The avian influenza that struck a chicken farm in Kumamoto Prefecture was the first outbreak in Japan in three years and came as authorities were already on high alert about migrant birds after reports of the disease hitting South Korea since the beginning of this year.
As officials worked to contain the virus, however, lessons appear to have been learned from the last outbreak, which caused widespread damage, mostly in western Japan.
The farm in the town of Taragi first reported suspected infections at 3:30 p.m. Saturday to the prefecture’s Jonan domestic animal health center. The farm reported an unusually large number of chickens dying in one of its poultry sheds.
Normally, the farm experiences 10 to 20 chicken deaths per day. In the 24 hours through Friday morning, the death toll hit 34 and shot up to over 200 in the next 24 hours, according to the report.
The Agriculture, Forestry and Fisheries Ministry requires a report if deaths rise to more than double the daily average. “The farm operator knew the rule, so the report was made,” a ministry official said, commending the farm’s response. “The Kumamoto Prefectural Government also responded promptly.”
The prefecture started culling more than 110,000 birds Sunday and worked through the night. The task was done at “the fastest pace possible,” the official said.
In the previous outbreak, in November 2010, over 1.8 million birds were killed at 24 farms in nine prefectures from Chiba in the east to Kagoshima in the southwest before it was contained in March 2011.
Farmers and officials took note of inadequate measures at farms to stave off infections, such as big holes found in netting to protect against wild birds entering the chicken houses.
The agriculture ministry thus called for increased preparedness.
When an outbreak was reported in South Korea on Jan. 17, the ministry promptly issued an alert the same day to relevant prefectural governments to bolster readiness, judging that the virus could be carried to Japan by migrant birds.
The Kumamoto farm hit by the latest outbreak was equipped with protective nets, which apparently did not help. The ministry official said, “We are fighting against a virus. It could be brought in by a mouse or a fly. Nothing offers 100 percent (protection).”
The ministry is focusing its attention now on identifying the potential infection route and measures to prevent damage from spreading further.
Since prompt actions were taken at the initial stage this time, the infection is unlikely to have spread further, the official said.
Nonetheless, pinning down how the virus traveled will likely take time and there is no guarantee that damage will be contained in Kumamoto.
If the infection strikes other farms, it could disrupt egg supplies and cause egg prices to rise.
Koichi Otsuki, head of Kyoto Sangyo University’s Avian Influenza Research Center, said, “We cannot rest assured because infections are spreading on an unprecedented scale globally.”
In Asia, infections have been reported in various locations at increasing intervals since the major outbreak in 2003. Europe and Africa have not been spared.
Otsuki, an animal microbiology expert, noted the need for divergent preparedness depending on virus types. H5N1, which has been detected across wide swaths of Asia and elsewhere, could be carried to Japan by migrant birds as they migrate from the south to the north around this time of year.
H5N8, which struck South Korea, can be transported by wild birds regardless of the season.
“Migrant birds from the south could stop over anywhere in Japan, while wild birds from South Korea could arrive in western Japan,” he said.
Otsuki said the initial actions taken this time at the farm and by the prefectural government were “extremely good.” But, he added, “Since birds were infected, there must have been a hole. The government needs to review if day-to-day measures were taken really fully and issue guidance anew.”