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Biomedical subjects

M R Evans

Publications and source records attributed to M R Evans.

At least 37 records · Page 2Linked to original sources

Presumed Pseudomonas folliculitis outbreak in children following an outdoor games event.

In early summer 2001, an outbreak of atypical rash occurred among children from 24 junior schools who attended an outdoor games event. The event comprised a series of five water games including a water slide, and within 24 hours of attending the event 151/593 (26%) children developed a papulopustular rash. The rash had a characteristic distribution, predominantly over the lower trunk and buttocks, with some involvement of the arms and legs. Pseudomonas aeruginosa was isolated from a water butt used to draw water for the games, and from the tank of a fire engine that supplied the water. Similar outbreaks, due to Pseudomonas folliculitis, have been previously described and in immunocompromised people this can be associated with serious illness. We recommend that superchlorinated water be used for water play events and that care be taken to avoid abrasive surfaces.

Child↗

Lee-Yang zeros and phase transitions in nonequilibrium steady states.

We consider how the Lee-Yang description of phase transitions in terms of partition function zeros applies to nonequilibrium systems. Here, one does not have a partition function; instead we consider the zeros of a steady-state normalization factor in the complex plane of the transition rates. We obtain the exact distribution of zeros in the thermodynamic limit for a specific model, the boundary-driven asymmetric simple exclusion process. We show that the distributions of zeros at the first- and the second-order nonequilibrium phase transitions of this model follow the patterns known in the Lee-Yang equilibrium theory.

Journal Article↗

An outbreak of viral gastroenteritis following environmental contamination at a concert hall.

In January 1999, an outbreak of viral gastroenteritis affected more than 300 people who attended a metropolitan concert hall over a 5-day period. Norwalk-like virus (NLV) was confirmed in faecal samples by reverse transcription polymerase chain reaction assay. The index case was a concert attendee who vomited in the auditorium and adjacent male toilet. Gastrointestinal illness occurred among members of 8/15 school parties who attended the following day. Children who sat on the same level of the auditorium as the index case were much more likely to be ill than those seated elsewhere (relative risk 7.1, 95% confidence interval 5.4-9.2. P < 0.001). The majority of other reported cases had not been present on the evening of the vomiting incident. Disinfection procedure was poor and the disinfectant used contained no sodium hypochlorite. Transmission most likely occurred through direct contact with contaminated fomites. The outbreak has implications for disinfection procedures following vomiting incidents at public venues.

Adult↗

Slow crossover to Kardar-Parisi-Zhang scaling.

The Kardar-Parisi-Zhang (KPZ) equation is accepted as a generic description of interfacial growth. In several recent studies, however, values of the roughness exponent alpha have been reported that are significantly less than that associated with the KPZ equation. A feature common to these studies is the presence of holes (bubbles and overhangs) in the bulk and an interface that is smeared out. We study a model of this type in which the density of the bulk and sharpness of the interface can be adjusted by a single parameter. Through theoretical considerations and the study of a simplified model we determine that the presence of holes does not affect the asymptotic KPZ scaling. Moreover, based on our numerics, we propose a simple form for the crossover to the KPZ regime.

Journal Article↗

The health of children in refuges for women victims of domestic violence: cross sectional descriptive survey.

OBJECTIVES: To describe the health and developmental status of children living in refugees for women victims of domestic violence and to investigate their access to primary healthcare services. DESIGN: Cross sectional survey. SETTING: Women's refugees in Cardiff. PARTICIPANTS: 148 resident children aged under 16 years and their mothers. MAIN OUTCOME MEASURES: Completeness of records on the child health system (register of all children that includes data on the child's health) for named health visitor, named general practitioner, and immunisation uptake; satisfactory completion of child health surveillance; Denver test results for developmental status; Rutter test scores for behavioural and emotional problems; reports of maternal concerns. RESULTS: 148/257 (58%) children living in refugee between April 1999 and January 2000 were assessed. Child health system data were incorrect (general practitioner and/or address) or unavailable for 85/148 (57%) children. Uptake of all assessments and immunisations was low. 13/68 (19%) children aged <5 years had delayed or questionable development on the Denver test, and 49/101 (49%) children aged 3-15 years had a Rutter score of >10 (indicating probable mental health problems). Concerns were expressed by mothers of 113/148 (76%) children. After leaving the refuge, 22 children were untraceable and 36 returned home to the perpetrator from whom the families had fled. CONCLUSIONS: The children had a high level of need, as well as poor access to services. Time spent in a refuge provides a window of opportunity to review health and developmental status. Specialist health visitors could facilitate and provide support, liaison, and follow up.

Adolescent↗

Testosterone influences basal metabolic rate in male house sparrows: a new cost of dominance signalling?

Sexually selected signals of individual dominance have profound effects on access to resources, mate choice and gene flow. However, why such signals should honestly reflect individual quality is poorly understood. Many such signals are known to develop under the influence of testosterone. We conducted an experiment in male house sparrows in which testosterone was manipulated independently during two periods: before the onset of the breeding season and prior to the autumn moult. We then measured the effects of these manipulations on basal metabolic rate and on the size of the chest bib, a sexually selected signal. The results demonstrate that testosterone simultaneously affects both signal development and basal metabolic rate in the house sparrow (Passer domesticus). This evidence, therefore, supports a novel conclusion: that testosterone-dependent signals act as honest indicators of male quality possibly because only high-quality individuals can sustain the energetic costs associated with signal development.

Animals↗

Risk factors for meningococcal disease in university halls of residence.

