As the number of the nation’s commercial poultry affected by highly pathogenic avian influenza over the past nine months passed 12 million, South Africa’s poultry sector is considering the prospect of vaccinating birds against the virus.
Losses of poultry from highly pathogenic avian influenza (HPAI) approaching 12.3 million over the course of less than a year have been devastating for South Africa — not the poultry sector, but also for its people coping with a cost-of-living crisis. Previous outbreak waves have been ongoing sporadically since 2017.
Targeted vaccination of poultry — as initiated in a government scheme in France since October last — may help to prevent a recurrence of the disease in South Africa.
However, there is much work to be done before this becomes realistic option there. This is according to the South African Poultry Association (SAPA) in its latest publication Poultry Bulletin.
Following the government’s decision in principle to allow vaccination against HPAI in September, SAPA has carried out an assessment of this option.
It found that protection against the H5N1 HPAI virus could be achieved successfully as this strain is currently circulating widely across the world. Furthermore, a number of effective vaccines are already available for H5 protection.
However, the simultaneous circulation of a second virus serotype — H7N6 — in South Africa represents a bigger challenge, according to SAPA. This strain is unlike any other currently circulating in the rest of the world, and current vaccines may not be effective against it.
Locally produced vaccines are in development, according to SAPA, but protocols for testing under field conditions are still to be finalized before testing can begin.
Availability of an effective, authorized and commercially available vaccine against the H7N6 HPAI virus in South Africa appears to be a distant prospect for the time being.
Further HPAI outbreaks reported in South Africa
Based on official notifications, the HPAI situation in South African poultry flocks appears to be easing.
Since the start of the year, just four further outbreaks in commercial birds have been reported to the World Organisation for Animal Health (WOAH).
At two farms, presence of an HPAI virus of the H5N1 serotype was detected. One of the outbreaks began in a small flock of 113 birds at a farm in Gauteng at the end of November. This was the first premises in the province in this outbreak series. The other was retrospectively reported after 42 individuals out of a flock of 4,250 commercial ostriches in Western Cape tested positive for the virus in July of last year.
First detected in South Africa in May of 2023, the H7N6 HPAI virus was detected in October in a flock of more than 900 commercial ostriches in Western Cape. In December, the same serotype was identified in a flock of around 5,000 poultry at a premises in Limpopo after 500 of the birds died.
These latest outbreaks bring to 111 the total outbreaks linked to the H7N6 virus variant recorded in South Africa so far. Directly impacted have been almost 10.5 million commercial poultry.
In addition, just over 1.79 million farmed birds at 25 locations have been involved in outbreaks linked to the H5N1 serotype in the country since April of last year.
Furthermore, another backyard poultry flock was hit by this virus strain at the end of November, according to a separate notification to WOAH. Located in KwaZulu-Natal, it comprised seven birds other than poultry.
Outbreaks widespread
Infections linked to both HPAI virus variants have occurred widely across South Africa.
Majority of the H5N1 outbreaks have occurred in Western Cape, while most of the H7N6 cases have been in Gauteng. However, one or more cases of each strain have been detected in seven or eight provinces.
During the current HPAI “season” in South Africa, which started in October, 80 HPAI outbreaks have occurred in domestic poultry, according to the latest update from the United Nations’ Food and Agriculture Organization [http://www.fao.org/] (FAO; dated January 11).
Over this period, the only other African nation to have reported HPAI to the FAO is Mozambique. One outbreak occurred in this East African state at the end of September.
View our continuing coverage of the global avian influenza situation.
