DEUTSCHE STIFTUNG FÜR INTERNATIONALE ENTWICKLUNG...
DEUTSCHE STIFTUNG FÜR INTERNATIONALE ENTWICKLUNG (DSE)
GERMAN FONDATION FOR INTERNATIONAL DEVELOPMENT
FOOD AND AGRICULTURE DEVELOPMENT CENTRE (‘ZEL)
SERO-EPIDEMIOLOGICAL DIAGNOSIS IN THE LABORATORY AND IN
ANIMAL DISEASE CONTROL
INTERNATIONAL TRAINING COURSE 2/ 1998
REPORT
Individual S tudy Project
FOOT-AND-MOUTH DISEASE:
Diagnostic methods
By Modou Moustapha LO
from Senegal
Collaborating Institution: Department of tropical Veterinary Medicine and Epidemiologv,
Freie Universitat Berlin
Berlin
November 1998
techniques developed to identify FMD replace animal experiments in the
diagnosis. Three of the serotypes are endemic to sub-Saharan Africa, namely
SATl, SAT2, SAT3 (South African Territory) (Bastos, 1997). The European
serotypes 0, A and C were historically exotic to southem Africa but have
been identified in a number of Northern African countries . Although disease
eradication has been achieved in North America and Western Europe, the
chances of achieving this in sub-Saharan Africa are remote due to the role
wildlife plays in the epidemiology of this disease and the greater complexity
of antigenic types. The situation is further exacerbated by the presence of six
of the seven serotypes and high levels of intratypic variation in the
indigenous virus type making prevention and control problematic.
At present the disease is controlled in South Africa by the restriction of
animal movement,and by vaccination.Early diagnosis and virus
characterization is thus critical to minimize the potential detrimental
economic effects of an outbreak . Presently this is achieved by virus
isolation on tissue culture and/or serological techniques. The reported speed
and sensitivity of virus detection by means of the polymerase chain reaction
(PCR) prompted an investigation into the applicability and usefulness of the
techniques in the African context. For the detection of FMD virus by PCR
there are a number of primers sequences, but these primers do not readily
amplify the SAT-types in particular (Vos100 et al., 1995). It is apparent that
universal FMD detection cari only be substantiated by testing a wide range
of divergent viral subtypes or prototypes.
Materials and methods
Clinically typical cases of FMD are characterized by vesicular conditions of
the feet, buccal mucosa, and , in female, the mammary glands. Clinical signs
cari vary from mild to severe and fatalities may occur, especially in Young
. .
animals. The tissue preferred for diagnosis is epitheliae tissue from
unruptured or freshly ruptured vesicles. Where this is not possible, blood
and/or oesophageal-pharyngeal tluid samples taken (probang) in ruminants
and throat swabs from pigs, provide an alternative source for virus isolation.
From fatal cases, myocardial tissue or blood cari be sampled, but vesicles are
again preferable if present. It is vital that samples from suspected cases are
transported under secure conditions and according to international
regulations.
To screen for this disease, samples are taken from diseased and apparently
non-diseased animals by random sampling method in a cross-sectional
study. However, non-diseased animals in an FMD infected herd may be a
Introduction
During 1996, an epidemic of FMD disease was reported in West Africa
(OIE/FAO Reference Laboratory for FMD Jan-March), ( 1996).
With the fast expansion of FMD disease, was of interest for me to
familiarise myself with diagnostic methods for FMD.
FMD disease is a highly contagious, economically devastating disease of
cloven-hoofed animals. There are seven serotypes of FMD virus, namely 0,
A, C, SATl, SAT2, SAT3 and ASIAl. Infection with one serotype does not
confer immunity against another.Clinically, FMD cannot be differentiated
from other vesicular diseases, like swine vesicular disease,vesicular
stomatitis and vesicular exanthema. Laboratory diagnosis of any suspected
FMD case is therefore a matter of urgency.
The World Reference Laboratory of FMD Disease makes the confirmatory
diagnosis (Pirbright in Great Britain) for the International Office of
Epizooties (OIE).
During my stay at the Federal Research Institut for Animal Virus Disease in
Tiirbingen (Federal Republic of Germany) 1 had the opportunity to acquire
some useful and relevant diagnostic techniques to investigate FMD disease.
