1 current public health problems related to pork arie havelaar brussels, 25 october 2010
TRANSCRIPT
1
Current public health problems related to pork
Arie HavelaarBrussels, 25 October 2010
2
Main hazards associated with pork consumption
● Campylobacter spp.● Listeria monocytogenes● Mycobacterium spp.● Salmonella spp.● Staphylococcus aureus● VTEC● Yersinia spp.
● Hepatitis E virus
● Ascaris suum● Echinococcus spp.● Cryptosporidium spp.● Taenia solium● Trichinella spp.● Toxoplasma gondii
● Antimicrobial resistance
Source: EFSA Opinion 613
3
What are the risks and how do they compare?
●Epidemiology–Incidence–Mortality–Severity–Attribution
●(Comparative) risk assessment–Risk Ranger–sQMRA–iRisk
4
Data on human illness at EU level
● Available data in Annual Community Summary Report on Trends and Sources of Zoonoses and Zoonotic Agents and Food-borne Outbreaks in the European Union (Annual)
5
Main hazards associated with pork consumption:data availability EU
● Campylobacter spp.● Listeria monocytogenes● Mycobacterium spp.● Salmonella spp.● Staphylococcus aureus● VTEC● Yersinia spp.
● Hepatitis E virus
● Ascaris suum● Echinococcus spp.● Cryptosporidium spp.● Taenia solium● Trichinella spp.● Toxoplasma gondii
● Antimicrobial resistance
6
Foodborne outbreaks in 2008
Source: Community Summary Report 2008 (EFSA, 2010)
7
Reported incidence of human salmonellosisin the EU
Source: Community Summary Report 2008 (EFSA, 2010)
8
The surveillance pyramid for gastrointestinal pathogens
# cases of AGI in community, due to specific pathogen
# cases seeking medical care
# cases submitting stool sample
# tested for pathogen
# positive lab results
# reported cases
# asymptomatic infections with specific pathogen in community
sero-survey of population
Methods used for calibration:
Cohort studies
Multiplier methods
Travelers as sentinels
Modelling
Seroepidemiology
Reported fraction differs between countries and
between diseases
9
Reported salmonella infectionsper 1000 py
< 0.20.2 - 0.40.41 - 0.5
Source: dr. K. Mølbak, SSI, Denmark
10
Salmonella sero-incidenceper 1000 py
< 100100 - 300301 - 550
Source: dr. K. Mølbak, SSI, Denmark
11
Salmonella sero-incidence and incidence estimates in Swedish travelers
0
10000
20000
30000
40000
50000
60000
1 10 100 1000 10000
incidence / 100000 by Swedish travellers
sero
-inci
den
ce /
1000
00
Spearman’s rho=0.9, p=0.007
* D
ata
fro
m:
de
Jo
ng
B,
Ekd
ah
l K.
Th
e c
om
pa
rativ
e b
urd
en
of
salm
on
ello
sis
in t
he
Eu
rop
ea
n U
nio
n m
em
be
r st
ate
s,
ass
oci
ate
d a
nd
ca
nd
ida
te c
ou
ntr
ies.
BM
C P
ub
lic H
ea
lth 2
00
6;
6:4
d
oi:1
0.1
18
6/1
47
1-2
45
8-6
-4
Source: dr. K. Mølbak, SSI, Denmark
12
Salmonella prevalence in layers (baseline study, all serovars) and sero-incidence
Spearman’s rho=0.90, p=0.005
FR
0
10000
20000
30000
40000
50000
60000
0.1 1 10 100
layer hen holding prevalence (%)
sero
-in
cid
ence
/ 1
0000
0
FR
Source: dr. K. Mølbak, SSI, Denmark
13
What are the priorities?
Outcome Norovirus Rotavirus Campylo-bacter
Salmonella
Gastro-enteritis
640,000 300,000 79,000 43,000
GE – visit to GP
16,000 21,000 19,000 7,600
GE – hospital
2,000 4,400 570 650
GE – death
6 2 46 47
Reactive arthrititis
- - 1,500 1,700
Guillain-Barré S.
- - 65 -
Irr. Bowel Syndrome
- - 6,900 3,900
14
HALYs: integrated measures of disease burden
● Integrate morbidity and mortality● Incorporate age and health status of those affected● Address incidence, severity and duration of adverse health
consequences● One example, frequently used in public health:
Disability Adjusted Life Years
DALY = YLL + YLD– mortality: years of life lost
YLL = all diseases ( D x e)D: number of deaths; e: life expectancy of fatal cases
– morbidity: years lived with disability, weighted for severity of illness
YLD = all diseases ( N x t x w)N: number of non-fatal cases; t: duration, w: severity weight
15
Disease burden in the Netherlands (all sources)
0
500
1.000
1.500
2.000
2.500
Campylobacter
Noroviru
s
Salmonell
a
Rotaviru
s
Toxoplasma (
cong.)
