South African grocery retailers Woolworths and Pick n Pay are limiting the amount of eggs shoppers can buy as the country's worst outbreak of avian influenza hits table egg supplies and threatens the supply of chicken meat, reported Reuters.

South Africa is currently grappling with an outbreak of a high-pathogenic avian influenza (HPAI), a bird flu that spreads rapidly in an infected flock causing a high death rate.

Producers have warned of chicken meat shortages in the coming weeks, while rows of egg shelves at some shops visited by a Reuters journalist were empty.

"As is the case across the market, we're experiencing significant challenges with our supply due to avian flu," Woolworths, an upmarket grocery retailer, said.

"Because of this, we've implemented a limit on whole egg purchases in our stores to six eggs per customer while we work with our farmers to ensure regular supply returns as soon as possible."

Pick n Pay said it will limit purchases to one or two egg packs per customer, depending on the region.

The country's biggest retail group Shoprite told Reuters that it was working closely with suppliers, "securing as much stock as possible and utilising our supply chain to transport it to regions experiencing shortages."

The retailer, which also owns Checkers chains, added that it had no plans to ration eggs at the moment. Its Checkers Sixty60 online shopping app in the northern part of Johannesburg showed all eggs were out of stock, while some chicken meat brands were also out of stock.

Massmart, owned by US Walmart Inc, told Reuters that eggs were selling through very quickly amid "erratic" supply.

Last week, RCL Foods said its poultry unit Rainbow has culled 410,000 chickens, while its peers, including the country's largest integrated poultry processor Astral Foods and Quantum Foods, said the avian infleunza outbreak was ravaging a sector already burdened by South Africa's electricity crisis and rising costs.