Health officials fear that the high rates of influenza cases at two elementary schools in Arkansas are a sign that a strain of flu not covered by this year's vaccine is circulating in the state.
The two schools also have a high rate of student and staff vaccinations, said Dirk Haselow, Arkansas Department of Health epidemiologist. Haselow said it is unusual for a school to have a high rate of influenza cases and a high rate of vaccinations.
Haselow would not identify the schools nor where they are located in the state.
"We have no direct evidence to say that the strain is not in the vaccine, but the fact that we are seeing illness is suggestive of that," Haselow said.
Centers for Disease Control and Prevention officials announced last week that 90 percent of flu viruses circulating in the country are H3N2. About 50 percent of the H3N2 strains have drifted or mutated into a virus not included in the vaccine this year.
Haselow said about 77 percent of flu cases tested in Arkansas are H3N2. He said the CDC is the only agency able to test for the drifted strain. Nasal swabs collected from the students and staff members who have the flu at the two schools will be sent to the CDC for testing, he said.
A report from the Arkansas Department of Health shows that flu cases in the state have moved from a local geographical level to a regional level. This means that flu activity has grown from small clusters that included counties to larger clusters that includes portions of the state, often multiple counties in one region.
The Arkansas Department of Health report includes a map that shows clusters of the flu in more than 30 counties with a large portion reaching from just north of central Arkansas to the southern part of the state. Counties in northwest, northeast and southwest Arkansas also are reporting flu cases.
Jennifer Dillaha, Department of Health medical director for immunizations, said the state is seeing an uptick in reported flu cases.
"We are seeing almost twice as many cases this week than we had the week before," Dillaha said.
There have been 73 hospitalizations from the flu in the state since September, the report shows. Twenty-nine of the hospitalizations occurred between Nov. 30 and Dec. 6.
Dillaha said some states that border Arkansas are seeing even higher reported cases of influenza.
Louisiana and Texas are reporting widespread flu activity, according to a CDC report. The CDC is also reporting seven pediatric deaths nationwide from the flu.
Haselow said that flu cases most likely will increase "dramatically" in Arkansas in the next couple of weeks. He said a 2-inch-thick stack of documents on his desk outlines flu cases reported to the Arkansas Department of Health in recent days. He said the stack is a lot higher than it was last week.
It is important that people who have not been vaccinated do so now, Haselow said. He said it is possible that the vaccine will still provide some protection against the drifted strain.
"It may still prevent severe illness or death," Haselow said. "It just may not prevent someone from missing a day of school or work."
The CDC has warned that the H3N2 virus is historically more deadly than other flu viruses. People older than 65, children and those with other health risks such as asthma, heart or liver disease are more at risk. Pregnant women or women who recently delivered are also at risk.
The public is also encouraged to seek anti-viral medications from their doctors immediately after developing flu-like symptoms, the CDC has said. The medication is more successful if administered within the first 48 hours of the onset of symptoms.
Haselow said students and staff at the two schools with high levels of flu cases have been instructed to seek anti-viral medication if they develop symptoms.
Metro on 12/13/2014