Microbiological safety of sandwiches from hospitals and other health care establishments in the United Kingdom with a focus on Listeria monocytogenes and other Listeria species.

In the United Kingdom between 1999 and 2004, there were four outbreaks of Listeria monocytogenes infection associated with sandwiches purchased from or provided in hospitals. Elderly or immunocompromised individuals and pregnant women are particularly vulnerable to infection; therefore, the focus of this study was on sandwiches served in health care establishments. Of 3,249 sandwich samples collected between April 2005 and March 2006, 3.3% were of unsatisfactory microbiological quality because of high levels of Enterobacteriaceae (2.0%; > or = 10(4) CFU/g for sandwiches not containing salad), Escherichia coli (0.8%; > or = 10(2) CFU/g), Staphylococcus aureus (0.6%; > or = 10(2) CFU/g), and/or Listeria spp. (0.1%; two samples with L. welshimeri at 1.8 x 10(2) and 7.4 x 10(3) CFU/g and one sample with L. seeligeri at 1.8 x 10(3) CFU/g). Overall, 7.6% of sandwiches were contaminated with Listeria spp. L. monocytogenes was detected in 2.7% (88) of samples: 87 samples at < 10 CFU/g and 1 sample at 20 CFU/g. More frequent contamination with Listeria spp. and L. monocytogenes was found in sandwiches collected from hospital cafeterias, shops, or wards and in sandwiches stored and/or displayed at temperatures higher than 8 degrees C. The presence of Listeria spp. and L. monocytogenes also was associated with sandwiches that (i) were supplied from outside the establishment, (ii) were prepacked, (iii) had a main sandwich filling of poultry meat, or (iv) contained salad ingredients, soft cheese, and/or mayonnaise. Control of L. monocytogenes in sandwich manufacturing and within health care establishments is essential to minimize the potential for consumption of this bacterium at levels hazardous to health. The findings from this study support the proposal that manufacturers supplying sandwiches to health care establishments should follow the British Sandwich Association recommended guidelines of complete absence of L. monocytogenes in sandwiches at the point of production.

Farm visits and zoonoses.

Recent reports of outbreaks of gastrointestinal illness, such as cryptosporidiosis, associated with visits to farms have drawn attention to the possible risks of acquiring zoonotic infections through contact with farm animals. These risks seem to be small, but it is important that people who work in urban and rural farms, and such establishments as animal sanctuaries where the general public can come into close contact with farm livestock and other animals, should be alerted to the simple precautions needed to prevent transmission of infections.

Toxoplasmosis in England and Wales 1981 to 1992.

We have examined laboratory reports of toxoplasmosis received by the PHLS Communicable Disease Surveillance Centre between January 1981 and December 1992 in order to describe epidemiological trends in the three main clinical manifestations of toxoplasmosis-lymphadenopathy, eye disease, and neurological disease; and the two most important risk groups-fetuses and people whose immunity is impaired. The total numbers of reports each year did not change significantly between 1981 and 1992 and were similar to the numbers between 1976 and 1980, but different trends emerged in each subgroup. Reports of acute lymphadenopathic toxoplasmosis declined in children and young adults and eye disease associated with toxoplasmosis fell markedly in all age groups. Reports of neurological disease and severe toxoplasmosis complicating impaired immunity, due mainly to HIV infection or transplant surgery, rose. Reports of infections diagnosed in pregnancy rose steeply in the late 1980s although reports of congenital toxoplasmosis were no more common than in 1975 to 1980. Reports of acute toxoplasmosis came mainly from southern England. The emergence of these diverse trends from apparently unchanging totals emphasises the importance of surveillance systems capable of discrimination.

Increasing incidence of cryptococcosis in the United Kingdom.

The incidence of infection with Cryptococcus neoformans in the United Kingdom during the years between 1953 and 1981 is compared with that between 1982 and 1991. The patients were those from whom samples were submitted to the PHLS Mycological Reference Laboratory (MRL), or those in whom the disease was confirmed elsewhere in the United Kingdom and reported to PHLS Communicable Disease Surveillance Centre (CDSC). In all, 83 cases were identified between 1953 and 1981 and 322 between 1982 and 1991, 201 of which were known to be HIV-associated. The incidence of infection with Cryptococcus neoformans has increased four-fold in the last decade. It is an increasing cause of infection in immunosuppressed patients, most notably those with HIV infection. Currently, 4.0% patients with AIDS in the United Kingdom are known to have developed cryptococcosis.

