More bird flu to come in the fall?

The New York Times cites a report from Reuters that

U.S. agriculture officials say it is “highly probable” that the virulent avian flu viruses that have hit U.S. poultry operations hard in recent weeks will return next fall when wild bird populations migrate south, potentially spreading the viruses into new regions of the country.

Officials with the Agriculture Department’s Animal and Plant Health Inspection Service said the H5N2 virus, along with two other highly pathogenic strains of bird flu, would probably be passed among birds at breeding grounds in the northern United States and Canada through the summer.

The strains are difficult to control, say scientists, in part because wild birds can carry the viruses without appearing to be sick.

The statement marks a shift in tone in the agency’s assessment of the likelihood for a renewed outbreak tied to fall migration. More than 15 million commercial birds nationwide have died or are expected to be killed in the current outbreak, and exports of U.S. poultry and eggs have slowed sharply.

A key concern has been whether the viruses will become endemic in the nation’s wild bird population, eventually spreading them to the East Coast and down into the heart of the nation’s chicken broiler production states in the South and Southeast.

What effect the virus would have on chicken farms in the South is not known. But the nation’s poultry industry, which is taking an economic hit from the rapidly escalating outbreak, is alarmed at the prospect of wider exposure.

One turkey processing plant in Willmar, Minn., has reduced its operations to four days a week because “they don’t have enough birds,” Representative Collin Peterson, a Democrat from Minnesota, told reporters on Tuesday.

The outbreak’s reach expanded to 14 states on Tuesday, when the government reported that highly pathogenic H5N2 was identified in two wild birds in Kentucky.

Based on evidence gathered so far from tracking wild and domestic birds between December and April, “it is highly probable” that the viruses will be maintained in some of the North American wild duck populations through the summer breeding season, officials from the agriculture department said in an email.