Download Salmonella newport infection in England

Eurosurveillance Weekly, funded by Directorate General Health and Consumer Protection of the
European Commission, is also available on the world wide web at <http://www.eurosurv.org/>. If you have
any questions, please contact Birte Twisselmann <[email protected]>, +44 (0)20-8200 6868
extension 4417. Neither the European Commission nor any person acting on its behalf is liable for any
use made of the information published here.
Eurosurveillance Weekly: Thursday 28 June 2001. Volume 5, Issue 26
Contents:
1. Syphilis transmission in homo/bisexual men : New outbreak in London, continuing outbreak in
Dublin
2. Salmonella newport infection in England associated with the consumption of ready to eat salad
3. Cases of legionnaires’ disease in the UK and Sweden linked with a London site
4. Behavioural intervention does not reduce incidence of sexually transmitted diseases in
homosexual men
Syphilis transmission in homo/bisexual men : New outbreak in London,
continuing outbreak in Dublin
In the past eight weeks, 18 cases of infectious syphilis have been diagnosed in homo/bisexual men
attanding sexually transmitted infection clinics in North, East and South East London (1). Fifteen of the
cases are in men who are known to be infected with HIV, including some who are known to have been
HIV-infected for a considerable period of time. Local surveillance has been intensified. Outbreak control
measures have been instituted, including increased syphilis testing in known HIV-infected patients and
increased health promotion activities in venues frequented by homo/bisexual men.
The enhanced syphilis surveillance in Ireland has ascertained over 10 cases of primary and secondary
syphilis each month since the beginning of 2001, including 17 cases in March and 13 cases in April (2).
Of the 109 cases reported since January 2000, 106 are associated with the outbreak in Dublin (3). Fourfifths of the cases are in homo/bisexual men.
These syphilis outbreaks in homo/bisexual men in London and Dublin follow the large outbreak reported
recently from Antwerp (4), and earlier outbreaks in Paris (5) and Oslo (6), and in Manchester and
Brighton in England (7).
References:
1. PHLS CDSC (London). News Bulletin 25/01, week beginning June 18th 2001.
2. Domegan L, Cronin M. Enhanced surveillance of syphilis. EPI-INSIGHT 2001; 2 (June):4.
3. NDSC. Update: Syphilis outbreak. EPI-INSIGHT 2001; 2 (April):1.
4. De Schrijver K. Syphilis outbreak in Antwerp, Belgium. Eurosurveillance weekly 2001; 5: 010510.
(<http://www.eurosurv.org/2001/010510.html>)
5. Doherty L, Fenton K, O'Flanagan D, Couturier E. Evidence for increased transmission of syphilis among homosexual
men and heterosexual men and women in Europe. Eurosurveillance Weekly 2000; 4: 001214.
(<http://www.eurosurv.org/2000/001214.htm>).
6. Blystad H, Nilsen Ø, Aavitsland P. An outbreak of syphilis among homosexual men in Oslo, Norway. Eurosurveillance
Weekly 1999; 3: 991118. (<http://www.eurosurv.org/1999/991118.html>)
7. Fenton K. Syphilis continues in gay men in Greater Manchester, England. Eurosurveillance Weekly 2001; 5: 010409.
(<http://www.eurosurv.org/2001/010419.html>)
Reported by Noel Gill, ([email protected]), Public Health Laboratory Service, Communicable Disease
Surveillance Centre, London.
Salmonella newport infection in England associated with the consumption of
ready to eat salad
Nine human cases of infection with Salmonella newport with a possible link to a salad item have been
identified in England. The cases were identified following the isolation of S. newport from a salad item as
part of the PHLS/LACOTS survey of retail prepared pre-packed ready-to-eat salad vegetables in the
United Kingdom (1).
Cases range in age from 4 to 74 years (median 33 years) and are distributed throughout England. Onset
dates of illness range from June 2 nd to 8th. Salad consumption has been confirmed in six cases and food
histories are awaited from the other two. The two cases from one area (who are not related to each
other) are known to have consumed the implicated salad item three and six days prior to the onset of
illness. One of the six cases from whom a food history has been obtained, is known to be a vegetarian.
None of the cases travelled abroad during the incubation period.
Isolates from the salad item and the nine cases exhibit an unusual reaction with the PHLS Laboratory of
Enteric Pathogens phage typing scheme for S. newport. Additional molecular work has shown that
isolates from the salad and five of the human cases have a unique plasmid profile. The salad isolate and
three of the human isolates are also indistinguishable using pulsed field gel electrophoresis. Examination
of the remaining human isolates using molecular methods is underway.
On June 22nd an urgent request for information was sent to all participants in the Enter-net
(http://www.Enter-net.org.uk) surveillance network (2). Of the seven countries that had replied by June
28th, none reported an increase in human cases of S. newport in recent weeks. Several countries
reported on foodstuffs contaminated with this serotype, but these were predominantly strains from poultry
samples, and a few strains had been isolated from reptiles.
Salmonellosis associated with the consumption of salad items is relatively uncommon, although two
notable outbreaks occurred last year. In a widespread outbreak of multiresistant S. typhimurium DT104
infection in England, where 361 people were affected and one person was known to have died, illness
was epidemiologically linked to the consumption of lettuce away from home in the three days prior to the
onset of illness. Investigations in Iceland into a Europe-wide outbreak of multiresistant S. typhimurium
DT204b (which included 125 cases in England and Wales) revealed an association between illness and
the consumption of imported iceberg lettuce (3).
Reported by S O’Brien ([email protected]) and I Fisher, Enter-net scientific co-ordinator,
([email protected]).
References:
1. LACOTS/PHLS co-ordinated Food Liaison Group Studies: microbiological examination of retail prepared pre-packed
ready-to-eat salad vegetables; sampling protocol. Available to subscribers online at (<http://www.LACOTS.com>.)
