Biomedical subjects
G Duckworth
Publications and source records attributed to G Duckworth.
National glycopeptide-resistant enterococcal bacteraemia surveillance Working Group report to the Department of Health - August 2004.
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Isolation measures in the hospital management of methicillin resistant Staphylococcus aureus (MRSA): systematic review of the literature.
OBJECTIVE: To evaluate the evidence for the effectiveness of isolation measures in reducing the incidence of methicillin resistant Staphylococcus aureus (MRSA) colonisation and infection in hospital inpatients. DESIGN: Systematic review of published articles. DATA SOURCES: Medline, Embase, CINAHL, Cochrane Library, System for Information on Grey Literature in Europe (SIGLE), and citation lists (1966-2000). REVIEW METHODS: Articles reporting MRSA related outcomes and describing an isolation policy were selected. No quality restrictions were imposed on studies using isolation wards or nurse cohorting. Other studies were included if they were prospective or employed planned comparisons of retrospective data. RESULTS: 46 studies were accepted; 18 used isolation wards, nine used nurse cohorting, and 19 used other isolation policies. Most were interrupted time series, with few planned formal prospective studies. All but one reported multiple interventions. Consideration of potential confounders, measures to prevent bias, and appropriate statistical analysis were mostly lacking. No conclusions could be drawn in a third of studies. Most others provided evidence consistent with a reduction of MRSA acquisition. Six long interrupted time series provided the strongest evidence. Four of these provided evidence that intensive control measures including patient isolation were effective in controlling MRSA. In two others, isolation wards failed to prevent endemic MRSA. CONCLUSION: Major methodological weaknesses and inadequate reporting in published research mean that many plausible alternative explanations for reductions in MRSA acquisition associated with interventions cannot be excluded. No well designed studies exist that allow the role of isolation measures alone to be assessed. None the less, there is evidence that concerted efforts that include isolation can reduce MRSA even in endemic settings. Current isolation measures recommended in national guidelines should continue to be applied until further research establishes otherwise.
Methicillin-resistant Staphylococcus aureus in hospitals and the community: stealth dynamics and control catastrophes.
Methicillin-resistant Staphylococcus aureus (MRSA) represents a serious threat to the health of hospitalized patients. Attempts to reduce the spread of MRSA have largely depended on hospital hygiene and patient isolation. These measures have met with mixed success: although some countries have almost eliminated MRSA or remained largely free of the organism, others have seen substantial increases despite rigorous control policies. We use a mathematical model to show how these increases can be explained by considering both hospital and community reservoirs of MRSA colonization. We show how the timing of the intervention, the level of resource provision, and chance combine to determine whether control measures succeed or fail. We find that even control measures able to repeatedly prevent sustained outbreaks in the short-term can result in long-term control failure resulting from gradual increases in the community reservoir. If resources do not scale with MRSA prevalence, isolation policies can fail "catastrophically."
Emergence of methicillin resistant Staphylococcus aureus (MRSA) bacteraemia among children in England and Wales, 1990-2001.
Methicillin resistant Staphylococcus aureus (MRSA) is now a major cause of adult bacteraemia. All reports of Staphylococcus aureus bacteraemia to the Health Protection Agency were analysed from 1990 to 2001. There were 376 cases of MRSA bacteraemia in children <15 years over this time. The proportion of Staphylococcus aureus bacteraemia due to MRSA increased steadily from 0.9% in 1990 to 13% in 2000. The proportion was higher in infants. MRSA bacteraemia is now a serious problem in children in England and Wales. More data on the risk factors for acquisition and spread of MRSA in children are required.
Outbreak of isoniazid resistant tuberculosis in north London.
