Brian Smyth

Nursing homes as a reservoir of extended-spectrum β-lactamase (ESBL)-producing ciprofloxacin-resistant Escherichia coli

BACKGROUND To assess the prevalence and risk factors for faecal carriage of fluoroquinolone-resistant, extended-spectrum beta-lactamase (ESBL)-producing, Escherichia coli (MDR E. coli) among residents in nursing homes in Northern Ireland. METHODS Between January 2004 and May 2006, retrospective histories of hospital admissions, antimicrobial treatment and co-morbidities were collected. Faecal samples were cultured for MDR E. coli. These isolates and their ESBL genes were typed by a reference laboratory. RESULTS Of the 294 patients included in the study, faecal samples from 119 (40.5%) grew MDR E. coli. The proportion of carriers in the different homes ranged from 0% to 75%. Epidemic strain A belonging to the ST131, O25:H4 lineage with the CTX-M-15 enzyme accounted for 58 (49%) of all isolates; its proportion varied from 0% to 100% among homes. Fifty-one percent of carriers had no history of recent hospital admission and only 13.5% had a known history of ESBL E. coli colonization or infection. In a multivariate logistic regression model, days of fluoroquinolone use [odds ratio (OR) = 1.33, 95% confidence interval (CI) 1.04-1.69, P = 0.02] and a history of urinary tract infection (OR = 2.56, 95% CI 1.37-4.78, P = 0.003) were the only variables independently associated with the risk of carrying MDR E. coli. CONCLUSIONS The high level of faecal carriage of MDR E. coli in nursing home residents demonstrates their importance as a reservoir population. Public health measures to combat spread of these organisms should address the needs of this group.

Effectiveness of trivalent seasonal influenza vaccine in preventing laboratory-confirmed influenza in primary care in the United Kingdom: 2012/13 end of season results.

In 2015/16, the influenza season in the United Kingdom was dominated by influenza A(H1N1)pdm09 circulation. Virus characterisation indicated the emergence of genetic clusters, with the majority antigenically similar to the current influenza A(H1N1)pdm09 vaccine strain. Mid-season vaccine effectiveness (VE) estimates show an adjusted VE of 41.5% (95% confidence interval (CI): 3.0-64.7) against influenza-confirmed primary care consultations and of 49.1% (95% CI: 9.3-71.5) against influenza A(H1N1)pdm09. These estimates show levels of protection similar to the 2010/11 season, when this strain was first used in the seasonal vaccine.

Pandemic (H1N1) 2009 influenza in the UK: clinical and epidemiological findings from the first few hundred (FF100) cases.

The UK was one of few European countries to document a substantial wave of pandemic (H1N1) 2009 influenza in summer 2009. The First Few Hundred (FF100) project ran from April-June 2009 gathering information on early laboratory-confirmed cases across the UK. In total, 392 confirmed cases were followed up. Children were predominantly affected (median age 15 years, IQR 10-27). Symptoms were mild and similar to seasonal influenza, with the exception of diarrhoea, which was reported by 27%. Eleven per cent of all cases had an underlying medical condition, similar to the general population. The majority (92%) were treated with antiviral drugs with 12% reporting adverse effects, mainly nausea and other gastrointestinal complaints. Duration of illness was significantly shorter when antivirals were given within 48 h of onset (median 5 vs. 9 days, P=0.01). No patients died, although 14 were hospitalized, of whom three required mechanical ventilation. The FF100 identified key clinical and epidemiological characteristics of infection with this novel virus in near real-time.

Methods for determining disease burden and calibrating national surveillance data in the United Kingdom: the second study of infectious intestinal disease in the community (IID2 study)

BackgroundInfectious intestinal disease (IID), usually presenting as diarrhoea and vomiting, is frequently preventable. Though often mild and self-limiting, its commonness makes IID an important public health problem. In the mid 1990s around 1 in 5 people in England suffered from IID a year, costing around £0.75 billion. No routine information source describes the UKs current community burden of IID. We present here the methods for a study to determine rates and aetiology of IID in the community, presenting to primary care and recorded in national surveillance statistics. We will also outline methods to determine whether or not incidence has declined since the mid-1990s.Methods/designThe Second Study of Infectious Intestinal Disease in the Community (IID2 Study) comprises several separate but related studies. We use two methods to describe IID burden in the community - a retrospective telephone survey of self-reported illness and a prospective, all-age, population-based cohort study with weekly follow-up over a calendar year. Results from the two methods will be compared. To determine IID burden presenting to primary care we perform a prospective study of people presenting to their General Practitioner with symptoms of IID, in which we intervene in clinical and laboratory practice, and an audit of routine clinical and laboratory practice in primary care. We determine aetiology of IID using molecular methods for a wide range of gastrointestinal pathogens, in addition to conventional diagnostic microbiological techniques, and characterise isolates further through reference typing. Finally, we combine all our results to calibrate national surveillance data.DiscussionResearchers disagree about the best method(s) to ascertain disease burden. Our study will allow an evaluation of methods to determine the community burden of IID by comparing the different approaches to estimate IID incidence in its linked components.

