Flu activity rises slightly, CDC reports

According to the U.S. Centers for Disease Control and Prevention, flu activity in the United States demonstrated a moderate spike in late February, including an increase in the number of states reporting widespread activity.

The number of respiratory specimens that tested positive for flu also increased to 18.4 percent, compared with 14.4 percent the previous week. The increase of flu activity comes during one of the latest flu season starts in close to three decades, CIDRAP News reports.

The level of influenza-like illnesses is relatively low overall, though the northeast, the northern Midwest and the central Midwest have reported levels at or above baseline. The most commonly detected strain has been H3N2, though the CDC noted a growing number of pandemic 2009 H1N1 viruses, particularly in the southwestern and western states.

The CDC reported one additional pediatric flu death, bringing the total to four so far this season. The death involved an unsubtyped influenza virus. The percentage of deaths from flu and pneumonia increased to 7.3 percent while staying below the epidemic threshold. The report also noted the first detection of an oseltamivir-resistant pH1N1 virus, according to CIDRAP News.

The six states reporting widespread flu activity are Virginia, Oklahoma, Nevada, Illinois, Colorado and California. There are 18 states that have reported a regional geographic spread of influenza.