Two separate outbreaks of Salmonella enteritidis phage type 14b food poisoning linked to the consumption of the same type of frozen food.

OBJECTIVES: To ascertain, using a combination of epidemiological, environmental and microbiological methods of investigation, a possible link between two outbreaks of salmonella food poisoning. METHODS: Case-control studies were carried out on the known at-risk populations. Environmental investigations took place in the food preparation areas used for the social functions and microbiological examinations were carried out on faecal specimens obtained from cases, environmental swabs, and food specimens when these were available. RESULTS: In both outbreaks, illness was associated with the consumption of sesame prawn toast (outbreak one P<0.004; outbreak two P<0.0001). Salmonella enteritidis phage type 14b was cultured from the faecal specimens of cases in both outbreaks and from a packet of sesame prawn toast used for the second outbreak function. Molecular typing methods indicated that the salmonella cultures obtained in both outbreaks were indistinguishable from each other and from cultures obtained from imported Spanish eggs in a previous survey. Imported Spanish eggs were used in the manufacture of the sesame prawn toast. CONCLUSIONS: Adequate cooking must take place of raw food products, which should be clearly labelled as such. Manufacturers should consider, when possible, the use of pasteurized egg in the preparation of food products.

Immunisation of babies of women who screen positive for hepatitis B.

Pregnant women from countries with high prevalence rates of hepatitis B virus (HBV) infection may have significant HBV DNA levels despite being hepatitis B e antigen (HBeAg) negative and having antibody to HBeAg (anti-HBe positive). It is suggested that their babies, following delivery, should be given hepatitis B specific immunoglobulin (HBIG) in addition to hepatitis B vaccine in order to ensure their protection against infection.

Outbreak of Norwalk-like virus infection associated with salad provided in a restaurant.

Preliminary enquiries following the reporting of some cases of suspected food poisoning by members of the public revealed that they had all eaten at the same restaurant during the preceding weekend. Subsequent investigation, including a merged cohort study, identified 49 people with gastrointestinal symptoms, six of whom showed evidence of infection with Norwalk-like virus (NLV). Over a four day period all had eaten at the restaurant. Eating salad was strongly associated with infection. One of the chefs, who handled salad in the food preparation area and who had been absent from work with symptoms of gastrointestinal illness, had returned to work the day before the four-day period, reporting that he was 48-hours symptom free. He was subsequently shown to have been infected with NLV by reverse transcriptase polymerase chain reaction (RT-PCR) assay. The NLV belonged to the same genogroup as that infecting the cases who had eaten at the restaurant.

Survey of the prescribing of chemoprophylaxis to index cases of invasive meningococcal disease.

Chemoprophylaxis is given to contacts of cases of invasive meningococcal disease to reduce the risk of secondary cases by eradicating carriage. In the United Kingdom index cases are also recommended to receive chemoprophylaxis. This is usually undertaken by the clinical team managing the case. One hundred and fifty cases of probable meningococcal infection notified to the consultants in communicable disease control in a local health authority were reviewed to identify the proportion receiving chemoprophylaxis and to examine the final clinical outcome, in terms of diagnosis, of each case. Twenty-five per cent of notified cases (37) did not receive chemoprophylaxis and this proportion varied significantly between three local hospitals. We estimate that 15 of the 37 index cases who did not receive chemoprophylaxis were likely to have had invasive meningococcal disease.

Audit of clinical judgements and actions in an audiological investigation of school entrant children screened positive for hearing loss.

Of 117 children attending an aural clinic after screening positive by one or both of two tests for hearing loss at school entry, 43 (36.8%) were either seen again for review or listed for surgery. Clinical findings which were significantly associated with either being reviewed or listed for surgery, as opposed to being discharged, were the presence of conductive or sensory neural hearing loss, pronounced negative pressure, reduced compliance volume or absent stapedial reflexes on impedance testing and the presence of an abnormal tympanic membrane associated with effusion on otoscopy. This population of children were then followed up through their school medical records over 4 y to determine what proportion of those discharged from the clinic had subsequently required some form of surgical intervention due to a hearing problem. Note was also taken of all those actually receiving surgery or long term review for sensory neural hearing loss, these cases being designated as true positives in the aural clinic assessment process. This assessment, albeit of a 'high-risk group', gave rise to a sensitivity of 88.9% and a specificity of 68.0%.

Outbreak of Salmonella enteritidis phage type 6 infection associated with food items provided at a buffet meal.