Theses techniques include the neutralisation test, the FMD-plaque test and
the Enzym Linked Immunosorbent Assay (ELISA) antibody detection. Some
others techniques such as.:methods to inactivate FMD virus and to isolate
the virus in ce11 culture (infected ce11 culture by FMD, or African swine
Fever) were also demonstrated.
Statement of study objectives
The objectives of this project are to learn methods to diagnose Foot-and-
Mouth Disease.
Literature review
Foot-and-Mouth Disease remains currently the most contagious disease with
a great potential for causing heavy losses in susceptible cloven-hoofed
animais. Most veterinarians and scientists in the world deal with the
problematic disease and many publications were made. (OIE chapter 2.1.1.
1996)
The seven serotypes 0, A. C, SATl, SAT2, Sat3 and ASIAl originally were
determined by cross-challenge experiments in cattle; now serological
problem due to the contagiosity of this disease; if necessary a neighbouring
non- infected herd cari be choosen to find non-diseased animals.
Some difficulties may also occur with some diagnostic methods based on
serological responses in endemic areas due to the possibility of a previous
infection. The detection of specific humoral antibodies requires also absence
of any history of vaccination, as it is not always possible to differentiate a
serological response due to natural infection from a response due to
vaccination.
A/ Materials
ELISA antibody detection
1/ Phenol red solution (0,2%)
2/ Azide solution/lM)
3/ Coating buffer(0,05M carbonate-bicarbonate buffer ph 9,6)
4/ Phosphate buffered saline (Dulbeccoo PBS)
.Y ELISA diluent
6/ Blocking buffer
7/ Substrate (OPD in phosphate-citrate buffer, ph 5,O)
8/ Acid stopper solution
9/ Disinfectant
lO/ PBS T
B/ Others materials
l/ Fiat bottomed ELISA
2/ Tips multichannel pipette and one channel pipette
3/ Centrifuge
4/ Incubator
,
5/ Gloves and others protectives
6/ Orbital shaker, and magnetic stirrer
7/ Flat Nunc
C/ Others reagents
1/ ELIS A FMD- Antigen
2/ Serum
3/ Rabbit anti-FMD serum
4/ Guinea pigs anti-FMD serum
5/ Peroxidase conjugated rabbit immunoglobulins to Guinea Pigs
immunoglobulins (conjugate)
61 OPD-substrate
Method
l/ Coating with rabbit serum in coating buffer (0,05M NaC03/NaHC03, ph
9,6) the flat bottomed ELISA plates
2/Incubation over night at 4°C or freeze at -70°C 2H-3H
Add 50pl/well in a11 Wells
21
Prepare the mixture sample (serum) plus antigen (Serotypes:
OMannish, A22, and C 10)
Serum dilution: 1/5 ,l/lO, 1/20, 1/40 .
0 Mannish dilution: 10 20
A22 dilution: l/l 00
C 10 dilution: l/lOO
Hyper-immune serum against FMD dilution: 1/5, l/lO, 1/20, 1/40.
Control 50% positive dilution for A22: 1/3000, Omannish1/4400,
c 10: 1/4400
Control 100% positive only with virus and buffer
Keep some Wells as blank for each serotype
31
This plate of mixture is incubated over night at +4”C
4/
Flick off the solution of the coating rabbit serum
51
From the mixture antigen/sample take 50pl/well at column 1 to
I’
column lof the flat bottomed test ELISA .Column 2 to column 2 etc until
column 12 .
6/
Incubate 1 hour at 37°C
71
Flick off the solution and wash 3 times with PBS-Tween 20
O,OS%;dry the Rat with filter paper
81
Add the guinea pig anti-serum against FMD diluted in PBS-Tween20
O,l% + 5% skimmed milk powder of each serotype :5Oyl by well in a11 well
4
91
Repeat step 6
101
Dilute the conjugate at 1/2000 and add 50~1 by well in a11 Wells
N B :Guinea Pig serum against these serotypes and the conjugate must be
pre-diluted at 1/2 with normal rabbit serum before the proper dilution with
PBS Tween 20 1%.
1 l/
Flick off the solution and wash 5 times and dry carefully the flat.
12/
Mix the OPD-substrat : 1Oml OPD + lml H202(pre-dilute at 1/60 )
add 50 pl by well in a11 Wells
13/
Incubate 15 minutes at room temperature in a dark box.