A retrospective ecological study was undertaken to identify social and environmental factors associated with increased incidence of meningococcal disease in university halls of residence. A standardized questionnaire was sent to UK universities and colleges of higher education outside London, for distribution to halls containing at least 50 students. Incidence rate ratios of invasive meningococcal disease were obtained for a range of social and environmental variables. Multi-variable Poisson regression analysis identified 3 factors as having a strong association: a high proportion of first year undergraduate residents (P = 0.0008), decreasing smokiness of the hall bar (P < 0.0001), and opening of hall bar before 1990 (P = 0.0001). The inverse relationship between disease incidence and smokiness of bars was an unexpected finding, and may be due to confounding factors. Universities should continue to promote awareness of meningococcal disease, encourage vaccination of first year students against serogroup C disease, and where appropriate, take measures to reduce overcrowding.

Adult↗

Travel illness in British package holiday tourists: prospective cohort study.

OBJECTIVES: To examine the relationship between knowledge of travel health matters, health preparation for travel and risk of travel related illness. METHODS: Travellers on holiday charter flights from Cardiff-Wales Airport provided information on holiday preparation before departure and were surveyed 2 weeks after return for details of holiday lifestyle and travel illness. RESULTS: Travellers' diarrhoea was reported by 25.7% of 1469 travellers; 24.4% had sunburn and 7.6% had respiratory infection. Attack rates for travellers' diarrhoea were highest in people aged 15-34 years (34.1%). Rates were higher the shorter the interval between holiday booking and departure (chi(2)for linear trend 13.5, 1df, P <0.001) and lower in travellers who sought advice from their general practitioner before departure (adjusted odds ratio 0.6, 95% confidence interval 0.4-0.9). The most important predictors for travellers' diarrhoea were travel with friends, country of destination, stay in room only or bed and breakfast accommodation, and type of meals most frequently eaten. CONCLUSIONS: Better holiday preparation seems to reduce risk of travel illness, even after adjusting for variables that may reflect the more cautious personality of the traveller. Encouragement to book early, take medical advice and travel well prepared could have a positive health benefit, but intervention studies are required.

Adolescent↗

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↗

In vitro activity of ciprofloxacin, sparfloxacin, ofloxacin, amikacin and rifampicin against Ghanaian isolates of Mycobacterium ulcerans.

MICs of ciprofloxacin, sparfloxacin, ofloxacin, amikacin and rifampicin were determined for 14 primary clinical isolates and three reference isolates of Mycobacterium ulcerans by modifying a standard agar dilution method for testing Mycobacterium tuberculosis sensitivity. All these antimicrobials were active against every isolate of M. ulcerans. Sparfloxacin exhibited the highest activity and ofloxacin was the least effective. Rifampicin exhibited the broadest range of activity.

Amikacin↗

Help--we need a helpline! A public health audit case study.

Multi-disciplinary public health audit involving whole departments is often perceived as difficult to carry out in areas other than the annual report of the Director of Public Health. This paper describes the audit of an emergency telephone helpline set up during a meningococcal disease outbreak and provides standards that could be applied to any emergency helpline set up in response to issues of public health concern.

Benchmarking↗

Minimization and management of wastes from biomedical research.

Several committees were established by the National Association of Physicians for the Environment to investigate and report on various topics at the National Leadership Conference on Biomedical Research and the Environment held at the 1--2 November 1999 at the National Institutes of Health in Bethesda, Maryland. This is the report of the Committee on Minimization and Management of Wastes from Biomedical Research. Biomedical research facilities contribute a small fraction of the total amount of wastes generated in the United States, and the rate of generation appears to be decreasing. Significant reductions in generation of hazardous, radioactive, and mixed wastes have recently been reported, even at facilities with rapidly expanding research programs. Changes in the focus of research, improvements in laboratory techniques, and greater emphasis on waste minimization (volume and toxicity reduction) explain the declining trend in generation. The potential for uncontrolled releases of wastes from biomedical research facilities and adverse impacts on the general environment from these wastes appears to be low. Wastes are subject to numerous regulatory requirements and are contained and managed in a manner protective of the environment. Most biohazardous agents, chemicals, and radionuclides that find significant use in research are not likely to be persistent, bioaccumulative, or toxic if they are released. Today, the primary motivations for the ongoing efforts by facilities to improve minimization and management of wastes are regulatory compliance and avoidance of the high disposal costs and liabilities associated with generation of regulated wastes. The committee concluded that there was no evidence suggesting that the anticipated increases in biomedical research will significantly increase generation of hazardous wastes or have adverse impacts on the general environment. This conclusion assumes the positive, countervailing trends of enhanced pollution prevention efforts by facilities and reductions in waste generation resulting from improvements in research methods will continue.

Biomedical Technology↗

Prevention and treatment of malaria in UK travellers.

With around 2500 new cases of malaria being reported each year and more than a million UK residents visiting malaria endemic countries, there has never been a greater need for effective prevention and treatment. The latest information on malaria management is outlined below.

Age Factors↗

An 'inherent' biodegradability test for oil products: description and results of an international ring test. CONCAWE Biodegradation Task Force.

Current test guidelines for assessing 'inherent' (potential) biodegradability were designed for water-soluble, organic compounds of low volatility and are unsuitable for most oil products. It was against this background, that CONCAWE (the oil companies' European organisation for environment, health and safety) formed a task force to develop a standard test protocol for assessing the 'inherent' biodegradability of oil products.

Biodegradation, Environmental↗

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↗

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↗