Dartmouth-Hitchcock Medical Center sees surge of influenza cases

by Wally Joe Cook | 1/29/18 2:04am

With flu season in full swing, Dartmouth-Hitchcock Medical Center is seeing a greater number of influenza cases than any time since the 2014-15 season, according to Michael Calderwood, infectious disease physician and regional hospital epidemiologist at DHMC. The Center for Disease Control is expecting similar numbers this year to the 2014-2015 season, during which the H3N2 strain was also the dominant strain of influenza and about 34 million Americans contracted the flu and about 56,000 died, he said.

“Any season when we have H3N2 being the predominant strain we tend to see more severe illness and more hospitalizations,” said Calderwood, adding that these more severe flu seasons are cyclical and arise once every few years.

Calderwood said that this flu season has been dramatic on a national level; 6 to 7 percent of outpatient visits have been for influenza-like illnesses.

“For three weeks in a row, we have had 49 out of the 50 states reporting widespread activity,” said Calderwood.

However, because this flu season was so intense early on, Calderwood said there is hope that it has already peaked and will end quickly.

“There is some thought that things are beginning to improve on the West Coast, but it is thought that up in New England things are still on the rise,” Calderwood said.

This year’s flu season has also affected the Hanover area. According to Calderwood, during the first week of January, DHMC saw more outpatient visits for influenza-like illnesses that it had seen in the prior two years.

“The whole state is reporting widespread activity,” Calderwood said.

He also mentioned that there is hope that activity peaked the first week of January and the situation may slowly be improving.

Flu vaccines have been less effective this season and the percent of outpatients that come in with the flu at DHMC are about 3.5 to 4 percent, which Calderwood said is less than the national rate, but still a significant number.

Typically, flu vaccines reduce the risk of illness for 40 to 60 percent of users, but this year the number may be closer to 10 percent. However, this number is only an estimation based on observations of southern hemisphere countries, which have earlier flu seasons. The true efficacy will not be known until the end of the flu season, Calderwood said.

According to Calderwood, flu vaccines are designed to protect against circulating strains such as H3N2, H1N1 and one or two strains of influenza B. However, circulating H3N2 strains have likely mutated since the vaccines were designed this year, which can decrease the efficacy of the shot.

“There is a big push right now to try and develop a universal influenza vaccine,” he said. “Right now, the vaccines are targeted against parts of the virus that mutate and change from year to year ... Trying to figure out how to create an influenza vaccine that is targeted at more conserved parts of the virus to provide more than a single year of protection is kind of the holy grail.”

Even though the vaccine has been less effective this season, Calderwood still recommends people get the shot since there are still a few months left in the flu season and should someone get the flu, they may have a “more mild disease.” Additionally, influenza B can circulate until around April or May.

“People say, ‘Well, it doesn’t have great efficacy,’ but the point there is the efficacy is not zero percent and some protection is better than no protection,” he said.

Flu symptoms include fever and severe muscle aches. Jada Brown ’21, who said she has had the flu for nearly two weeks, experienced these symptoms. Brown got the flu shot this year, but still had to miss two days of classes because of the illness.

“The flu is horrible, that’s all I have to say,” Brown said.

In terms of treatment, Calderwood emphasized the importance of prevention. According to Mary Nyhan, assistant director for health improvement at the Student Wellness Center, hand washing, adequate sleep and healthy eating are all important for disease prevention. Nyhan also emphasized that students should contact Dick’s House if there is any question of whether or not they have the flu.

“You should stay out of classes until your symptoms have resolved,” Calderwood said.

He mentioned other methods of suppression as well, such as covering your cough and even possibly wearing face masks if you are contagious. Oseltamivir or Tamiflu prescriptions may also be good prescription treatment options, Calderwood added.