The resurgence of scabies.

The prevalence of scabies infection shows a cyclical pattern with a periodicity of 10-30 years. Various sources indicate that a major increase has been underway since 1991 and CDSC has received several reports of outbreaks in schools, hospitals and nursing homes in recent months. This brief review outlines the clinical features, diagnosis, epidemiology and management of this time-honoured infection.

A case of intracerebral air embolism secondary to the insertion of a Hickman line.

Complications following the insertion of intravenous catheters are relatively uncommon. We report a potentially serious, hitherto unrecognized complication of Hickman line insertion, and discuss the condition.

Communicable disease associated with milk and dairy products in England and Wales: 1983-1984.

During the period 1983-1984 32 outbreaks of disease (II in 1983 and 21 in 1984) associated with consumption of milk and dairy products and affecting at least 714 people were reported from England and Wales. Twenty-seven of the outbreaks were attributed to raw milk, two to contaminated pasteurised milk and one each to cheese, cream and ice-cream. Twenty-two were due to salmonellas, seven to campylobacters and one each to Staphylococcus aureus, Yersinia enterocolitica and Streptococcus zooepidemicus. Two sporadic cases of Corynebacterium ulcerans infection associated with raw milk were also reported. There were eight deaths, all associated with the S. zooepidemicus outbreak. The continuing occurrence of milk-borne outbreaks, and an increasing number of incidents affecting rural communities, emphasises the urgent need for enforcing pasteurisation of milk and dairy products in England and Wales.

Pasteurisation and the control of milkborne infection in Britain.

Infections carried in milk, particularly salmonellosis and campylobacter enteritis, have continued to feature in Great Britain in recent years. Less commonly reported infections included an outbreak in 1984 in England due to Streptococcus zooepidemicus, in which 12 people, eight of whom died, were admitted to hospital. The implementation of legislation in 1983 requiring heat treatment of cows' milk for sale to the public reduced the incidence of milkborne infection in Scotland compared with previous years and compared with England and Wales, where, without legislative control, outbreaks continue to occur. Until compulsory pasteurisation is introduced throughout Britain and dairy farming communities can be persuaded to drink only heat treated milk outbreaks of milkborne infection will continue.

Isolation, fractionation and partial characterization of the tegumental surface from protoscoleces of the hydatid organism, Echinococcus granulosus.

Several approaches were adopted for the disruption and removal of the tegumental surface from protoscoleces of the horse strain of the hydatid organism, Echinococcus granulosus. The effectiveness of each method and the purity of subsequent microthrix-enriched fractions obtained by differential centrifugation were evaluated by electron microscopy, by the amount of protein released and by the degree of enrichment of surface plasma membrane marker enzymes. Incubation in saponin for 10 min produced the purest microtriche preparation, but in low yield; freeze/thawing, incubation in Triton X-100 for 10 min or in saponin for 20 min produced fractions containing significant amounts of relatively pure microtriches, but mild homogenization was a poor method for surface disruption and subsequent isolation of microtriches. Phosphodiesterase, adenosine triphosphatase (total and ouabain-inhibited), leucine aminopeptidase and glutamyltransferase were active in the protoscoleces but none were enriched in any of the microthrix fractions. In contrast, alkaline phosphatase, acid phosphatase, 5' nucleotidase and maltase were enriched significantly in all of the isolated microtriche preparations, which suggests that these enzymes are predominantly surface membrane bound. The protein profiles of the microthrix-enriched fractions, following SDS-PAGE, were basically similar, although there were some qualitative and quantitative differences in the proteins released by each isolation procedure. Three major PAS-staining components were present in all the preparations and these probably originated from the glycocalyx. One of these PAS-positive components, with an approximate molecular weight of 110 kDa, may be a glycoprotein specific to the horse strain of E. granulosus.

Procedures for testing the viability of human hydatid cysts following surgical removal, especially after chemotherapy.

The basic problems involved in assessing the viability of hydatid material following surgical removal from human cases are outlined and the use of enzyme digestion techniques is shown to provide a rapid and relatively simple diagnostic procedure. The method is described in detail and examples of its practicability are cited. Infection in laboratory animals provides a back-up diagnostic procedure but cyst development in them is too slow to be of value for most clinical work.