Rates of surgical site infection after hip replacement as a hospital performance indicator: analysis of data from the English mandatory surveillance system

OBJECTIVE

To describe rates of surgical site infection (SSI) after hip replacement and to use these data to provide a simple mechanism for identifying poorly performing hospitals that takes into account variations in sample size.

DESIGN

Prospective surveillance study.

SETTING

A total of 125 acute care hospitals in England that participated in mandatory SSI surveillance from April 1, 2004 through March 31, 2005.

PATIENTS

Patients who underwent total hip replacement (THR) or hip hemiarthroplasty (HH).

METHODS

A standard data set was collected for all eligible operations at participating hospitals for a minimum of 3 months annually. Defined methods were used to identify SSIs that occurred during the inpatient stay. Data were checked for quality and accuracy, and funnel plots were constructed by plotting the incidence of SSI against the number of operations.

RESULTS

Data were collected on 16,765 THRs and 5,395 HHs. The cumulative SSI incidence rates were 1.26% for THR and 4.06% for HH; the incidence densities were 1.38 SSIs per 1,000 postoperative inpatient days for THR and 2.3 SSIs per 1,000 postoperative inpatient days for HH. The risk of infection associated with revision surgery was significantly higher than that associated with primary surgery (2.7% [95% confidence interval, 2.0%-3.5%] vs. 1.1% [95% confidence interval, 1.0%-1.2%]; P=.003). Rates varied considerably among hospitals. Nineteen hospitals had rates above the 90th percentile. However, the use of funnel plots to adjust for the precision of estimated SSI rates identified 7 hospitals that warranted further investigation, including 2 with crude rates below the 90th percentile.

CONCLUSIONS

Funnel plots of rates of SSI after hip replacement provide a valuable method of presenting hospital performance data, clearly identifying hospitals with unusually high or low rates while adjusting for the precision of the estimated rate. This information can be used to target and support local interventions to reduce the risk of infection.

Reverse transcriptase activity in patients with primary biliary cirrhosis and other autoimmune liver disorders

BACKGROUND

Patients with biliary disease make retroviral antibodies and the Human Betaretrovirus has been characterized in patients with primary biliary cirrhosis.

AIM

To screen patients with autoimmune liver disease for evidence of retroviral infection.

METHODS

Real-time reverse transcriptase polymerase chain reaction was used to detect Human Betaretrovirus, and a reverse transcriptase assay to measure reverse transcriptase activity in plasma.

RESULTS

Using reverse transcriptase polymerase chain reaction, 24% of primary biliary cirrhosis samples were positive for Human Betaretrovirus when compared to 13% with autoimmune hepatitis, 5% of other liver diseases and 3% of the non-liver disease control subjects. Reverse transcriptase activity was found in 73% of patients with autoimmune hepatitis, 42% with primary biliary cirrhosis, 22% of liver patients without viral or autoimmune disease and 7% of subjects without liver disease. In patients with autoimmune liver disease, detection of reverse transcriptase activity was related to higher ALT levels, whereas others stabilized on immunosuppressive therapy either preliver or postliver transplantation were less likely to be reverse transcriptase-positive.

CONCLUSIONS

Most patients with autoimmune hepatitis have detectable reverse transcriptase activity. Investigations will be required to assess whether this represents the expression of endogenous retroviruses and retrotransposable elements in inflamed tissue, or signifies the presence of exogenous retroviral infection.

epic2: National evidence-based guidelines for preventing healthcare-associated infections in NHS hospitals in England

National evidence-based guidelines for preventing healthcare-associated infections (HCAI) in National Health Service (NHS) hospitals in England were commissioned by the Department of Health (DH) and developed during 1998-2000 by a nurse-led multi-professional team of researchers and specialist clinicians. Following extensive consultation, they were published in January 2001. These guidelines describe the precautions healthcare workers should take in three areas: standard principles for preventing HCAI, which include hospital environmental hygiene, hand hygiene, the use of personal protective equipment, and the safe use and disposal of sharps; preventing infections associated with the use of short-term indwelling urethral catheters; and preventing infections associated with central venous catheters. The evidence for these guidelines was identified by multiple systematic reviews of experimental and non-experimental research and expert opinion as reflected in systematically identified professional, national and international guidelines, which were formally assessed by a validated appraisal process. In 2003, we developed complementary national guidelines for preventing HCAI in primary and community care on behalf of the National Collaborating Centre for Nursing and Supportive Care (National Institute for Healthand Clinical Excellence). A cardinal feature of evidence-based guidelines is that they are subject to timely review in order that new research evidence and technological advances can be identified, appraised and, if shown to be effective in preventing HCAI, incorporated into amended guidelines. Periodically updating the evidence base and guideline recommendations is essential in order to maintain their validity and authority. Consequently, the DH commissioned a review of new evidence published following the last systematic reviews. We have now updated the evidence base for making infection prevention and control recommendations. A critical assessment of the updated evidence indicated that the original epic guidelines published in 2001 remain robust, relevant and appropriate but that adjustments need to be made to some guideline recommendations following a synopsis of the evidence underpinning the guidelines. These updated national guidelines (epic2) provide comprehensive recommendations for preventing HCAI in hospitals and other acute care settings based on the best currently available evidence. Because this is not always the best possible evidence, we have included a suggested agenda for further research in each section of the guidelines. National evidence-based guidelines are broad principles of best practice which need to be integrated into local practice guidelines. To monitor implementation, we have suggested key audit criteria for each section of recommendations. Clinically effective infection prevention and control practice is an essential feature of protecting patients. By incorporating these guidelines into routine daily clinical practice, patient safety can be enhanced and the risk of patients acquiring an infection during episodes of healthcare in NHS hospitals in England can be minimised.

