Monitoring FMD is key principle of PCP
Measuring FMD occurrence to:
1. Assess FMD risk
– Within country:
oSpecies, sector, husbandry system, area
oTo target control and inform FMD impact
assessment
2. Monitor changes over time
– Detect ‘events’ (epidemics)
– Efficacy of control strategy
But what is the best way to do it?
2. Acknowledgements
•Chris Bartels: EuFMD
•Naci Bulut: FMD Institute, Ankara, Turkey
•Theo Knight Jones: Institute for Animal Health, Pirbright, UK
•Shams Amin Abo Gabal, Rehab Abdel-Kader El Bassal, Animal
Health Research Institute, Cairo, Egypt
Soheir Hassan Abdel-Kader, Iman Ali Farag, Amaal Ibrahim Attya
Mansour, General Organization for Veterinary Services, Cairo,
Egypt
•General Directorate for Food and Control, Ankara, Turkey
•Iranian Veterinary Organization, Tehran, Iran
3. Key points
• Data from Turkey and Iran show:
– Yearly incidence rate 10-30 X higher when measured
using NSP serosurveys compared to reports of
suspected cases
– Provincial (or district) level FMD incidence measured
by 1) reports and 2) serological data were poorly
correlated
• FMD reporting should be encouraged and reports
analysed continuously (monthly) to detect ‘events’
• Carefully designed serosurveys should be conducted
regularly (annually if possible)
– Unbiased measure of FMD infection, best
information about risk factors
4. Monitoring FMD is key principle of PCP
Measuring FMD occurrence to:
1. Assess FMD risk
– Within country:
o Species, sector, husbandry system, area
o To target control and inform FMD impact
assessment
2. Monitor changes over time
– Detect ‘events’ (epidemics)
– Efficacy of control strategy
But what is the best way to do it?
5. Monitoring FMD Occurrence: Case Reports
2009-2010 All FMD reports
Turkey Turkey:2009-2010
300
number of reports
200
100
2010 Village level incidence
0
9
09
0
10
9
0
09
10
00
01
00
01
20
20
20
20
r2
r2
l2
l2
ct
ct
n
n
Ju
Ju
Ap
Ap
Ja
Ja
O
O
2010 Village Incidence FMD reports month
no. villages reporting in 2010 / ttl villages in province
Incidence (%)
