Reduction in cryptosporidiosis associated with introduction of enhanced filtration of drinking water at Loch Katrine, Scotland.

Previous evidence has suggested an association between cryptosporidiosis and consumption of unfiltered drinking water from Loch Katrine in Scotland. Before September 2007, the water was only micro-strained and chlorinated; however, since that time, coagulation and rapid gravity filtration have been installed. In order to determine risk factors associated with cryptosporidiosis, including drinking water, we analysed data on microbiologically confirmed cases of cryptosporidiosis from 2004 to 2010. We identified an association between the incidence of cryptosporidiosis and unfiltered Loch Katrine drinking water supplied to the home (odds ratio 1.86, 95% confidence interval 1.11-3.11, P = 0.019). However, while filtration appears to be associated with initially reduced rates of cryptosporidiosis, evidence suggests it may paradoxically make those consumers more susceptible to other transmission routes in the long-term. These findings support implementation of similar treatment for other unfiltered drinking-water supplies, as a means of reducing cryptosporidiosis associated with drinking water.

Syndromic surveillance to assess the potential public health impact of the Icelandic volcanic ash plume across the United Kingdom, April 2010.

The Health Protection Agency and Health Protection Scotland used existing syndromic surveillance systems to monitor community health in the UK following the volcanic eruption in Iceland in April 2010.

An outbreak of infection with Bacillus anthracis in injecting drug users in Scotland.

An investigation is currently underway to explore and control an outbreak of Bacillus anthracis among drug users (mainly injecting) in Scotland. Contaminated heroin or a contaminated cutting agent mixed with the heroin is considered to be the most likely source and vehicle of infection. Heroin users have been advised of the risk. The risk to the general public is regarded as very low.

Spatial and temporal epidemiology of sporadic human cryptosporidiosis in Scotland.

The spatial and temporal epidemiology of human cryptosporidiosis was described by analysing sporadic cases reported in Scotland from 2005 to 2007. Measures of livestock density and human population density were explored as indicators of the geographical variation in prevalence. Cryptosporidium parvum was more common in areas with lower human population densities, with a higher ratio of the number of farms to human inhabitants and with a higher ratio of the number of private water supplies to human inhabitants. Cryptosporidium parvum caused disease in humans in rural areas and in areas with high ruminant livestock density, whereas Cryptosporidium hominis was more common in the more densely human populated areas of Scotland. The association of private water supplies and increased Cryptosporidium reports merits further public health efforts.

The reported incidence of work-related ill-health in Scotland (2002-2003).

BACKGROUND: Although incidence data for work-related ill-health in the UK are available, more detailed information for smaller geographical areas has hitherto been unpublished. AIMS: To estimate the incidence of work-related ill-health reported by clinical specialists in Scotland, 2002-2003. METHODS: THOR (The Health and Occupation Reporting network) is a UK wide reporting scheme for work-related ill-health. In 2002-2003, 241 out of 2162 physicians in THOR were based in Scotland. We have summarized the reported cases and calculated incidence rates for categories of ill-health by age, gender and industry. The UK Labour Force Survey (2002) was used to provide denominator data, with comparisons made between rates for Scotland and the rest of the UK. RESULTS: In 2002-2003, 4043 estimated cases were reported from Scotland. Mental ill-health was most frequently reported (41%); followed by musculoskeletal disorders (31%), skin disorders (16%), respiratory disease (10%), hearing disorders (2%) and infection (1%). The reported average annual incidence rate per 100,000 employees for all work-related ill-health in Scotland was 86.0. The highest reported rate for mental ill-health was found for employees in public administration and defence (76.7 per 100,000), and health and social work (72.3 per 100,000). The construction industry had the highest reported rate of musculoskeletal disorders (41.6 per 100,000), while hairdressers appeared at most risk of developing occupational contact dermatitis (rate=86.4 per 100,000). CONCLUSIONS: Despite its limitations, THOR has indicated types of work-related ill-health and related industries for targeted disease prevention in Scotland.

Risk factors for sporadic cases of Escherichia coli O157 infection: the importance of contact with animal excreta.

To determine environmental risk factors for sporadic E. coli O157 infection in Scotland we undertook a prospective, matched case-control study between 1 October 1996 and 31 March 1999. One hundred and eighty-three cases and 545 matched controls were recruited. Contact with animal faeces (OR = 3.65; 95% CI 1.81, 7.34: P < 0.0005) and likely contact with animal faeces (OR = 4.8; 95% CI 2.42, 9.48; P < 0.0005) emerged as strong risk factors for infection. Certain exposures (mainly food-related) were inversely associated with infection i.e. were statistically protective. Most striking was the consumption of bottled water (OR = 0.28; 95% CI 0.15, 0.52; P < 0.0005). Transmission of E. coli O157 does not occur simply through contaminated food. Members of the public need to be aware of the potential for acquiring E. coli O157 through contamination of the environment with animal faeces so that they may take measures to mitigate their risk.