Interventions for drug-using offenders in the courts, secure establishments and the community

BACKGROUND

Drug strategies internationally recognize link between drug use and crime. This review consider interventions for drug-using offenders under the care of the criminal justice system.

OBJECTIVES

To assess the effectiveness of interventions for drug-using offenders in reducing criminal activity and drug use in the courts, secure establishments and community-based settings.

SEARCH STRATEGY

Twenty two electronic databases were searched (1980 to 2004). Internet sites and experts in the field were contacted for further information.

SELECTION CRITERIA

Randomised Controlled Trials designed to reduce, eliminate or prevent relapse in drug using offenders

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trials for inclusion. Data were extracted by one author and double checked.

MAIN RESULTS

Twenty four studies, 8936 participants, met the inclusion criteria. Results show that comparing a court-based community pre-trial release with drugs testing and sanctions versus routine pre-trial, for arrest at 90 days results favoured the comparison group OR 1.33 (95% CI 1.04 to 1.70). Comparing therapeutic community with aftercare with a mental health programme with a waiting list control, considering incarceration at 12 months OR 0.37 (95% CI 0.16 to 0.87), results in favour of the treatment Comparing intensive supervision with routine parole/probation, for recidivism OR 1.98 (95% CI 1.01 to 3.87) results in favour of comparison group, no statistically significant difference between the groups for arrest OR 1.49 (95% CI 0.88 to 2.51), drug arrest OR 1.10 (95% CI 0.50 to 2.39), conviction OR 0.93 (95% CI 0.55 to 1.58 ) and incarceration at one year OR 0.88 (95% CI 0.50, 1.54). Comparing intensive supervision and increased surveillance with intensive supervision alone, no statistically significant difference between the groups for recidivism OR 2.09 (95% CI, 0.86 to 5.07), arrest OR 1.22 (95% CI 0.51 to 2.88]), drug arrest, OR 1.29 (95% CI 0.35 to 4.85), conviction OR0.1.14 (95% CI, 0.22, to 5.91) and incarceration OR 1.30 (95% CI 0.39, to 4.30]) at one year.

AUTHORS' CONCLUSIONS

Limited conclusions can be drawn about the effectiveness of drug treatment programmes for drug-using offenders in the courts or the community. This is partly due to the broad range of studies and the heterogenity of the different outcome measures presented. Therapeutic communities with aftercare show promising results for the reduction of drug use and criminal activity in drug using offenders. Standardisation of outcome measures and costing methodology would help improve the quality of research conducted in the area.

The epic project: developing national evidence-based guidelines for preventing healthcare associated infections. Phase I: Guidelines for preventing hospital-acquired infections. Department of Health (England)

In 1998, the Department of Health (England) commissioned the first phase of national evidence-based guidelines for preventing healthcare associated infections. These focused on developing a set of standard principles for preventing infections in hospitals together with guidelines for preventing hospital-acquired infections (HAI) associated with the use of short-term indwelling ureteral catheters in acute care and with central venous catheters in acute care. These guidelines are systematically developed broad statements (principles) of good practice that all practitioners can use and which can be incorporated into local protocols. A nurse-led, multi-professional team composed of infection prevention practitioners, clinical microbiologists/retrovirologist, epidemiologists, and researchers developed the guidelines. A rigorous guideline development process was used to inform the systematic reviews, the clinical and critical appraisal of relevant evidence, and linking that evidence to evolving guidelines. Both general and specialist clinical practitioners were involved in all stages of developing these guidelines, as were representatives from relevant Royal Colleges, learned societies, other professional organisations and key stakeholders. The introduction to these guidelines describes a robust and validated guideline development model that can be used by others to develop future guidelines. This model is described in more detail in the associated technical reports that can be found on the project web site http://www.epic.tvu.ac.uk. Locating and appropriately using good quality evidence to inform guideline development in this field is challenging. Evidence from rigorously conducted experimental studies was frequently limited and consequently a range of other types of evidence were systematically retrieved and carefully appraised. The concluding discussion on implementation highlights potential issues for clinical governance and areas for future research and suggests issues that need to be addressed to allow practitioners to successfully incorporate these guidelines into routine clinical practice.

