The Incursion and Spread of Highly Pathogenic Avian Influenza H5N8 Clade 2.3.4.4 Within South Africa.

The report of a mass die-off of white-winged terns (Chlidonias leucopterus) along the shores of Lake Victoria in Uganda in January 2017 was a warning that highly pathogenic avian influenza (HPAI) H5N8 clade 2.3.4.4 had entered the avian populations of the African Rift Valley. In early June 2017, Zimbabwe reported an outbreak of the virus in commercial breeder chickens near Harare, and on June 19, 2017, the first case of HPAI H5N8 was confirmed in a broiler breeder operation near Villiers, Mpumalanga Province, South Africa, representing the first ever notifiable influenza in gallinaceous poultry in South Africa. Forty viruses were isolated from wild birds, backyard hobby fowl, zoo collections, commercial chickens, and commercial ostriches over the course of the outbreak and full genomes were sequenced and compared to determine the epidemiologic events in the introduction and spread of clade 2.3.4.4 H5N8 across the country. We found that multiple virus variants were involved in the primary outbreaks in the north-central regions of South Africa, but that a single variant affected the southernmost regions of the continent. By November 2017 only two of the nine provinces in South Africa remained unaffected, and the layer chicken industry in Western Cape Province was all but decimated. Two distinct variants, suggesting independent introductions, were responsible for the first two index cases and were not directly related to the virus involved in the Zimbabwe outbreak. The role of wild birds in the incursion and spread was demonstrated by shared recent common ancestors with H5N8 viruses from West Africa and earlier South African aquatic bird low pathogenicity avian influenza viruses. Improved wild bird surveillance will play a more critical role in the future as an early warning system.

Incursión y propagación del virus de la influenza aviar altamente patógena H5N8 clado 2.3.4.4 en Sudáfrica. El informe de una muerte masiva de fumareles aliblancos (Chlidonias leucopterus) a lo largo de las orillas del lago Victoria en Uganda en enero del 2017 fue una advertencia de que la influenza aviar de alta patogenicidad (HPAI) H5N8, clado 2.3.4.4 había ingresado en las poblaciones de aves del Valle del Rift Africano. A principios de junio del 2017, Zimbabwe reportó un brote del virus en pollos reproductores comerciales cerca de Harare, y el 19 de junio del 2017, el primer caso de influenza aviar de alta patogenicidad H5N8 se confirmó en una operación de pollos de engorde en la provincia de Mpumalanga cerca de Villiers, Sudáfrica, que representa el primer caso de influenza notificable en aves gallináceas en Sudáfrica. Se aislaron cuarenta virus de aves silvestres, aves de traspatio, colecciones de zoológicos, pollos comerciales y avestruces comerciales durante el transcurso del brote. Se secuenciaron los genomas completos y se compararon para determinar los eventos epidemiológicos en la introducción y propagación del subtipo H5N8 clado 2.3.4.4 a través del país. Se encontró que múltiples variantes del virus estaban involucradas en los brotes primarios en las regiones centro y norte de Sudáfrica, pero que una sola variante afectaba a las regiones más al sur del continente. En noviembre de 2017, solo dos de las nueve provincias de Sudáfrica permanecían sin afectarse y la industria de pollos en la Provincia de Cabo Occidental resultó casi diezmada. Dos variantes distintas, que sugieren introducciones independientes, fueron responsables de los dos primeros casos índices y no estuvieron directamente relacionados con el virus involucrado en el brote de Zimbabwe. El papel de las aves silvestres en la incursión y diseminación fue demostrado por los ancestros comunes compartidos con los virus H5N8 de África Occidental y los virus de la influenza aviar de baja patogenicidad de aves acuáticas de Sudáfrica detectados anteriormente. La mejora de la vigilancia de aves silvestres jugará un papel más crítico en el futuro como un sistema de alerta temprana.

Identification of three novel mycoplasma species from ostriches in South Africa.

Mycoplasmas have been implicated in certain clinical syndromes in ostriches and are associated with upper respiratory tract infections. As these infections result in production losses, they are of considerable economic importance to the South African ostrich industry. Although poultry mycoplasmas have been shown to infect ostriches, the existence of unique ostrich-specific mycoplasmas has been suggested. In this study, mycoplasmas were isolated from ostriches in the Klein Karoo, Central Karoo and Garden Route areas of the Western and Northern Cape Provinces of South Africa and identified using 16S rRNA gene sequencing. These sequences indicated that ostriches in these areas carry three unique mycoplasmas and were not infected with chicken mycoplasmas. Phylogenetic analysis of the 16S rRNA sequences of the three isolated ostrich mycoplasmas showed them to be quite divergent and to fall into two distinct phylogenetic groupings. Unique sequences within the 16S rRNA gene of the ostrich mycoplasmas were subsequently used for the development of specific primers for the detection and diagnosis of mycoplasma infections in ostriches. Chickens kept in close proximity to infected ostriches were not infected with these ostrich mycoplasmas.