Moreover, the percentage of outpatient visits for influenza-like illness (ILI) was 3.2% for W5, compared to 3.3% in W4 and 3.4% in W3. And just seven states are now reporting "high" levels of ILI, compared to 10 states in W4 and 13 states in W3.
Although cases are dwindling in the southern parts of the United States, where the virus was spreading most rapidly earlier in the season, cases are on the rise in the Northeast. In the Northeast, Mid-Atlantic, and upper Midwest about 30% of patients with flu-like symptoms tested positive for the flu in W5.
People should continue to get flu shots because the virus can be unpredictable—sometimes resurging in waves, according to Anat Feingold, a pediatric infectious disease specialist at Cooper University Hospital.
"If you haven't yet been vaccinated it's definitely worth getting vaccinated — there's no down side," she said. Although children and elderly people remain the most vulnerable to the flu, this year's prevalent strain—H1N1—has infected an unusually high number of young, healthy adults.