Published Date: 2009-08-17 21:00:06
Subject: PRO/AH/EDR> E. coli O157 - UK (02): Wales, HUS cluster
Archive Number: 20090817.2916
E. COLI O157 - UK (02): WALES, HUS CLUSTER
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Thu 13 Aug 2009
Source: Eurosurveillance [edited]
The National Public Health Service for Wales (NPHS) and Environmental
Health Officers from Wrexham County Borough Council (WCBC) are
currently investigating 4 cases of verocytotoxin-producing
_Escherichia coli_ O157 (VTEC O157) in the Wrexham area.
The cases are all females, aged 3, 23, 32 and 32 years. Case 1 had an
onset date of 20 Jul 2009 and was reported to the NPHS on 22 Jul 2009
after a positive stool sample result. She later developed hemolytic
uremic syndrome and thrombocytopenic purpura and was admitted to
hospital on 28 Jul 2009. She is currently receiving renal dialysis
and ongoing plasmapheresis. Case 2 had an onset date of 21 Jul 2009
and was reported to the NPHS on 24 Jul 2009. She is recovering at
home. Case 3 and 4 are a mother and daughter, both with onset of
symptoms on 21 Jul 2009. The child was admitted to hospital on 27 Jul
2009 with hemolytic uremic syndrome and required dialysis for 5 days.
She has now been discharged. Samples were taken from mother and child
at the hospital, and the results were reported to the NPHS on 30 Jul
2009. All 4 cases reported eating different products (chicken, beef
and vegetarian burgers) from a fast food outlet in the area in the
week before becoming unwell. The possi!
bility that the cases have links involving other common exposures is
still being explored.
Fecal samples from all the cases were confirmed as positive for _E.
coli_ O157. Confirmation and typing at the Laboratory of
Gastrointestinal Pathogens (LGP) at the Health Protection Agency in
London have shown them all to belong to phage type (PT) 2 and to
possess genes encoding verocytotoxin VT2. The isolates were
indistinguishable from each other by pulsed field gel electrophoresis
(PFGE) of XbaI fragments. Variable number tandem repeat typing showed
that they had the same profile that was not found in other isolates
of PT2 from 2009 tested so far.
The food outlet was visited by Environmental Health Officers from
WCBC on 30 Jul 2009. Several problems were identified, such as poor
food handling techniques, lack of hand washing equipment, no evidence
of food hygiene training for staff and no food safety management
system in place. As a precaution, the outlet is currently the subject
of a Hygiene Emergency Prohibition Order and is closed until further
notice. This means that the owners have to demonstrate that systems
are in place to correct the deficiencies identified and satisfy the
Environmental Health Officers that food handling practices will
change before reopening. Food and environmental samples were taken
from the food outlet for laboratory investigations. Results are pending.
Active case finding has been pursued using local general
practitioners, but there have been no further cases reported to date.
VTEC O157 PT2 strains may be associated with the development of
serious illness. They have represented around 10 percent of isolates
in England and Wales since 2005, compared with the most prevalent
type, PT21/28, that accounted for up to 40 percent of reports (1,2).
24 isolates of VTEC O157 were confirmed from Welsh laboratories in
2009 up until 3 Aug 2009. Prior to the cases reported here, there
were only 2 sporadic infections with PT2 (in mid-March 2009), and
neither was from North Wales. Food or animal sources were not
investigated for these unlinked cases.
1. Health Protection Agency: Verocytotoxin-producing Escherichia coli
O157: 2006. Health Protection Report 2007;1(32). Available from:
2. Health Protection Agency: Verocytotoxin-producing Escherichia coli
O157: 2007 and 2008. Health Protection Report 2009. Available from:
[Reported by: Hart J (1), Smith G (2)
1. North Wales Health Protection Team, National Public Health
Service for Wales, Mold, Flintshire, United Kingdom
2. Laboratory of Gastrointestinal Pathogens, Health Protection
Agency Centre for Infections, London, United Kingdom]
[Even though phage type 2 can be associated with a higher incidence
of complications, in this report, 2 of 4 cases developed hemolytic
uremic syndrome. It is likely that a significant number of less
severe cases may have occurred in association with these cases. - Mod.LL]