14/
Add the stopper solution: H2S04 dilute at 1/4 :amount 50~1 by well in
a11 well .
151
Read the flat with a wavelenght of 492 nm by using the photometer
ELISA reader.
For this test two sera were tested for demonstration .
Results
Both sera which were tested (for demonstration) by ELISA antibody
detection were negative. The optical densities for serum 1 were 0.8 15 ,
0.912 ,0.85 1 ,0.931 at the respective four dilutions 1/5 , l/lO , 1/20 , 1/40 .
The optical densities for serum 2 were 0.90 1, 0.873, 0.824, 0.93 1 at the same
dilutions like serum 1 .
/’
The tut-off of this test was set at 1.5
In the neutralisation test the results indicate a certain cross-reaction between
C IN and A24 and further cross-reaction between Asial and A24. No
crossing was observed with reaction A87, SATI and A24 .
With the plaque test we had also positive reactions which were indicated by
the presence of virus forming plaques on the surface of the agarose gel
medium. Observing theses plaques under the microscope with the 40”’
objective, beautiful a,,
uoregates, destroyed by the virus, could be seen .
With these results obtained during this study the major findings for me are
that:
these test are relevant and useful and not very expensive for
developing countries; they give satisfactory results during and after the
viraemic period of FMD.
using these tests, two types of studies cari be applied:a cross sectional
study and a case control study.
for antibody detection using ELISA, 1 have learnt to adjust the reagent
dilution (antigen, sera, conjugate, OPD-substrat) to fmally get the correct
result as titer or in measured optical densities.
Discussion
The Virus Neutralisation Test as an accepted test for the quantification of
antibodies against FMD has been used successfully. This test is considered
sensitive, specific and relatively simple to perform but requires tissue culture
cells which a11 too often vary in their sensitivity or fail to grow because of
contamination, poor growth conditions or toxic substances in the test
samples.
During my study a specific ce11 culture the so-called FMD Ct cells, from
baby hamster kidneys which were treated to get the ce11 line were used. This
neutralisation test requires also incubation at 37°C for three days before
results cari be read.
In the ELISA test using homologous reference serum antibody titers for each
virus studied results were generally higher than those recorded in the virus
neutralisation test. Cross reactions were recorded in both assays but the
difference between the homologous and the heterologous antibody titers was
greater using ELISA. The high intratypic variation observed for a11 FMD
i’
virus types make the disease difficult to handle. The cross-reactions in both
tests with SATl and SAT3 reflect the true relationship between these two
virus types. In such a case another test like the monoclonal ELISA or the
polymerase chain reaction antibody should be performed.
SO, for a first check for FMD virus the antibody detection ELISA which is
rapid and relatively simple to perform should be applied. It is also economic
in terms of reagents and results cari be reported after one day .
It is aiso very important in case of a FMD epidemic to determine the strains
(serotype) before rnaking any proposa1 for control by vaccination.
References
1
Anon .( 1994) .Bulletin de l‘Office International des Epizooties ,109 -
273
2
Anon. (1997). Bulletin de l‘Office International des Epizooties , 106 -
450 .
3
FREBERG, B., HAAS, K.and R. AHL (1996). Detection of 12s and
146s antigen and strains differentiation by recently developed monoclonal
antibodies to foot and mouth disease virus. FMD, 1996, Israel. Appendix 8,
page 64-69.
4
HAMBLIN, C. , BARNETT, 1. T. R. & HEDGER, R. S. (1986) A
new Enzyme Linked Immunosorbent Assay (ELISA ) for the detection of
antibodies against foot-and-mouth disease virus : development and method
of ELISA. Journal of Immunological Methods 93, 115- 12 1.
5
HAMBLIN, C. , BARNETT, 1. T. R. & HEDGER, R. S., (1986) A
new Enzyme Linked Immunosorbent Assay (ELISA) for the detection
of antibodies against foot-and-mouth disease virus: application.
Journal of Immunological Methods, 93, 123- 129
6
HAPPY, K. , SHIEF, C. ( 1997). Update on foot-and-mouth disease
outbreaks in TAIPEH CHINA, May 22. Animal Industry Department
Tapei China .