Age-specific vaccine effectiveness of seasonal 2010/2011 and pandemic influenza A(H1N1) 2009 vaccines in preventing influenza in the United Kingdom

An analysis was undertaken to measure age-specific vaccine effectiveness (VE) of 2010/11 trivalent seasonal influenza vaccine (TIV) and monovalent 2009 pandemic influenza vaccine (PIV) administered in 2009/2010. The test-negative case-control study design was employed based on patients consulting primary care. Overall TIV effectiveness, adjusted for age and month, against confirmed influenza A(H1N1)pdm 2009 infection was 56% (95% CI 42-66); age-specific adjusted VE was 87% (95% CI 45-97) in <5-year-olds and 84% (95% CI 27-97) in 5- to 14-year-olds. Adjusted VE for PIV was only 28% (95% CI -6 to 51) overall and 72% (95% CI 15-91) in <5-year-olds. For confirmed influenza B infection, TIV effectiveness was 57% (95% CI 42-68) and in 5- to 14-year-olds 75% (95% CI 32-91). TIV provided moderate protection against the main circulating strains in 2010/2011, with higher protection in children. PIV administered during the previous season provided residual protection after 1 year, particularly in the <5 years age group.

Use of Antiviral Drugs to Reduce Household Transmission of Pandemic (H1N1) 2009, United Kingdom

The United Kingdom implemented a containment strategy for pandemic (H1N1) 2009 through administering antiviral agents (AVs) to patients and their close contacts. This observational household cohort study describes the effect of AVs on household transmission. We followed 285 confirmed primary cases in 259 households with 761 contacts. At 2 weeks, the confirmed secondary attack rate (SAR) was 8.1% (62/761) and significantly higher in persons <16 years of age than in those >50 years of age (18.9% vs. 1.2%, p<0.001). Early (<48 hours) treatment of primary case-patients reduced SAR (4.5% vs. 10.6%, p = 0.003). The SAR in child contacts was 33.3% (10/30) when the primary contact was a woman and 2.9% (1/34) when the primary contact was a man (p = 0.010). Of 53 confirmed secondary case-patients, 45 had not received AV prophylaxis. The effectiveness of AV prophylaxis in preventing infection was 92%.

Harmonizing influenza primary-care surveillance in the United Kingdom: piloting two methods to assess the timing and intensity of the seasonal epidemic across several general practice-based surveillance schemes.

General Practitioner consultation rates for influenza-like illness (ILI) are monitored through several geographically distinct schemes in the UK, providing early warning to government and health services of community circulation and intensity of activity each winter. Following on from the 2009 pandemic, there has been a harmonization initiative to allow comparison across the distinct existing surveillance schemes each season. The moving epidemic method (MEM), proposed by the European Centre for Disease Prevention and Control for standardizing reporting of ILI rates, was piloted in 2011/12 and 2012/13 along with the previously proposed UK method of empirical percentiles. The MEM resulted in thresholds that were lower than traditional thresholds but more appropriate as indicators of the start of influenza virus circulation. The intensity of the influenza season assessed with the MEM was similar to that reported through the percentile approach. The MEM pre-epidemic threshold has now been adopted for reporting by each country of the UK. Further work will continue to assess intensity of activity and apply standardized methods to other influenza-related data sources.

Minimum dataset for confirmed human cases of influenza H5N1

Sheila Bird and Jeremy Farrar’s Comment (Aug 30, p 696) raises important issues that the Health Protection Agency and the UK devolved administrations have worked on for some time: the timely, consistent collection of detailed clinical and epidemiological data on cases of avian and pandemic infl uenza and their contacts. The output, the UK Avian Infl uenza Management System (AIMS), is a password-protected, web-based software package designed to collate epidemio logical, clinical, and personal data on human cases of avian in fl uenza (particularly, although not ex clusively, H5N1) and in the event of a pan demic, on the fi rst few hundred pandemic infl uenza cases in the UK. The minimum dataset has relied heavily on the multidisciplinary input of public-health professionals, infectiousdisease modellers, and clinicians. The system design allows data on cases to be entered in real time until discharge or death (fi gure). Data extracts are available as predetermined reports or fl at fi les for detailed statistical analysis. However, a database on its own is in suffi cient; for consistency and comparability, protocols—agreed and test ed before hand—are necessary for im portant issues such as case defi nitions, identifi cation and follow-up of con tacts, what happens to contacts who become cases, and the testing of cases and contacts. The European Centre for Disease Prevention and Control (ECDC) has suggested that individual countries should populate WHO/ECDC international databases with H5N1 cases. The UK is well placed to provide the international community with data for any internationally agreed minimum dataset. We look forward to continuing dialogue with ECDC and hope that other countries consider our system when designing their own.