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R L Salmon

Publications and source records attributed to R L Salmon.

At least 19 recordsLinked to original sources
PubMed2006

Risk factors for hospital-acquired methicillin-resistant Staphylococcus aureus bacteraemia: a case-control study.

A case-control study was undertaken in an acute district general hospital to identify risk factors for hospital-acquired bacteraemia caused by methicillin-resistant Staphylococcus aureus (MRSA). Cases of hospital-acquired MRSA bacteraemia were defined as consecutive patients from whom MRSA was isolated from a blood sample taken on the third or subsequent day after admission. Controls were randomly selected from patients admitted to the hospital over the same time period with a length of stay of more than 2 days who did not have bacteraemia. Data on 42 of the 46 cases of hospital-acquired bacteraemia and 90 of the 92 controls were available for analysis. There were no significant differences in the age or sex of cases and controls. After adjusting for confounding factors, insertion of a central line [adjusted odds ratio (aOR) 35.3, 95% confidence interval (CI) 3.8-325.5] or urinary catheter (aOR 37.1, 95% CI 7.1-193.2) during the admission, and surgical site infection (aOR 4.3, 95% CI 1.2-14.6) all remained independent risk factors for MRSA bacteraemia. The adjusted population attributable fraction, showed that 51% of hospital-acquired MRSA bacteraemia cases were attributable to a urinary catheter, 39% to a central line, and 16% to a surgical site infection. In the United Kingdom, measures to reduce the incidence of hospital-acquired MRSA bacteraemia in acute general hospitals should focus on improving infection control procedures for the insertion and, most importantly, care of central lines and urinary catheters.

Bacteremia↗
PubMed2005

Borna disease virus and the evidence for human pathogenicity: a systematic review.

BACKGROUND: Borna disease is a neurological viral disease of veterinary importance in central Europe, although Borna Disease virus (BDV) has been reported to be present in animals in most continents. The hypothesis that BDV is associated with human illness is controversial. However, should even a small fraction of mental illness be attributable to infection with BDV, this would be an important finding, not least because illness in that sub-population would, theoretically, be preventable. METHODS: We systematically reviewed the evidence: that BDV infects humans; for the role of BDV in human neuropsychiatric illness; to assess the suitability of currently available laboratory methods for human epidemiological studies. RESULTS: We identified 75 documents published before the end of January 2000, describing 50 human studies for BDV. There were five case studies and 44 (sero)prevalence studies, in a variety of patient groups. Nineteen prevalence studies (43%) investigated seroprevalence, 11 (25%) investigated viral prevalence and 14 (32%) investigated both. Seroprevalence ranged from 0% to 48%, and prevalence of virus or viral footprints from 0% to 82%. DISCUSSION: Although agreed gold standard tests and evidence for test specificity are lacking, there is evidence that humans are exposed to the virus. Further epidemiological studies are required to establish whether there are associations with disease.

Antibodies, Viral↗
PubMed2005

Borna disease virus and mental health: a cross-sectional study.

BACKGROUND: Borna disease is an infectious neurological disease of horses, sheep and possibly other animals. A role for Borna disease virus (BDV) in human neurological and psychiatric illness has been proposed, but this hypothesis remains controversial. AIM: To investigate the epidemiology of BDV in UK farming communities. DESIGN: Retrospective cohort study. METHODS: We measured the seroprevalence of BDV in the PHLS Farm Cohort, a representative sample of those employed in agriculture in the UK, and investigated the clinical significance of our findings by comparing the prevalence of symptoms of neurotic psychopathology in those found seropositive and seronegative. RESULTS: Seroprevalence was 2.3% (95%CI 1.3- 4.0%) in 1994, 3.1% in 1996 (95%CI 1.9-5.0%) and 2.6% in 1999 (95%CI 1.5%-4.6%). Those living or working on livestock farms had higher seroprevalence (2.6%) than those on mixed (2.3%) or arable (1.6%) farms, but this was not statistically significant. Exposure to horses, sheep and cats did not increase risk of seropositivity. Seropositives were no more likely to report symptoms of psychiatric morbidity. DISCUSSION: UK farming populations appear to be exposed to Borna disease virus. However, we found no evidence that exposure to BDV was associated with morbidity in this healthy occupational cohort.

Adult↗
PubMed2004

Declining incidence of chickenpox in the absence of universal childhood immunisation.

