Scottish national survey of tuberculosis notifications 1993 with special reference to the prevalence of HIV seropositivity.

BACKGROUND: The study sought to determine the contribution of HIV seropositivity to the arrest of decline in tuberculosis notifications in Scotland. METHODS: Survey forms relating to each tuberculosis notification in 1993 were completed by the notifying consultant. Voluntary anonymous HIV testing of tuberculosis cases aged under 65 was requested. Age, sex, ethnic status, country of birth, employment status, occupation, previous tuberculosis, contact status, risk factors for HIV infection, HIV serostatus of cases aged under 65, site, radiological extent, and bacteriological status of tuberculous disease were determined. RESULTS: Five hundred and seventy four cases of tuberculosis were originally notified, of which 77 (14%) subsequently proved to be non-tuberculous and were therefore denotified. Of the 497 cases 423 (85%) were white and 58 (12%) were from the Indian subcontinent. Eighty five per cent of patients from the Indian subcontinent were aged < 55 years whereas 64% of white patients were aged > 55 years. Pulmonary disease was found in 74%, non-pulmonary in 22%, and combined disease in 4% of patients. Of 242 HIV tests performed, three were positive and five other HIV positive patients were known, giving an HIV positivity rate of 1.6% of all tuberculosis notifications in 1993. Annual notification rates for Scotland were 9.7 per 10(5) before and 8.7 per 10(5) after exclusion of previously treated cases; rates were 8.4 per 10(5) for the white population and 179 per 10(5) for those from the Indian subcontinent. CONCLUSIONS: The study documents the distribution of tuberculous disease in Scotland by age, sex, site, and ethnic group for the first time. Notification practices, with respect to denotification, need to be improved. Infection with HIV is presently uncommon in cases of tuberculosis in Scotland but continued vigilance is essential.

National recording of environmental incidents in Scotland.

One of the main problems in determining the environmental status of a territory is the common failure to accurately record the occurrence of environmental incidents. All too often control of pollution is the responsibility of various independent central and local government departments without overall cooperation and recording of incidents. If an official recording mechanism is not in place no determination of the number of environmental incidents that occur in a given period of time can be determined, no relation of connected incidents can be made, no lessons can be learned and passed on to all those working in the pollution control field, and no assessment of improved environmental standards can be achieved. In Scotland for the past 3 years a central system for recording environmental health incidents has been in place and many benefits from this administrative arrangement are already evident. The implementation, management benefits and results obtained from the programme are given and suggestions are made as to how this programme could be extended internationally.

The epidemiological relationship between Salmonella isolated from poultry meat and sewage effluents at a long-stay hospital.

Between February 1988 and March 1989 chicken carcases delivered to the kitchen of a long stay psycho-geriatric hospital were screened every week for salmonella contamination. While 214 of 477 (45%) individual carcases carried one or more salmonella types, every single consignment examined contained affected carcases. Simultaneously, sewers draining the residential accommodation and excluding kitchen effluent, were also monitored. Thirty out of 79 (38%) of Moore's swabs were positive for salmonella. There was a statistically significant association between the salmonella types isolated from chicken and those isolated from sewers the following week. Following a change in kitchen policy to order only cooked chicken there was a significant reduction in the isolation of salmonella from the sewers.

An outbreak of waterborne cryptosporidiosis caused by post-treatment contamination.

An outbreak of waterborne cryptosporidiosis affecting 27 persons, diagnosed stool positive, occurred in Ayrshire in April 1988. Twenty-one in 27 confirmed cases required some form of fluid replacement therapy. Local general practitioners indicated a two- to fivefold increase in diarrhoeal disease during the outbreak, and following enquiries made by Environmental Health Officers it became apparent that many hundreds of people had suffered a diarrhoeal illness at that time. Cryptosporidium spp. oocysts were detected in the treated chlorinated water supply system, in the absence of faecal bacterial indicators. Oocyst contamination of a break-pressure tank containing final water for distribution was the cause of this waterborne outbreak. An irregular seepage of oocyst-containing water, which increased during heavy rains, was the cause of the break-pressure tank contamination, rather than a failure of the water-treatment processes. The waterborne route should be considered when clusters of cryptosporidiosis-associated with potable water occur. Waterborne cryptosporidiosis can occur in the absence of other faecal indicators of contamination.

