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.
Vet Microbiol. 2020 Sep;248:108820. doi: 10.1016/j.vetmic.2020.108820. Epub 2020 Aug 13.
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.
2018 年 12 月，在尼日利亚最西北边境与尼日尔共和国接壤的索科托州，发现驴中疑似暴发马流感（EI）。使用实时 RT-qPCR 和部分血凝素（HA）基因及全基因组测序，鉴定出暴发的病原体是 H3N8 亚型马流感病毒（EIV）。此后，该 H3N8 病毒传播到尼日利亚 19 个北部州中的 7 个州，影响了驴和马。部分和完整 HA 基因的系统进化分析显示，与 2018 年从阿根廷和智利分离的属于美洲谱系佛罗里达 1 分支（Fc-1）的 EIV 最接近，核苷酸相似性为 99.7%。与 OIE 推荐的 Fc-1 疫苗株相比，病毒蛋白共观察到 80 个氨基酸取代。HA 和神经氨酸酶蛋白分别有 13 个和 16 个氨基酸取代。本研究代表了在尼日利亚和西非次区域首次报告的由 Fc-1 病毒引起的 EI 暴发。根据该报告，需要对马属动物进行广泛的疾病监测，以确定流行株系并制定有效的控制策略，以保护该国数量可观的马和驴。
