenging to treat. How this organism is acquired is not currently known, but there is growing concern that person-to-person transmission could occur. We aimed to define the mechanisms of acquisition of M abscessus in individuals with cystic fibrosis.MethodWhole genome sequencing and antimicrobial susceptibility testing were done on 168 consecutive isolates of M abscessus from 31 patients attending an adult cystic fibrosis centre in the UK between 2007 and 2011. In parallel, we undertook detailed environmental testing for NTM and defined potential opportunities for transmission between patients both in and out of hospital using epidemiological data and social network analysis.FindingsPhylogenetic analysis revealed two clustered outbreaks of near-identical isolates of the M abscessus subspecies massiliense (from 11 patients), differing by less than ten base pairs. This variation represents less diversity than that seen within isolates from a single individual, strongly indicating between-patient transmission. All patients within these clusters had numerous opportunities for within-hospital transmission from other individuals, while comprehensive environmental sampling, initiated during the outbreak, failed to detect any potential point source of NTM infection. The clusters of M abscessus subspecies massiliense showed evidence of transmission of mutations acquired during infection of an individual to other patients. Thus, isolates with constitutive resistance to amikacin and clarithromycin were isolated from several individuals never previously exposed to long-term macrolides or aminoglycosides, further indicating cross-infection.InterpretationWhole genome sequencing has revealed frequent transmission of multidrug resistant NTM between patients with cystic fibrosis despite conventional cross-infection measures. Although the exact transmission route is yet to be established, our epidemiological analysis suggests that it could be indirect.FundingThe Wellcome Trust, Papworth Hospital, NIHR Cambridge Biomedical Research Centre, UK Health Protection Agency, Medical Research Council, and the UKCRC Translational Infection Research Initiative.

HIV incidence in men who have sex with men in England and Wales 2001–10: a nationwide population study

SummaryBackgroundControl of HIV transmission could be achievable through an expansion of HIV testing of at-risk populations together with ready access and adherence to antiretroviral therapy. To examine whether increases in testing rates and antiretroviral therapy coverage correspond to the control of HIV transmission, we estimated HIV incidence in men who have sex with men (MSM) in England and Wales since 2001.MethodsA CD4-staged back-calculation model of HIV incidence was used to disentangle the competing contributions of time-varying rates of diagnosis and HIV incidence to observed HIV diagnoses. Estimated trends in time to diagnosis, incidence, and undiagnosed infection in MSM were interpreted against a backdrop of increased HIV testing rates and antiretroviral-therapy coverage over the period 2001–10.FindingsThe observed 3·7 fold expansion in HIV testing in MSM was mirrored by a decline in the estimated mean time-to-diagnosis interval from 4·0 years (95% credible interval [CrI] 3·8–4·2) in 2001 to 3·2 years (2·6–3·8) by the end of 2010. However, neither HIV incidence (2300–2500 annual infections) nor the number of undiagnosed HIV infections (7370, 95% CrI 6990–7800, in 2001, and 7690, 5460–10 580, in 2010) changed throughout the decade, despite an increase in antiretroviral uptake from 69% in 2001 to 80% in 2010.InterpretationCD4 cell counts at HIV diagnosis are fundamental to the production of robust estimates of incidence based on HIV diagnosis data. Improved frequency and targeting of HIV testing, as well as the introduction of ART at higher CD4 counts than is currently recommended, could begin a decline in HIV transmission among MSM in England and Wales.FundingUK Medical Research Council, UK Health Protection Agency.

Expression of toxic shock syndrome toxin-1 by epidemic meticillin-resistant Staphylococcus aureus 16

