Effect of ethnicity on care pathway and outcomes in patients hospitalized with influenza A(H1N1)pdm09 in the UK.

Data were extracted from the case records of UK patients admitted with laboratory-confirmed influenza A(H1N1)pdm09. White and non-White patients were characterized by age, sex, socioeconomic status, pandemic wave and indicators of pre-morbid health status. Logistic regression examined differences by ethnicity in patient characteristics, care pathway and clinical outcomes; multivariable models controlled for potential confounders. Whites (n = 630) and non-Whites (n = 510) differed by age, socioeconomic status, pandemic wave of admission, pregnancy, recorded obesity, previous and current smoking, and presence of chronic obstructive pulmonary disease. After adjustment for a priori confounders non-Whites were less likely to have received pre-admission antibiotics [adjusted odds ratio (aOR) 0·43, 95% confidence interval (CI) 0·28-0·68, P < 0·001) but more likely to receive antiviral drugs as in-patients (aOR 1·53, 95% CI 1·08-2·18, P = 0·018). However, there were no significant differences by ethnicity in delayed admission, severity at presentation for admission, or likelihood of severe outcome.

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.

Risk factors for hospitalisation and poor outcome with pandemic A/H1N1 influenza: United Kingdom first wave (May-September 2009).

BACKGROUND: During the first wave of pandemic H1N1 influenza in 2009, most cases outside North America occurred in the UK. The clinical characteristics of UK patients hospitalised with pandemic H1N1 infection and risk factors for severe outcome are described. METHODS: A case note-based investigation was performed of patients admitted with confirmed pandemic H1N1 infection. RESULTS: From 27 April to 30 September 2009, 631 cases from 55 hospitals were investigated. 13% were admitted to a high dependency or intensive care unit and 5% died; 36% were aged <16 years and 5% were aged > or = 65 years. Non-white and pregnant patients were over-represented. 45% of patients had at least one underlying condition, mainly asthma, and 13% received antiviral drugs before admission. Of 349 with documented chest x-rays on admission, 29% had evidence of pneumonia, but bacterial co-infection was uncommon. Multivariate analyses showed that physician-recorded obesity on admission and pulmonary conditions other than asthma or chronic obstructive pulmonary disease (COPD) were associated with a severe outcome, as were radiologically-confirmed pneumonia and a raised C-reactive protein (CRP) level (> or = 100 mg/l). 59% of all in-hospital deaths occurred in previously healthy people. CONCLUSIONS: Pandemic H1N1 infection causes disease requiring hospitalisation of previously fit individuals as well as those with underlying conditions. An abnormal chest x-ray or a raised CRP level, especially in patients who are recorded as obese or who have pulmonary conditions other than asthma or COPD, indicate a potentially serious outcome. These findings support the use of pandemic vaccine in pregnant women, children <5 years of age and those with chronic lung disease.

Four country healthcare-associated infection prevalence survey: pneumonia and lower respiratory tract infections.

In 2006, the Hospital Infection Society was funded by the respective health services in England, Wales, Northern Ireland and the Republic of Ireland to conduct a prevalence survey of healthcare-associated infection (HCAI). Here, we report the prevalence of pneumonia and lower respiratory tract infection other than pneumonia (LRTIOP) in these four countries. The prevalence of all HCAIs was 7.59% (5743 out of 75 694). Nine hundred (15.7%) of these infections were pneumonia, and 402 (7.0%) were LRTIOP. The prevalence of both infections was higher for males than for females, and increased threefold from those aged <35 to those aged >85 years (P<0.001). At the time of the survey or in the preceding seven days, 23.7% and 18.2% of patients with pneumonia and LRTIOP, respectively, were mechanically ventilated compared to 5.2% of patients in the whole study population. Meticillin-resistant Staphylococcus aureus (MRSA) was the cause of pneumonia and LRTIOP in 7.6% and 18.1% of patients, respectively (P<0.001). More patients with LRTIOP (4.2%) had concurrent diarrhoea due to Clostridium difficile compared to patients with pneumonia (2.4%), but this did not reach statistical significance. Other HCAIs were present in 137 (15.2%) of patients with pneumonia and 66 (16.4%) of those with LRTIOP. The results suggest that reducing instrumentation, such as mechanical ventilation where possible, should help reduce infection. The higher prevalence of MRSA as a cause of LRTIOP suggests a lack of specificity in identifying the microbial cause and the association with C. difficile emphasises the need for better use of antibiotics.

Observational study to investigate vertically acquired passive immunity in babies of mothers vaccinated against H1N1v during pregnancy.