7
KEET, D. F. , HUNTER, P. , BENGIS, R. C. , BASTOS, A. D. &
THOMSON, G. C. 1996. The 1992 foot-and-mouth diasease
epizootic in the Kruger National Park.Journal of the South African
Veterinary Association, 67 80-87.
,’
MEYER, R. F. , PACCIARRINI, M. , HILYARD, E: J. , FERRARY,
8
S. , VAKHARIA, V. N. , DONINI, G. , BROCCHI, E. & MOTOR, T.
. 1994. Genetic variation of foot-and-mouth disease virus from field
outbreaks to laboratory isolation .Virus Research, 32,299 -3 12 .
THANKS TO
The Government of the Federal Republic of Germany
The General Director of DSE .
Doctor Zimmermann /DSE Feldafing and a11 his staff.
Professor Dr Karl Hans Zessin, Tropical Veterinary Medicine :Freie
Universitat Berlin
5
Doctor Max Baumann, Tropical Veterinary medecine :Freie
Universitat Berlin .
6
Director of BGVV Berlin . Marienfelde
7
Professor Dr Staak, BGVV, and a11 his staff
8
Doctor Greiner , Doctor Peter Clausen : Tropical Veterinary Medicine
Freie Universitat Berlin .
9
Director of the Federal Research Center for Virus Diseases of
Animals Tübingen
1 0
Doctor Haas, Head of the FMD department , Federal Research Center
for Virus Diseases of Animals, Tübingen and a11 his technicians and
staff.
11
Doctor Freiberg and her staff, Federal Research Center for Virus
Disease of Animals Tübingen.
1 2
Mister Kindie, informatician and his collaborator Freie Universitat
Berlin.
13
Missis Esser, Andrea, Gudrun, Mirjam Steglich, DSE
1 4
My Country: Senegal.
15
My Ministry of Agriculture.
16
General Director of the Livestock in Senegal.
17
Doctor Raphael Coly, Doctor Bouna Alboury Diop, Doctor M‘Bargou
Lo.
13
General Director of the Senegalese Research Institut of Agriculture.
I’
19
Director of the National Laboratory of Health and Animal Production.
20
My head, Dr Yaya Thiongane and a11 his staff.
21
My mother, my wife, and my children.
x
GERMAN FONDATION FOR INTERNATIONAL DEVELOPMENT
FOOD AND AGRICULTURE DEVELOPMENT CENTRE (‘ZEL)
SERO-EPIDEMIOLOGICAL DIAGNOSIS IN THE LABORATORY AND IN
ANIMAL DISEASE CONTROL
INTERNATIONAL TRAINING COURSE 2/ 1998
REPORT
Individual S tudy Project
FOOT-AND-MOUTH DISEASE:
Diagnostic methods
By Modou Moustapha LO
from Senegal
Collaborating Institution: Department of tropical Veterinary Medicine and Epidemiologv,
Freie Universitat Berlin
Berlin
November 1998
techniques developed to identify FMD replace animal experiments in the
diagnosis. Three of the serotypes are endemic to sub-Saharan Africa, namely
SATl, SAT2, SAT3 (South African Territory) (Bastos, 1997). The European
serotypes 0, A and C were historically exotic to southem Africa but have
been identified in a number of Northern African countries . Although disease
eradication has been achieved in North America and Western Europe, the
chances of achieving this in sub-Saharan Africa are remote due to the role
wildlife plays in the epidemiology of this disease and the greater complexity
of antigenic types. The situation is further exacerbated by the presence of six
of the seven serotypes and high levels of intratypic variation in the
indigenous virus type making prevention and control problematic.
At present the disease is controlled in South Africa by the restriction of
animal movement,and by vaccination.Early diagnosis and virus
characterization is thus critical to minimize the potential detrimental
economic effects of an outbreak . Presently this is achieved by virus
isolation on tissue culture and/or serological techniques. The reported speed
and sensitivity of virus detection by means of the polymerase chain reaction
(PCR) prompted an investigation into the applicability and usefulness of the
techniques in the African context. For the detection of FMD virus by PCR
there are a number of primers sequences, but these primers do not readily
amplify the SAT-types in particular (Vos100 et al., 1995). It is apparent that
universal FMD detection cari only be substantiated by testing a wide range
of divergent viral subtypes or prototypes.
