ANIMAL HEALTH EMERGENCY OR FOLLOW –UP REPORT
1.
4.
6.
7.
9.
10.
7
2.
0
9
D
E
C
0
0
No.
Report date (dd/mmm/yy)
DR EMILY MOGAJANE
Name of Sender
PROGRAM MANAGER AGRICULTURAL PRODUCTION
Position
+27-12-319 7679
8.
+27-12-329 7218
Telephone number
Fax number
DVS@nda.agric.za
E-mail number
3.
SOUTH AFRICA
Country
5.
PRIVATE BAG X138
PRETORIA
0001
SOUTH AFRICA
Address
FOOT AND MOUTH DISEASE (TYPE O)
11.
Disease Name
If
If
If Emergency report
A
0
1
1
Disease Code
12.Nature of diagnosis
13.
Suspicion
1 2
S
E P
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0
Date of initial detection (dd/mmm/yy)
X
Clinical
14.
X
Post- mortem
X
Laboratory
0
7
S
E
P
0
0
Estimated date of first infection (dd/mmm/yy)
On 8 November 2000, 4 positive serological results without evidence of clinical symptoms were detected on the
Liquid Phase Blocking ELISA Tests (LPBE) for FMD serotype O (log titres equal to or greater than 1,6. The test
was conducted on 24 sera from cattle at a dipping tank at 29°38’46.5’’S; 30°44’39.5’’E. The dipping tank is
outside the 10km radius quarantine zone but still within the surrounding 20km surveillance zone. This was the
result of intensive surveillance in the foot and mouth disease surveillance area in KwaZulu-Natal.
The tests were repeated on the LPBE and the results were confirmed. No clinical signs of the disease were
seen and, as LPBE’s are known to sometimes provide false positive results, all such tests are repeated using the
virus neutralisation test (VNT). The VNT on the 4 sera concerned proved negative (log titres equal to or less
than 1,3). The VNT was repeated and the results were inconclusive. The sera were then tested using 3ABC
ELISA that detects antigens produced during virus replication. These results were negative.
A further 108 serum samples were collected on 11 November from cattle at this dipping tank.
Immediate actions had to be taken in the light of the initial LPBE results. The area under suspicion made the
rationale to continue with a stamping-out policy questionable and it was therefore decided to abandon the
stamping-out policy and apply limited vaccination within a radius of 15km. The foot and mouth disease control
area was also enlarged as a precautionary measure with strict control on the movement of animals and animal
products into, out of and within this control area. Meanwhile the LPBE tests performed on the 108 sera from the
cattle at the dipping tank in question tested negative. For confirmation of these results, the sera (108 samples
PLUS the original 23 serum samples that remained from this dipping tank) were sent to the World Reference
Laboratory (Pirbright, UK) on 16 November. The Pirbright Laboratory found 18 animals positive, 57 animals
weak positive and 53 animals negative on LPBE. For confirmation, they tested the positive cases using the VNT
and found all animals to be negative. They also used the 3ABC ELISA to confirm 28 of the sera as negative.
The final results from Pirbright were received on 30 November 2000.
The conclusion is therefore that these cattle were not infected with foot and mouth disease. Further intensive
sero-surveillance data and clinical inspection, indicates that the disease has not spread outside the 30km
surveillance zone. In view of these results, and the fact that it is now more than 30 days since the last positive
foot and mouth disease case, Cabinet decided to reduce the control area to the original 30km zone.
Vaccination and intensive surveillance around the original epicentre will continue and will cover a radius of about
10 to 15km. Intensive sero-surveillance will continue throughout the 30km control area.
Surveillance data up to 6 December 2000
Total number of animals inspected:
156 075 cattle
148 921 pigs
2 999 sheep
8 124 goats
10 cloven-hoofed game animals
Number of animals tested serologically: 7 566 cattle
1 056 pigs
786 sheep
902 goats
45 cloven-hoofed game animals
Vaccination data up to 6 December 2000
Number of animals vaccinated: 6 003 cattle
720 sheep
555 goats