OBJECTIVE: The primary objective was to determine the proportion of babies who acquired passive immunity to A/H1N1v, born to mothers who accepted vaccination as part of the national vaccination programme while pregnant (during the second and/or third trimesters) against the novel A/H1N1v influenza virus (exposed group) compared with unvaccinated (unexposed) mothers. DESIGN: An observational study at three sites in the UK. The purpose was to determine if mothers immunised against A/H1N1v during the pandemic vaccination period transferred that immunity to their child in utero. SETTING: Three sites in the UK [Queen's Medical Centre, Nottingham; City Hospital, Nottingham (both forming University Hospitals Nottingham), and Leicester Royal Infirmary (part of University Hospitals Leicester)]. PARTICIPANTS: All pregnant women in the second and third trimester presenting at the NHS hospitals above to deliver were eligible to participate in the study. Women were included regardless of age, social class, ethnicity, gravida and parity status, past and current medical history (including current medications), ethnicity, mode of delivery and pregnancy outcome (live/stillbirth). INTERVENTIONS: At enrolment, participants provided written consent and completed a questionnaire. At parturition, venous cord blood was obtained for serological antibody analysis. Serological analysis was undertaken by the Respiratory Virus Unit (RVU), Health Protection Agency (HPA) Centre for Infections, London. MAIN OUTCOME MEASURES: The primary end point in the study was the serological results of the cord blood samples for immunity to A/H1N1v. Regarding a suitable threshold for the determination of a serological response consistent with clinical protection, this issue is somewhat complex for pandemic influenza. The European Medicines Agency (EMEA) Committee for Human Medicinal Products (CHMP) judges that a haemagglutination inhibition (HI) titre of 1 : 40 is an acceptable threshold. However, this level was set in the context of licensing plain trivalent seasonal vaccine, where a titre of 1 : 40 is but one of several related immunogenicity criteria, and supported by paired sera capable of demonstrating a fourfold rise in antibody titre in response to vaccination. The current study mainly investigated the effects of an AS03-adjuvanted monovalent vaccine, and it was not possible to obtain paired sera where the initial sample was taken before vaccination (in vaccinated subjects). Of possibly greater relevance is the fact that it has been established from the study of early outbreaks of pandemic influenza in secondary schools in the UK (HPA, unpublished observations) that an HI antibody titre of 1 : 32 seems to be the threshold for a humoral response to 'wild-type' A/H1N1v infection. On that basis, a threshold of 1 : 32 is at least as appropriate as one of 1 : 40, especially in unvaccinated individuals. Given the difficulties that would accrue by applying thresholds of 1 : 32 in unvaccinated patients and 1 : 40 in vaccinated patients, we have therefore applied a threshold of 1 : 32 and 1 : 40, to increase the robustness of our findings. Differences arising are described. A microneutralisation (MN) titre of 1 : 40 may be also used, although it is not part of the CHMP criteria for vaccine licensure. Nonetheless, we utilised this analysis as a secondary end point, based on a conservative threshold of 1 : 60. RESULTS: Reverse cumulative distribution percentage curves for haemagglutinin dilution and MN titres demonstrate background immunity in babies of unvaccinated mothers of 25%-30%. Humoral immunity in babies of vaccinated mothers was present in 80% of the group. The difference in positive immunity between the babies of unvaccinated and vaccinated mothers was statistically significant (chi-squared test, p < 0.001). CONCLUSIONS: Our findings reveal a highly significant difference in HI titres between babies born to mothers vaccinated with pandemic-specific vaccine against A/H1N1v during the 2009-10 pandemic period. The subjects recruited were comparable from a baseline perspective and thus do not represent different groups that otherwise could have introduced bias into the study. Continued circulation of 2009 A/H1N1-like viruses is uncertain, but is possible as seasonal influenza in years to come. It is possible that future seasonal waves may display increased virulence. Given the adverse outcomes experienced for a small proportion of pregnant women during the influenza pandemic of 2009-10, this study provides useful evidence to support vaccination in pregnancy to protect both the mother and baby. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Personal protective equipment in an influenza pandemic: a UK simulation exercise.

There is limited experience of both operational and financial impacts that adoption of UK pandemic influenza infection control guidance will have on the use of personal protective equipment (PPE), patients and staff. We attempted to assess these issues from a live exercise in a hospital in north-west England. During this 24h exercise, all staff on an acute general medical ward wore PPE and adopted the procedures described in the UK pandemic influenza infection control guidance. Teams of infection control nurses observed and recorded staff behaviour and practice throughout the exercise, including staff attitudes towards the use of PPE. Although World Health Organization recommendations on the likely use of high-level PPE (FFP3 respirators) proved to be excessive, more gloves and surgical masks were used than expected. Despite pre-exercise training, many staff lacked confidence in using PPE and following infection control measures. They found PPE uncomfortable, with even basic tasks taking longer than usual. Large quantities of clinical waste were generated: an additional 12 bags (570 L) per day. The estimates of PPE usage within this exercise challenge assumptions that large amounts of high-level PPE are required, with significant implications for healthcare budgets. A programme of ongoing infection control education is needed. Healthcare in a pandemic situation is not simply a case of applying pandemic influenza infection control guidance to current practice; hospitals need to consider changing the way care and services are delivered.

