An outbreak of H5 avian influenza has been confirmed in a commercial layer flock on the East Rand of Johannesburg (Ekurhuleni). According to a press release by the South African Poultry Association (SAPA), tests conducted at Onderstepoort Veterinary Institute still need to confirm the N-type of the virus. The Department of Agriculture Land Reform and Rural Development (DALRRD), confirmed in a press release that the tests will also indicate whether the pathotype is high pathogenic avian influenza (HPAI), or low pathogenic avian influenza (LPAI).

SAPA and DALRRD confirmed that the farm has been quarantined by the Gauteng veterinary authorities and that the animal health departments of the national and provincial DALRRD have implemented the required control measures. The Gauteng veterinary authorities are also investigating the outbreak. They are performing back and forward tracing to determine the extent of the outbreak. They are also assisting with the safe disposal of dead and culled chickens, as well as disinfecting the farm.

According to SAPA, the outbreak is currently contained to only the one farm and the organisation is closely monitoring the situation. Engagement with DALRRD and other relevant stakeholders will continue to contain the outbreak. The DALRRD stated that “it must be said this farm was also part of the H5N8 HPAI outbreak in 2017”.

High alert after 2017 outbreak

According to SAPA, the entire industry has been placed on high alert and the appropriate biosecurity contingency plans implemented as advised. Biosecurity protocols will include the restriction on people and bird movement for large companies as well as small, medium and micro-enterprises (SMMEs).

This is the first outbreak of avian influenza (H5) on a commercial farm in South Africa since the outbreak of H5N8 HPAI in 2017, said SAPA. The previous outbreak had a significant impact on the layer industry, whereas the broiler industry was only marginally affected.

It is well-known that at the moment there is a widespread outbreak of avian influenza in Europe, which was first confirmed in October 2020. Northern European countries have been predominantly affected. SAPA said “these outbreaks have not caused as much of a loss to the poultry industry as the previous large-scale outbreaks of 2015 and 2017, due to lessons learnt previously”.

SAPA also emphasised that “the role of migratory wild birds in the spread of the virus has been previously proven. Thus, the containment of poultry flocks in covered environments is recommended to avoid possible contamination as far as possible”.

H5N8 HPAI not a threat to humans

“The World Health Organisation (WHO) and the World Organisation for Animal Health (OIE) have been advised and confirmed that this strain of the virus has been found to not be dangerous to humans, and in the isolated cases where transmission occurred, it could be treated effectively,” SAPA stated. They also reminded consumers that the meat and eggs in the country are safe for consumption.

SAPA and DALRRD requested the co-operation of the industry to curb the spread of this virus. Producers are urged to remain vigilant and ensure that biosecurity measures are adhered to. The public is requested to report any sightings of mortalities in backyard chickens or wild birds to their nearest state veterinarian.

The DALRRD confirmed that they were notified of large wild bird die-offs in Stutterheim in the Eastern Cape. Samples from chickens that were collected at the end of March 2021 in two villages in Stutterheim, tested negative for Newcastle disease and avian influenza. Follow-up investigations are ongoing.

What farmers should know

The DALRRD has asked poultry farmers to be on the lookout for signs of the disease. The following symptoms are commonly seen in birds infected with HPAI:

  • Uncommunicative and extreme depression.
  • Sudden drop in production of eggs, many of which are soft-shelled or shell-less.
  • Wattle and combs become red and swollen.  
  • Swelling of the skin under the eyes.
  • Coughing, sneezing and signs of nervousness.
  • Diarrhoea.
  • Haemorrhages (blood spots) on the hock.
  • A few deaths may occur over several days, followed by rapid spread of disease and deaths of up to 100% within 48 hours.

All poultry farmers, as well as those with birds kept for hobby or zoo purposes, are encouraged to implement the following biosecurity measures:

  • Keep birds away from areas that are visited by wild birds.
  • Control access of people and equipment to poultry houses.
  • Avoid provision of water and food in a way that may attract wild birds. Rather feed free-range birds undercover or in a confined structure.
  • Maintain proper disinfection of the property, poultry houses and equipment.
  • Avoid the introduction of birds of unknown disease status into your flock(s).
  • Report illnesses and deaths of birds to your designated state or private veterinarian.
  • Implement procedures for safe disposal of manure and dead birds.  – Ursula Human, AgriOrbit