Origin of human bird flu case in Missouri still unknown, US CDC says

By Leah Douglas and Julie Steenhuysen

WASHINGTON (Reuters) – Epidemiologists have not yet determined exactly how someone in Missouri contracted bird flu last week, the U.S. Centers for Disease Control and Prevention said on Thursday.

The human case was the 14th identified in the U.S. this year. The other 13 cases were among farmworkers and were linked to outbreaks of bird flu on poultry or dairy farms.

The infected person was taken to the hospital with symptoms including chest pain, nausea, vomiting and diarrhea, Nirav Shah, deputy director of the CDC, said in a call with reporters on Thursday.

It was unclear whether the patient’s underlying conditions were causing the symptoms or whether it was the flu.

The investigation into the origin of the infection is ongoing and the CDC has not yet determined whether the case is related to the current outbreak of bird flu in dairy cattle, Shah said.

“At this point, the evidence suggests this is a unique case,” Shah said.

Missouri has not invited the CDC to conduct an on-site investigation, but the CDC is working closely with state health authorities on the response to the case, Shah said.

Shah also said the CDC will partner with five commercial laboratory companies — Aegis, ARUP, Gingko BioWorks, Labcorp and Quest — to develop their own diagnostic tests for public health outbreaks, including bird flu.

According to the U.S. Department of Agriculture (USDA), eight dairy herds in California have been infected with bird flu since the first case in cattle was identified on Aug. 30. Data from the U.S. Department of Agriculture shows that bird flu has infected more than 200 dairy herds in 14 states since March.

California’s herds have been quarantined and the state is expected to conduct bulk milk testing at dairies in a geographic area around the affected farms, said Eric Deeble, USDA deputy undersecretary for marketing and regulatory programs.

The agency does not know how the virus got to California, Deeble said.

The CDC will launch its program to vaccinate farmworkers against seasonal flu in October, Shah said. The campaign is intended to prevent dual infection with bird flu and seasonal flu, which can lead to virus mutations.

(Reporting by Leah Douglas in Washington and Julie Steenhuysen in Chicago; additional reporting by Ahmed Aboulenein; editing by Richard Chang)