OIE Reference Laboratory Reports
Activities in 2011
Name of disease (or topic) for
which you are a designated OIE
Reference Laboratory:
Address of laboratory:
Porcine reproductive and respiratory
syndrome
National Veterinary Research Institute
Department of Swine Diseases
Partyzantow 57
24-100 Pulawy
POLAND
Tel.:
+48 81 889 30 99
Fax:
+48 81 886 25 95
e-mail address:
website:
Tomasz_stadejek@sggw.pl
www.piwet.pluawy.pl
Name (including Title and
Position) of Head of Laboratory
(Responsible Official):
Professor Tomasz Stadejek
Name(including Title and
Position) of OIE Reference
Expert:
Professor Tomasz Stadejek
Name (including Title and
Position) of writer of this report
(if different from above):
Annual reports of OIE Reference Centres, 2011
1
Porcine reproductive and respiratory syndrome
Part I: Summary of general activities related to the disease
1.
Test(s) in use/or available for the specified disease/topic at your laboratory
Test
For
Specificity
Total
ELISA
Antibody
Species
11877
ELISA
Antigen
Genotype
114
ELISA
Antibody
Porcilis PRRS MLV
0
PCR
Genome
Species
1500
PCR
Genome
Genotype
210
Genome
Strain
130
DNA sequencing
2.
Production and distribution of diagnostic reagents
Indirect ELISAs for detection of PRRSV and discrimination of the North American and European genotypes and
standard sera are being produced for own laboratory use. In the reporting period ELISA plates were produced for
testing of about 15 000 serum samples. Also, 15 coated microplates (in house ELISA) were supplied to the
laboratories of Aristotle University of Thessaloniki, Greece and Roslin Institute of the University of Edinburgh,
UK. Six isolates of PRRSV type 2 were provided to Istituto Zooprofilattico Sperimentale Lombardia ed EmiliaRomagna, Brescia, Italy.
Part II: Activities specifically related to the mandate
of OIE Reference Laboratories
3.
International harmonisation and standardisation of methods for diagnostic testing or the
production and testing of vaccines
a) Establishment and maintenance of a network with other OIE Reference Laboratories
designated for the same pathogen or disease and organisation of regular inter-laboratory
proficiency testing to ensure comparability of results
As there is no other reference laboratory for porcine reproductive and respiratory syndrome active
collaboration was established with the leading diagnostic laboratories in Europe, China and USA. The aim of
the collaboration was to increase availability of different PRRSV strains and sera for the purpose of diagnostic
tests validation. This network was partially supported by the EuroPRRS COST projects as well as PoRRSCon
FP7 project.
b)
Organisation of inter-laboratory proficiency testing with laboratories other than OIE
Reference Laboratories for the same pathogens and diseases to ensure equivalence of
results
The laboratory participated in the organization of the PCR ring trial that was conducted by FLI, Riems Island,
Germany. Originally the trial was aimed for members of EPIZONE consortium but the same set samples were
also distributed among the PoRRSCon members. The results are submitted for publication. The outcome of the
ring trial clearly identified strong need for better validation of commercial and in house assays to diagnose
PRRS. There is a need for continuously updated set of reference RNA’s representing a full range of genetic
diversity of PRRSV.
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Annual reports of OIE Reference Centres, 2011
Porcine reproductive and respiratory syndrome
4.
Preparation and supply of international reference standards for diagnostic tests or vaccines
None
5.
Research and development of new procedures for diagnosis and control
The study was conducted to develop in house indirect ELISA for the detection of PRRSV specific antibodies in
oral fluids. Oral fluid has been proved to be a very important material for both, PCR and ELISA. However, there is
no commercially available ELISA for oral fluids. The in house ELISA developed in our laboratory was modified
to address the problem of lower antibody levels in oral fluids than in serum that can affect the sensitivity of the
PRRS detection.
Serum and oral fluid samples were collected from 4 farms known to be free from PRRSV and 18 farms where
PRRSV infection was previously identified. From 60 to 574 serum samples were obtained from each farm that
represented pigs from 4 to 23 weeks of age. From each age group 10-25 serum samples collected from animals
housed in 2-5 pens. From each pen one oral fluid sample was collected by hanging a piece of rope to which pigs
had access for 30-60 minutes. From 12 to 36 oral fluid samples were collected from each farm. The antigen
(capsid protein expressed in E. coli) for the oral fluid ELISA was produced and purified as described earlier, but
the protocol was modified to address lower antibody concentration in oral fluid than in serum. The sensitivity of
serum and oral fluid ELISAs to detect antibodies in individual pens (n=427) was compared using McNemar’s test.
Specificity of oral fluids ELISA was high and only 1 of 55 samples from 4 PRRSV free herds reacted positive.
