Patrick G. Wall

Study of infectious intestinal disease in England: rates in the community, presenting to general practice, and reported to national surveillance

Abstract Objective: To establish the incidence and aetiology of infectious intestinal disease in the community and presenting to general practitioners. Comparison with incidence and aetiology of cases reaching national laboratory based surveillance. Design: Population based community cohort incidence study, general practice based incidence studies, and case linkage to national laboratory surveillance. Setting: 70 general practices throughout England. Participants: 459 975 patients served by the practices. Community surveillance of 9776 randomly selected patients. Main outcome measures: Incidence of infectious intestinal disease in community and reported to general practice. Results: 781 cases were identified in the community cohort, giving an incidence of 19.4/100 person years (95% confidence interval 18.1 to 20.8). 8770 cases presented to general practice (3.3/100 person years (2.94 to 3.75)). One case was reported to national surveillance for every 1.4 laboratory identifications, 6.2 stools sent for laboratory investigation, 23 cases presenting to general practice, and 136 community cases. The ratio of cases in the community to cases reaching national surveillance was lower for bacterial pathogens (salmonella 3.2:1, campylobacter 7.6:1) than for viruses (rotavirus 35:1, small round structured viruses 1562:1). There were many cases for which no organism was identified. Conclusions: Infectious intestinal disease occurs in 1 in 5 people each year, of whom 1 in 6 presents to a general practitioner. The proportion of cases not recorded by national laboratory surveillance is large and varies widely by microorganism.Ways of supplementing the national laboratory surveillance system for infectious intestinal diseases should be considered.

Enterobacter sakazakii: An Emerging Pathogen in Powdered Infant Formula

Enterobacter sakazakii represents a significant risk to the health of neonates. This bacterium is an emerging opportunistic pathogen that is associated with rare but life-threatening cases of meningitis, necrotizing enterocolitis, and sepsis in premature and full-term infants. Infants aged <28 days are considered to be most at risk. Feeding with powdered infant formula (PIF) has been epidemiologically implicated in several clinical cases. Infants should be exclusively breast-fed for the first 6 months of life, and those who are not should be provided with a suitable breast-milk substitute. PIF is not a sterile product; to reduce the risk of infection, the reconstitution of powdered formula should be undertaken by caregivers using good hygienic measures and in accordance with the product manufacturers food safety guidelines.

The study of infectious intestinal disease in England: risk factors for cases of infectious intestinal disease with Campylobacter jejuni infection.

This is a case-control study aimed at identifying risk factors for intestinal infection with Campylobacter jejuni. Cases were defined as subjects with diarrhoea occurring in community cohorts or presenting to General Practitioners (GPs) with Campylobacter jejuni in stools. Controls were selected from GP lists or cohorts, matched by age, sex, and GP practice. Travel abroad and consumption of chicken in a restaurant were statistically significantly associated with being a case. There was no statistically significant risk associated with consumption of chicken other than in restaurants nor with reported domestic kitchen hygiene practices. Consumption of some foods was associated with a lower risk of being a case. Most cases remained unexplained. We suggest that infection with low numbers of micro-organisms, and individual susceptibility may play a greater role in the causation of campylobacter infection than previously thought. It is possible that in mild, sporadic cases infection may result from cross contamination from kitchen hygiene practices usually regarded as acceptable. Chicken may be a less important vehicle of infection for sporadic cases than for outbreaks, although its role as a source of infection in both settings requires further clarification in particular in relation to the effect of domestic hygiene practices. The potential effect of diet in reducing the risk of campylobacteriosis requires exploration.

Dissemination of Cronobacter spp. (Enterobacter sakazakii) in a Powdered Milk Protein Manufacturing Facility

ABSTRACT The microbial contamination of air filters and possible links to contaminated product in a powdered milk protein-processing facility were investigated. Over a 10-month period, seven air filters, the environment, and powdered product were analyzed for the presence of Cronobacter spp. The effects of air filter installation, maintenance, and subsequent dissemination of Cronobacter were investigated. A total of 30 isolates were characterized by pulsed-field gel electrophoresis (PFGE). PFGE revealed the presence of three clonal populations distributed throughout the manufacturing site. This study highlights the need for proper installation of air filters to limit the dissemination of microorganisms into processing sites.

Molecular Analysis of the Enterobacter sakazakii O-Antigen Gene Locus

ABSTRACT Nucleotide polymorphism associated with the O-antigen-encoding locus, rfb, in Enterobacter sakazakii was determined by PCR-restriction fragment length polymorphism analysis. Based on the analysis of these DNA profiles, 12 unique banding patterns were detected among a collection of 62 strains from diverse origins. Two common profiles were identified and were designated serotypes O:1 and O:2. DNA sequencing of the 12,500-bp region flanked by galF and gnd identified 11 open reading frames, all with the same transcriptional direction. Analysis of the proximal region of both sequences demonstrated remarkable heterogeneity. A PCR assay targeting genes specific for the two prominent serotypes was developed and applied for the identification of these strains recovered from food, environmental, and clinical samples.

