PROVIDENCE, R.I. — Physicians should treat the high fever and dry cough of classic flu promptly with antiviral medications, whether or not patients test positive for H1N1, the virus which is making people sick in epidemic proportions.

That advice came from Dr. Steven M. Opal, a professor at the Warren Alpert Medical School of Brown University and the chief of infectious diseases at Memorial Hospital in Pawtucket, during a joint conference on Wednesday at the Westin Providence hotel for physicians and veterinarians on emerging diseases that affect both humans and animals.

Opal said the public-health system nationwide has sent physicians mixed messages about the best time to administer antivirals.

If someone comes in with a high fever and other obvious symptoms of the flu, he said, a doctor should not wait to see if the patient improves.

Opal, who treats patients only after they’ve failed to respond to outpatient care, acknowledged that it’s relatively simple for him to decide whether to turn to antivirals. It is trickier to evaluate more ambiguous cases, he said, citing an example of a patient with chronic asthma whose condition becomes only a little worse and who has a mild fever.

But in general, he said, physicians are not giving antivirals early enough in the course of the disease.

The public-health system needs to send physicians clear and consistent messages about treatment protocols, Opal said..

Opal also faulted national health officials for their handling of the H1N1 vaccine.

“First they said there would be plenty of vaccine. They got us all fired up to immunize,” he said.

But after raising expectations, officials failed to deliver.

“They must have known” that an abundant supply of the vaccine would not materialize, Opal said.

And “they should have worked at it more” to find a method of growing the vaccine faster, he said.

During the conference, sponsored by Coastal Medical and the Companion Animal Parasite Council, Opal put the H1N1, or “swine” flu in perspective.

“This current event is bad, but it could get much worse,” he said.

There have been a total of 10 swine flu-related deaths in Rhode Island since last spring; 7 occurring after Sept. 1.

The virus could develop a resistance to antiviral drugs, or there could be a mutation that would make it more virulent, Opal said.

H1N1 virus is very contagious but has trouble getting from the upper airway into the lungs, he said.

The worst news would be a hybrid combining the contagion of H1N1 with the virulence of the avian, or H5N1 virus. Swine play a role in influenza by facilitating a genetic shift in the strain that comes from birds so that it is more likely to strike humans, Opal said.

He said those who provide medical care to animals and humans must work together to minimize the spread of influenza and other zoonotic diseases.

gmacris@projo.com