Association of CCR5 delta32 with reduced risk of asthma

We report that individuals carrying the CCR5 delta32 mutation, a naturally occurring variant of the C-C chemokine receptor 5 (CCR5), are at reduced risk of developing asthma. These data suggest a possible explanation for the high prevalence of this mutation in the general population.

A comparative study of one-year weight gain among users of medroxyprogesterone acetate, levonorgestrel implants, and oral contraceptives

With the recent introduction and growing popularity of Depo-Provera Contraceptive Injection, concern about the potential for weight gain during treatment has been raised. The purpose of the present study was to determine whether or not Depo-Provera Contraceptive Injection is associated with greater weight gain, and incidence thereof, than Norplant implants or oral contraceptives. A retrospective chart review of patients seen at a state- and federally-funded clinic was conducted. Fifty women in each treatment group who met the study criteria were identified and included in the study evaluation. Mean one-year weight gain for subjects in each group was as follows: -2.0 pounds in the oral contraceptive group, -1.8 pounds in the Norplant implants group, and +0.1 pounds in the Depo-Provera Contraceptive Injection group. While results among treatment groups differed slightly, no significant weight change occurred in any of the treatment groups.

Causes and clinical management of vertebral osteomyelitis in Saskatchewan

A retrospective review of all patients with vertebral osteomyelitis admitted to all Saskatchewan referral hospitals from 1973 to 1986 was undertaken to determine the incidence and clinical characteristics of the disease. There were 73 patients, an incidence of 5.3 cases/million per year. Erroneous initial diagnoses were common (41%). There was a significantly increased risk in patients older than 60 years. Staphylococcus aureus was the most frequent organism. Mycobacterium tuberculosis was present in 29.5% and was more common in native Indian patients. Surgery was performed in 31% of all patients, and in 50% of those with tuberculous infections. The outcome was excellent in 92% of patients. Diabetes and transurethral resection of the prostate were risk factors for vertebral osteomyelitis.

Conjunctivitis in clean room workers. Nursing evaluation and intervention

Conjunctivitis, in the industrial setting, can be attributed to eye contact with contaminated microscope oculars. Establishing a simple, convenient process for cleaning microscope oculars as well as educating employees and their management is important to reduce risk of contamination. Early identification and treatment of an isolated infection by the occupational health nurse and temporary exclusion from microscope work is essential in controlling the spread of infection and preventing a potential epidemic. The occupational health nurse plays a pivotal role in the recognition of and response to workplace health concerns and development of targeted strategies to promote and maintain health in the workplace.

Characterization of surface polypeptides on different life-cycle stages of Theileria annulata

We describe the characterisation of polypeptides located on the surface of Theileria annulata sporozoites, macroschizonts, piroplasms and infected lymphoblastoid cells using surface iodination techniques. The sporozoite stage exhibited a complex profile of surface polypeptides. However, using data from experiments with defined monoclonal antibodies, the sporozoite surface appeared to be composed of several distinct groups of related polypeptides. Analysis of the macroschizont detected seven surface polypeptides, while eight polypeptides were identified for the piroplasm stage. On the basis of molecular weight comparisons, one of the surface polypeptides appeared to be common to the sporozoite, macroschizont and piroplasm. Stage cross-reactive monoclonals failed to immunoprecipitate a surface-radiolabelled polypeptide, and this prohibited the characterisation of a stage common surface antigen. From the surface labelling studies of Theileria-infected and uninfected lymphoblastoid cell lines, we concluded that infection results in major changes at the surface of the host cell, including both the appearance and loss of specific polypeptides. By employing monoclonal antibodies which detect infection-associated determinants, and a polyclonal antiserum raised against a glycoprotein fraction of an infected cell lysate, surface-labelled polypeptides were specifically immunoprecipitated from extracts of infected cells. The polypeptide detected by monoclonal antibody 4H5 was characterised as an infection-associated glycoprotein which varies in molecular mass when immunoprecipitated from different infected cell lines. The identification of infection-associated glycoproteins on the surface of the lymphoblastoid cell suggests that these molecules may be recognised by the cytotoxic T cells of immune animals.