Environmental risk factors for sporadic Escherichia coli O157 infection in Scotland: results of a descriptive epidemiology study.

The objective of the study was to obtain detailed descriptive epidemiological information on sporadic verocytotoxin-producing Escherichia coli O157 infection in Scotland in relation to transmission routes and host-related risk factors. Using a standardized questionnaire, the study was carried out throughout Scotland over an 18-month period from July 1992 and co-ordinated at the Communicable Diseases and Environmental Health (Scotland) Unit, Glasgow (CDEH(S)U). The subjects were laboratory-confirmed cases of Escherichia coli O157 infection, of whom 138 met the criteria for inclusion in the study. The most important findings were the high proportion of cases who had been exposed to environmental factors such as farm animals and/or their by-products; or who had participated in gardening or garden-play; or who had suspected or confirmed household water supply problems, prior to the onset of illness. The frequency and relative importance of environmental risk factors requires further quantification and study in order to assess where control measures can be directed most effectively. The implications for the NHS in preventing this crippling, life-threatening infection are considerable, not least in relation to hospitalization, dialysis and renal transplantation costs.

Acute hepatitis B in Edinburgh 1975-92: a retrospective study in a population where human immunodeficiency virus is highly prevalent.

A retrospective study of notified hepatitis B virus (HBV) infection in Edinburgh during 1975-92 identified 525 acute cases. For 343 where a probable transmission route could be determined, 215 were due to shared equipment by injection drug users (IDUs), 29 to homosexual intercourse, 25 to heterosexual or household contact with IDUs, 21 to heterosexual contact with infected non-IDU partners and 53 to various other or multiple routes. Cases were unevenly distributed geographically, particularly those among IDUs. The highest incidence within a post code district was approximately 2.5 times that for all Edinburgh. Annual cases peaked in 1984 then declined to low levels in the early 1990s. This reduction was most marked among IDUs, and may be ascribed both to changed injecting behaviour and decreased susceptibility within this group. The latter factor implies that HBV infections may be an unreliable guide to human immunodeficiency virus (HIV) infection in populations where HBV is highly prevalent.

Impact of prenatal diagnosis on revised livebirth prevalence estimates of Down syndrome in the Lothian region of Scotland, 1978-1992.

Ramsay et al. [(1991) Biomed Pharmacother 45:267-272] reported on the livebirth prevalence of Down syndrome in the Lothian region of Scotland during 1978-1989. Their results suggested a temporal association between the events of Chernobyl in April 1986 and a significant-excess of cases in 1987. In the current study the data were extended for 3 years and reanalyzed, a major objective being to correct for the differential loss of fetuses with Down syndrome which occurs between prenatal diagnosis and birth. Other objectives were to estimate the prevalence reduction due to prenatal diagnosis, quinquennial maternal age-specific risk rates, and the level of ascertainment of cases. The reanalysis found a 12-year prevalence rate of 1.29 vs. the previous rate of 1.34, and a shift of the annual prevalence peak to 1988, with a reduced prevalence in 1987 compared to that found in the earlier study. The new results are less consistent in showing an association of Down syndrome clustering with the Chernobyl accident. For the 15-year study period, a 23% overall reduction in prevalence occurred due to prenatal diagnosis and elective abortion of affected fetuses, with a 50% reduction to women > or = 35 years of age. For 1988-1992, these reductions were 33% and 60%, which are among the highest reported in the literature for these time periods. The estimated quinquennial maternal risk rates were very similar to others already reported, and the data are consistent with a high level of case ascertainment. Since these women are approaching the upper limits of fetal detection through advanced maternal age alone, continued reduction in prevalence rates for Down syndrome through prenatal diagnosis and elective abortion will come mostly from increased use of other (chemical) screening techniques now available.

Down's syndrome in the Lothian region of Scotland--1978 to 1989.

A study of Down's syndrome in Lothian for the years 1978-1989 revealed a significantly higher than expected incidence of cases in 1987. The increased incidence was particularly significant among women aged 35 years or more. The increase could not be attributed to demographic changes on birth rates or to the age distribution of the women concerned. A temporal association between the cluster of cases and the events at Chernobyl in April 1986 was demonstrated. However, according to current understanding, there is no biologically plausible explanation to link the 2 events, given the reported levels of radioactive fallout in the Lothian region, resulting from the Chernobyl disaster. An explanation for the increased incidence of Down's syndrome in 1987 remains outstanding.