S. aureu
s
C. perfr
ingens
Listeri
a
G. lamblia
STEC O157
Hepatiti
s E viru
s
B. cere
us
Hepatiti
s A viru
s
Cryptosp
oridium
DA
LY
s pe
r ye
ar
Not discounted Discounted (4%)
Campylobacter has the highest
burden
Burden of Toxoplasma very uncertain, recent data suggest 4x higher burden
Strong effect of discounting
(child deaths)
16
Disease burden per case
1
10
100
1000
10000
100000
L. m
onoc
ytoge
nes (
perin
atal)
T. go
ndii (
cong
enita
l)
L. m
onoc
ytoge
nes (
acqu
ired)
Hepa
titis
E viru
s
Hepa
titis
A vir
us
STEC
O15
7
Salm
onell
a spp
.
Cam
pylob
acter
spp.
C. pe
rfring
ens
Rotav
irus
S. au
reus
B. ce
reus
Noro
virus
C. pa
rvum
G. la
mbli
a
DA
LY p
er
1000 c
ase
s
undiscounted
discounted
Diseases affecting unborn or young children have the highest
burdenSystemic
infections also have a high
burden
Lowest burden for protozoa
17
Attribution
●The partitioning of the human disease burden of one or more foodborne infections to specific sources (animal reservoirs and vehicles such as foods)
●Microbiological approaches–Microbial subtyping–Comparative exposure assessment
●Epidemiological approaches–Case-control studies of sporadic infections–Outbreak investigations
●Intervention studies–Surveillance after new legislation–Natural experiments
●Expert elicitation
●Currently most data available for Salmonella
18
Attribution of salmonellosis in the Netherlands, 1984-2009
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008
lab
-co
nfi
rme
d c
as
es
of
sa
lmo
ne
llos
is
0
20000
40000
60000
80000
100000
120000
140000
160000
Sa
lmo
ne
llos
is c
as
es
, ge
ne
ral p
op
ula
tio
n
Singled out Explosionstravel/otherCattlePigsLayers/Repro/EggsBroilers/products
Manure
transports
ST DT104
AI outbreak
Spanish egg
imports
Peak Enteritidis epidemic
Improved slaughter hygiene
Poultry control program
Italian
cattle meat
ST DT104
Cheese
incident
ST DT7
Dairy (ST DT15A)
J uice (Panama)
Butcher Trnzn(ft507)
Beef (ST qDT104)
Egg (SE Pt8)
? Gr. Fr. (ft507)
raw cattle
products
ST ft90
ST ft132
Source: dr. Wilfrid van Pelt, RIVM, the Netherlands
19
Estimated major sources of human salmonellosis in Denmark, 1988-2009
Source: prof. Tine Hald, Food-DTU, Denmark
10-20% of human
Salmonella infections
in EU may be attributable
to the pig reservoir as a whole
EFSA Opinion 1547, 2010
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Monophasic Salmonella (1,4,[5],12:i)
● … are regarded as variants deriving from S. Typhimurium
● … have been shown to have similar virulence and antimicrobial resistance characteristics to strains of S. Typhimurium
● … the third most common serovar from human infections
● …. the second most common serovar from pigs
● …. the third serovar from bovine samples
Source: EFSA Opinion 1826
21
Attribution of the burden of 14 pathogensto major pathways in the Netherlands
Disease burden (DALY per year)
Food50%
Environment18%
Human22%
Animal10%
Estimates based on expert elicitation
22
Attribution of the foodborne burden of 14 pathogensto food groups in the Netherlands
Disease burden (DALY per year)
Beef and mutton15%
Pork12%
Poultry19%
Eggs6%
Dairy9%
Cereal products4%
Other food11%
Human and animal9%
Fish and shellfish7%
Fruit and vegetables6%
Beverages2%
Estimates based on expert elicitation
Mainly T. gondii and Salmonella spp.
23
Filling the data gaps
● ECDC– Burden of Communicable Diseases in Europe– Sero-epidemiology of Salmonella and Campylobacter
● WHO– Foodborne Epidemiology Disease Burden Reference Group
24
Conclusions
● Surveillance systems for the main pathogens in pork are in place in the EU, but coverage varies between Member States
● Reported data represent only a fraction of all cases in the population
● The reported fraction varies strongly between Member States and between pathogens
● Severity of acute illness, sequelae and mortality need to be taken into account when deciding about public health priorities
● Data for attribution of human illness to animal reservoirs and foods are poorly available
● Major international projects are on-going to fill data gaps, but Member States need to invest in more systematic surveillance
● Based on current evidence, Salmonella spp., Toxoplasma gondii and Trichinella spp. appear to be the most important pathogens in pork