OBJECTIVE: To examine the epidemiology of chickenpox in Wales from 1986 to 2001. DESIGN: Descriptive analysis of chickenpox consultations reported by the Welsh general practice sentinel surveillance scheme for infectious diseases, compared with annual shingles consultation rates from the same scheme to exclude reporting fatigue and data from a general practice morbidity database to validate results. SETTING: A total of 226,884 patients registered with one of 30 volunteer general practices participating in the sentinel surveillance scheme. MAIN OUTCOME MEASURES: Age standardised and age specific incidence of chickenpox. RESULTS: Crude and age standardised consultation rates for chickenpox declined from 1986 to 2001, with loss of epidemic cycling. Rates remained stable in 0-4 year olds but declined in all older age groups, particularly those aged 5-14 years. Shingles consultation rates remained constant over the same period. Data from the morbidity database displayed similar trends. CONCLUSION: General practitioner consultation rates for chickenpox are declining in Wales except in pre-school children. These findings are unlikely to be a reporting artefact but may be explained either by an overall decline in transmission or increased social mixing in those under 5 years old, through formal child care and earlier school entry, and associated increasing rates of mild or subclinical infection in this age group. Further investigation, particularly by serological surveillance, is necessary before universal varicella immunisation can be considered in the UK.

Adolescent↗
PubMed2003

Mental health of British farmers.

AIMS: To estimate the prevalence of neurotic symptoms in a sample of British farmers, to investigate whether farming characteristics are associated with psychiatric morbidity, and to test the hypothesis that British farmers have a higher prevalence of depression and thoughts of life not worth living than the British household population. METHODS: A total of 425 farmers from Hereford, Norwich, and Preston completed the Revised Clinical Interview Schedule (CIS-R) by computer between March and July 1999. The comparison cohort consisted of 9830 private householders aged 16-64 from the Office of Population Censuses and Surveys National Psychiatric Morbidity Surveys of Great Britain carried out in 1993 in which the CIS-R was administered. All analyses used the commands developed specifically for survey data available in Stata version 6.0. RESULTS: Taking a threshold of an overall score of 12 or more on the CIS-R, only 6% of farmers reported clinically relevant psychiatric morbidity. Psychiatric morbidity was not significantly associated with farm type or size in this study. Farmers reported a lower prevalence of psychiatric morbidity than the general population but were more likely to report thinking that life is not worth living, particularly after the low prevalence of psychiatric morbidity had been taken into account (odds ratio 2.56, 95% CI 1.39 to 4.69). When restricting the comparison to only rural or semirural householders, this increased risk was even more pronounced (odds ratio 3.26, 95% CI 1.51 to 7.02). CONCLUSIONS: The relation between depression and suicidal ideation seems to be quite different among farmers and the general population and warrants further investigation. We have shown it is possible to measure mental health systematically in a sample of British farmers. This study should be repeated in the aftermath of the foot and mouth crisis.

Adolescent↗
PubMed2002

Possible underascertainment of variant Creutzfeldt-Jakob disease: a systematic study.

OBJECTIVES: To predict the size of the vCJD epidemic it is important to know whether the description of cases of vCJD in 1996 represent the first cases of a new disease entity or whether detection was due to increased surveillance of CJD in humans. Detection of earlier cases would suggest a shorter incubation period and might lead to predictions of epidemic size being revised. METHODS: All certified deaths (excluding external injury and poisoning) in residents of Wales aged 15-45, between 1985 and 1995, were reviewed to detect vCJD deaths that might have been overlooked. 12 091 deaths were reviewed. "Non-specific fatal disorders compatible with vCJD" were defined. Deaths recorded to diseases other than those defined were rejected from further analysis (8769). Remaining cases (3322) were subdivided. Group A comprised deaths recorded to suicide, transport accidents, and those that could not be ascertained (ICD9 rubrics E950-959, E800-848, and 7999), a total of 2698 cases. Group B comprised deaths due to neurological disease, psychiatric disease, or substance abuse (624). RESULTS: For group A, remaining brain material was identified (n=218, 8.1%) and examined by routine histology and immunocytochemistry for prion protein. No cases of vCJD were detected. For group B, review of remaining clinical information was undertaken. Of 624 cases, information was available on 447 (72%). Brain tissue was examined by routine histology and immunocytochemistry in 47 (7.5%) cases. Sufficient clinical and pathological information was available to exclude all these as potential cases of vCJD. CONCLUSION: Variant CJD is a new disease entity and not simply the result of better case ascertainment.

