US flu cases over epidemic threshold
Influenza has reached epidemic proportions in the US, say health officials, but the outbreak may be showing signs of having peaked.
Last week 7.3% of US deaths were caused by pneumonia and the flu, just above epidemic threshold, said the US Centers for Disease Control and Prevention.
Flu activity was widespread in 47 states, up from 41 the week before.
But the worst of the flu cases could be past as the number of hardest-hit states dropped to 24 from 29.
Experts recommend flu vaccines, which have been found to be 62% effective.
The 2012-13 flu season is said to have started earlier than usual, with many cases of the H3N2 strain, which can be severe.
"Only time will tell how moderate or severe this flu season will be," Thomas Frieden, the CDC director, told reporters on Friday.
Nationally, 20 children have died from the flu this season, the CDC has reported. They do not count adult deaths, but estimate it kills about 24,000 Americans each year.
Some analysts say the latest numbers suggest the worst of the season may have passed.
The only states without widespread flu were California, Hawaii and Mississippi.
Flu symptoms can include fever, cough, runny nose, body ache and fatigue.
Severe cases could see vomiting and diarrhoea or develop into pneumonia. Many cases are much milder.
Some shortages of children's liquid Tamiflu, a prescription drug, have been reported. But health officials say pills of adult Tamiflu could be converted to children's doses.