Minnesota doctors have been alerted to a new strain of influenza circulating in China and are urged to notify state health authorities if they have patients who traveled to the Asian nation and have flu-like symptoms.

An alert sent by the Minnesota Department of Health April 5 has already resulted in doctors finding a couple of patients who fit the profile and submitting lab samples to the state for testing.

The new strain, known as H7N9, migrated from birds to humans in China. So far there have been no cases in Minnesota — or the United States.

“This is a new strain for the human population,” said Kris Ehresmann, who directs the Health Department’s influenza vaccination programs. “That’s a concern.”

The alert is the first sent to Minnesota doctors about a novel human influenza strain since the H1N1 pandemic of 2009. A second alert went out to doctors and clinics this week about the public health precautions they should take if they encounter patients who are potentially infected.

There are no signs yet that H7N9 could produce a pandemic on the scale of H1N1, which emerged months before the typical flu season in 2009 and was eventually linked to at least 63 deaths in Minnesota. There is no evidence that the new virus can pass from person to person. Most of the cases involved people who had contact with poultry, but 40 percent involved people who had no such contact.

Ehresmann said public health officials still need to be aware of the potential spread of the virus and prepared.

“It’s time to dust off your plans from H1N1,” she said.

On Wednesday, the World Health Organization reported 82 human cases, all in China, including 17 deaths. The figures might overstate the death rate from H7N9, Ehresmann said, because there could be mild cases that aren’t reported.

Ehresmann said it was a relief that doctors reported a couple of potential cases, even if they turned out to be negative, because it means they are heeding the state’s health alerts.

“You’re casting this super-wide net. You want to make sure you don’t miss anything.”