Adolescent↗
PubMed2001

Public health management of an outbreak of group C meningococcal disease in university campus residents.

BACKGROUND: Increasing numbers of outbreaks of Group C meningococcal disease in teenagers and young adults led to a new policy in the UK in 1999 of vaccinating all new college students. The largest of these outbreaks involved seven students in one university, six of whom were from one hall of residence, and two of whom died. METHODS: Control of the outbreak involved close medical surveillance of resident students, mass chemoprophylaxis and vaccination, and wide dissemination of daily information bulletins. Investigation of the epidemiology of the outbreak involved searching for the network of close contacts between cases, a prevalence survey of carriage of meningogocci and a case control study of risk factors for carriage. RESULTS: Clinical cases could be linked by a discrete network of social contacts within the halls of residence, but the Group C epidemic strain (2a P1.5) was not detected in 454 students (upper 95% confidence interval 0.7%). Carriage of any meningococcal strain (19%) was associated with patronage of the campus bar (OR = 3.0, 0.99-9.1). CONCLUSION: Important factors in the control of the outbreak were rapid institution of mass chemopropylaxis and immunisation of residents, and involvement of student organizations in the dissemination of information about the disease and its control. The role of campus bars in dissemination of the carriage of meningogocci deserves further investigation.

Adolescent↗
PubMed2001

Outbreak of Salmonella indiana associated with egg mayonnaise sandwiches at an acute NHS hospital.

An outbreak of Salmonella indiana infection in December 2000 affected 17 staff, relatives and patients at an acute NHS Hospital in Swansea. Epidemiological investigation identified egg mayonnaise sandwiches as the vehicle of infection. It was not possible to definitively determine the source of the infection or how the prepared sandwiches became contaminated. The most likely explanation was a pasteurisation failure of a batch of the egg roll used to make these sandwiches. Sandwiches are the most frequently identified vehicle of infection in foodborne outbreaks of salmonella infection in hospitals in England and Wales. The process of sandwich preparation has inherent risks because it involves considerable handling of food, which is consumed without further cooking. Care is required in all stages of preparation including the sourcing of materials used to produce the sandwiches. NHS Trusts should review their Hazard Analysis Critical Control Point plans for sandwich production.

Case-Control Studies↗
PubMed2000

Evidence of persisting serum antibodies to Escherichia coli O157 lipopolysaccharide and Verocytotoxin in members of rural communities in England.

The techniques of enzyme-linked immunosorbent assay (ELISA) and immunoblotting were used to examine a total of 1667 sera, from apparently healthy members of rural communities in England, for antibodies to the lipopolysaccharide (LPS) of Escherichia coli O157 and Verocytotoxins (VT). Twenty-nine sera from 22 individuals were shown to have antibodies specific for E. coli O157 LPS. Some of these lived on livestock farms and had occupational contact with cattle, suggesting that personnel working with farm animals may produce serum antibodies to the O157 LPS antigens. Fifteen people had IgG class antibodies to O157 LPS, suggesting long-term exposure to E. coli O157 and five people had serum antibodies on more than one occasion showing evidence of persistent antibodies to O157 LPS. Thirteen sera from 12 of 22 individuals also contained antibodies to VT1, VT2 or both toxins. Ten sera contained antibodies to VT1 and VT2, three sera contained antibodies to VT2 only.

Adult↗
PubMed1999

Orf (contagious pustular dermatitis) in farmworkers: prevalence and risk factors in three areas of England.

Orf is a zoonotic skin disease which is commonly self-diagnosed by those who tend sheep and goats. This paper reports the prevalence, incidence and risk factors associated with the infection in a cohort of farmworkers from three areas of England, derived from the results of self-reporting and serology. Twenty-three per cent of those employed or living on a sheep farm reported ever having had orf, and the antibody serological profiles indicated a prevalence of 4 per cent and an annual incidence of 2.8 per cen. The main risk factors associated with the infection were contact with sheep, the size of the sheep flock, and contact with dogs.

Animal Husbandry↗
PubMed1999

A community outbreak of food-borne small round-structured virus gastroenteritis caused by a contaminated water supply.