Lochgoilhead fever: outbreak of non-pneumonic legionellosis due to Legionella micdadei.

Analysis of case histories from 187 people who had visited a hotel and leisure complex in Lochgoilhead, a village on the west coast of Scotland, indicated that 170 had had an acute illness characterised by headache, fatigue, arthralgia, myalgia, cough, and breathlessness. These symptoms were consistent with Pontiac fever-like illness. Legionella micdadei was isolated from the leisure complex whirlpool spa at the time that 60 of 72 individuals with symptoms seroconverted to L micdadei antigen. This outbreak is thought to be the first of a Pontiac fever-like illness ascribed to L micdadei and the first large-scale outbreak of its kind to have occurred outside North America. Whirlpool spas can be a major reservoir of legionella organisms; they must therefore be properly maintained and operated to prevent outbreaks of infection.

Food poisoning in hospitals in Scotland, 1978-87.

During the 10-year period 1978-87 there were 48 outbreaks of food poisoning in Scottish hospitals affecting a total of 2287 persons of whom 12 died. This compared with 50 outbreaks during the previous 5 years (1973-77) when over 1500 persons and 7 deaths were recorded. Although the incidence of outbreaks has decreased the average number of persons affected in outbreaks has increased. A marked reduction was seen in the incidence of outbreaks due to Clostridium perfringens, in contrast to foodborne salmonellosis which remains a problem. Thirty-four hospitals, of which 10 reported two or more outbreaks, were involved. The type of hospitals most frequently affected were general (14), psychiatric (13), geriatric (9) and hospitals for the mentally subnormal (7). Meat, including poultry meat, was incriminated in over 90% of outbreaks where a food vehicle was identified. In modern or re-equipped kitchens cooking in advance with subsequent reheating is being progressively discontinued as more food is being cooked on the day of consumption, a practice which may readily explain the decreasing incidence of outbreaks due to Cl. perfringens. Bacterial cross-contamination from poultry-meat and other raw foods, compounded by inadequate temperature control, however, continues to be a problem in some hospitals. It is too early as yet to determine whether the removal of Crown immunity will have any effect on the future incidence of hospital 'food poisoning'.

Poultry-borne salmonellosis in Scotland.

Between 1980-5, 224 outbreaks of salmonellosis associated with poultry-meat were reported in Scotland. In total 2245 persons were affected, 12 of whom died. Twenty-one salmonella serotypes were identified from those affected, while 33 serotypes were isolated from poultry during routine monitoring and disease investigation. Existing measures to prevent the spread of salmonellae within poultry flocks and processing plants are failing. It is suggested that irradiation of poultry-meat may be the only effective method of reducing the public health problem of poultry-borne salmonellosis.

Costing of a hospital-based outbreak of poultry-borne salmonellosis.

Poultry-borne salmonellosis is the most common form of foodborne infection in Scotland for which the vehicle can be identified, yet little is known about the costs imposed on society by this disease, or the costs of preventing it. The present study identifies and values the costs of a hospital based outbreak of poultry-borne salmonellosis. Account is taken of costs falling on individuals, the health services and society as a whole. Depending on assumptions made about the value of 'intangibles', the cost of the outbreak is estimated to be between pounds 200,000 and pounds 900,000.

Surveillance programme for the control of foodborne infections and intoxications in Europe: the first 6 years' experience in Scotland, 1980-85.

In 1979 WHO recommended the establishment of a surveillance programme in Europe for foodborne infections and intoxications that incorporated an early warning system for incidents affecting more than one country as well as a routine reporting system to record details of outbreaks of foodborne disease. The Early Warning System was introduced in Scotland in July 1979 and the Routine Reporting System in January 1980. By the end of 1985, 23 European countries were participating in the programme.The introduction of the surveillance programme in Scotland permitted the formation of a standard national reporting system for foodborne infections and intoxications. During the 6 years from 1980 to 1985, the major features of the programme in Scotland have been the introduction of compulsory pasteurization of cows' milk, in 1983, with the consequent eradication of general outbreaks of milkborne salmonellosis; the emergence of poultry meat as the major food vehicle of infections; and the development of techniques for costing foodborne disease outbreaks.

Prevention of poultry-borne salmonellosis by irradiation: costs and benefits in Scotland.

