The Yamaguchi Prefectural Government failed to conduct nationally mandated monitoring for bird flu before the recent outbreak of the disease at a poultry farm in the prefecture, sources close to the case said Thursday.

The Agriculture, Forestry and Fisheries Ministry issued a manual in September on controlling epidemics to all prefectural governments as part of efforts to prevent an outbreak of the avian flu virus, according to the Yamaguchi Prefectural Government.

The manual requires prefectural governments to monitor poultry farms by picking a farm and testing 10 chickens for antibodies and signs of the virus on a monthly or bimonthly basis. The results must then be reported to the ministry.

The Yamaguchi Prefectural Government informed local livestock health centers about the monitoring measures Oct. 14.