Some discrepancies between the results of serum and oral fluid ELISAs regarding individual pens were observed
in PRRSV positive farms but generally both methods provided similar serological profiles of these herds. These
preliminary results indicate that the developed ELISA allows substituting serum with oral fluid samples for
surveillance and serological diagnosis of PRRS. This method can be a convenient, cost effective alternative to
detection of PRRSV antibodies in serum. However, further studies in are needed to fully assess the test’s
specificity and sensitivity.
6.
Collection, analysis and dissemination of epizootiological data relevant to international disease
control
None
7.
Maintenance of a system of quality assurance, biosafety and biosecurity relevant to the
pathogen and the disease concerned
The laboratory has accredited ELISA method (X3, IDEXX) to detect seroconversion to PRRSV. All other
diagnostic methods are being performed according to good laboratory practice. Biosecurity and biosafety measures
relevant to porcine reproductive and respiratory syndrome virus have been applied applied.
8.
Provision of consultant expertise to OIE or to OIE Member Countries
Consultations on diagnosis of PRRS were provided to Mongolia, Nepal, Nigeria, Belarus, Romania, Greece.
9.
Provision of scientific and technical training to personnel from other OIE Member Countries
None
10. Provision of diagnostic testing facilities to other OIE Member Countries
In the reporting period the tests were performed for the following countries: Belarus (routine diagnosis, ELISA:
600; PCR: 60), Mongolia (confirmatory diagnosis, ELISA and PCR: 26), Nepal (confirmatory diagnosis, ELISA
and PCR: 40).
Annual reports of OIE Reference Centres, 2011
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Porcine reproductive and respiratory syndrome
11. Organisation of international scientific meetings on behalf of OIE or other international bodies
The laboratory co-organized a scientific meeting
The laboratory co-organized a scientific meeting EuroPRRS2011 that was held in Novi Sad, Serbia on 12-14
October 2011. The meeting gathered about 100 participants from Europe, Asia and North America, including
leading international experts in PRRSV research. The program, the abstract book and the presentations can be
found at http://europrrs.net/.
12. Participation in international scientific collaborative studies
The laboratory has been participating in COST Action FA0902: Understanding and combating porcine
reproductive and respiratory syndrome in Europe chaired by Dr. Tahar Ait-Ali from Roslin Institute, Edinburgh,
UK. COST Action FA0902 was approved by the Committee of Senior Officials on 26/05/2009. The Action
entered into force on 11/07/2009 after five Parties had accepted the Memorandum of Understanding. The Action
officially started on 26/11/2009 with the first MC Meeting and will end in four years.
Another international project funded by 7th Framework Program that the laboratory has been participating in 2010
has started in 2010, namely „New tools and approaches to control Porcine Reproductive and Respiratory
Syndrome in the EU and Asia” (PoRRScon), coordinated by Prof. Hans Nauwynck from Gent University,
Belgium
13. Publication and dissemination of information relevant to the work of OIE (including list of
scientific publications, internet publishing activities, presentations at international conferences)

Presentations at international conferences and meetings
Jabłoński A., Strawa M., Stadejek T. Impact of selected parameters on efficacy of pen based oral fluid collection
from pigs. Materiały 6th International Symposium on Emerging and Re-emerging Pig Diseases Barcelona,
Hiszpania, 2011, p. 59
Stadejek T., Jablonski A., Skrzypiec E., Chabros K., Podgorska K., Pejsak Z.. Development of in house ELISA for
the detection of antibodies to PRRSV in oral fluids. Materiały 6th International Symposium on Emerging and Reemerging Pig Diseases Barcelona, Hiszpania, 2011, p. 217
Stadejek T., Jablonski A., Chabros K., Skrzypiec E., Pejsak Z. Analysis of circulation of porcine reproductive and
respiratory syndrome virus in 22 Polish pig farms: implications for diagnosis and control. 2011 International
PRRS Symposium, Chicago, p. 98
Stadejek T., Jablonski A., Podgorska K., Chabros K., Skrzypiec E., Pejsak Z..Development of indirect ELISA to
detect antibodies to porcine reproductive and respiratory syndrome virus (PRRSV) in oral fluids of pigs. 2011
International PRRS Symposium, Chicago, p. 99

Scientific publications in peer-reviewed journals
Stadejek T, Podgorska K, Porowski M, Jabłoński A, Pejsak Z., 2011, Linked outbreaks and control of porcine
reproductive and respiratory syndrome and postweaning multisystemic wasting syndrome in a pig farm in Poland.
Vet Rec. 2011 Oct 22;169(17):441.
Podgórska K., Stadejek T. 2011. Porcine circovirus type 2 viremia and seroconversion in pigs from a farm affected
by postweaning multisystemic wasting syndrome. Polish Journal of Veterinary Sciences Vol. 14, No. 4 (2011),
667-669
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Annual reports of OIE Reference Centres, 2011