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Microbiology laboratory reports are the principal data source for nosocomial infection surveillance in most European countries. Such laboratory based surveillance inherently lacks sensitivity so that additional sources of data are necessary to increase the detection of infections. Long term compliance of voluntary reporting by clinical or ward nursing staff has rarely been achieved but continuous and selective clinical surveillance has been implemented successfully in the USA. Selective clinical surveillance, supplemented by laboratory data, may be a practical proposition in Europe, even with existing staffing levels and validation studies of the various methods are needed urgently.

Early in 1981, cases of hepatitis possibly associated with the consumption of cockles were reported mainly from south-east England. A case-control study was undertaken in 19 local authority districts. Between Nov. 1, 1980, and April 30, 1981, 424 cases of infective jaundice were formally notified and case-finding yielded 26 additional cases. 42.6% of those with hepatitis and 17.5% of the controls reported consumption of cockles. There was a statistically significant association between infective jaundice and the consumption of cockles but not other sea foods. The cockles had probably been insufficiently processed and stricter controls on treatment of such shellfish are needed.

In January 1984 the River Dee in north Wales was contaminated with phenol, with subsequent contamination of the tap water received by about two million consumers. A retrospective postal survey of 594 households was undertaken to determine whether consumption of this contaminated water was associated with illness. Subjects in areas that received contaminated water reported significantly more gastrointestinal illness than those in a nearby unexposed area (32.6% v 8.7%, p less than 0.00001) as well as reporting a higher incidence of any symptoms (43.6% v 18.4%, p less than 0.00001). Symptoms were consistent with phenol poisoning and bore a strong temporal relation to the pollution of the supply, but they developed at concentrations of phenols previously considered to be safe by the water authorities concerned. Chlorophenols produced during the treatment of water may have aggravated the problem.

An outbreak of Salmonella typhimurium DT 124 infection which affected 101 people in England in December 1987 and January 1988 was detected through surveillance of laboratory reports from medical microbiology laboratories of the NHS and PHLS. Within 1 week of noting the increase in reports, epidemiological and microbiological investigations identified a small German salami stick as the vehicle of infection and the product was withdrawn from sale. The epidemiological investigation highlighted the occurrence of a long incubation period, bloody diarrhoea. Prompt recognition and investigation of the outbreak prevented further cases of severe infection.

Data on sporadic cases of Legionnaires' disease in Great Britain reported to the Communicable Disease Surveillance Centre, London, and the Communicable Diseases (Scotland) Unit, Glasgow, were analysed. Eighty-four cases, including 18 patients who died, were identified with dates of onset between 1 January 1976 and 30 September 1978. The age and sex distribution showed a predominance of middle-aged men. The incidence trends suggest that true seasonal variation may occur. Eighteen patients developed illness during or shortly after a holiday abroad. All patients had pneumonia, but many also had features suggesting involvement of the central nervous system and gastrointestinal tract. Person-to-person spread was not observed.

An outbreak of staphylococcal food poisoning in Europe caused by contaminated lasagne was detected and monitored by both national and international surveillance systems. The common source was a pasta-producing factory in Italy and high levels of Staphylococcus aureus were detected in packets of dried lasagne distributed in Luxembourg, the UK, France and Italy. Forty-seven cases were reported in the UK. Outbreaks of staphylococcal food poisoning attributed to mishandling during the food processing stage are uncommon and pasta as the food vehicle is rare. Prompt recognition of the outbreak and rapid identification of the food vehicle enabled most of the consignment to be withdrawn from the market.

A large outbreak of viral gastroenteritis occurred in which oysters eaten raw were the vehicle of infection. Laboratory findings indicated that a small round structured virus was the infecting agent. Adults of all ages were equally susceptible to infection with the virus. Investigation cast doubt on the efficacy of depuration as a method for rendering oysters free of virus, and hence the public should be warned of the hazard of eating raw shellfish.

Objective: To determine the source of indigenous sporadic infection with Salmonella enteritidis phage type 4., Design: Case-control study of primary sporadic cases identified by the Public Health Laboratory Service between 1 August and 30 September 1988., Setting: PHLS Communicable Disease Surveillance Centre, Division of Enteric Pathogens, 11 PHLS laboratories, and 42 local authority environmental health departments in England., Subjects: 232 Patients (cases) with confirmed primary sporadic infection, for 160 of whom (88 female) (median age 30 years, age range 4 months to 85 years) data were obtained by questionnaire about consumption of fresh eggs, egg products, precooked chicken, and minced meat in the three days and one week before onset of the symptoms. Up to three controls, matched for neighbourhood, age, and sex (if aged greater than 11 years), were asked the same questions for the same calendar period., Main Outcome Measure: Association of primary sporadic infection with consumption of suspected food items., Results: Illness due to S enteritidis phage type 4 was significantly associated with consumption of raw shell egg products (homemade mayonnaise, ice cream, and milk drinks containing eggs) (matched p = 0.02) and shop bought sandwiches containing mayonnaise (matched p = 0.00004) or eggs (matched p = 0.02). Illness was also significantly associated with eating lightly cooked eggs (unmatched p = 0.02), but not soft boiled eggs, and precooked hot chicken (matched p = 0.006). Reported consumption of eggs was not appreciably different between cases and controls before or after the median date of interview., Conclusions: Fresh shell eggs, egg products, and precooked hot chicken are vehicles of S enteritidis phage type 4 infection in indigenous sporadic cases. Public health education and reduction in contamination of eggs and infection of poultry with S enteritidis are needed to reduce the incidence of human infection.