Teaming up for animal health
PED: Monitoring and eradication experience in eleven pig herds in the Netherlands Paul Franssen, Manon Houben, Jos Dortmans GD Animal Health, Deventer, the Netherlands
Introduction In November 2014, after the first case of an infection with the Porcine Epidemic Diarrhea virus (PEDv) in The Netherlands was confirmed by GD Animal Health, eleven infected herds were followed to monitor course of a PEDv infection in Dutch pig herds. This study was financed by the Dutch government and pig industry.
Materials and methods Eleven infected herds are selected in order of date of infection (table 1).
Table 1. Herds Type
Table 2. Results fattening herds # herds
# animals
Multiplier / sow herd(s)
5
400 - 1700
Nursery herd(s)
1
1800
Fattening herd(s)
5
440 - 2300
Diagnostics All herds were diagnosed using an adapted commercial semi quantitative reverse transcriptase PEDv PCR on feces. Regular testing of pooled fecal samples was performed on all farms to monitor the PEDv infection over time. PEDv was considered to be successfully eradicated if 3 consecutive sampling rounds of 30 randomly taken fecal samples proved to be PCR negative. Herds were then classified ‘unsuspicious’.
farm
% of infected compartments
Speed of transmission
Clinical signs (in days)
Number of samplings/ number of (pooled) samples
Number of days before regaining status ‘unsuspected’
1
50
inapplicable
21
8/489
128
2
100
Within 3 days
Incidentally, (after newly incoming piglets)
2/60
Not determined
3
20
inapplicable
21
5/80
180
4
60
inapplicable
14
3/90
180
5
100
Within 3 days
21 days
None
Completely depopulated
Table 3. Results sow herds farm
Actions and interventions The virus introduction route for each farm was investigated. Tailor made advices, mainly based on biosecurity issues, was given to prevent new virus introduction and to control the transmission of PEDv within the herd.
Results After the introduction of PEDv, the virus could be detected for 4-6 weeks at room level. Strict biosecurity proved to effectively prevent the transfer of PEDv to naive rooms in a fattening herd. Three of the fattening herds (table 2) and three of the sow herds (table 3) were classified ‘unsuspicious for PEDv’ within 6 months after the diagnosis of PED. The nursery herd was totally depopulated and after repopulation no clinical signs were seen.
Sow immunized
% of infected compartments
Speed of transmission (in days)
Clinical signs (in days)
sows
piglets
sows
piglets
Number of samplings/ number of (pooled) samples
Number of days before regaining status ‘unsuspected’
1
yes
100
7
21
10
14
6/31
Not determined
2
Yes, 21 days after start of the outbreak
100
21
30
40
40
2 / 28
Not determined
3
yes
100
3
12/ 163
172
4
no
100
3
2
14
14
4 / 99
170
5
yes
100
5
14
21
14
3 / 80
185
Discussion The successful approach on a PEDv infected herd requires a tailor made plan, based on strict protocols and cooperation between motivated farmers and farm contacts. Regular monitoring of fecal samples is a useful tool to monitor the herd status and can motivate the farmer to keep up a high level of biosecurity until the virus is completely eradicated.
Fecal sample Photo: GD Animal Health, The Netherlands
GD, P.O. Box 9, 7400 AA Deventer, the Netherlands, T. +31 (0)570-63 33 91, F. +31 (0)570-63 41 04 www.gdanimalhealth.com, info@gdanimalhealth.com
GDOV1063/04-17
contact: m.houben@gdanimalhealth.com