A new wave of highly pathogenic avian influenza (HPAI) appears to have begun in South Africa, affecting both poultry farms and wild birds. For the first time, the H5N1 variant of the virus has been detected in wild birds in Guinea, and one further outbreak has been confirmed on a Nigerian poultry farm.
For South Africa, the arrival of winter in the Southern Hemisphere has unfortunately also brought the return of HPAI.
Over the past few weeks, the disease has caused havoc for poultry farmers in the Western Cape area, according to the South African Poultry Association (SAPA). Around 540,000 laying hens had been lost, the association reported in the current issue of its Poultry Bulletin.
By the end of May, five outbreaks among commercial chickens in the Western Cape Province were confirmed by the government’s agriculture department, DALRRD.
While stressing there was no immediate danger to human health from the consumption of poultry meat and eggs, citizens are urged to prepare these food carefully to avoid other foodborne pathogens.
To poultry owners, officials sent a warning to be alert for signs of ill-health in their birds, as well as to report any suspicions of HPAI to a private or state veterinarian. Furthermore, they urged all poultry owners —including those with birds kept as a hobby or for zoo purposes — to follow strict biosecurity measures to prevent the introduction of the virus.
Although some other countries see the prospect of the introduction of a vaccine to protect poultry from HPAI, SAPA says there is a “long way to go” before vaccination will become an option in South Africa.
Six outbreaks confirmed in South African poultry flocks
So far, commercial birds have tested positive for an HPAI virus of the H5 family on six farms in Western Cape.
In mid-April, the first cases in this new outbreak wave were detected at a farm in the West Coast district, according to official notifications to the World Organisation for Animal Health (WOAH). Subsequent reports confirmed outbreaks to the south and east of the province in Cape Winelands, the Cape Town city area, and most recently, the Garden Route district. Latest premises to be affected was around 300km to the east of the earlier infections.
So far, just over 1.1 million poultry have been impacted by these outbreaks though mortality or culling. Individual flock sizes ranged from 77,000 to 420,000.
At the end of April, the South African authorities declared the previous HPAI outbreak wave “closed.”
Starting in March of 2021, this was linked to the H5N1 virus serotype. It had affected just over 4.96 million of the nation’s commercial poultry at 94 farms across much of the country.
Also testing positive for an H5 HPAI virus since March of this year have been 22 wild birds at 19 locations in Western Cape and Gauteng — mainly in the cities of Cape Town, Johannesburg, and Tshwane.
Between May of 2021 and February this year, more than 21,800 other birds were reported to have died from infection with the H5N1 HPAI virus. Particularly hard hit by this infection were Cape cormorants, of which almost 20,700 died over this period, as well as 2,196 domestic poultry in backyard flocks.
HPAI situation elsewhere in Africa
So far this year, HPAI has caused a total of 36 outbreaks in poultry and other birds across Africa so far this year. This is according to the EMPRES system of the United Nations’ Food and Agriculture Organization (FAO; as of June 13).
This total includes 16 outbreaks in Niger, 13 in South Africa, four in the Republic of Senegal, and one each in The Gambia, the Republic of Guinea, and Nigeria.
For the first time, mass mortality of wild birds in Guinea has been linked to the H5N1 HPAI virus.
Affected in mid-April were around 750 migratory birds, according to an official WOAH notification. Of these, 745 died in a natural park off the coast of this West African state. The birds were identified as migratory birds, mainly terns, and included two pelicans.
Based on recent reports to WOAH, there have been no further cases of HPAI in poultry or wild birds in Côte d’Ivoire (Ivory Coast), or Senegal.
Following a brief hiatus from HPAI, one further outbreak has occurred in Nigeria. At the end of April, presence of the H5N1 virus was confirmed in a flock of 1,800 poultry in the southern state of Rivers.
This brought the country’s total outbreaks since December of 2020 to 451, based on WOAH data. Directly affected have been almost 2.4 million poultry.