Molecular fingerprinting defines a strain of Salmonella enterica serotype Anatum responsible for an international outbreak associated with formula-dried milk

Molecular analyses based on plasmid profile typing and pulsed-field gel electrophoresis have defined a strain of Salmonella enterica serotype Anatum associated with the consumption of a particular brand of formula-dried milk responsible for an outbreak in late 1996/early 1997 involving 15 infants and 2 relatives in the UK, and 2 infants in France. The study has demonstrated the value of laboratory-based surveillance involving identification of the outbreak strain at the molecular level coupled with food microbiology and targeted epidemiological investigations, and has highlighted the importance of rapid communication and subsequent international collaboration through the European Union-funded Salm-Net salmonella surveillance network.

MULTIRESISTANT SALMONELLA TYPHIMURIUM DT104 IN CATS : A PUBLIC HEALTH RISK

1Of particular importance in this increase has been the epidemic spread of a multiresistant strain of R type ACSSuT (A ampicillin; C, chloramphenicol; S, streptomycin, Su, sulphonamides; T, tetracyclines). 1 In 1995 over 87% of strains from human beings were resistant to these five antibiotics, with 26·9% and 6·2% of strains having additional resistances to trimethoprim and ciprofloxacin, respectively. 2

Trends in antimicrobial susceptibility among isolates of Campylobacter species in Ireland and the emergence of resistance to ciprofloxacin

Measurements were made of the susceptibility to six commonly prescribed antibiotics, including erythromycin, tetracycline and ciprofloxacin, of 130 isolates of Campylobacter jejuni and 15 isolates of Campylobacter coli cultured from human and poultry sources during 2000. The results were compared with the results from a collection of strains isolated between 1996 and 1998. The levels of resistance to erythromycin remained low, 2 per cent and 4.4 per cent for the human and poultry isolates, respectively. Resistance to tetracycline had increased to 31 per cent and 24.4 per cent from 13.9 per cent and 18.8 per cent for the human and poultry isolates, respectively. However, the resistance to ciprofloxacin of the strains isolated during 2000 had increased to 30 per cent, whereas between 1996 and 1998 there had been no resistance to this agent among human isolates, and only 3-1 per cent resistance among poultry isolates. The molecular basis for this resistance has been shown to be the result of a single amino acid substitution, Thr-86-lle, in the gyrA subunit of DNA gyrase in C jejuni. A subset of 59 isolates was tested by molecular methods and all of the 25 phenotypically resistant isolates possessed this substitution. None of the human isolates had been treated with ciprofloxacin before their laboratory isolation.

An estimate of the proportion of diarrhoeal disease episodes seen by general practitioners attributable to rotavirus in children under 5 y of age in England and Wales.

Mean weekly incidence rates for a 4‐week period of new episodes of infectious intestinal disease (IID) and laboratory reports of faecal isolations in children under 5 y of age presenting in general practice were used to estimate the incidence of IID due to rotavirus infection in England and Wales. Between January 1992 and December 1996, a total of 92452 new episodes of IID were seen at sentinel general practices and reported to the Royal College of General Practitioners (RCGP) Research Unit in Birmingham, UK. Of these 32% (29592) were in children under 5 y of age. During the same period the Communicable Disease Surveillance Centre (CDSC) in London, UK received 159532 reports of faecal identifications in children under 5 yof age; 69219 (43%) of these wer due to rotavirus. By modelling RCGP data and laboratory reports, the proportion of episodes attributable to rotavirus infection was estimated to be 29% (95% CI: 24% to 34%). By extrapolation of RCGP data it was estimated that rotavirus accounted for 762000 of new episodes of IID nationally in children under 5 y of age between January 1992 and December 1996. Implementation of a rotavjrus vaccinatio programme could substantially reduce the incidence of childhood diarrhoea. □General practice, rotavirus

A Tale of Two Crises: The Belgian and Irish Dioxin Contamination Incidents

Purpose – This paper aims to provide a focused overview of two dioxin incidents, with particular emphasis on regulatory successes and failures and their respective causes. The paper seeks to adopt a comparative approach to the case studies, with considerable use made of primary sources such as parliamentary debate, government reports and EC legislation.Design/methodology/approach – The paper is a review of the strengths and weaknesses in the management of the Belgian and Irish dioxin contanimation incidents.Findings – It is concluded that open, transparent and decisive risk management, based on robust risk assessment, is paramount in ensuring confidence in both the food supply chain and, in the feed and food safety regulatory process. It is also concluded that the 2008 Irish dioxin incident tested the reforms prompted by previous food scares.Practical implications – It is important that the lessons from these two incidents are learnt if they are not to be repeated in other jurisdictions.Originality/value ...