Poultry-borne salmonellosis is the most common foodborne infection in Scotland for which the vehicle can be identified. The cost of the disease to society in terms of health service use, absence from work, morbidity, and mortality is substantial. The study estimates the total cost of poultry-borne salmonellosis in Scotland and compares it with the cost of a single preventive measure: the irradiation of poultry meat. The results suggest that the public health benefits exceed irradiation costs. This conclusion is, however, sensitive to assumptions made in the analysis, particularly those related to the cost of unreported cases of salmonellosis.

Surveillance programme for the control of foodborne infections and intoxications in Europe: The first 6 years' experience in Scotland, 1980-85

In 1979 WHO recommended the establishment of a surveillance programme in Europe for foodborne infections and intoxications that incorporated an early waning system for incidents affecting more that one country as well as a routine reporting system to record details of outbreaks of foodborned disease. The Early Warning System was introduced in Scotland in July 1979 and the Routine Reporting System in January 1980. By the end of 1985, 23 European countries were participating in the programme. The introduction of the surveillance programme in Scotland permitted the formation of a standard national reporting system for foodborne infections and intoxications. During the 6 years from 1980 to 1985, the major features of the programme in Scotland have been the introduction of compulsory pasteurization of cow's milk, in 1983, with the consequent eradication of general outbreaks of milkborne salmonellosis; the emergence of poultry meat as the major food vehicle of infections; and the development of techniques for costing foodborne disease outbreaks

Dietary copper intake in artificially fed infants.

Plasma concentrations of copper and zinc and leucocyte concentrations of zinc were measured in mothers during later pregnancy, at delivery, and 8-10 weeks after birth, and plasma concentrations of copper and zinc were measured in their infants at delivery and 8-10 weeks after birth. The 145 infants were either breast fed or fed one of two milk formulas supplying copper at different concentrations. None of the infants achieved the minimum copper intakes recommended by the World Health Organisation (WHO). At 2 months of age there were no major differences in growth or health detected in infants fed the different copper intakes. Infant birth weight correlated well with the ratio of maternal venous plasma zinc:maternal leucocyte zinc at delivery. Maternal venous plasma copper and zinc concentrations at birth correlated with umbilical venous plasma copper and zinc concentrations. Infants fed the higher copper content formulas had a low mean plasma zinc concentration without a significant increase in the mean plasma copper concentration. The present WHO recommendations regarding minimum copper intakes for infants fed formulas cannot be achieved with currently available formulas and are probably wrong.

Reduction in exposure to lead from drinking water and its effect on blood lead concentrations.

The water supply in Ayr (Scotland, UK) was plumbosolvent and many dwellings in Ayr contained lead pipes. In 1981 treatment of the water supply to reduce its plumbosolvency was initiated. Measurements of water and blood lead concentrations were made before and subsequent to the treatment. Most of the measurements made before and after water treatment began were made on water samples from the same dwellings and blood samples from the same women. Water treatment produced a sharp fall in water lead concentrations and a decrease in the median blood lead concentration from 21 to 13 micrograms/100 ml. Two women had higher than expected blood lead concentrations, both these women had been removing old paint. Women who had lead pipes removed from their dwellings all showed substantial decreases in their blood lead concentrations. The curvilinearity of the relation between blood lead and water lead concentrations is confirmed. Even relatively low (less than 40 micrograms/l) water lead concentrations may make a substantial contribution to blood lead concentrations.

A cost benefit study of milk-borne salmonellosis.

An estimate of the benefits which would result from a ban on the sale of non-pasteurized milk in Scotland has been assessed by costing a recent outbreak of milk-borne salmonellosis in the Grampian Region. The cost of such a ban would not exceed the benefits under any but the most severe assumptions about the values attached to intangible benefits.

Milkborne salmonellosis in Scotland 1980 to 1982.

In Scotland between 1980 and 1982 there were 21 episodes of milkborne salmonella affecting a total of 1090 persons (range one to 654). There were eight deaths, including two children, in people associated with these outbreaks. The problem of milkborne salmonellosis continues to be greater in Scotland, where dairy herds on average are larger and a greater proportion of raw milk is consumed, than elsewhere in Britain. It is anticipated that legislation requiring the pasteurisation of virtually all milk sold for human consumption in Scotland by August 1983, will help to correct the situation.