In August 1994, 30 of 135 (23%) bakery plant employees and over 100 people from South Wales and Bristol in the United Kingdom, were affected by an outbreak of gastroenteritis. Epidemiological studies of employees and three community clusters found illness in employees to be associated with drinking cold water at the bakery (relative risk 3.3, 95%, CI 1.6-7.0), and in community cases with eating custard slices (relative risk 19.8, 95%, CI 2.9-135.1) from a variety of stores supplied by one particular bakery. Small round-structured viruses (SRSV) were identified in stool specimens from 4 employees and 7 community cases. Analysis of the polymerase and capsid regions of the SRSV genome by reverse transcription-polymerase chain reaction (RT-PCR) demonstrated viruses of both genogroups (1 and 2) each with several different nucleotide sequences. The heterogeneity of the viruses identified in the outbreak suggests that dried custard mix may have been inadvertently reconstituted with contaminated water. The incident shows how secondary food contamination can cause wide-scale community gastroenteritis outbreaks, and demonstrates the ability of molecular techniques to support classical epidemiological methods in outbreak investigations.

Adolescent↗
PubMed1999

An outbreak of Salmonella typhimurium DT170 associated with kebab meat and yogurt relish.

During July 1995, an outbreak of Salmonella typhimurium definitive type (DT) 170, an unusual strain, occurred in South Wales. A case-control study found that illness was associated with eating kebabs (odds ratio undefined, P = 0.002), doner kebabs (odds ratio 7.9, 95 % confidence interval 1.5-20.5, P = 0.02) and kebabs with yoghurt based relish (odds ratio undefined, P = 0.009) but not with eating kebabs with mayonnaise-based relish (odds ratio 2.4, 95 % confidence interval 0.4-13.9, P = 0.53). Environmental investigations discovered a complex web of producers and wholesale suppliers. Kebab meat and yoghurt had been supplied to the two main implicated outlets by a single wholesaler. Samples of raw minced lamb and several environmental swabs taken at the wholesaler were positive for S. typhimurium DT170. Blood-stained, unsealed yoghurt pots were observed to be stored under a rack of raw lamb. Investigators of food poisoning outbreaks linked to takeaway food should consider cross-contaminated relishes and dressings as well as undercooked meat as potential vehicles of infection.

Adolescent↗
PubMed1999

Outbreak of Escherichia coli O157 in a nursery: lessons for prevention.

OBJECTIVES: To identify risk factors for transmission of verocytotoxin producing Escherichia coli O157 (VTECO157) and means of prevention. STUDY DESIGN: Outbreak investigation: retrospective cohort study. SETTING: A nursery (child care centre) in North Wales. SUBJECTS: Children attending (n = 104). METHODS: Faeces were examined using sorbitol MacConkey agar (SMAC), with cefixime, tellurite, and rhamnose; enrichment in modified tryptone soya broth; and immunomagnetic separation. Symptoms and exposure data were obtained from questionnaires to parents/guardians and children's toiletting and feeding records kept at the nursery. MAIN OUTCOME MEASURE: A "case" was defined as a child with verocytotoxin producing E coli O157 isolated from faeces, or a history of haemolytic uraemic syndrome (HUS) and antibodies to E coli O157 lipopolysaccharide, during the period 10 August to 30 September 1995. RESULTS: The attack rate was 31 in 104. Two children developed HUS. There were higher attack rates among girls and friends who played together. Cases were more likely to attend the nursery more frequently. The mean number of recorded bowel motions/child/half day was 0.51 in cases and 0.21 in well children. Child to staff ratios were high preceding and during the outbreak. CONCLUSIONS: A sick child is the most plausible source of infection with subsequent person to person transmission. The record of children's toiletting discriminated between cases and well children and might have allowed earlier detection of the outbreak. This simple record could be considered by other child care facilities as a means of giving early warning of problems with infectious intestinal diseases.

Child↗
PubMed1999

Investigation of an outbreak of gastroenteritis at a hospital for patients with learning difficulties.

Eighty of the 460 patients and staff (attack rate 22%) in a long-stay hospital for patients with learning difficulties became ill in a general outbreak of gastrointestinal infection that followed a buffet style party on one ward. Illness in the cohort of 47 resident patients, relations, and staff who attended that party was associated with having eaten ham, coleslaw, bread rolls, and cheese and pineapple on sticks. Food from the hospital kitchen was supplemented by food brought in and prepared on the ward by staff and patients. The investigation suggested that food items were contaminated either during preparation by staff and patients or during the party when people served themselves. Microbiological and virological investigations were negative, but small round structured virus was thought to be responsible. Hospitals could do more to prevent outbreaks of foodborne infection by undertaking risk assessment as required by the Food Safety Act (General Food Hygiene) Regulations 1995. Purchasers of hospital infection control should ensure compliance with this legislation.

Cohort Studies↗