HPAI

The H5N1 avian flu virus infected three dairy herds in California's Central Valley, the first time the disease has been confirmed in the nation's largest milk-producing state, said officials. California was the first new state to be hit by the disease since Oklahoma reported cases on July 11.

The federal government should compensate dairy farmers who send dairy cattle to slaughter because of the H5N1 avian flu virus, said Iowa state Agriculture Secretary Mike Naig, in announcing the second outbreak in the state. At least 90 herds in 12 states from Wyoming to North Carolina have been infected since bird flu was discovered in cattle in Texas in March.

Four alpacas in a small Idaho herd were infected with the H5N1 bird flu virus —  the first known infection of alpacas in the world, said the Agriculture Department on Tuesday. The alpacas were on the same backyard farm that culled its poultry earlier this month due to an outbreak of highly pathogenic avian influenza (HPAI).

At least 200 people have been monitored for possible exposure to the H5N1 bird flu virus and 30 people have been tested, but a dairy worker in Texas is the only person known to contract the disease from cattle, said the Centers for Disease Control. "No additional human cases have been detected" since bird flu was discovered for the first time in cattle six weeks ago.

Genetic testing indicates the H5N1 bird flu virus jumped from wild birds to dairy cattle in Texas approximately four months before it was identified in late March, said a nationwide team of researchers. “Continued transmission of H5N1 HPAI [highly pathogenic avian influenza] within dairy cattle increases the risk for infection and subsequent spread of the virus to human populations.”

Agriculture Department scientists are conducting three beef safety studies following the first-ever discovery of bird flu in dairy cows a month ago, said a USDA spokesperson on Monday. The studies include tests of ground beef purchased at grocery stores in states with infected herds.

Testing has confirmed that antiviral medications used against the seasonal flu would be effective against the H5N1 bird flu virus that also infects dairy cattle, said the Centers for Disease Control. The USDA said on Monday the virus has been confirmed in 33 dairy herds in eight states since it was first identified on March 25.

The Agriculture Department said its research agency “has begun to assess the potential to develop an effective vaccine” against the H5N1 bird flu virus in cattle, although it warned that it is too early to say how long the process would take. The virus has so far infected 29 dairy herds in eight states, though there have been no detections in commercial beef herds since the disease was identified in cattle in late March.

Michigan officials said the H5N1 bird flu virus has infected three additional dairy herds in the state, just as the USDA recommended farmers test their herds for the virus before moving cattle between states. The tests "should both give us more ... information and should mitigate further state-to-state spread between herds," said the USDA's animal health agency.

Dairy herds in Kansas and New Mexico are infected with the H5N1 bird flu virus, raising the U.S. total to 15 herds in six states, said the Agriculture Department on Thursday. Texas has the most infected herds, with seven, followed by Kansas with three and New Mexico with two.

Samples of the H5N1 bird flu virus that has infected dairy cattle and a dairy worker retain avian genetic characteristics and “for the most part lack changes that would make them better able to infect mammals,” said the Centers for Disease Control and Prevention in a technical update. “The overall risk to human health associated with the ongoing HPAI A(H5) outbreaks in poultry and detections in wild birds and cattle remains low,” said the CDC.

USDA scientists confirmed the bird flu virus in a dairy herd in Idaho on Tuesday — the 12th herd in five states — with Ohio appearing for the first time on the list of states with "presumptive positive" results that will be double-checked. Meanwhile, officials said a Texas egg farm suffered the largest U.S. outbreak of bird flu in four months.

A Texas patient tested positive for the bird flu virus after exposure to dairy cattle believed to be carrying the disease — the first known instance of cattle-to-human transmission in the United States, said public health officials on Monday. The patient reported eye redness, consistent with conjunctivitis, as the only symptom and was recovering, said the Centers for Disease Control.

Bird flu, which killed more than 82 million birds in U.S. domestic flocks in the past two years, has appeared in dairy herds in Idaho, Kansas, Michigan, New Mexico, and Texas, said federal officials. The outbreaks, affecting a relatively small number of cattle, are not expected to affect milk supply or prices at the grocery store.