6.00 - 12.00
4.00 - 6.00
2.00 - 4.00
1.00 - 2.00
0.50 - 1.00
0.00 - 0.50
No data
6. Ja 100 150 200 250
n 50
20 0 100 200 300 400
01 Ja
Ja n
n 0
20 20
02
Ja 01
n Ja
20
O
Ja
03 n
n 20
20 02
04
Ja Ja
n n
20
05 20
Ja
n 03
20 Ja
06
Ja
n
n
20 20
07 04
Ja
Month
n Ja
20
n
Serotype O
08
Ja
n
20
20 05
Turkey: 2001-2012
09 Ja
Ja
n n
20
10 20
Ja
n
06
20 Ja
11 n
Ja
n 20
20
12 07
number of outbreaks Ja
Month
n
20
08
All Outbreaks
Ja
n
20
09
Ja
100 150 200 250 n
Ja 50
n
20
20 0 10
01
Ja Ja
n n
20
02 20
Ja
n 11
A
20 Ja
03
Ja
n
n
20 20
04 12
Ja
n
20
05
Ja
n
20
06
Ja
n
20
07
Ja
Month
n
20
Serotype A
08
Ja
n
20
09
Ja
n
20
10
Ja
n
20
11
Ja
n
20
12
number of outbreaks
Ja 100 150 200 250
n 50
20 0
01
Ja
n
20
02
Ja
n
20
03
Ja
n
20
04
Ja
n
20
Asia-1
05
Ja
n
20
06
Ja
n
20
07
Ja
Month
n
20
08
Ja
n
Serotype Asia1
20
09
Ja
n
20
10
Ja
n
20
11
• Most are laboratory
Ja
n
20
Monitoring FMD Occurrence: Case Reports
12
confirmed & serotyped
7. Monitoring FMD Occurrence: Active surveillance
• Clinical cases
• NSP serology
– Sampling young stock gives picture of FMD
infection in recent months
2010 Village Seroprevalence
Incidence
80.00 - 100.00
60.00 - 80.00
40.00 - 60.00
20.00 - 40.00
0.00 - 20.00
No data
Turkey: 2010
8. How to relate reporting and serological data?
• Compare FMD incidence measured using survey data
and reports in Turkey and Iran
• Well developed passive reporting systems
• Extensive serosurveys
Turkey (spring 2009) Turkey (spring 2010) W. Azerbaijan, June 2011
-32,670 samples -64,765 samples -8349 samples
78 provinces, 334 74 provinces, 460 1 province, 14 districts
districts, 554 villages districts, 946 villages 281 epi-units
-60 samples /village -60 samples /village - 30 samples/epi unit
-cattle only 50% cattle, 50% SR -cattle only
-mostly 4-18 months -mostly 4-18 months -6-24 months
9. How to relate reporting and serological data?
2009 2010
Serology 2009 Village Seroprevalence
2010 Village Seroprevalence
Incidence
Incidence 80.00 - 100.00
80.00 - 100.00 60.00 - 80.00
60.00 - 80.00 40.00 - 60.00
40.00 - 60.00 20.00 - 40.00
20.00 - 40.00
0.00 - 20.00 0.00 - 20.00
No data No data
Reports 2010 Village Incidence FMD reports
no. villages reporting in 2010 / ttl villages in province
2009 Village Incidence FMD reports
no. villages reporting in 2010/ttl villages in province Incidence (%)
6.00 - 12.00
4.00 - 6.00
2.00 - 4.00
Incidence 1.00 - 2.00
6.00 - 12.00 0.50 - 1.00
4.00 - 6.00 0.00 - 0.50
2.00 - 4.00 No data
1.00 - 2.00
0.50 - 1.00
0.00 - 0.50
No data
All FMD reports
Turkey:2009-2010
300
number of reports
200
100
0
9
09
0
10
09
9
10
0
00
01
00
01
20
20
20
20
r2
r2
l2
l2
ct
ct
n
n
Ju
Ju
Ap
Ap
Ja
Ja
O
O
month
10. Relative comparison
(serological ÷ report incidence)
Serological/Report Village Incidence 2009
Relative Incidence
200.00 - 500.00
100.00 - 200.00
80.00 - 100.00
2009:
60.00 - 80.00
40.00 - 60.00
20.00 - 40.00
Median 30X
0.00 - 20.00
No data
Serological/Report Village Incidence 2010
Relative Incidence
200.00 - 500.00
100.00 - 200.00
80.00 - 100.00 2010:
60.00 - 80.00
40.00 - 60.00
20.00 - 40.00 Median 11X
0.00 - 20.00
No data
11. Absolute comparison
(Serology minus Report incidence)
Serological and Report Village Incidence 2009: Absolute difference
Incidence difference (%)
Median
80 - 100
60 - 80
40 - 60
20 - 40
0 - 20 difference:
20%
-10 - 0
No data
Serological and Report Village Incidence 2010: Absolute difference
Incidence difference (%)
80 - 100
60 - 80
40 - 60
Median
20 - 40
0 - 20 difference:
29%
-10 - 0
No data
12. W. Azerbaijan serosurvey
• 80.2% of epi-units had at least 5 calves with a
high titre (>70% inhibition)
• 18% observed clinical signs in their stock in the
previous 12 months (questionnaire)
District-level FMD Incidence:
Serosurvey Clinical signs: Survey Clinical signs: Offical reports
2011 Incidence FMD serosurvey Incidence FMD reports (sample) Incidence FMD reports
16 mo prior to survey
Incidence Incidence
85.71 - 100.00 28.57 - 40.00 Incidence
80.71 - 85.71 27.27 - 28.57 13.77 - 32.76
19.81 - 27.27 9.97 - 13.77
71.43 - 80.71 9.18 - 9.97
66.67 - 71.43 16.67 - 19.81
8.57 - 16.67 7.81 - 9.18
50.00 - 66.67 7.37 - 7.81
0.00 - 8.57
1.52 - 7.37
13. How to relate reporting and serological data?
Epi-unit level Turkey Turkey W. AZB
2009 2010
Median serological incidence 20% 33% 81%
GISVet survey
Median report incidence 0.22% 2.8% 9% 20%
Median relative incidence 30.8 11.8 8.2 3.7
Median incidence difference 20% 29% 69% 65%
Turkey 2010 W. Azerbaijan serosurvey
100
100
No significant
90
80
serological incidence
serological incidence
correlation
80
60
70
40
(Spearman’s)
60
20
50
0
0 5 10 15 0.00 10.00 20.00 30.00 40.00
report incidence report incidence
14. Differences: Serological and Report data
May be due to:
1. Under-reporting
2. Subclinical infection
• FMD signs observed by farmers on:
– 17% NSP+ epi-units in W. Azerbaijan
– 41% NSP+ calves (0-12 months) in Asia-1 outbreak
investigation in Turkey
– 86% NSP+ calves (0-12 months) in Asia-1 outbreak
investigation in Turkey
• Will vary by FMD strain, species infected,
vaccination status
15. Differences: Serological and Report data
May be due to:
3. NSP antibody induced by vaccine rather
than infection
• Especially if use unpurified vaccine
• Less likely if youngstock targeted in survey (?)
4. Reflection of previous year’s cases?
• Compared Turkish serosurvey results to previous
year’s reports and correlation not improved
16. Both approaches contribute to assessing and
monitoring FMD risk
• Reports of suspect clinical cases
– Essential for early detection & response (PCP Stage 3
and higher)
– Real-time, linked to control
– Laboratory confirmation including serotype
– Cost-effective
– Effectiveness dependent on favourable ‘attitude’ to
reporting
– Subject to bias, under-reporting
17. • Nationwide serosurvey in 2011
Egypt – 5299 ruminant samples tested in 310 villages
• NSP-Ab positive:
– 17.6% samples (95%CI: 16.6 – 18.6%)
– 78% villages (95% CI: 73-82%)
• 2011: 15 reports of suspect disease
Egypt 2011:
Large ruminant results in serosurvey
80 350
number villages sampled
70 300
60 250
% positive
50
200
40
150
30
20 100
10 50
0 0
Nile Central Upper East West Total
delta
% villages with >=2 seropositive % cattle % buffalo Nr villages tested
18. Both approaches contribute to assessing and
monitoring FMD risk
• NSP serology
– Detects clinical and subclinical FMD (ie measures FMD
infection)
– Less biased (with careful design!)
• Unit of analysis: what is a ‘case’?
• Target young stock
– Combine with questionnaire about risk factors
– Resource intensive
• Survey can be combined with post-vaccination monitoring
(SP serosurvey)
19. Key points
• Data from Turkey and Iran show:
– Yearly incidence rate 10-30 X higher when measured
using NSP serosurveys compared to reports of
suspected cases
– Provincial (or district) level FMD incidence measured
by 1) reports and 2) serological data were poorly
correlated
• FMD reporting should be encouraged and reports
analysed continuously (monthly) to detect ‘events’
• Carefully designed serosurveys should be conducted
regularly (annually if possible)
– Unbiased measure of FMD infection, best
information about risk factors
20. Thank you!
•EuFMD
•FMD Institute, Ankara, Turkey
•Institute for Animal Health, Pirbright, UK
•Animal Health Research Institute, Cairo, Egypt
•General Organization for Veterinary Services, Cairo, Egypt
•General Directorate for Food and Control, Ankara, Turkey
•Iranian Veterinary Organization, Tehran, Iran
21. 2010 epidemic in Turkey:
Use of reports to detect surge in cases
ANIMAL LEVEL VILLAGE
SEROPREVALENCE LEVEL
Serosurveys
2009 2010 2009 2010
<4 mo 16.67% - 20% 33%
(0-49%)
4-12 8.9% 12.9 All FMD reports
mo (8.4-9.3%) (12.5-13.2) Turkey:2009-2010
300
13-18 9.1% 15.4
mo (8.4-9.7%) (14.9-15.9)
number of reports
200
19-24 19.1% (18.0- 17.3
mo 20.1%) (16.3-18.2)
100
>24 mo 16% 21.3
(2.8-28.4%) (18.0-24.5)
0
9
09
0
10
9
0
09
10
00
01
00
01
20
20
20
20
r2
r2
l2
l2
ct
ct
n
n
Ju
Ju
Ap
Ap
Ja
Ja
O
O
month