Transcript Emerging Food Pathogens

Emerging Food Pathogens
Irene Gallou
Helen Greet
Jo McIntyre
We considered a number of pathogens : •
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E.coli
Salmonella
Campylobacter
Listeria
Norwalk Virus
Data from the Public Health Laboratory
Service was used to compile the graphs
on the following slides.
• All the pathogens studied are
notifiable infections.
• The authorities, in the shape of
the Communicable Disease
Surveillance Centre must be
informed of any suspected cases
of these infections.
• The GP or attending medical
officer is responsible for
notifying the CDSC of any
suspected infection.
E.coli 0157and Salmonella Infections in England and
Wales, 1981/2 – 2001.
Salmonella Infections
35000
1000
30000
20000
15000
Year
E.coli infections have increased dramatically
over the years and remain high to date.
99
96
19
93
19
90
19
81
19
00
20
98
19
96
19
94
19
92
19
19
19
19
19
19
90
0
88
0
86
5000
84
200
87
10000
19
400
S.typhimurium
S.enteritidis
Other Serotypes
Total Salmonellas
84
600
25000
19
800
19
No. of Cases
1200
82
No. of Cases
E.coli 0157 Infections
Year
S.enteridis is the most common salmonella
infection since 1988, accounting for two
thirds of all cases reported.
Campylobacter and Listeria Infections in England and
Wales, 1980/6 – 2001.
Listeriosis Cases
300
70000
60000
50000
40000
30000
20000
10000
0
No. of Cases
250
200
Total
Pregnancy
Non-Pregnancy
150
100
00
20
98
19
96
19
94
19
92
19
90
19
88
50
19
19
86
No. of Cases
Campylobacter Infections
Year
Campylobacter is the most prevalent food
pathogen, and cases have increased steadily
since data began in 1980.
0
1980 1985 1990 1995 2000 2005
Year
Listeria in pregnancy can cause damage
or death to the fetus and is a very serious
condition. Cases of listeria peaked in
1987 and have decreased since, though a
smaller peak occurred mid 1990s.
Norwalk Virus
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This virus is becoming more widely
recognised as a common pathogenic
agent in cases of gastroenteritis,
particularly in children.
The rate of transmission is greater than
50% in outbreaks among children such
as in schools and nurseries.
It is thought the virus can be
transmitted through the air as well as in
contaminated food and/or water.
Several modes of transmission would
account for the high infectivity of this
virus.
From 1992 – 2000 there were 1877
outbreaks of Norwalk related disease in
England and Wales, and three quarters
of them were in ‘Health Care
Situations’, i.e. nursing homes and
hospitals.
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Negative stain Transmission Electron
microscopy of Norwalk Virus: (From a stool sample of a patient suffering
from gastroenteritis)
Norwalk is a ‘Small Round Structured
Virus’ (SRSV)
Total Food Poisoning Cases in England and Wales,
1982 – 2000.
Statutory Notification of Food
Poisoning
Note: Formal =
Formally
Notified.
No. of Cases
100,000
80,000
Total
Formal
Other
60,000
40,000
20,000
2000
1998
1996
1994
1992
1990
1988
1986
1984
1982
0
Year
Food poisoning cases rose steadily to peak in the mid-1990s and have
declined slightly since then.
Other =
Informally
Notified/
Reported.
Trends in Food Poisoning Cases
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Food poisoning cases tend to follow a
pattern, reported cases increase to a
peak, and become ‘News’.
Then public awareness of the pathogen
in question is raised by media coverage
of outbreaks and increasing prevalence.
Media campaigns disseminate the
necessary information to allow the
public to guard against the pathogen.
Guidelines are published by the
Department of Health or similar
organisations, on how to avoid a
particular infection, or how to minimise
the risk of contracting it.
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Cases will fall as the public becomes
aware of guidelines and procedures to
avoid infection.
A ‘new’ pathogen will emerge and the
cycle begins again with the ‘latest
thing’ as the major source of outbreaks.
Many food poisoning cases are
underreported, particularly if medical
attention is not sought.
Also people tend to ‘suffer from’
whichever pathogen was last brought to
their attention, i.e salmonella in the
1980s and E.coli in the 1990s etc.
Particular pathogens in the News at any
time become ‘fashionable’ and are
blamed for every upset stomach that
occurs.
Public Health Laboratory Service.
• The PHLS publish data relating to the numbers of reported cases of
various diseases and infections, including food poisonings.
• They also publish guidelines on the control of outbreaks, for example
in schools and nurseries.
• PHLS data is accurate and reported without hysteria or ‘hype’. The
PHLS deal with the FACTS of the infections and pathogens they deal
with.
• The PHLS publish accurate figures for confirmed cases of all the
diseases they deal with.
www.phls.co.uk
References.
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Baron RC, Murphy FD, Greenberg HB, Davis CE, Bregman DJ, Gary GW, Hughes
JM, Schonberger LB. Norwalk gastrointestinal illness: an outbreak associated with
swimming in a recreational lake and secondary person-to-person transmission. Am J
Epidemiol 1982; 115: 163-72.
Kaplan JE, Feldman R, Campbell DS, Lookabaugh C, Gary GW. The frequency of a
Norwalk-like pattern of illness in outbreaks of acute gastroenteritis. Am J Public
Health 1982; 72: 1329-32.
Kaplan JE, Gary GW, Baron RC, Singh N, Schonberger LB, Feldman R, Greenberg
HB. Epidemiology of Norwalk gastroenteritis and the role of Norwalk virus in
outbreaks of acute nonbacterial gastroenteritis. Ann Intern Med 1982; 96: 756-61.
PHLS. www.phls.co.uk/home
PHLS. Outbreaks of Norwalk-like virus infection. Commun Dis Rep CDR Weekly
[serial online] 2002 [cited 10 April 2002]: 12 (4): news. Available at
<http://www.phls.org.uk/publications/CDR%20Weekly/archive02/News/news0402.h
tml#Norwalk>.
Sawyer LA, Murphy JJ, Kaplan JE, et al. 25- to 30-nM virus particle associated with
a hospital outbreak of acute gastroenteritis with evidence for airborne transmission.
Am J Epidemiol 1988; 127: 1261-71.
References 2.
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Thornhill TS, Kalica AR, Wyatt RG, Kapikian AZ, Chanock RM. Pattern of shedding of
the Norwalk particle in stools during experimentally induced gastroenteritis in
volunteers as determined by immune electron microscopy. J Infect Dis 1975; 132: 2834.
URL: http://www.epa.gov/nerlcwww/norwalk.htm
White KE, Osterholm MT, Mariotti JA, Korlath JA, Lawrence DH, Ristinen TL,
Greenberg HB. A foodborne outbreak of Norwalk virus gastroenteritis: evidence for
post-recovery transmission. Am J Epidemiol 1986; 124: 120- 6.