Influenza is widespread across the United States and this flu season is shaping up to be especially harsh, the director of the U.S. Centers for Disease Control and Prevention said on Friday.
Antiviral drugs such as Roche's Tamiflu were underutilized, the CDC's Dr. Thomas Frieden said, urging doctors to prescribe the drugs to patients with flu-like symptoms even before tests confirm influenza as the cause.
The United States is about midway through the 2014-15 flu season, Frieden said on a conference call, adding this was "a bad year for flu, especially for older people and people with underlying health conditions."
Frieden acknowledged that some doctors in the United States may not be prescribing Tamiflu because they believe the drugs do not work.
The effectiveness of such antivirals has been the subject of fierce debate, with some researchers from the Cochrane Collaboration, a non-profit group, claiming there is little evidence Tamiflu works.
Frieden, however, defended the drugs. He said CDC scientists have combed through studies on Tamiflu, including observational studies published after the treatments were approved, and found "compelling evidence" that when used early, the drugs help.
"What we see is quite consistent. Particularly when given in the first 48 hours, there is an impact in reducing how long people are sick and how sick they get," Frieden said.
Frieden said drug companies report sufficient supplies of antivirals, with only a few spot shortages that might require patients to "call around" to a few pharmacies before getting the drug.
Antivirals are one of the few weapons public health officials have this flu season because the current vaccine is a poor match for the most common strain of virus causing illness in the United States. Frieden said two thirds of cases of flu analyzed by the CDC were caused by the influenza A (H3N2) strain now circulating, which he described as an especially "nasty strain" of flu.
CDC expects to have data on the effectiveness of the flu shot over the next few weeks.
In the week between Dec. 28 and Jan. 3, five children died from the flu, bringing the total number of pediatric flu deaths to 26 in the current flu season.
Frieden said flu may be easing in areas of the country that were first affected by the illness, but said it was "too soon to say whether we've peaked."