South Africa's worst avian influenza outbreak is now under control and egg supplies are improving, Reuters reported, citing the department of agriculture on Wednesday.

The country has been battling an outbreak of a high-pathogenic avian influenza (HPAI), an avian influenza that spreads rapidly in an infected flock causing a high death rate, since April.

About six million egg layers and 2.5 million breeder chickens, nearly a third of the national flock, have been culled due to avian influenza, according to the South African Poultry Association. This has led to a shortage of eggs and fears of poultry meat shortages heading into the festive season.

In a statement, the department of agriculture said the government had facilitated increased imports of eggs, fertilised eggs, egg powder and liquid eggs to ease shortages.

"The department is happy that the HPAI outbreak is under control and that 70% of farms that were not infected continue to produce eggs and chickens," the department said, adding that "egg stock levels are replenishing steadily".

South Africa's leading poultry producers and processors Astral Foods, RCL Foods and Quantum Foods have said the bird flu outbreak has ravaged a sector already burdened by the country's frequent electricity cuts and rising costs.