BackgroundStaphylococcal toxic shock syndrome (TSS) is a fatal illness attributed to Staphylococcus aureus toxic shock syndrome toxin-1 (TSST-1), encoded by the tst gene. No epidemiological data on TSS exist from the UK. Strains of S aureus may carry the tst gene but not cause TSS, such as the UK strain epidemic meticillin-resistant SA-16 (EMRSA-16). The aim of this study was to determine the epidemiology of TSS in the UK and investigate the expression of TSST-1 by EMRSA-16 and tst+ meticillin-sensitive S aureus (MSSA). MethodsCases of TSS were identified at the UK Health Protection Agency (HPA) and epidemiological features analysed. A selection of clonal complex (CC)-30 EMRSA-16 and TSS-associated MSSA strains was chosen for investigation. The tst gene and promoter region were sequenced in all strains. The staphylococcal pathogenicity island (SaPI) harbouring tst was determined by PCR. Growth of strains in brain heart infusion broth was monitored by optical density (OD600). TSST-1 in supernatants was quantified by western blot using densitometry according to a TSST-1 standard curve. RNA was isolated for tst transcript analysis by quantitative reverse-transcription-PCR (qRT-PCR). Whole genome sequencing was performed on all strains to identify potential mutations in known regulators of toxin synthesis. Findings150 cases of TSS were reported to the HPA over a period of 4 years. Six cases (4%) were attributable to MRSA and the remainder to MSSA. There was no difference in the tst gene or promoter sequence among the strains and tst was carried by SaPI2. TSST-1 production by EMRSA-16 strains commenced earlier in growth than did MSSA strains and was greater in TSS-associated MSSA than in EMRSA-16 strains throughout growth. These results were compared with tst transcription by MSSA and EMRSA16 using qRT-PCR. InterpretationEMRSA-16 produces less TSST-1 than does MSSA of the same lineage; this may be due to differences in global gene regulators, perhaps as a result of changes in PBP2a expression, or the carriage of a large SCCmec element by EMRSA-16. This difference in production may explain the paucity of TSS cases caused by MRSA. FundingUK National Centre for Infection Prevention and Management.

Concordance in diabetic foot ulcer infection

IntroductionAccurate identification of pathogens, rather than colonising bacteria, is a prerequisite for targeted antibiotic therapy to ensure optimal patient outcome in wounds, such as diabetic foot ulcers. Wound swabs are...

Infectious disease surveillance update

15 people have now died from the Ebola outbreak in the northeast of the Democratic Republic of the Congo, and the virus has spread to a second centre after a woman was contaminated during a patient's funeral before travelling home to the east. The Congolese authorities are warning of the risk of spreading Ebola by washing and displaying dead bodies, which is a widespread practice. There are 29 confirmed cases and about 170 people are being monitored after coming into contact with infected patients. The US Centers for Disease Control and Prevention (CDC) says 22 000 people are at risk of the deadly respiratory disease hantavirus pulmonary syndrome after staying in Yosemite National Park (CA). Eight cases have been recorded, including three fatalities, in people who visited between June and August. The rare disease is spread by contact with infected rodents or inhaling dust contaminated with their urine, faeces, or saliva. The CDC has urged laboratory testing of potential people who exhibit the virus's influenza-like symptoms, which can lead to severe breathing difficulties, since early treatment can save lives. The incubation period is up to 6 weeks, and roughly 60% of cases are fatal. 1047 cases of pertussis in England and Wales were reported to the UK Health Protection Agency (HPA) in July, 2012, bringing this year's total to 3523. Most sufferers are teenagers and young adults; however, high numbers of young babies, who are most at risk of severe complications and death, have been affected. The Department of Health's Joint Committee on Vaccination and Immunisation is considering combative options such as introducing a booster dose in teenagers and vaccinating pregnant women. The rate of new cholera cases in Sierra Leone has accelerated rapidly since July. 16 360 cases have been recorded this year, including 255 deaths, from 12 of 13 districts. The Ministry Of Health and Sanitation, with national and international partners, is increasing the response, emphasising early detection and treatment. Laboratories are being supplied with materials to collect, transport, and analyse specimens, and community meetings in Freetown are raising awareness of the importance of avoiding drinking water from unprotected sources. For more on Ebola in the Democratic Republic of the Congo see http://www.washingtonpost.com/world/deadly-ebola-virus-spreads-to-second-center-in-eastern-congo/2012/09/08/497d2ea2-f9c7-11e1-a0a1-b07778c66e04_story.htmlFor more on hantavirus in the USA see http://www.cdc.gov/hantavirus/outbreaks/yosemite-national-park-2012.htmlFor more on pertussis in the UK see http://www.hpa.org.uk/NewsCentre/NationalPressReleases/2012PressReleases/120831Whoopingcoughcasescontinuetoincrease/For more on cholera in Sierra Leone see http://www.who.int/csr/don/2012_09_08/en/index.html For more on Ebola in the Democratic Republic of the Congo see http://www.washingtonpost.com/world/deadly-ebola-virus-spreads-to-second-center-in-eastern-congo/2012/09/08/497d2ea2-f9c7-11e1-a0a1-b07778c66e04_story.html For more on hantavirus in the USA see http://www.cdc.gov/hantavirus/outbreaks/yosemite-national-park-2012.html For more on pertussis in the UK see http://www.hpa.org.uk/NewsCentre/NationalPressReleases/2012PressReleases/120831Whoopingcoughcasescontinuetoincrease/ For more on cholera in Sierra Leone see http://www.who.int/csr/don/2012_09_08/en/index.html