Materials and methods
Clinically typical cases of FMD are characterized by vesicular conditions of
the feet, buccal mucosa, and , in female, the mammary glands. Clinical signs
cari vary from mild to severe and fatalities may occur, especially in Young
. .
animals. The tissue preferred for diagnosis is epitheliae tissue from
unruptured or freshly ruptured vesicles. Where this is not possible, blood
and/or oesophageal-pharyngeal tluid samples taken (probang) in ruminants
and throat swabs from pigs, provide an alternative source for virus isolation.
From fatal cases, myocardial tissue or blood cari be sampled, but vesicles are
again preferable if present. It is vital that samples from suspected cases are
transported under secure conditions and according to international
regulations.
To screen for this disease, samples are taken from diseased and apparently
non-diseased animals by random sampling method in a cross-sectional
study. However, non-diseased animals in an FMD infected herd may be a
Introduction
During 1996, an epidemic of FMD disease was reported in West Africa
(OIE/FAO Reference Laboratory for FMD Jan-March), ( 1996).
With the fast expansion of FMD disease, was of interest for me to
familiarise myself with diagnostic methods for FMD.
FMD disease is a highly contagious, economically devastating disease of
cloven-hoofed animals. There are seven serotypes of FMD virus, namely 0,
A, C, SATl, SAT2, SAT3 and ASIAl. Infection with one serotype does not
confer immunity against another.Clinically, FMD cannot be differentiated
from other vesicular diseases, like swine vesicular disease,vesicular
stomatitis and vesicular exanthema. Laboratory diagnosis of any suspected
FMD case is therefore a matter of urgency.
The World Reference Laboratory of FMD Disease makes the confirmatory
diagnosis (Pirbright in Great Britain) for the International Office of
Epizooties (OIE).
During my stay at the Federal Research Institut for Animal Virus Disease in
Tiirbingen (Federal Republic of Germany) 1 had the opportunity to acquire
some useful and relevant diagnostic techniques to investigate FMD disease.
Theses techniques include the neutralisation test, the FMD-plaque test and
the Enzym Linked Immunosorbent Assay (ELISA) antibody detection. Some
others techniques such as.:methods to inactivate FMD virus and to isolate
the virus in ce11 culture (infected ce11 culture by FMD, or African swine
Fever) were also demonstrated.
Statement of study objectives
The objectives of this project are to learn methods to diagnose Foot-and-
Mouth Disease.
Literature review
Foot-and-Mouth Disease remains currently the most contagious disease with
a great potential for causing heavy losses in susceptible cloven-hoofed
animais. Most veterinarians and scientists in the world deal with the
problematic disease and many publications were made. (OIE chapter 2.1.1.
1996)
The seven serotypes 0, A. C, SATl, SAT2, Sat3 and ASIAl originally were
determined by cross-challenge experiments in cattle; now serological
problem due to the contagiosity of this disease; if necessary a neighbouring
non- infected herd cari be choosen to find non-diseased animals.
Some difficulties may also occur with some diagnostic methods based on
serological responses in endemic areas due to the possibility of a previous
infection. The detection of specific humoral antibodies requires also absence
of any history of vaccination, as it is not always possible to differentiate a
serological response due to natural infection from a response due to
vaccination.
A/ Materials
ELISA antibody detection
1/ Phenol red solution (0,2%)
2/ Azide solution/lM)
3/ Coating buffer(0,05M carbonate-bicarbonate buffer ph 9,6)
4/ Phosphate buffered saline (Dulbeccoo PBS)
.Y ELISA diluent
6/ Blocking buffer
7/ Substrate (OPD in phosphate-citrate buffer, ph 5,O)
8/ Acid stopper solution
9/ Disinfectant
lO/ PBS T
B/ Others materials
l/ Fiat bottomed ELISA
2/ Tips multichannel pipette and one channel pipette
3/ Centrifuge
4/ Incubator
,
5/ Gloves and others protectives
6/ Orbital shaker, and magnetic stirrer
7/ Flat Nunc
C/ Others reagents
1/ ELIS A FMD- Antigen
2/ Serum
3/ Rabbit anti-FMD serum
4/ Guinea pigs anti-FMD serum
5/ Peroxidase conjugated rabbit immunoglobulins to Guinea Pigs
immunoglobulins (conjugate)
61 OPD-substrate
Method
l/ Coating with rabbit serum in coating buffer (0,05M NaC03/NaHC03, ph
9,6) the flat bottomed ELISA plates
2/Incubation over night at 4°C or freeze at -70°C 2H-3H
Add 50pl/well in a11 Wells
21
Prepare the mixture sample (serum) plus antigen (Serotypes:
OMannish, A22, and C 10)
Serum dilution: 1/5 ,l/lO, 1/20, 1/40 .