Four country healthcare associated infection prevalence survey 2006: risk factor analysis.

Point prevalence surveys are useful in detecting changes in the pattern of healthcare-associated infection (HCAI). In 2004 the Hospital Infection Society was asked to conduct a third national prevalence survey, which included England, Wales, Northern Ireland and the Republic of Ireland. A similar but not identical survey was carried out in Scotland. Data were collected on standardised forms using Centres for Disease Control and Prevention definitions. This report considers associations with a wide range of risk factors for all HCAI and for four main categories. The overall prevalence rate of HCAI was 7.6% and increased significantly with age. All risk factors considered were associated with highly significantly increased risk of HCAI, except recent peripheral IV catheter and other bladder instrumentation use. Primary bloodstream infection (PBSI) was associated with antibiotic, central intravenous catheter and parenteral nutrition use. Pneumonia was associated with antibiotic, central catheter, parenteral nutrition use, mechanical ventilation and current peripheral catheter use. Surgical site infection was associated with recent surgery, antibiotic and central catheter use, mechanical ventilation and parenteral nutrition. Urinary instrumentation and antibiotic use were associated with urinary tract infection. Patients under a critical care medicine consultant had the highest prevalence of HCAI (23.2%). This report highlights those areas requiring attention to prevent HCAI, i.e. device-related infections such as PBSI (e.g. central catheters) and pneumonia (e.g. mechanical ventilation) and should influence protocols for future prevalence surveys of HCAI, e.g. the recording of risk factors at the time of assessment only is sufficient.

Four country healthcare associated infection prevalence survey 2006: overview of the results.

A survey of adult patients was conducted in February 2006 to May 2006 in acute hospitals across England, Wales, Northern Ireland and the Republic of Ireland to estimate the prevalence of healthcare-associated infections (HCAIs). A total of 75 694 patients were surveyed; 5743 of these had HCAIs, giving a prevalence of 7.59% (95% confidence interval: 7.40-7.78). HCAI prevalence in England was 8.19%, in Wales 6.35%, in Northern Ireland 5.43% and in the Republic of Ireland 4.89%. The most common HCAI system infections were gastrointestinal (20.6% of all HCAI), urinary tract (19.9%), surgical site (14.5%), pneumonia (14.1%), skin and soft tissue (10.4%) and primary bloodstream (7.0%). Prevalence of MRSA was 1.15% with MRSA being the causative organism in 15.8% of all system infections. Prevalence of Clostridium difficile was 1.21%. This was the largest HCAI prevalence survey ever performed in the four countries. The methodology and organisation used is a template for future HCAI surveillance initiatives, nationally, locally or at unit level. Information obtained from this survey will contribute to the prioritisation of resources and help to inform Departments of Health, hospitals and other relevant bodies in the continuing effort to reduce HCAI.

Monitoring infective complications following hip fracture.

Hip fracture affects more than 55,000 people in the UK each year and this number is increasing. Because of their advanced age and other risk factors, hip fracture patients are at risk of developing infection and a variety of other non-infective complications. Surveillance of superficial wound and deep joint infection is important because of the large number of patients involved and represents a good example of targeted surveillance. Furthermore this may be conducted as part of a quality control programme monitoring other interventions such as prophylaxis for vascular thrombosis. However, to carry this out successfully, a simple but efficient system for recording, collecting and analysing data is required and adequate post-discharge surveillance must be carried out.

The Second National Prevalence Survey of infection in hospitals--overview of the results.

This study was designed to assess the overall prevalence of infection among the patients in hospitals in the UK and the Republic of Ireland. Patient data were collected and entered directly into a portable Olivetti (A12 notebook) computer with a custom-designed program (Epi-Info version 5.01). The statistical analysis was performed using the Statistical Package for Social Sciences software (SPSS). In all, 37,111 patients from 157 centers were studied, and a mean hospital acquired infection (HAI) prevalence rate of 9.0% (range 2-29%) was calculated. HAI rates were higher in teaching hospitals (11.2%) than in non-teaching hospitals (8.4%) P < 0.001. Four major sites of infections--infections of the urinary tract (23.2%), surgical-wound infections (10.7%), lower-respiratory tract (22.9%) and skin infections (9.6%)--accounted for 66.5% (2559 of 3848) of the total infections identified.

The Second National Prevalence Survey of infection in hospitals: methodology.

This paper describes the methods used to perform a very large multicentred prevalence survey of infection in hospitals. Infection control teams were trained centrally to use a standardized questionnaire and agreed definitions to collect prevalence data on a portable computer. The study was coordinated from a single centre and the analysis performed by the statistics department at Central Public Health Laboratory, Colindale, London. The survey included 157 centres throughout England and Wales, Scotland and all Ireland. The survey was carried out as a joint venture by members of The Hospital Infection Society, The Public Health Laboratory Service and the Infection Control Nurses' Association of the British Isles and was organized by a Steering Committee.