The Centers for Disease Control and Prevention (CDCP) on Thursday encouraged labs to determine, within 24 hours after admission, whether patients hospitalized for the flu are suffering from seasonal influenza or if they have the bird flu which is caused by an outbreak in poultry and dairy cows.

Since last fall, labs have been given guidelines to perform this type of testing. However, the process is slow. Many hospitals send out large quantities of flu samples for testing every few days.

Dr. Nirav Shah, principal deputy director of the CDC, told a Thursday media briefing that by the time the results are back, many patients have already been sent home.

This could hamper bird flu investigations. It would become increasingly difficult to remember where people may have been infected as the days and weeks passed.

Shah explained that “the more time passes, the more the memories fade away and the harder it becomes to identify the source.” It’s also possible that “their close contact may be outside the window of preventative medication like Tamiflu.”

According to the latest CDC warning, testing for bird influenza should be done more quickly. Ideally within 24 hours after a patient is admitted to hospital.

The system tells us right now what’s already happened. “What we need to do is shift to a new system that shows us what’s going on in the present moment,” Shah said.

The CDC is sending out this message at a time when the seasonal flu activity in the U.S. is very high. The virus has spread to most states. It is especially prevalent in Louisiana, New Mexico and Oregon.

Only patients with influenza A are covered by the new guidelines. H5N1, the bird flu subtype, is flu A. Currently, the seasonal flu is mainly flu A. This includes H3N2 as well as H1N1.

It is only possible to identify the subtype of influenza A that a person possesses in a laboratory with specialized equipment. The tests that are used by doctors in their offices usually only determine whether someone has flu A and B.

“It is a step in the right directions,” said Dr. Alex Greninger of University of Washington Medical Center, Seattle. It will illuminate the current disease landscape and pave the path for identifying any possible human-human transmission.

People who are in close contact with poultry, dairy cattle and wild birds continue to be at risk for bird flu. The bird flu risk is low for the general public. The virus has not been spread from one person to another.

Only three cases of flu were found in the 83,000 samples that were tested over the last year.

Greninger added that the effort should have been intensified “months ago”.

Kelly Wroblewski said that the labs in the United States are “well-positioned” to meet the increased demand.

Wroblewski stated, “This is an additional precaution that puts us in a more prepared position.” She said that there was no evidence to suggest that labs were missing cases of bird flu.

According to the latest report from the CDC, there have been approximately 110,000 hospitalizations related to flu since the flu season started. Only 67 cases of human bird flu have been reported.

The majority of cases have been mild. One person has died, an older woman with underlying medical conditions.

All cases are linked to poultry and dairy cows.