Published Date: 2005-10-07 23:50:00
Subject: PRO/EDR> E. coli O157, schools - UK (Wales)(05)
Archive Number: 20051007.2929
E. COLI O157, SCHOOLS - UK (WALES)(05)
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Date: Thu, 6 Oct 2005
From: ProMED-mail <firstname.lastname@example.org>
Source: Eurosurveillance [edited]
By 3 Oct 2005, 157 cases of infection had been reported in an outbreak of
verotoxin-producing _Escherichia coli_ (VTEC) O157 in south Wales in the
United Kingdom [1,2]. A case was defined as any person living in south Wales
who presented with bloody diarrhea or had a fecal isolate of presumptive VTEC
O157 in September 2005. 97 of the cases have been microbiologically confirmed
as VTEC O157, and all are phage type (PT) 21/28 and produce verotoxin (VT) 2,
with the exception of 1 case that is PT32 VT2. 4 other microbiologically
confirmed cases of _E. coli_ O157 infection have phage types not associated
with the outbreak (3 VT-negative strains of PT1, and 1 isolate of PT8, VT1+2),
and have been excluded from the outbreak case list because the patients have
plausible alternative histories to explain their infection.�
67 males and 90 females are affected, and 65 percent of cases (102/157) are in
children of school age. Dates of symptom onset range from 10 to 30 Sep 2005
[for figure, see URL above - Mod.LL], and over 40 schools have recorded cases.
There has been one death, a 5-year-old boy.
Evidence suggests a link between the outbreak and a supplier of cooked meats
to the school meals services. The distribution of cases is small numbers in a
large number of schools and suggests a centrally distributed product with low
levels of contamination rather than a problem in individual schools. This was
followed by secondary person-to-person spread.
10 of the first 18 primary cases in infected schoolchildren with early symptom
onset dates before 17 Sep 2005 were contacted between 16 and 20 Sep 2005. All
reported having eaten lunch in the school canteen, compared with 8 out of 13
controls who were selected at random from the school register (p less than
0.05). Overall, approximately 60 percent of children in the affected areas eat
lunch in their school canteens each day.
A single main supplier distributes cooked meats to the affected schools. Local
authorities took action on 19 Sep 2005, after identifying practices that could
result in contamination of cooked meat at the supplier's premises, and the
Food Standards Agency Wales issued a food alert on 21 Sep 2005 .
_E. coli_ O157 has been isolated from 3 samples of sliced cooked meat obtained
by environmental health staff. Isolates have been confirmed as PT21/28, VT2
and examined by pulsed field gel electrophoresis (PFGE). Results on cultures
from 2 samples have so far shown that PFGE profiles of strains from the food
samples are indistinguishable from those found in people with the infection.
PFGE typing is continuing on the 3rd strain. Contaminated cooked meats have
been associated with previous outbreaks of VTEC O157 infection in the United
Control measures to remove ready-to-eat foods (that is, foods not cooked on
the premises) from schools, and to cancel educational activities that
facilitate person-to-person spread, have been in place since the week
beginning 19 Sep 2005 and are under constant review by the outbreak control
This article has been adapted from reference 2.
1.Health Protection Agency. Verotoxin-producing E.coli O157 (VTEC O157) at a
school in the south Wales valleys. Commun Dis Rep CDR Wkly 2005; 15(38): news.
2.Health Protection Agency. Vero-cytotoxin producing E. coli O157 (VTEC O157)
outbreak in the south Wales valleys: update. Commun Dis Rep CDR Wkly 2005; 15
3.Food Standards Agency. Withdrawal of cooked meats produced by John Tudor &
Son of Bridgend, Wales. Food Alert, 21 Sep 2005.
4.PHLS. Outbreak of VTEC O157 infection in East Sussex. Commun Dis Rep CDR
Wkly 1999; 9(25):219, 222.
5.The Scottish Office. The Pennington Group Report on the circumstances
leading to the 1996 outbreak of infection with E. coli O157 in Central
[Byline: Roland Salmon (<email@example.com>), on behalf of the
outbreak control team, Communicable Disease Surveillance Centre, National
Public Health Service for Wales, Cardiff, United Kingdom]
[This is the official version of this outbreak of VTEC. - Mod.LL]