Serotype Specificity of Antibodies against FMDV in Cattle in Selected Districts in Uganda FRANK NORBERT MWIINE Department of Biomolecular Resources & Biolab Sciences (BBS) School of Biosecurity, Biotechnical & Laboratory Sciences (SBLS) College of Veterinary Medicine, Animal Resources and Biosecurity (COVAB) Ph.D dissemination of research findings
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Serotype Specificity of Antibodies against FMDV in Cattle in Selected
Districts in Uganda
FRANK NORBERT MWIINE
Department of Biomolecular Resources & Biolab Sciences (BBS)
School of Biosecurity, Biotechnical & Laboratory Sciences (SBLS)
College of Veterinary Medicine, Animal Resources and Biosecurity (COVAB)
Ph.D dissemination of research findings
Introduction
• Foot-and-mouth disease (FMD) is one of the most important livestock diseases globally due to its economic impact
• Affects cattle, pigs, sheep, goats, buffalos, and all cloven hoofed wildlife species.
• FMD virus (FMDV): classified within the Aphthovirus genus as a member of the Picornaviridae family
• Extremely contagious, difficult and expensive to control and eradicate
Introduction
• FMDV: 7 immunologically distinct serotypes:-O, A, C, Asia 1, SAT 1, SAT 2 & SAT 3
• In Africa, 6 serotypes exist apart from Asia 1 that has never been reported
• In Uganda FMD is endemic, first confirmed in 1953
• Control measures based on vaccination and quarantine of livestock
Clinical signs of FMDCharacterized by fever and vesicles in the mouth, muzzle, teats, and feet. Excess salivation (drooling) is obvious
Clinical signs of FMD
Severe erosions on the dental pad and gums. (mouth lessions)
Raw tongue
FMD, Ruptured tongue
FMD lesion on the tongue
Classical FMD, raw tongue, flothing
Clear FMD wounds on coronary band
FMD lesion on the gum
FMD, Raw gum
FMD classical sign
FMD, lesion on nostril
FMD Lesion on the tongue
Healing tongue, FMD
Burning FMD infected cattle
Study objective• To determine the serotype-specificity of the circulating
FMDV antibodies in cattle in selected districts in Ugandaduring the major FMD outbreak in 2006.
Map of Uganda showing FMD post-outbreak study districts, 2006.
study carried out in 7 districts;
Bushenyi, Isingoro, Mbarara, Kasese, Mpigi, Kiboga and Kiruhura
A total of 349 cattle sera were collected from 28 herds
30 OP collected from 9 herds (Mb,Ks)
Methods• Serum antibody assays
i. Screening for antibodies to FMDV Non Structural Proteins (NSP) & Structural Proteins (SP) was performed using Ceditest® FMDV-NS & FMDV type O test kits (Cedi Diagnostics BV, Lelystad, The Netherlands).
ii. Solid Phase Blocking ELISA (SPBE) an in-house system set up at DTU, National Veterinary Institute, Lindholm Denmark/MAAIF-Uganda
• FMD Virus isolation /Ag ELISA
ELISA TEST
ELISA TESTColour development, FMD serotype O
After addition of stop solution FMD serotype O
Results From 22 cattle herds with visible typical clinical signs
to FMD, 285 sera were obtained; NSP= 78%, SP-O=82%
From 6 cattle herds that had no visible c/s to FMD,64 sera were obtained; NSP= 5%, SP-O=6%
SPBE; serotypes O (38%, 22/58), SAT 1 (11%, 5/45),SAT 2 (2%, 1/49) and SAT 3 (9%, 7/79) at cut-off of≥160
Only FMD serotype O virus was isolated(GBACN:EF611987)
District Village Herd no. No. of samp. tested NSP Positive (%) SP-O Positive (%)Bushenyi Kitwe Bs6 9 9 (100) 9 (100)
Serotype-specificity of antibodies towards FMD in cattle herds surrounding Lake Mburo National Park in
2008
Study areaLake Mburo National Park (LMNP) in the South-Western part of Uganda-Kiruhura District
211 sera samples from 23 herds of long horned Ankole breeds aged more than four years were collected with a history of previous FMD outbreaks
Methods• Antibody assays
i. Screening for antibodies to FMDV Non Structural Proteins (NSP) & Structural Proteins (SP) was performed using Ceditest® FMDV-NS & FMDV type O test kits (Cedi Diagnostics BV, Lelystad, The Netherlands).
ii. Solid Phase Blocking ELISA (SPBE) an in-house system set up at DTU, National Veterinary Institute, Lindholm Denmark/MAAIF-Uganda
Results• Out of 211 cattle sera samples:-
– 42.7% (90/211) were positive for antibodies against NSP of FMDV
– 75.4% (159/211) were positive for SP of FMDV serotype O
FMDV Titres ≥ 1:160 in SPBEs were:-
– Serotype O, 61% (19/31),
– Serotype A, 33% (5/15),
– SAT 1, 67% (20/30),
– SAT 2, 37% (10/27)
– SAT 3, 2% (4/33)
conclusions
• FMD outbreaks in cattle herds around LMNP were probably caused by FMDV serotype O, A and/ or SAT-serotype(s).
• Usage of non-purified, multivalent vaccines obscures the serological diagnosis of FMDV outbreaks
General Recommendations
• Regional studies should be carried out to establishFMDV serotypes and/or strains involved in diseaseoutbreaks and emphasis should be on virus recovery.
• For future serological work, circulating field viruses inUganda should be obtained and homologous reagentbe made for SPBE.
• Post outbreak sampling for serological diagnosisshould be focused on young unvaccinated stock of 6-12-months of age.
• Carrier status should be evaluated in districts whereFMD outbreaks are frequent.
FMD Control
• Vaccination of animals –cattle and sheep goats and pigs
• Strict quarantine of animals
• Establish FMD free zones in Uganda/regions
• Observe all-in-all out rule of animals
• Restriction of persons and trucks and proper sanitation(animal owners, vets, trucks)
Acknowledgements
• This study was funded by DANIDA under the Livestock Wildlife Diseases in East Africa Project (LWDEA), grant number: P104.Dan.8.1.316.
1. National Animal Disease Diagnostics and Epidemiology Centre, Ministry of Agriculture Animal Industry and Fisheries, Entebbe, Uganda
2. Makerere University Institute of Environment and Natural Resources, Kampala, Uganda
3. National Veterinary Institute, Danish Technical University, Kalvehave, Denmark
4. Department of Biology, University of Copenhagen, Denmark
• My former supervisors,
William Olaho-Mukani, Kirsten Tjørnehøj
• Project coordinators and scientists/advisors
Anna Rose Ademun Okurut, Prof. Søren Alexandersen, Vincent Muwanika,, Laurids Siig Christensen, Hans Redlev Siegismund, Charles Masembe , Karl Johan Sørensen, Graham Belsham, Jorn Klien, Bøtner Annete
• Former PhD scientists on LWDEA project : Chrisostom Ayebazibwe, Sheila Nina Balinda, Abraham Kiprotich Sangula
• Technical team:
Esau Martin, Eugene Arinaitwe, Zac Duluga (deceased), Patrick Atim Nedi, Preben Norman, Jani Christensen, Jane Borch and Tina Fredricksen