0 Mannish dilution: 10 20
A22 dilution: l/l 00
C 10 dilution: l/lOO
Hyper-immune serum against FMD dilution: 1/5, l/lO, 1/20, 1/40.
Control 50% positive dilution for A22: 1/3000, Omannish1/4400,
c 10: 1/4400
Control 100% positive only with virus and buffer
Keep some Wells as blank for each serotype
31
This plate of mixture is incubated over night at +4”C
4/
Flick off the solution of the coating rabbit serum
51
From the mixture antigen/sample take 50pl/well at column 1 to
I’
column lof the flat bottomed test ELISA .Column 2 to column 2 etc until
column 12 .
6/
Incubate 1 hour at 37°C
71
Flick off the solution and wash 3 times with PBS-Tween 20
O,OS%;dry the Rat with filter paper
81
Add the guinea pig anti-serum against FMD diluted in PBS-Tween20
O,l% + 5% skimmed milk powder of each serotype :5Oyl by well in a11 well
4
91
Repeat step 6
101
Dilute the conjugate at 1/2000 and add 50~1 by well in a11 Wells
N B :Guinea Pig serum against these serotypes and the conjugate must be
pre-diluted at 1/2 with normal rabbit serum before the proper dilution with
PBS Tween 20 1%.
1 l/
Flick off the solution and wash 5 times and dry carefully the flat.
12/
Mix the OPD-substrat : 1Oml OPD + lml H202(pre-dilute at 1/60 )
add 50 pl by well in a11 Wells
13/
Incubate 15 minutes at room temperature in a dark box.
14/
Add the stopper solution: H2S04 dilute at 1/4 :amount 50~1 by well in
a11 well .
151
Read the flat with a wavelenght of 492 nm by using the photometer
ELISA reader.
For this test two sera were tested for demonstration .
Results
Both sera which were tested (for demonstration) by ELISA antibody
detection were negative. The optical densities for serum 1 were 0.8 15 ,
0.912 ,0.85 1 ,0.931 at the respective four dilutions 1/5 , l/lO , 1/20 , 1/40 .
The optical densities for serum 2 were 0.90 1, 0.873, 0.824, 0.93 1 at the same
dilutions like serum 1 .
/’
The tut-off of this test was set at 1.5
In the neutralisation test the results indicate a certain cross-reaction between
C IN and A24 and further cross-reaction between Asial and A24. No
crossing was observed with reaction A87, SATI and A24 .
With the plaque test we had also positive reactions which were indicated by
the presence of virus forming plaques on the surface of the agarose gel
medium. Observing theses plaques under the microscope with the 40”’
objective, beautiful a,,
uoregates, destroyed by the virus, could be seen .
With these results obtained during this study the major findings for me are
that:
these test are relevant and useful and not very expensive for
developing countries; they give satisfactory results during and after the
viraemic period of FMD.
using these tests, two types of studies cari be applied:a cross sectional
study and a case control study.
for antibody detection using ELISA, 1 have learnt to adjust the reagent
dilution (antigen, sera, conjugate, OPD-substrat) to fmally get the correct
result as titer or in measured optical densities.
Discussion
The Virus Neutralisation Test as an accepted test for the quantification of
antibodies against FMD has been used successfully. This test is considered
sensitive, specific and relatively simple to perform but requires tissue culture
cells which a11 too often vary in their sensitivity or fail to grow because of
contamination, poor growth conditions or toxic substances in the test
samples.
During my study a specific ce11 culture the so-called FMD Ct cells, from
baby hamster kidneys which were treated to get the ce11 line were used. This
neutralisation test requires also incubation at 37°C for three days before
results cari be read.
