scholarly journals Novel application of the matched case–control design to compare food supply chains during an Escherichia coli O157 outbreak, United Kingdom, 2016

2018 ◽  
Vol 23 (18) ◽  
Author(s):  
Thomas Inns ◽  
Paul Cleary ◽  
Nick Bundle ◽  
Sarah Foulkes ◽  
Ashley Sharp ◽  
...  

There is a need for innovative methods to investigate outbreaks of food-borne infection linked to produce with a complex distribution network. The investigation of a large outbreak of Escherichia coli O157 PT34 infection in the United Kingdom in 2016 indicated that catering venues associated with multiple cases had used salad leaves sourced from one supplier. Our aim was to investigate whether catering venues linked to cases were more likely to have used salad leaves from this supplier. We conducted a matched case–control study, with catering venues as the units of analysis. We compared venues linked to cases to those without known linked cases. We included 43 study pairs and obtained information on salad leaf products received by each venue. The odds of a case venue being supplied with salad leaves by Supplier A were 7.67 times (95% confidence interval: 2.30–25.53) those of control venues. This association provided statistical evidence to support the findings of the other epidemiological investigations undertaken for this outbreak. This is a novel approach which is labour-intensive but which addresses the challenge of investigating exposures to food across a complex distribution network.

2011 ◽  
Vol 44 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Hong-Jyun Chang ◽  
Po-Chang Hsu ◽  
Chien-Chang Yang ◽  
An-Jing Kuo ◽  
Ju-Hsin Chia ◽  
...  

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S409-S410
Author(s):  
Shota Myojin ◽  
Kyongsun Pak ◽  
Mayumi Sako ◽  
Tohru Kobayashi ◽  
Takuri Takahashi ◽  
...  

Abstract Background The role of therapeutic intervention, particularly antibiotics, for Shiga toxin-producing Escherichia coli (STEC) related infection is controversial. Methods We performed a population based matched case-control study to assess the association between treatment (antibiotics, antidiarrheal agents and probiotics) for STEC related infections and HUS development. We identified all STEC HUS patients as cases and matched five non-HUS patients as controls using the data from the National Epidemiological Surveillance of Infectious Diseases (NESID) between January 1, 2017, and December 31, 2018. Further medical information was obtained by standardized questionnaires answered by physicians who registered each patient. We used multivariate conditional logistic regression model to evaluate the association between exposures (use of antibiotics, use of antidiarrheal agents, days between disease onset and fosfomycin administration [within two or three days]) and the development of HUS, by matched odds ratios (OR) and 95% confidence intervals (CI). Covariates we used were sex, age group, area code, presence of diarrhea and other factors. We also performed subgroup analyses using age (adults and children) as a stratification factor. Results 7,760 STEC related patients were registered in the NESID. We selected patients who had a record of HUS diagnosis (n=182) and matched controls without HUS (n=910). After collecting standardized paper-based questionnaires, we enrolled 90 HUS patients and 371 non-HUS patients for analysis. In the main analysis, matched OR of fosfomycin was 0.75(0.47-1.20) in all ages, 1.41(0.51-3.88) in adults and 0.58(0.34-1.01) in children. Matched OR of antidiarrheal agents was 2.07(1.07-4.03) in all ages, 1.84(0.32-10.53) in adults, 2.65(1.21-5.82) in children. Matched OR of probiotics was 0.86(0.46-1.61) in all ages, 0.76(0.21-2.71) in adults, 1.00(0.48-2.09) in children. There was no significant association between the timing of fosfomycin use in the first two or five days of illness and HUS development in any age group. Conclusion Our results suggest that fosfomycin might decrease the risk of HUS in children younger than 15 years of age with STEC confirmed bacterial gastroenteritis. Disclosures All Authors: No reported disclosures


2004 ◽  
Vol 132 (2) ◽  
pp. 283-289 ◽  
Author(s):  
D. M. MacDONALD ◽  
M. FYFE ◽  
A. PACCAGNELLA ◽  
A. TRINIDAD ◽  
K. LOUIE ◽  
...  

An outbreak of E. coli O157:H7 infections was identified in November 1999 with a fivefold increase in the occurrence of laboratory-confirmed cases of E. coli O157:H7 infection. A matched case-control study was conducted. Samples of food from cases and from retailers were analysed for the presence of E. coli O157:H7. A total of 143 cases were identified over a 12-week period with the same pulsed-field gel electrophoresis (PFGE) pattern. The case-control study found that Company A salami was significantly associated with illness (Mantel–Haenszel matched odds ratio 10·0, 95% CI 1·4–434, P=0·01). Company A salami tested positive for E. coli O157:H7 and isolates had the same PFGE pattern as case isolates. An immediate voluntary national recall of Company A dry fermented meat products took place. Findings from the investigation of this outbreak suggest that the hold-and-test option may not be adequate to prevent shiga-toxigenic Escherichia coli (STEC) infection in salami consumers.


