US orders bird flu testing of national dairy supply

The US national milk supply will begin being tested for bird flu, according to a new federal order announced on Friday by the Department of Agriculture.

As part of the mandate, entities and firms that handle raw milk - such as dairy processors - must collect samples to share with agriculture officials.

The announcement comes as US authorities seek to stem the rapid spread of bird flu in US dairy herds.

More than 700 dairy herds have been infected across the country since March, mostly in California, government statistics show.

Nearly 60 people have also contracted the virus since April, albeit with mild symptoms. The virus does not spread easily among humans.

Health bodies such as the World Health Organization and the Centers for Disease Control and Prevention (CDC) consider the overall public health risk from bird flu to be low. But scientists say we need to keep a close eye on the spread of the virus.

In a statement published on Friday, the Department of Agriculture - the USDA - said that the campaign is aimed at "swiftly and diligently" identifying affected dairy herds.

"Among many outcomes, this will give farmers and farmworkers better confidence in the safety of their animals and ability to protect themselves," Agriculture Secretary Tom Vilsack said in the statement.

"It will put us on a path to quickly controlling and stopping the virus' spread nationwide," he added.

The testing plan will involve monthly or weekly sample collections, and will initially be rolled out in California, Colorado, Michigan, Mississippi, Pennsylvania and Oregon.

Mr Vilsack told Reuters news agency that the initial round of testing will begin on 16 December.

In a separate federal mandate published in April, the USDA said that milk-producing cows must be tested before they are moved between states.

The new order does not supersede or override the April mandate, but is instead intended to "complement and enhance" it.

A total of 57 human cases of bird flu have been confirmed in seven US states this year, according to the US Centers for Disease Control and Prevention.

In September, US officials confirmed a human case of the disease that had no known animal exposure. The patient, in the state of Missouri, was treated in hospital and has since recovered, the CDC said.

Just this Friday, Arizona confirmed its first human cases of bird flu. The two people both tested positive after working with poultry, and state officials said the risk to the public remains low.

Bird flu was first detected in China in the 1990s, and has since spread across every continent including Antarctica. World health officials believe the current risk to humans is low, but have actively monitored the disease for years.

The disease has affected wildlife worldwide, infecting species as varied as sea lions, seals and bears.