The farm ministry will begin seeking ways to detect weak strains of bird flu in the early stages, in light of the latest case in Ibaraki Prefecture where it took more than two months for the outbreak to be confirmed.
Although the deadlier types of bird flu are easily noticed, including sudden mass deaths of infected poultry, weaker strains are more difficult to determine as their symptoms, such as a decrease in eggs, may also be due to illnesses other than bird flu.
Measures being considered by the Agriculture, Forestry and Fisheries Ministry include stepping up cooperation among private testing organizations and local government livestock hygiene service centers, so the centers will be informed of abnormalities when the organizations are approached by farms.
The ministry may also increase supervision of farms and alert farmers to the existence of weaker bird flu strains.
In the Ibaraki case, the farm in Mitsukaido saw an average of 10 of its 250,000 chickens dying every day around April, slightly more than normal.
Egg production also dropped.
On May 23, it asked a private organization to probe, but it took another month before the result of "suspected bird flu" was issued.
The ministry will take samples from nearby farms to check if the virus has spread, because even a weak strain could develop into a deadly one if poultry continue to become infected for six months or more, the officials said.
"This time, it took a bit too long for the virus to be detected," said Hiroshi Kida, a veterinarian and microbiology professor at Hokkaido University. "Since it's possible that similar symptoms have been missed at other facilities, it is necessary to strengthen measures to monitor the situation."