BACKGROUND: A description is given of a major outbreak of isoniazid monoresistant tuberculosis (TB) chiefly in north London, including prisons. The earliest case was diagnosed in 1995 with most cases appearing after 1999. METHODS: Confirmation of a local cluster of cases was confirmed by restriction fragment length polymorphism (RFLP IS6110) typing or "rapid epidemiological typing" (RAPET). Further cases were found by retrospective analysis of existing databases, prospective screening of new isolates, and targeted epidemiological case detection including questionnaire analysis. RESULTS: By the end of 2001, 70 confirmed cases in London had been linked with a further 13 clinical cases in contacts and nine epidemiologically linked cases outside London. The epidemic curve suggests that the peak of the outbreak has not yet been reached. Cases in the outbreak largely belong to a social group of young adults of mixed ethnic backgrounds including several individuals from professional/business backgrounds. Compared with other cases of TB reported to the enhanced surveillance scheme in London during 1999-2001, the cases are more likely to be of white (26/70 (37%) v 1308/7666 (17%)) or black Caribbean ethnicity (17/70 (24%) v 312/7666 (4%)), born in the UK (41/70 (59%) v 1335/7666 (17%)), and male (52/70 (74%) v 4195/7666 (55%)). Drug misuse and/or prison detention are factors common to many cases. CONCLUSIONS: The investigation of the outbreak revealed significant problems on an individual patient and population based level including difficulties with contact tracing, compliance, and the risk of developing multidrug resistance. This incident has demonstrated the value of molecular strain typing in investigating an extensive outbreak of TB. This is the first documented outbreak involving a UK prison.
Administration of the BCG vaccination using the multipuncture method in schoolchildren: a comparison with the intradermal method.
BACKGROUND: BCG vaccination using the multipuncture device (the Heaf gun) is recommended in the UK for infants and very small children only. The aim of this study was to investigate the rate of conversion of the tuberculin test, the safety and acceptability of BCG vaccination using the multipuncture device and to compare it with the conventional intradermal method in schoolchildren. METHODS: Schoolchildren attending schools in Tower Hamlets who were eligible for BCG vaccination were tuberculin tested using the Heaf gun. Those with grade 0-1 reaction were randomised to receive BCG vaccination using either the multipuncture or the intradermal method. The site of BCG vaccination was inspected after eight weeks for inflammatory changes and scarring. A questionnaire about pain and inflammation at the site of vaccination was completed. The Heaf test was repeated at eight weeks and its results were assessed by an examiner unaware of the results of the previous Heaf test and the method of BCG administration. The Heaf test conversion was deemed to have occurred if there was a change of at least one grade in the response. RESULTS: One hundred and sixty nine children (83 girls) of mean age 11.8 years completed the study, of which 81 received BCG by the multipuncture method. The Heaf test did not convert in 22 of 81 (27. 2%) receiving BCG by the multipuncture device compared with six of 88 (6.8%) who received the vaccine by the intradermal method (odds ratio 0.2, 95% confidence interval 0.07 to 0.55). The BCG scar was visible in all children who had intradermal BCG compared with 67 of 81 (81.8%) of the multipuncture group. The multipuncture method was less painful and caused fewer inflammatory changes than the intradermal method. CONCLUSIONS: In schoolchildren the multi-puncture device for administering BCG caused a lower rate of tuberculin conversion as measured by the Heaf test and less of an inflammatory response than the intradermal method. The method needs to be modified before it is applied on a wider scale to schoolchildren.
Are HIV lookbacks worthwhile? Outcome of an exercise to notify patients treated by an HIV infected health care worker. Incident Management Teams.
This report describes the management and outcome of one of the largest exercises undertaken in the United Kingdom to notify patients exposed to an HIV infected health care worker. Eighty-six per cent (1597/1852) of patients on whom the infected junior doctor in obstetrics and gynaecology had performed surgical procedures were contacted and 1180 women (64% of those exposed) elected to be tested. None was found to be positive. Of those tested, 651 had undergone procedures classified as 'higher risk' and 529 'low risk' procedures. These data provide further evidence that the overall risk of transmission from an infected health care worker to patients is likely to be very low. HIV lookbacks may be worthwhile but we consider that it would be justifiable to notify and offer HIV testing only to patients who have undergone higher risk procedures. The estimated cost to the NHS of this exercise exceeded 200,000 Pounds.
Escherichia coli O157 incident associated with a farm open to members of the public.
Three children, one who lived on an open farm and two who visited the farm in school parties, developed Vero cytotoxin producing Escherichia coli (VTEC) O157 infection in 1997. All had been in direct contact with animals. All were admitted to hospital with diarrhoea and two developed the haemolytic uraemic syndrome, one of whom developed severe neurological impairment. E.coli O157 phage type 21 that produced Vero cytotoxin 2 were isolated from the three children and from a goat paddock and two cows at the farm. The isolates were indistinguishable by molecular typing. The farm closed voluntarily for six weeks while recommendations to reduce the exposure of visitors to faecal contamination and to improve hygiene procedures (especially handwashing) were implemented. More research is needed into all aspects of VTEC O157 on farms, including the natural history of carriage in animals, the organism prevalence and factors that affect infectivity to humans. Further consideration is needed about the role of open farms in zoonoses, and how open farms can be assisted in reducing risks for visitors. The public need to be educated about the risks and about their responsibilities, which include the need to wash hands thoroughly and to avoid hand to mouth contact when visiting farms.
