HARTFORD -- There are now 97 deaths, up by 20 since last week, and 1,951 patients hospitalized, up over 300 since last week, according to the Connecticut Department of Public Health Thursday.
Given the severity of this latest flu season, and the number of news stories it had generated, perhaps you’ve heard of the terms “Influenza A” and “Influenza B” by now. They refer to the two most common forms of flu that affect humans, and each year, their respective peaks tend to come at different times.
“Flu A tends to come early and flu B tends to come late,” said Nick Bennett, the head of the Infectious Diseases and Immunology Department at Connecticut Children’s Medical Center.
This year is not different. While experts aren’t expecting infections from B viruses to explode the way they have for A viruses, we have reached the portion of the flu season when new infections from A viruses are starting to drop off, while infections from the B strains are picking up steam. Dr. Jack Ross, the Chief of Infectious Disease at Hartford Hospital, said the reasons for the lag aren’t completely understood.
“That’s a question that’s unknown in terms of why later in the season, but we see it every year,” he said.
“The way it goes through the globe, around the globe, is just different,” said Bennett.
Bennett said part of the reason is that flu A and flu B are about as different as they can be, while still both being the flu.
“We could just call them Fred and Barney and they’re two completely different viruses and Fred comes first and Barney comes second,” he said, “We call them the flu because they feel the same. They are definitely related viruses, but they’re genetically, very distinct.”
There are loads of influenza A strains, like H1N1, and the most problematic strain this year, H3N2. However, for influenza B, there are essentially only two main types, and while they can be just as deadly to each infected person, both types are accounted for each year in the most common form of the flu shot, the quadrivalent vaccine.
“So, what really you’re then crossing your fingers for [then] is that the virus doesn’t mutate,” Bennett said.
While we are getting towards the tail end of influenza A season, it isn’t over yet.
“We still have a few weeks left in this flu season,” said Dr. Ross, “if you have an opportunity to get vaccinated, that would protect you, in two weeks, against influenza B, and perhaps also against H1N1 because we’re starting to see an increase in that strain as well.”
The good news is that the latest C.D.C. report estimates that this year’s flu shot, despite concerns for its overall effectiveness, does appear to offer substantial protection against H1N1 and the B viruses.
According to the CCD Flu View report for the week ending Jan. 27, there were 857 influenza deaths and 3,081 deaths from pneumonia, out of a total of approximately 40,012 deaths nationwide.
The CDC is set to announce Thursday new flu statistics. So far, in Connecticut, there has been 77 flu-related deaths, including a 6-year-old girl in Norwalk.