Investigating a cluster of Legionnaires' cases: public health implications.

OBJECTIVES: To describe the multidisciplinary investigation and management of a rapidly increasing number of cases of Legionnaires' disease in the North Shropshire area, UK during August 2006. STUDY DESIGN: Epidemiological and environmental investigation of a cluster of cases of Legionnaires' disease. METHODS: Outbreak investigation included: agreeing case definitions; case finding; epidemiological survey; identification and environmental investigation of potential sources; microbiological analysis of clinical and environmental samples; mapping the location of potential sources; and the movement and residence of cases. RESULTS: Three cases of Legionnaires' disease were admitted to a local hospital between 30 and 31 August 2006. Two of these cases were Shropshire residents, with the third living in Wales. A fourth case was also identified which, it was thought, may have been linked to this cluster as the patient had a history of travel to the same area as the two Shropshire residents. Over the next few weeks, three more cases were identified, two of whom were admitted to hospital. Subsequent detailed environmental, epidemiological and microbiological investigation did not support the hypothesis that any of these cases could be linked to a common source. CONCLUSIONS: The results of this investigation strongly suggest that a single source was not responsible for the cluster, and it was concluded that this incident was a pseudo-outbreak. This investigation serves as a reminder that clusters can and do occur, and that an apparent outbreak may be a collection of sporadic cases distinguishable only by rigorous epidemiological, environmental and microbiological investigation.

Legionnaires' disease cluster linked to a metal product aqueous pre-treatment process, Staffordshire, England, May 2008.

In May 2008, a report of two workers from the same construction equipment manufacturing plant who were admitted to hospital with Legionnaires disease confirmed by urine antigen prompted an outbreak investigation. Both cases were middle aged men, smokers, and with no travel, leisure or other common community exposure to Legionella sources. There were no wet cooling towers at the plant or in the surrounding area. No increase in respiratory disease or worker absenteeism occurred at the plant during the preceding month. Wider case ascertainment including alerts to hospitals and medical practitioners yielded no further cases. The environmental investigation (and sampling of water systems for Legionella) identified a Legionella pneumophila serogroup1 (Mab 2b) count of >3.0x10(4)cfu/l in water samples from an aqueous metal pre-treatment tunnel, which generates profuse water aerosol. Drainage, cleaning and biocide treatment using thiazalone eliminated Legionella from the system.

Trends in sexually transmitted infections (other than HIV) in older people: analysis of data from an enhanced surveillance system.

OBJECTIVE: This study examines the distribution of selected sexually transmitted infections (STIs) in older people (aged >/=45 years) attending genitourinary medicine (GUM) clinics in the West Midlands, UK. METHODS: Analysis of data from the regional enhanced STI surveillance system for the period 1996-2003. Selected STIs were chlamydia, genital herpes, genital warts, gonorrhoea and syphilis. RESULTS: Altogether, 4445 STI episodes were reported among older people during the study period. Between 1996 and 2003 older people accounted for 3.7% and 4.3%, respectively, of all GUM clinic attendances. The rate of STIs in older people more than doubled in 2003 compared with 1996 (p<0.0001). Rates for all five selected diagnoses were significantly higher in 2003 compared to 1996. A significantly increasing trend over time was seen overall (p<0.0001) and for each of the selected diagnoses. Overall, males and those aged 55-59 years of age were significantly more likely to be affected. CONCLUSIONS: This study provides evidence of significant increases in attendance at GUM clinics by older people. Although it is recognised that young people should remain the focus of sexual health programmes, the results indicate that sexual risk-taking behaviour is not confined to young people but also occurs among older people. There is therefore a need to develop and implement evidence-based multifaceted sexual health programmes that while aiming to reduce STI transmission among all age groups should include interventions aimed specifically at older people and address societal and healthcare attitudes, myths and assumptions about sexual activity among older people.

A survey of the preparedness for an influenza pandemic of general practitioners in the West Midlands, UK.

