1. RAPID DETECTION OF FOOT AND MOUTH DISEASE NON-STRUCTURAL PROTEINS
USING A LATERAL FLOW ASSAY 1, 3 1 2 2 3
Lazarus, D. D *., Wungak, Y. , Omotainse, O. S ., Talabi, A. O. , Fasina, F. O .
1
Viral Research Division, National Veterinary Research Institute, Vom, Plateau State, Nigeria; 2Faculty of Veterinary Medicine, University of Agriculture, Abeokuta, Ogun State, Nigeria;
3
Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
Introduction
The detection of antibodies to the non-structural (NS) proteins of the Foot and Mouth Disease Virus (FMDV) is of great importance for the
detection of virus infected and carrier individual animals within a vaccinated herd and where the vaccination status of individual animals is not
known. Since many animal species are hosts of this virus, a simple rapid test that allows a simultaneous screening for antibodies to FMDV in all
the affected susceptible species is of great importance. We are presenting a preliminary report of a simple rapid lateral flow assay for the
detection of antibodies to Non-Structural proteins of FMDV in the sera of infected cattle. This is a newly introduced product into the Nigerian
livestock market, and we took time to preliminary evaluate its application in rapid diagnosis as a first line diagnostics for veterinarians especially
where facilities for FMD diagnosis are not in place. Fig. 1. Rapid Lateral Device cassette.
Objective
To preliminarily access the performance of Foot and Mouth Disease NSP Ab Rapid Test kit.
Material and Methods
Principle of the assay
Quicking Foot and Mouth Disease NSP Ab Rapid Test is based on sandwich lateral flow immuno-chromatographic assay. The test device has a
testing window. The testing window has an invisible T (test) zone and C (control) zone. When sample is applied into the sample hole on the
device, the liquid will laterally flow on the surface of the test strip. If there is enough FMD NSP antibodies in the sample, a visible T band will
appear. The C band should always appear after a sample is applied, indicating a valid result. By this means, the device can accurately indicate
the presence of FMD NSP antibodies in the sample. The panel of bovine sera that was used in this study was obtained from the serum bank of
the Foot and Mouth Disease Research Centre, National Veterinary Research Institute, Vom-Nigeria.
Test Procedure
Fig. 2. Panel of bovine sera being dropped unto the cassette.
The lateral device cassettes were removed from the foil pouch and labelled according to the samples, panels of bovine sera thawed at room
temperature were then dispensed gradually; 3 drops into the sample hole “S” of the cassette. This was allowed to flow along the surface of the
test strip for 5-10 minutes. The results was observed and interpreted within 10 minutes test time. Result after 10 minutes is considered as
invalid.
Results
The results obtained in this study showed a high level of sensitivity in comparison to conventional 3 ABC ELISA for FMD. In all the 40 panel of
positive bovine sera tested by 3 ABC ELISA, 38 tested positive by this assay; a sensitivity of 95%. These results were obtained in full
concordance with the results obtained from running the same panel of sera on 3 ABC ELISA for FMD.
Discussion
An essential component of any disease control strategy includes the deployment of diagnostic assays to rapidly confirm the initial clinical
determination of infection. The speed with which the results of suspected foot and mouth disease outbreak are released will maximise the
efficiency of disease control to stop further spread to non-infected areas. This has become necessary considering the dynamics of transmission
of FMD especially where large population of livestock exists within contiguous farms.
The result obtained from this study demonstrates that the assay could be used for rapid sero-monitoring in outbreak situations. Furthermore, Fig. 3. The first cassette is a negative result and the second cassette is
since it will differentiate infected from vaccinated animals, this will provide better epidemiological information for prompt actions. This assay a positive result.
although is not a substitute to the conventional ELISA protocol for the detection of antibodies against FMD NSP, can be used as a trigger for
taking rapid measures at the site of suspected FMD outbreak before a confirmatory diagnosis is established in a national laboratory that has the
facility for FMD diagnoses, thereby offering the possibility for implementing control measures more rapidly and limiting the spread of the
outbreak.
This assay is a simple direct test for the detection of antibodies to non-structural proteins of FMD in sera of infected animals, and can be carried
out at penside. It is a rapid test which may be carried out on the field, next to the animal. It may be used for early detection of infection as first line
diagnostics for veterinarians in slaughter houses, farms and in simply equipped national/regional laboratories to control the spread of
infections. The test procedure is rapid and simple, providing a result within 10 minutes.
Conclusion
These results reaffirm the apparent high sensitivity of this assay to detect antibodies to NSPs following infection with FMD viruses.
The results reported here originated from testing of field samples submitted during outbreaks and are in line with the laboratory-based
comparisons between this assay and conventional 3 ABC ELISA which found this assay to have a high sensitivity for FMD NSP antibodies in
sera of infected cattle.
The results add further knowledge to the application of lateral flow assay for diagnosis of FMD NSP in sera of infected cattle in Nigeria. Fig. 4. 3 ABC ELISA plate
Reference
Foot and Mouth Disease NSP Antibodies Rapid Test Cat No. : W81058. Quicking Biotech Co., Ltd. No. 1998. South Yanggao Road, Shanghai
China. Product Leaflet.
UNIVERSITEIT VAN PRETORIA
UNIVERSITY OF PRETORIA
Y U N I B E S I T H I YA P R E T O R I A
Faculty of Veterinary Science V O M