TOKYO, Dec. 14 (Reuters) - Japan’s worst bird flu outbreak on record spread to new farms and now affects more than 20% of the country’s 47 prefectures, with officials ordering cullings after more poultry deaths.

About 11,000 birds will be slaughtered and buried after avian influenza was discovered at an egg farm in Higashiomi city in Shiga prefecture in southwestern Japan, the agriculture ministry said over the weekend.

Another outbreak started in Kagawa prefecture, where the outbreak emerged last month, the ministry said on Monday.

The outbreak in Japan and neighbouring South Korea is one of two separate highly pathogenic avian influenza (HPAI) epidemics hitting poultry around the world, according the United Nations Food and Agriculture Organization (FAO).

Both the strain circulating in Asia and the one in Europe originated in wild birds, it said.

“The virus found in Japan is genetically very close to the recent Korean viruses and thus related to viruses in Europe from early 2020, not those currently circulating in Europe,” Madhur Dhingra, a senior animal health officer at the FAO, told Reuters by email.

“This means that we currently have two distinct H5N8 HPAI epidemics in eastern Asia and Europe,” she said.

The FAO has issued an alert to African health authorities for heightened surveillance of farms to avoid the spread of the more recent European strain there.

In Japan, 10 of the country’s 47 prefectures have been affected in the outbreak, with around 3 million birds culled to date, a record number.

All farms in Japan were earlier ordered to disinfect facilities and check hygiene regimes, and ensure that nets to keep out wild birds are installed properly, agriculture ministry officials told Reuters this week.

Japan has suspended poultry imports from seven countries, including Germany.

Japan has an egg-laying flock of about 185 million hens and a broiler population of 138 million head, according to the ministry of agriculture.