2. IST Fisher on behalf of the Enter-net participants. The Enter-net international surveillance network - how it works.
Eurosurveillance1999; 4: p 52-5. (http://www.eurosurveillance.org/eurosurveillance/v4n5/en33-22.htm)
3. PHLS. Outbreaks of Salmonella typhimurium DT204b infection in England and Wales and elsewhere in Europe.
Commun Dis Rep CDR Wkly 2000; 10 (39): 349. http://www.phls.co.uk/publications/CDR00/cdr3900.pdf)
Cases of legionnaires’ disease in the UK and Sweden linked with a London site
Three confirmed cases of legionnaires’ disease have been associated with central London, in particular
the area of Portman Square. The cases are all men aged between 31 and 61 years in whom illness
onsets were 22 May, 25 May, and 3 June. Two cases had worked in the area. The third case was
reported to the PHLS Communicable Disease Surveillance Centre (CDSC) by the Swedish collaborator in
the European Surveillance Scheme for Travel Associated Legionaires’ Disease (1). This case had visited
London and been in the Portman Square area before the onset of his illness. All cases were diagnosed
in their admitting hospital by urinary antigen detection. Legionella pneumophila serogroup1 infection has
been confirmed in the two British cases by the Respiratory and Systemic Infection Laboratory at the
PHLS Central Public Health Laboratory.
An outbreak control team has been convened and possible environmental sources of infection within a
500 metre radius of Portman Square are being investigated. L. pneumophila serogroup 1 has been
identified in water systems and cooling towers in three buildings in the vicinity. Control measures have
been taken at all three sites and further investigations are in hand.
All Consultants for Communicable Disease Control in England and Wales have been alerted to the
outbreak. Information has been disseminated in Europe through the European Surveillance Scheme for
Travel Associated Legionnaires’ Disease and in the United States via the Centers for Disease Control
and Prevention (CDC). CDSC would be grateful for information on any other suspected cases of
legionnaires’ disease who became ill during May or June that might be associated with this incident.
Please contact Carol Joseph, European legionella surveillance scheme project co-ordinator (tel: 0208 200
6868 ext 4497; email [email protected]).
Information on the European surveillance scheme for travel associated legionnaires’ disease can be
obtained from its website www.ewgli.org
Reported by Carol Joseph, ([email protected]), Public Health Laboratory Service, Communicable
Disease Surveillance Centre, London.
Behavioural intervention does not reduce incidence of sexually transmitted
diseases in homosexual men
The need for effective HIV prevention strategies based on reducing sexual risk behaviour remains
important. A study reported in the BMJ found, however, that even a carefully designed, brief, behavioural
intervention did not reduce the risk of participants acquiring new sexually transmitted infections (STIs) as
a proxy for unprotected anal intercourse (1).
The researchers conducted a randomised controlled trial with 12 months' follow up. Participants were 343
gay men attending a sexual health clinic in London from September 1995 to November 1997 who
presented with an acute STI, reported having had unprotected anal intercourse in the past year, or
expressed concern about their sexual practices.
All participants received standard management consisting of a 20 minute one to one counselling session
about sexual risk behaviour. Contact tracing was offered to those with a newly diagnosed infection; and
participants could also be referred to clinic-based or community-based education on HIV prevention and
counselling services. Additionally, participants assigned to the intervention were invited to a one-day
workshop.
Behavioural outcomes were followed up by using postal questionnaires. Clinic and laboratory databases
were reviewed to identify new STIs diagnosed at the clinic. Attendance at other clinics in greater London
was determined by matching individuals to a regional database. Re-attendance at the clinic was not
required by the protocol.
Self reported changes in sexual behaviour were modest, but generally there was more improvement in
the intervention group, where the proportion of men engaging in unprotected anal intercourse in the past
month decreased from 37% (63/172) at baseline to 24% (32/136) at 6 months and 27% (31/114) at 12
months. In the control group the proportion changed little: from 30% (50/166) at baseline to 32% (44/139)
at 6 months and 32% (39/124) at 12 months. After adjusting for infections and unprotected anal
intercourse at baseline, differences in these proportions between the arms of the trial were not significant
(P=0.07 at 6 months and P=0.31 at 12 months). Findings were similar for the proportions having
unprotected anal intercourse in the past 12 months (61% (106/174) in the intervention group and 63%
(104/166) in the control group at baseline, compared with 50% (58/116) and 59% (76/128) respectively at
12 months).
However, 31% (38/123) of the intervention group and 21% (35/168) of controls had had at least one new
STI diagnosed at the clinic. Considering only men who requested a check up for STIs, the proportion
diagnosed with a new infection was 58% (53/91) for men in the intervention group and 43% (35/81) for
men in the control group (adjusted odds ratio 1.84, 95% confidence interval 0.99 to 3.40). The higher risk
of acquiring a STI among participants in the intervention arm was unexpected, at odds with the data on
sexual behaviour, and clearly a cause for concern.
Despite its promise and acceptability, the brief cognitive intervention aimed at gay men at high risk of STI
did not reduce their risk of acquiring new infections. Even carefully formulated behavioural interventions
should not be assumed to bring benefit. It is important to evaluate their effects in randomised trials by
using clinical end points wherever possible.
Reference:
1.
Imrie J, Stephenson JM, Cowan FM, Wanigaratne S, Billing ton AJP, Copas AJ, et al. A cognitive behavioural intervention
to reduce sexually transmitted infections among gay men: randomised trial BMJ 2001;322:1451-6. (
http://www.bmj.com/cgi/content/full/322/7300/1451)
Reported by Birte Twisselmann ( [email protected]), Eurosurveillance editorial office.