There is a lack of evidence regarding the preparedness of general practitioners (GPs) to respond to pandemic influenza. A postal questionnaire survey was conducted to explore the self-perceived pandemic preparedness of GPs in the West Midlands, United Kingdom, and to determine differences between urban and non-urban GPs. The postal questionnaire was sent out to 773 GPs in November 2005, and a reminder was sent in January 2006. In all, 427/773 (55%) questionnaires were returned, and 56% of respondents were aware of influenza pandemic preparedness plans. Approximately one-quarter of respondents (28%, 114/401) thought the response of their practice to a pandemic event would be very poor/poor. Non-urban GPs were significantly more likely to rate the response of their practice to a pandemic as likely to be poor (OR 3.01, 95%CI 1.03-8.76) and were less likely to be aware of pandemic preparedness plans (OR 0.62, 95%CI 0.39-0.99). Non-urban GPs were also significantly more likely to feel less confident in their ability to explain to their patients what to do and why during an influenza pandemic than GPs based in urban areas (OR 4.68, 95%CI 1.78-12.31). GPs rating of the odds of a pandemic affecting the United Kingdom did not differ significantly by geographic location. The results of this paper can be used to inform and influence public health policy and as evidence of a need to provide additional education and training to improve pandemic preparedness among GPs, in particular those in non-urban areas.

What women want: convenient appointment times for cervical screening tests.

Little is known about women's preferred appointment times for cervical screening tests. Data from a postal questionnaire survey were used to compare preferred appointment times with those given. Although 33.4%[95% confidence intervals (CI) 31.8%-35.0%] of respondents received appointments between 10h00 and 11h55, only 17.0% (95% CI 15.3%-18.7%) wanted an appointment at that time. Nineteen per cent (95% CI 17.4%-21.0%) of respondents wanted appointments between 18h00 and 20h00, but only 4.4% (95% CI 3.7%-5.1%) received them. Saturday appointments for cervical screening are not given; however, overall approximately 13% of those surveyed would have preferred a Saturday appointment. Preferred times also varied significantly with age and deprivation category. Further research is required to determine whether appointment times for cervical screening can be tailored to meet these expressed needs, and the impact this has on service provision and uptake.

Information given to women invited for cervical screening: results of two postal surveys seven years apart.

In South Staffordshire, England, we compared women's views on information provided to them at different stages of the cervical screening program in 1994 with that provided in 2001. An age-stratified random sample of women aged 20-64 years who had a cervical smear taken between January and March 1994 (3856) or between January and March 2001 (4057) were sent postal questionnaires in June 1994 and July 2001, respectively. Response rates in 1994 (3124/3856, 81%) and 2001 (3288/4057, 81%) were similar. Compared to 1994, the proportion of women who thought the invitation letter was clear to read in 2001 increased (70% vs 98%, P < 0.0001); however, letters were thought to be less reassuring in 2001 compared to 1994 (P < 0.0001). In both study periods, 66% of women reported that the procedure was explained to them before the smear was taken. A greater proportion of women received their results by letter in 2001 compared to 1994 (57% vs 41%, P < 0.0001); however, 49% of women waited >4 weeks to receive their results in 2001 compared to 26% in 1994 (P < 0.0001). Bivariate analysis suggests that responses were age related, with older women (> or =45 years) experiencing poorer information provision. The issues highlighted by this study deserve further investigation in other areas.

An enquiry into the respiratory health effects on a rural community of a soil mound erected close to residential property.

The health concerns of a rural community were investigated following the erection of a soil mound in close proximity to residential property. Retrospective comparisons were made of respiratory and non-respiratory consultations with general practitioners between the exposed population and a sociodemographically similar comparison population. A 2-year period was examined, 1 year before and 1 year after the mound was erected. In the 1-year period prior to erection of the mound, similar consultation rates for both respiratory and non-respiratory conditions were observed in both populations. In the 1-year period following erection of the mound, the exposed population was more likely to consult for respiratory conditions than the comparison population (OR=4.10, 95% CI 2.26-7.44). No differences were observed for non-respiratory conditions. We identified a significant increase in respiratory consultations in the exposed population following erection of the soil mound. Limitations associated with this type of study should be considered when interpreting the results.