Preliminary enquiries following prompt notification of three cases of suspected food poisoning revealed that they had all attended the same three functions during the preceding weekend. Subsequent investigation identified 49 people with gastrointestinal symptoms, 13 of whom were infected with Salmonella enteritidis phage type 6. Forty-five of those with symptoms, including 11 with confirmed infection, had eaten a buffet meal at a public house. Eating egg sandwiches was strongly associated with infection. Defects in the kitchen structure and the storage and handling of the implicated food items provided the potential for cross contamination. Salmonella was isolated from several environmental sites, including a general purpose cleaning cloth. Two different quiches and pork pies, which were possible vehicles of infection were thought to have been contaminated after being brought into the kitchen. The investigation did not reveal whether or not shell eggs used in the sandwiches were the original source or whether they too had been contaminated during their preparation.

Is there a relationship between proximity to industry and the occurrence of otitis media with effusion in school entrant children?

In a study of the relationship between the prevalence of persistent otitis media with effusion (OME) in school entrant children in Redcar and Cleveland and the distance of the homes of these children from known industrial emission points, 1156 school entrant children were screened for the presence of persistent OME. The social disadvantage scores and map references were determined from the postcode area of each of the study entrants and map references were also obtained of known industrial emission points in the locality. Analyses were conducted on the association between the presence of OME and distance from emission sources and between the presence of OME and disadvantage score. A significantly greater proportion of study entrants with OME lived within 1000 meters of an industrial emission point than further away. However, there was no trend established between the proportion of study entrants with OME and increasing distance from an emissions source, nor was there any significant relationship established between the social disadvantage score of the areas of residence of the study entrants and the presence of OME. Further research is required to establish the effect of confounding variables on this relationship.

Pure tone audiometry and impedance screening of school entrant children by nurses: evaluation in a practical setting.

BACKGROUND: Screening for hearing loss in English children at entry to school (age 5-6 years) is usually by pure tone audiometry sweep undertaken by school nurses. This study aimed to compare the validity and screening rates of pure tone audiometry with impedance screening in these children. METHODS: Two stage pure tone audiometry and impedance methods of screening were compared in 610 school entry children from 19 infant schools in north east England. Both procedures were completed by school nurses. The results of screening were validated against subsequent clinical assessment, including otological examination and actions taken by an independent assessor. RESULTS: Both methods produced broadly similar validation indices after two stages of screening: sensitivity was 74.4% for both methods; specificity was 92.1% and 90.0%; and predicted values of a positive test 43.2% and 37.6% respectively for pure tone audiometry and impedance methods. Single stage screening in both methods produced higher sensitivity but lower specificity and predictive values of a positive test than two stage screening. Screening rates were appreciably higher with impedance methods than with pure tone audiometry. CONCLUSIONS: In choosing the method to be used, it must be borne in mind that the impedance method is technically more efficient but takes longer than pure tone audiometry screening. However, the latter method allows opportunity for other health inquiries in these children.

Outbreak of Salmonella enteritidis phage type 4 infection associated with cheese and onion quiche.

Twelve people developed gastrointestinal symptoms suggestive of food poisoning after a party attended by between 60 and 80 people. The outbreak went unrecognised, however, until general practitioners admitted three patients to hospital, where faecal specimens were examined. An epidemiological investigation identified 12 cases, and a case control study showed a significant association between illness and eating a cheese and onion quiche at the party. Salmonella enteritidis phage type 4 was cultured from three out of seven faecal specimens obtained from cases. Consultants in communicable disease control should continue to encourage general practitioners to investigate and notify suspected cases of food poisoning.

GPs and contracting for secondary health care.

Publication of the NHS White Paper Working for Patients and subsequent legislation has introduced the requirement for district health authorities to assess the health and health care needs of their resident populations. Sam Ramaiah and colleagues describe their experience in South Tees of working with GPs to fulfil this objective.

Evaluation of pure tone audiometry and impedance screening in infant schoolchildren.

STUDY OBJECTIVE: The aims were (1) to evaluate impedance measurements against pure tone audiometry as a screening method for the detection of middle ear changes associated with hearing loss in infant school children; (2) to estimate the costs of the health authority of each method. DESIGN: The study involved two stage screening in which both methods were offered, pure tone audiometry being carried out by school nurses and impedance screening by a doctor. SETTING: 18 infant or primary schools in Langbaurgh, Cleveland, UK. PARTICIPANTS: 610 previously unscreened infant school children took part in the study. MEASUREMENTS AND MAIN RESULTS: Main outcome measures were the sensitivity, specificity, and predictive value of each screening method, using clinical assessment and action as the validating technique. The sensitivity and the predictive value of a positive test in two stage impedance screening was markedly superior to that of pure tone audiometry. The specificity was similar using the two methods. In addition the impedance methods was more rapid and estimated to consume less resource as a screening procedure than pure tone audiometry. CONCLUSIONS: The superiority of the use of impedance screening established in this study should be confirmed in a subsequent audit carried out purely by school nurses.