Fatal multiple outbreaks of equine influenza H3N8 in Nigeria, 2019: The first introduction of Florida clade 1 to West Africa.
Abstract: In December 2018, suspected outbreaks of equine influenza (EI) were observed in donkeys in Sokoto State, in the extreme northwest of Nigeria bordering the Republic of the Niger. Equine influenza virus (EIV) subtype H3N8 was the etiologic agent identified in the outbreaks using real-time RT-qPCR and sequencing of both the partial haemagglutinin (HA) gene and the complete genome. Since then the H3N8 virus spread to 7 of the 19 northern states of Nigeria, where it affected both donkeys and horses. Phylogenetic analysis of the partial and complete HA gene revealed the closest nucleotide similarity (99.7%) with EIVs belonging to the Florida clade 1 (Fc-1) of the American lineage isolated in 2018 from Argentina and Chile. In total, 80 amino acid substitutions were observed in the viral proteins when compared to the OIE-recommended Fc-1 vaccine strains. The HA and neuraminidase proteins respectively had 13 and 16 amino acid substitutions. This study represents the first reported outbreak of EI caused by an Fc-1 virus in Nigeria and in the West Africa sub-region. Based on this report, extensive disease surveillance in equids is required to establish the circulating lineages and design an effective control strategy to protect the considerable population of horses and donkeys in the country.
Copyright © 2020 Elsevier B.V. All rights reserved.
Publication Date: 2020-08-13 PubMed ID: 32891950DOI: 10.1016/j.vetmic.2020.108820Google Scholar: Lookup
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Summary
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This research discusses the multiple fatal outbreaks of equine influenza subtype H3N8 in Nigeria during 2019, caused by a strain of the virus hitherto unknown in West Africa. It details the need for extensive disease surveillance in the region to control the outbreak and protect horses and donkeys.
About the Outbreak
In December 2018, suspected outbreaks of equine influenza, a highly contagious disease that affects horses, were noticed in donkeys in Sokoto State, in Nigeria’s extreme northwest, near the Republic of Niger.
The responsible virus, an equine influenza virus subtype H3N8, was identified in real-time through RT-qPCR and sequencing of both the haemagglutinin (HA) gene and the complete genome.
- This particular strain of H3N8 spread to 7 of the 19 northern states of Nigeria, affecting both donkeys and horses.
- This was the first reported outbreak of equine influenza caused by an Fc-1 virus in Nigeria and West Africa.
Findings from Phylogenetic Analysis
The researchers performed a phylogenetic analysis, a method used to research the evolutionary relationships between different organisms, of the partial and complete HA gene.
- The results showed a very high nucleotide similarity (99.7%) with EIVs from the Florida clade 1 (Fc-1) of the American lineage, which were isolated in 2018 from Argentina and Chile.
- This is significant because these kinds of amino acid substitutions could potentially affect the virus’s antigenicity, its ability to elicit an immune response.
Notable Differences
When comparing the H3N8 virus with the OIE-recommended Fc-1 vaccine strains, 80 amino acid substitutions were noticed in the viral proteins.
- Among these, the HA and neuraminidase proteins, significant in viral entry into host cells and release of newly formed virus particles, had respectively 13 and 16 amino acid substitutions.
Implications and Recommendations
This research implies that a new strain of H3N8 virus, markedly different from current vaccine strains, is responsible for the equine influenza outbreaks in Nigeria.
- It is the first reported outbreak of equine influenza caused by the Fc-1 virus in Nigeria and West Africa.
- The researchers recommend extensive disease surveillance in equids to establish the circulating lineages and devise an effective control strategy to protect horses and donkeys.
- This strategy would help to contain the disease spread and mitigate the potential devastating effects on the considerable population of horses and donkeys in Nigeria and broader West Africa.
Cite This Article
APA
Shittu I, Meseko CA, Sulaiman LP, Inuwa B, Mustapha M, Zakariya PS, Muhammad AA, Muhammad U, Atuman YJ, Barde IJ, Zecchin B, Quaranta EG, Shamaki D, Alabi O, Monne I, Fusaro A, Joannis TM.
(2020).
Fatal multiple outbreaks of equine influenza H3N8 in Nigeria, 2019: The first introduction of Florida clade 1 to West Africa.
Vet Microbiol, 248, 108820.
https://doi.org/10.1016/j.vetmic.2020.108820 Publication
Researcher Affiliations
- Regional Laboratory for Animal Influenza and other Transboundary Animal Diseases, National Veterinary Research Institute, Vom, Plateau State, Nigeria. Electronic address: ismaila.shittu@gmail.com.
- Regional Laboratory for Animal Influenza and other Transboundary Animal Diseases, National Veterinary Research Institute, Vom, Plateau State, Nigeria.
- Regional Laboratory for Animal Influenza and other Transboundary Animal Diseases, National Veterinary Research Institute, Vom, Plateau State, Nigeria.
- Regional Laboratory for Animal Influenza and other Transboundary Animal Diseases, National Veterinary Research Institute, Vom, Plateau State, Nigeria.
- Department of Veterinary and Pest Control Services, Federal Ministry of Agriculture and Rural Development, Sokoto field office, Sokoto State, Nigeria.
- Zonal Veterinary Office, Kaduna State Ministry of Agriculture, Kaduna State, Nigeria.
- Ministry of Animal Health, Husbandry and Fisheries, Birnin-Kebbi, Kebbi State, Nigeria.
- Directorate of Animal Health and Livestock Development, Gusau, Zamfara State, Nigeria.
- National Veterinary Research Institute, Bauchi Outstation Diagnostic Laboratory, Bauchi State, Nigeria.
- Central Diagnostic Laboratory, National Veterinary Research Institute, Vom, Plateau State, Nigeria.
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Padova, Italy.
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Padova, Italy.
- Regional Laboratory for Animal Influenza and other Transboundary Animal Diseases, National Veterinary Research Institute, Vom, Plateau State, Nigeria.
- Department of Veterinary and Pest Control Services, Federal Ministry of Agriculture and Rural Development, Abuja, Federal Capital Territory, Nigeria.
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Padova, Italy.
- Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Padova, Italy.
- Regional Laboratory for Animal Influenza and other Transboundary Animal Diseases, National Veterinary Research Institute, Vom, Plateau State, Nigeria.
MeSH Terms
- Africa, Western / epidemiology
- Animals
- Disease Outbreaks / veterinary
- Genome, Viral
- Horse Diseases / mortality
- Horse Diseases / virology
- Horses
- Influenza A Virus, H3N8 Subtype / pathogenicity
- Nigeria / epidemiology
- Orthomyxoviridae Infections / mortality
- Orthomyxoviridae Infections / veterinary
- Phylogeny
- Viral Proteins / genetics
Citations
This article has been cited 13 times.- Pellegrini F, Buonavoglia A, Omar AH, Diakoudi G, Lucente MS, Odigie AE, Sposato A, Augelli R, Camero M, Decaro N, Elia G, Bányai K, Martella V, Lanave G. A Cold Case of Equine Influenza Disentangled with Nanopore Sequencing. Animals (Basel) 2023 Mar 24;13(7).
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