Methicillin-resistant Staphylococcus aureus (MRSA)--a re-appraisal of control measures in the light of changing circumstances.
Methicillin-resistant Staphylococcus aureus (MRSA) remains an important nosocomial pathogen and the number of affected patients is rising. Increasing numbers of patients at risk of acquisition, inadequate isolation facilities, problems in identifying the source of outbreaks and the perception amongst some clinical colleagues that control measures are too disruptive have contributed to the problems faced by infection control teams. Recent controlled studies indicate that MRSA is no less virulent than sensitive strains and emphasize the continuing need for control measures even where MRSA is endemic. Efforts to control spread should be targeted to key clinical areas, such as intensive care units, where the impact of infection is likely to be greatest, whilst general infection control measures should be strengthened throughout the hospital.
Outbreak of acute hepatitis A among homosexual men in East London.
We report an outbreak of hepatitis A among homosexual men. There was no indication of a common source outbreak or any connection with foreign travel. It is likely that infection was sexually acquired.
Quarterly Communicable Disease Review January to March 1997. From the PHLS Communicable Disease Surveillance Unit.
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Preparation of oligoribonucleotides containing 4-thiouridine using Fpmp chemistry. Photo-crosslinking to RNA binding proteins using 350 nm irradiation.
The preparation of a 4-thiouridine phosphoramidite suitable for RNA synthesis and its subsequent incorporation into oligoribonucleotides is described. The thiol group is protected with a 2-cyanoethyl group and the 2'-OH with a 1-(2-fluorophenyl)-4-methoxypiperidin-4-yl function. Thiouridine-containing oligoribonucleotides were used as 350 nm UV crosslinking probes for the photoaffinity labelling of RNA binding proteins. Specific crosslinking was demonstrated between the Rev protein of HIV-1 (as a glutathione S-transferase fusion protein) and its RNA target, the Rev-responsive element. It was not possible to generate crosslinks between the RNA bacteriophage MS2 coat protein and the initiator stem-loop of the replicase gene, to which it binds. These results are consistent with the structural data available on both systems.
Suicide in old age: a tragedy of neglect.
OBJECTIVE: To investigate the incidence and treatment of depression in geriatric suicide. METHOD: All coroners' records, autopsy and police reports for suicide victims aged 65+ in Ontario (n = 543) over 3 years were examined. RESULTS: Over 80% of the elderly who committed suicide received no psychiatric referral. Of the sample, 87% were untreated while only 13% received antidepressants. Tricyclics, which are lethal in overdose, were the drugs of choice. None of the sample was treated with the safer specific serotonin reuptake inhibitors (SSRIs). Females were 3 times as likely to be treated as were males, and those seeing psychiatrists were 4 times more likely to be treated with antidepressants than those seeing general practitioners (GPs). The physically ill were rarely treated. CONCLUSIONS: These findings suggest that early geropsychiatric assessment and vigorous treatment could prevent many suicides in old age.
Improving notification rates for tuberculosis.
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Cryptococcal spondylitis: solitary infective bone lesions are not always tuberculous.
Tuberculous spondylitis is a well-recognized cause of back pain and vertebral collapse due to infection and with must not be overlooked even if it is not the most likely diagnosis. If a patient, particularly one of Asian origin, were to present with a solitary destructive bone lesion, without evidence of myeloma or other malignancy, a trial of anti-tuberculous chemotherapy would be one therapeutic approach, even if there was no evidence of tuberculosis elsewhere. However, failure to biopsy the bone lesion and undertake the appropriate microbiology could lead to other important diagnoses being missed. This is illustrated by the case which we report below.
Non-tuberculous mycobacteria in gastrointestinal biopsy specimens.
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Silicone oil as a reservoir for nosocomial infection.
Two episodes of infection with epidemic methicillin-resistant Staphylococcus aureus (EMRSA) associated with silicone oil baths are described. In vitro studies indicated that certain organisms, including EMRSA, can survive in silicone oil for several days. We conclude that the oil acted as a reservoir for continuing infection in our patients. We suggest routine care of silicone oil baths in order to prevent cross infection.