The document summarizes a study on the complex epidemiology of foot-and-mouth disease (FMD) in cattle in Nigeria from 2012-2017. Genetic analysis found half of outbreaks were the O/EA-3 topotype, while other prevalent topotypes were A/Africa/G-IV, SAT1/X, and SAT2/VII. The results indicate FMD outbreaks stem from both sustained local transmission of existing strains and repeated introductions of new strains through livestock trade with neighboring countries. More research is needed to understand the role of small ruminants and wildlife in FMD transmission to support an effective vaccination program.

1. Title of the poster
Sciensano • David Lefebvre • T + 32 2 379 05 13 • david.lefebvre@sciensano.be • www.sciensano.be
Conclusion
The results indicate that the epidemiology of FMD in Nigeria is
dynamic and complex and results from a combination of
sustained local transmission of present FMD virus strains and
the incursion of new FMD virus strains into Nigeria due to
trade of livestock entering from neighboring countries. More
studies, including studies in wildlife, are needed to support
the implementation of a vaccination-based control program.
Introduction
Nigeria is a large densely populated country in West Africa. Most of its livestock is raised in a
pastoralist production system with typical long distance migration in search of water and feed.
As the demand for animal products largely exceeds the domestic production, large numbers of
livestock are imported from neighboring countries without sanitary restrictions. In Nigeria foot-
and-mouth disease virus (FMDV) serotypes O, A and SAT2 are endemic since long time and
FMDV serotype SAT1 is described again since 2015, after an absence of more than 30 years.
Historically, outbreaks of FMD due to serotypes O, A, SAT1 and SAT2 were each time
associated with trade of cattle entering Nigeria from neighboring countries (Ehizibolo et al.,
2017a and 2017b).
Methods
Epithelial samples from 27 outbreaks of FMD were collected in Nigerian cattle from 2012 till
2017 in 6 different States and in the Federal Capital Territory. Samples positive for FMDV were
identified by real-time RT-PCR and virus isolation on cell culture and FMDV was characterized
by VP1 sequencing and phylogenetic analysis (Ayelet et al. 2009) and antigen ELISA,
respectively.
Results
Half of the outbreaks were characterized as FMDV topotype O/EA-3, while outbreaks with other
serotypes and topotypes were – in descending order – less prevalent: A/Africa/G-IV, SAT1/X,
SAT2/VII and O/WA.
• Serotype O
The data suggests the continued circulation in Nigeria with ∼1% change in VP1 nucleotide (nt)
identity per year of two different previously identified sub-lineages of FMDV topotype O/EA-3
(Ehizibolo et al., 2020). It could not be concluded whether this is a result of two separate
introductions of FMDV topotype O/EA-3 into Nigeria or a result of local virus evolution from a
common ancestor. One of these 2 sub-lineages has spread from West Africa into North Africa in
2018 (WRLFMD). The data also suggests that the FMDV topotype O/WA continues to circulate
in the West African region despite the abundant presence of clinical outbreaks caused by FMDV
topotype O/EA-3.
• Serotype A
The data suggests the presence of 3 different sub-lineages of FMDV topotype A/Africa lineage
G-IV. Based on the available sequence information, two of these result from continued
circulation in Nigeria of previously reported sub-lineages with ∼1% change in VP1 nt identity per
year while the third sub-lineage may result from a new introduction. One of these 3 sub-lineages
has spread from West Africa into North Africa in 2017 (Pezzoni et al., 2019).
• Serotype SAT1
The first described outbreak of the newly discovered FMDV topotype SAT1/X in 2015 occurred
at 150 km from a national park that houses African buffaloes but no samples were available
from these animals. However, 338 serum samples from sheep, goat and wildlife collected in the
outbreak region before 2015 were tested and all were negative for antibodies against FMDV
SAT1, further confirming the absence of this serotype before 2015. Since 2016, the new SAT1/X
topotype from Nigeria is also reported in the neighboring country Cameroon, suggesting long
distance spread of FMDV due to trade or livestock movements.
• Serotype SAT2
The data suggests the presence of 3 different lineages of FMDV topotype SAT2/VII. Since 2013,
the SAT2/VII/Lib-12 virus lineage, introduced from North Africa, seems to have become
dominant and circulates with ∼1% change in VP1 nt identity per year.
Discussion
The genetic and phylogenetic analysis suggests a mixed origin of FMD outbreaks. Some
outbreaks seem to be caused by sustained local transmission of FMDV strains present in
Nigeria since a number of years ago, while other outbreaks seem to be related to repeated
introductions of new FMDV strains, probably resulting from trade of cattle entering Nigeria from
neighboring countries, with shorter periods of sustained transmission. The role of small
ruminants and African buffaloes in the etiology of FMD in Nigeria is unclear. Our results indicate
that systematic sample collection is essential to understand the complex concomitance of
FMDV strains in Nigeria and essential to support the implementation of a vaccination-based
control plan.
______________________________________
REFERENCES
• Ayelet et al, Genetic characterization of foot-and-mouth disease viruses, ethiopia, 1981-
2007. Emerg Infect Dis. 2009, 15:1409–17
• Ehizibolo et al, Detection and Molecular Characterization of Foot and Mouth Disease
Viruses from Outbreaks in Some States of Northern Nigeria 2013-2015. Transbound Emerg
Dis. 2017a, 64:1979–90
• Ehizibolo et al, Foot-and-mouth disease virus serotype SAT1 in cattle, Nigeria. Transbound
Emerg Dis. 2017b, 64:683–90
• Ehizibolo et al, Characterization of transboundary foot-and-mouth disease viruses in Nigeria
and Cameroon during 2016. Transbound Emerg Dis. 2020, 67:1257–70
• Pezzoni et al, Foot-and-mouth disease outbreaks due to an exotic virus serotype A lineage
(A/AFRICA/G-IV) in Algeria in 2017. Transbound Emerg Dis. 2019), 66:7–13
• WRLFMD. FAO World Reference Laboratory for Foot-and-Mouth Disease. Genotyping
Report, 10th July 2018. BATCH: WRLFMD/2018/00019
COMPLEX CIRCULATION OF FOOT-AND-MOUTH DISEASE
VIRUS IN CATTLE IN NIGERIA
Ularamu Hussaini1, Lefebvre David2,*, Haegeman Andy2, Wungak Yiltawe1, Ehizibolo David1, Lazarus
David1, De Vleeschauwer Annebel2, De Clercq Kris2
1. FMD Laboratory, Viral Research Division, National Veterinary Research Institute (NVRI), Vom, Nigeria
2. Service for Exotic Viruses and Particular Diseases, Department of Infectious Diseases in Animals, Sciensano, Brussels, Belgium
* Presenting author
O/EA-3
A/Africa/G-IV