2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Joshua Kaduma ◽  
Jeremiah Seni ◽  
Clotilda Chuma ◽  
Richard Kirita ◽  
Fridolin Mujuni ◽  
...  

Urinary tract infection (UTI) and preeclampsia are common among pregnant women and are associated with adverse maternal-fetal and neonatal outcomes. Despite this, limited information exists on the association between UTIs and preeclampsia in Tanzania to guide specific management and thereby averting the adverse outcomes. A 1:2 matched case-control study (by age and gravidity) involving 131 pregnant women with preeclampsia (cases) and 262 without preeclampsia (controls) was conducted. Sociodemographic and clinical information was collected using a questionnaire. Midstream urine samples were collected during admission for culture and antimicrobial susceptibility testing (AST). Out of 393 pregnant women enrolled, 110 (28.0%), 95% CI: 23.8%-32.7%, had significant bacteriuria [cases: 50.4% (66/131) and control: 16.8% (44/262)]. Pregnant women with preeclampsia had 7.7 odds of having significant bacteriuria than those without preeclampsia [OR=7.7, 95% CI (4.11-14.49); p-value <0.001]. Escherichia coli, 50 (45.5%), and Klebsiella spp., 25 (23.6%), predominated, and resistance to gentamicin, ceftriaxone, and piperacillin-tazobactam ranged from 9.0% to 29.0% in these dominant species. Extended spectrum beta lactamases (ESBL) production in Escherichia coli and Klebsiella spp. was 18.0% (9/50) and 15.4% (4/26), respectively. Routine urine culture and AST among pregnant women with preeclampsia should be introduced in the antenatal clinics to ensure prompt management. Delineation of maternal-fetal and neonatal outcomes among pregnant women with preeclampsia and UTIs would be of interest in future studies.


2007 ◽  
Vol 70 (6) ◽  
pp. 1483-1488 ◽  
Author(s):  
ANDREA CURRIE ◽  
JUDY MACDONALD ◽  
ANDREA ELLIS ◽  
JENNIFER SIUSHANSIAN ◽  
LINDA CHUI ◽  
...  

The Calgary Health Region identified an outbreak of Escherichia coli O157:H7 infection in September 2004 following a fourfold increase in laboratory reports. Clinical isolates were indistinguishable by pulsed-field gel electrophoresis (PFGE), and the PFGE pattern was unique in North America. Most affected individuals reported beef donair consumption in 10-day food histories. We conducted a matched case-control study, inspected the implicated food premises, and conducted a traceback investigation of suspect ground beef to determine the source of the outbreak and implement prevention and control measures. A total of 43 laboratory-confirmed cases were identified, with symptom onsets between 8 September and 1 October 2004. Among 26 matched case-control pairs, consumption of beef donair from one of two locations of a local restaurant chain was the only statistically significant risk factor for infection (matched odds ratio undefined; P &lt; 0.01). No samples of the implicated ground beef were available for microbiological testing. We identified several opportunities for time-temperature abuse and other factors that may have contributed to the serving of unsafe donair meat at the implicated restaurants. This outbreak highlighted gaps in food safety policy related to beef donair and similar products in Canada. Immediately following the outbreak, the Region implemented new safe food handling requirements and a Federal/Provincial/Territorial Working Group was established to make recommendations for national food safety policies specific to these products.


2018 ◽  
Vol 23 (18) ◽  
Author(s):  
Maya Gobin ◽  
Jeremy Hawker ◽  
Paul Cleary ◽  
Thomas Inns ◽  
Daniel Gardiner ◽  
...  

We investigated a large outbreak of Escherichia coli O157 in the United Kingdom (UK) with 165 cases between 31 May and 29 July 2016. No linked cases were reported in other countries. Cases were predominately female (n = 128) and adult (n = 150), 66 attended hospital and nine had features of haemorrhagic uraemic syndrome. A series of epidemiological studies (case–control, case–case, ingredients-based and venue-based studies) and supply chain investigations implicated mixed salad leaves from Supplier A as the likely outbreak vehicle. Whole genome sequencing (WGS) indicated a link with strains from the Mediterranean and informed the outbreak control team to request that Supplier A cease distributing salad leaves imported from Italy. Microbiological tests of samples of salad leaves from Supplier A were negative. We were unable to confirm the source of contamination or the contaminated constituent leaf although our evidence pointed to red batavia received from Italy as the most likely vehicle. Variations in Shiga toxin-producing E. coli surveillance and diagnosis may have prevented detection of cases outside the UK and highlights a need for greater standardisation. WGS was useful in targeting investigations, but greater coverage across Europe is needed to maximise its potential.


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