Intercomparison of patient CTDI surveys in three countries

The results of large-scale computed tomography (CT) patient dose surveys from the USA, UK and Germany undertaken during the period 1999-2001 were reviewed. The mean values for volume-weighted CT dose index (CTDI(vol)) and dose length product (DLP) were extracted. For head CT examinations, the reported values for the three surveys were similar with a mean CTDI(vol) of 59±6 mGy and a mean DLP of 760±90 mGy cm. For the body, the values for CTDI(vol) in the USA (21±5 mGy) were nearly double those in the European countries (12±2 mGy). Average head CTDI(vol) values are comparable with the diagnostic reference levels (DRLs) recommended by the European Commission and the UK Health Protection Agency, but lower than the value of 75 mGy, which is currently used in the USA. DRLs for abdominal imaging are nearly a factor of 2 lower in the UK (14 mGy) than in other parts of the European Community and the USA (25 mGy).

A Headband Dosemeter for Measuring Occupational Radiation Dose to the Lens of the Eye in Terms of Hp(3)

Abstract: The forthcoming European Basic Safety Standards directive will require member states to enforce, within four or five years, a much-reduced dose limit for the lens of the eye. The limit will be reduced from 150 millisieverts (mSv) to 20 mSv per annum (with some flexibility for averaging over five years). This change will be important for applications in the medical sector, particularly those of interventional cardiology/radiology (IC/IR). In anticipation of this, the Personal Dosimetry Service of the UK's Health Protection Agency has worked with customers from NHS Trusts and other medical-sector colleagues to produce a simple and inexpensive headband dosemeter. This paper reports on a type test of the new dosemeter. Use was made of conversion coefficients from air kerma that have recently been developed by the European ORAMED group (http://www.oramed-fp7.eu), as well as of a simple cylindrical phantom recommended by the same group. Performance was judged against the published international standard for extremity and eye dosemeters, ISO 12794, as augmented by new, tighter ORAMED recommendations. The dosemeter was found to accurately measure the required operational quantity, Hp(3), in any photon or beta fields. Because of its tissue-equivalent design, the dosemeter will also respond correctly in any mixture of such fields. The new dosemeter will provide a useful tool to assess the scale of doses to IC/IR practitioners and their teams. Because the headband dosemeter can be positioned close to the eyes, its performance relies far less on uniformity of the radiation field than would, for example, a whole body dosemeter worn on the trunk. Thus, if monitoring by means of whole body dosemeters is preferred, the headband dosemeter can be used to validate that approach.

PWE-174 Proton pump inhibitors (PPI) use and Clostridium difficile infection: guilty or innocent bystander?

IntroductionPPIs have been implicated in predisposing to Clostridium difficile infection by causing hypochlorhydria. A 5–10% asymptomatic toxin burden in the community is also reported. The previously voluntary reporting of C...

The Influence of Geology on Indoor Radon Concentrations in Neelum Valley Azad Kashmir, Pakistan

Geology of parent rock controls strongly the soil properties which in turn effect the generation and transportation of radon from its point of production to the surface of earth’s crust. Indoor radon concentrations mainly depend upon uranium and thorium content beneath the earth surface and diffusion of radon from rock and soil fractures, stoma and fissures. This paper presents the results of a survey of indoor radon concentrations in Neelum Valley District. CR-39 detectors were installed in 210 houses covering the entire study area. The detectors were retrieved after exposing to indoor radon for a period of 90 days and then etched in 6 M NaOH at 80°C for 16 h. The observed track densities were converted into the indoor radon concentrations using calibration factor of 2.7 tracks cm−2·h−1 per kBq·m−3. Mean annual effective doses were calculated for each measured value of radon concentration using UNSCEAR 2000 model. Effects of geology, fissures, crevice and cracks on radon levels have also been discussed. Results obtained from this study have been compared with radon concentration action levels given by the World Health Organisation and US Environmental Protection Agency and UK Health Protection Agency.