In the ELISA test using homologous reference serum antibody titers for each
virus studied results were generally higher than those recorded in the virus
neutralisation test. Cross reactions were recorded in both assays but the
difference between the homologous and the heterologous antibody titers was
greater using ELISA. The high intratypic variation observed for a11 FMD
i’
virus types make the disease difficult to handle. The cross-reactions in both
tests with SATl and SAT3 reflect the true relationship between these two
virus types. In such a case another test like the monoclonal ELISA or the
polymerase chain reaction antibody should be performed.
SO, for a first check for FMD virus the antibody detection ELISA which is
rapid and relatively simple to perform should be applied. It is also economic
in terms of reagents and results cari be reported after one day .
It is aiso very important in case of a FMD epidemic to determine the strains
(serotype) before rnaking any proposa1 for control by vaccination.
References
1
Anon .( 1994) .Bulletin de l‘Office International des Epizooties ,109 -
273
2
Anon. (1997). Bulletin de l‘Office International des Epizooties , 106 -
450 .
3
FREBERG, B., HAAS, K.and R. AHL (1996). Detection of 12s and
146s antigen and strains differentiation by recently developed monoclonal
antibodies to foot and mouth disease virus. FMD, 1996, Israel. Appendix 8,
page 64-69.
4
HAMBLIN, C. , BARNETT, 1. T. R. & HEDGER, R. S. (1986) A
new Enzyme Linked Immunosorbent Assay (ELISA ) for the detection of
antibodies against foot-and-mouth disease virus : development and method
of ELISA. Journal of Immunological Methods 93, 115- 12 1.
5
HAMBLIN, C. , BARNETT, 1. T. R. & HEDGER, R. S., (1986) A
new Enzyme Linked Immunosorbent Assay (ELISA) for the detection
of antibodies against foot-and-mouth disease virus: application.
Journal of Immunological Methods, 93, 123- 129
6
HAPPY, K. , SHIEF, C. ( 1997). Update on foot-and-mouth disease
outbreaks in TAIPEH CHINA, May 22. Animal Industry Department
Tapei China .
7
KEET, D. F. , HUNTER, P. , BENGIS, R. C. , BASTOS, A. D. &
THOMSON, G. C. 1996. The 1992 foot-and-mouth diasease
epizootic in the Kruger National Park.Journal of the South African
Veterinary Association, 67 80-87.
,’
MEYER, R. F. , PACCIARRINI, M. , HILYARD, E: J. , FERRARY,
8
S. , VAKHARIA, V. N. , DONINI, G. , BROCCHI, E. & MOTOR, T.
. 1994. Genetic variation of foot-and-mouth disease virus from field
outbreaks to laboratory isolation .Virus Research, 32,299 -3 12 .
THANKS TO
The Government of the Federal Republic of Germany
The General Director of DSE .
Doctor Zimmermann /DSE Feldafing and a11 his staff.
Professor Dr Karl Hans Zessin, Tropical Veterinary Medicine :Freie
Universitat Berlin
5
Doctor Max Baumann, Tropical Veterinary medecine :Freie
Universitat Berlin .
6
Director of BGVV Berlin . Marienfelde
7
Professor Dr Staak, BGVV, and a11 his staff
8
Doctor Greiner , Doctor Peter Clausen : Tropical Veterinary Medicine
Freie Universitat Berlin .
9
Director of the Federal Research Center for Virus Diseases of
Animals Tübingen
1 0
Doctor Haas, Head of the FMD department , Federal Research Center
for Virus Diseases of Animals, Tübingen and a11 his technicians and
staff.
11
Doctor Freiberg and her staff, Federal Research Center for Virus
Disease of Animals Tübingen.
1 2
Mister Kindie, informatician and his collaborator Freie Universitat
Berlin.
13
Missis Esser, Andrea, Gudrun, Mirjam Steglich, DSE
1 4
My Country: Senegal.
15
My Ministry of Agriculture.
16
General Director of the Livestock in Senegal.
17
Doctor Raphael Coly, Doctor Bouna Alboury Diop, Doctor M‘Bargou
Lo.
13
General Director of the Senegalese Research Institut of Agriculture.
I’
19
Director of the National Laboratory of Health and Animal Production.
20
My head, Dr Yaya Thiongane and a11 his staff.
21
My mother, my wife, and my children.
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