Specific lysis of Theileria annulata-infected lymphoblastoid cells by a monoclonal antibody recognizing an infection-associated antigen

A monoclonal antibody (4H5) recognizing a Theileria annulata infection-associated antigen was assayed to see if it could either suppress the proliferation of T. annulata-infected lymphoblastoid cells, as monitored by the incorporation of tritiated thymidine by proliferating host cells, or lyse T. annulata-infected lymphoblastoid cells, as assessed by counts of target cell numbers and examination of Giemsa stained smears. These assays showed that binding of the monoclonal antibody, in the presence of complement, both lysed and suppressed the proliferation of the T. annulata Hissar-infected cell line against which this monoclonal antibody was raised. This effect extended both to other (allogeneic) T. annulata Hissar-infected cell lines and to lymphoblastoid cell lines infected with other geographical stocks of T. annulata. An uninfected bovine lymphoid cell line was not affected by the antibody. The results obtained in these in vitro experiments are taken to mean that binding of the monoclonal antibody 4H5 to a T. annulata infection-associated antigen, in the presence of complement, will lyse and suppress specifically the proliferation of T. annulata-infected lymphoblastoid cells. These observations raise the possibility that immunization of cattle with the purified T. annulata infection-associated antigen recognized by this monoclonal antibody may provoke immune responses which are capable of suppressing the proliferation of T. annulata-infected lymphoblastoid cells in vivo and thus provide an effective method of immunoprophylaxis against tropical theileriosis.

Antigenic diversity of Theileria annulata macroschizonts

A series of monoclonal antibodies has been produced which reacts with the intracellular macroschizont of Theileria annulata, and this series has been used to examine the level of antigenic diversity between and within stocks of the parasite in addition to species specificity within the genus. The majority of the monoclonal antibodies (six of eight) reacted with all stocks tested and four were species-specific. Two monoclonal antibodies detected variation between stocks and within stocks. The variation within a stock was manifest as only a proportion of the macroschizonts reacting with the monoclonal antibody. This was demonstrated as being due to the strain containing more than one antigenic type of parasite by cloning the infected lymphocyte cell line and showing that the resulting cloned cell lines were antigenically homogeneous. The variation between stocks allowed them to be divided into three groups on the basis of antigenic profile.

Ultrastructural and biochemical changes in human jejunal mucosa associated with enteropathogenic Escherichia coli (0111) infection

A case of prolonged diarrhoea following Escherichia coli 0111 gastroenteritis is reported. Electron microscopy of the jejunal biopsy revealed effacement of the brush border and attachment of bacteria by pedestal formation. Specific activities of brush border enzymes showed marked depression of disaccharidases, zinc-resistant alpha-glucosidase, and alkaline phosphatase. In contrast, marker enzymes for basolateral membranes and endoplasmic reticulum were unaffected. The biochemical changes support the pathogenic mechanism suggested by ultrastructural studies previously reported.

Identification of infection-associated antigens in Theileria annulata transformed cells

The protozoan parasite Theileria annulata causes a severe disease of cattle in tropical countries; one stage in the parasite life cycle involves the transformation of bovine lymphocytes leading to rapid lymphoproliferation. Immunity to this disease is largely cell mediated and directed against the infected lymphocyte. In this paper we report the identification of three classes of infection specific antigen (using monoclonal antibodies) one of which is found on the surface of the lymphocyte. Such antigens can be used in parasite strain typing, in providing an understanding of the molecules involved in immunity and in providing the basis for a vaccine.

Influence of antigenic competition on the development of antibody-forming cell clones

Isoelectric focusing in polyacrylamide gels was used to investigate the anti-sheep red blood cell antibody responses of mice subjected to antigenic competition. A reduction in the number and intensity of antibody bands was found, even in situations where the suppression of IgG antibody titres was minimal, while with large reductions in titre, antibody bands were rarely seen. It thus appeared that the output of individual B-cell clones was severely depressed during competition. It was concluded that inhibition of clonal expansion is an important feature of competition, and that this may reflect a normal regulatory activity which acts to limit cellular proliferation during immune responses. This conclusion was supported by observations on the level of DNA synthesis, following immunization with sheep red cells, in the spleens of normal and suppressed mice.

Clinical recognition of leprosy: some factors leading to delays in diagnosis

The case histories of eight patients in the United Kingdom admitted to hospital for the diagnosis of leprosy are examined in detail. Review of their early symptoms and signs showed that there had been delays in diagnosis, ranging from a few months to many years. Possible reasons for delay are discussed, and attention is called to the importance of nasal symptoms in the early diagnosis of lepromatous leprosy.