Carbon monoxide from neighbouring restaurants: the need for an integrated multi-agency response

Carbon monoxide (CO) is a colourless, odourless toxic gas produced during incomplete combustion of carbon-based fuels. Most CO incidents reported to the UK Health Protection Agency (HPA) are due to faulty gas appliances, and legislation exists to ensure gas appliances are properly installed. We present three CO poisoning incidents of unusual origin reported to the HPA. In each, residents living above restaurants were poisoned after workers left charcoal smouldering overnight in specialist or traditional ovens whilst ventilation systems were turned off. This led to production of CO, which travelled through floorboards and built up to dangerous concentrations in the flats. Working with local authorities, these incidents were investigated and resolved, and work was conducted to prevent further occurrences. The novel nature of these CO incidents led to delays in recognition and subsequent remedial action. Although previously undescribed, it is likely that due to the number of residences built above restaurants and the rising popularity of traditional cooking methods, similar incidents may be occurring and could increase in frequency. Multi-agency response and reporting mechanisms could be strengthened. Awareness raising in professional groups and the public on the importance of correct ventilation of such appliances is vital.

Radiation protection principles

The International Commission on Radiological Protection (ICRP) recommends a system ofradiological protection that is in use worldwide. This paper describes the elements of thatsystem, identifying the central assumptions and principles. A key assumption for protectionat low doses is that there is a simple proportionate relationship between increments in doseand increments in risk. The system focuses on changes to the level of peoples’ exposure,recommending that any change is justified (i.e., the benefit is clear) and protection is thenoptimised (i.e., improvement in dose reduction is promoted when possible andreasonable). In doing so, the system considers the amenability of the source ofexposure to control and the acceptability of the exposure to individuals or societyThe views expressed are those of the author and do not necessarily reflect those of theICRP or the UK Health Protection Agency..

Two Decades of Experience With the Haemophilus influenzae Serotype b Conjugate Vaccine in the United Kingdom

BackgroundThe Haemophilus influenzae serotype b (Hib) conjugate vaccine was introduced into the UK national childhood immunization program in 1992 after clinical trials reported the vaccine to be highly immunogenic in infants as young as two months of age. ObjectiveThe goal of this study was to describe and comment on the impact of routine Hib immunization on the epidemiology of invasive Hib disease in the United Kingdom. In addition, the development of Hib polysaccharide and conjugate vaccines was reviewed. MethodsA literature search was conducted of PubMed for invasive Hib disease epidemiology in the United Kingdom. The UK Health Protection Agency Web site was also searched for relevant publications. ResultsThe incidence of invasive Hib incidence in children aged <5 years fell from 21/100,000 to 44/100,000 in the prevaccine era to 0.63/100,000 in 1998, with an estimated vaccine failure rate of 2.2/100,000 vaccinees. After 1999, however, invasive Hib disease increased, particularly in toddlers, and peaked in 2003. Potential reasons for the resurgence included a greater-than-expected decline in Hib antibodies after primary immunization, waning of herd immunity offered by the initial catch-up campaign, and use of a less immunogenic Hib combination vaccine containing acellular pertussis in 2000–2001. In response to the resurgence, a Hib combination vaccine containing whole-cell pertussis was reintroduced in 2002, followed by a childhood Hib booster campaign in 2003. In 2004, the recommended infant vaccine was changed to a different Hib/acellular pertussis combination vaccine containing inactivated polio, which had a satisfactory Hib response, was less reactogenic, and eliminated the risk of vaccine-associated paralytic poliomyelitis. This action was followed by introduction of a routine 12-month Hib booster in 2006. Together, these measures led to a decline in invasive Hib disease across all age groups. In 2010, there were only 30 invasive Hib cases, with 6 reported in children aged <5 years and no deaths in this age group since 2007. ConclusionsControl of Hib disease is currently the best that has been achieved since the introduction of the routine Hib vaccination almost 20 years ago.

1 Introduction

1 Introduction