Response patterns to a postal survey using a cervical screening register as the sampling frame.

This study compared different types of respondent to a postal survey. A random sample of women aged 20-64 years (n = 4057) was selected from a population-based cervical screening register to examine their information experience during the screening programme. The initial response rate was 57%, and this increased to 81% after one reminder. Respondents were older (P < 0.0001) than non-respondents, but both groups were comparable with regard to attendance history for cervical screening (respondents 89.3%; non-respondents 89.1%) and normal smear test results (respondents 84.0%; non-respondents 81.4%). Early and late respondents were similar in age. Compared with late respondents, early respondents were more likely to live in highly affluent (P < 0.0001) and rural areas (P = 0.026). They were also more likely to be non-attenders (P < 0.0001), but they were less likely to have had inadequate smear results (P = 0.030) than late respondents. These results suggest that consideration should be given to factors other than sociodemographic differences when examining response patterns to postal surveys.

The knowledge of healthcare professionals with regard to the treatment and prevention of head lice.

This study examined the knowledge and practice of healthcare professionals regarding the prevention and treatment of head lice 18 months after dissemination of local guidelines. A self-administered postal questionnaire was sent to all primary healthcare professionals (general practitioners and practice nurses), community healthcare professionals (community paediatricians, health visitors and school nurses) and pharmacists in South Staffordshire health district, UK. The overall response rate was 48% (range 24-63%). Compared to other groups: community healthcare professionals were more likely to refer to the guidelines and have adequate knowledge of treatment and prevention; pharmacists were least likely to refer to the guidelines; and primary healthcare professionals were most likely to have poor knowledge about prevention and treatment. Overall, healthcare professionals' knowledge regarding prevention methods was significantly better than their knowledge of treatment methods (63% vs. 5%, P <0.00001). In conclusion, the results of this study suggest that healthcare professionals' knowledge of control methods for head lice varies widely and is sub-optimal and may contribute to ineffective head lice control.

The Stafford outbreak of Legionnaires' disease.

A large outbreak of Legionnaires' disease was associated with Stafford District General Hospital. A total of 68 confirmed cases was treated in hospital and 22 of these patients died. A further 35 patients, 14 of whom were treated at home, were suspected cases of Legionnaires' disease. All these patients had visited the hospital during April 1985. Epidemiological investigations demonstrated that there had been a high risk of acquiring the disease in the out patient department (OPD), but no risk in other parts of the hospital. The epidemic strain of Legionella pneumophila, serogroup 1, subgroup Pontiac 1a was isolated from the cooling water system of one of the air conditioning plants. This plant served several departments of the hospital including the OPD. The water in the cooling tower and a chiller unit which cooled the air entering the OPD were contaminated with legionellae. Bacteriological and engineering investigations showed how the chiller unit could have been contaminated and how an aerosol containing legionellae could have been generated in the U-trap below the chiller unit. These results, together with the epidemiological evidence, suggest that the chiller unit was most likely to have been the major source of the outbreak. Nearly one third of hospital staff had legionella antibodies. These staff were likely to have worked in areas of the hospital ventilated by the contaminated air conditioning plant, but not necessarily the OPD. There was evidence that a small proportion of these staff had a mild legionellosis and that these 'influenza-like' illnesses had been spread over a 5-month period. A possible explanation of this finding is that small amounts of aerosol from cooling tower sources could have entered the air-intake and been distributed throughout the areas of the hospital served by this ventilation system. Legionellae, subsequently found to be of the epidemic strain, had been found in the cooling tower pond in November 1984 and thus it is possible that staff were exposed to low doses of contaminated aerosol over several months. Control measures are described, but it was later apparent that the outbreak had ended before these interventions were introduced. The investigations revealed faults in the design of the ventilation system.