Did you know you can spread the influenza virus to others even before you know you're sick? Wochit
Flu is now widespread in every state but Hawaii — and Tennessee is no exception.
And though the national Centers for Disease Control and Prevention said Friday that the flu season has probably “peaked,” Tennessee and other states should still look for several more weeks of activity.
Flu season hit the eastern part of the state early and hard this season, and spread to Middle and West Tennessee in high numbers a few weeks later.
“We’re up to our proverbial ears in influenza,” said Dr. William Schaffner, an infectious disease specialist with Vanderbilt University Medical Center in Nashville. “Over the last two weeks, our hospitalization numbers in Middle Tennessee have gone through the roof. Every hospital, every emergency room, every Minute Clinic and, I think, virtually every doctor’s office … is full of flu, and influenza-like illness.”
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Flu came early
Outbreaks in East Tennessee started in December, said Dr. Mark Rasnake, infectious disease specialist at the University of Tennessee Medical Center.
“This is the earliest we’ve seen (large amounts of) flu since the pandemic in 2009,” said Rasnake, who said UT Medical Center had 76 patients test positive for flu in December and just more than 70 not even halfway through January.
While the 2009 pandemic centered around an H1N1-type flu virus, this year’s dominant virus is an H3N2 type. The seasonal flu vaccine contains H3N2, but experts are warning it’s not as effective as hoped against H3N2 — anywhere from 30 percent to as little as 10 percent, which reportedly was how effective it was against the virus during Australia’s flu season earlier. Rasnake said UT Medical Center doesn’t track how many flu-positive patients have the vaccine but knows vaccinated people are still getting flu because hospital employees, who are required to have the flu shot, still are getting sick.
Scientists have found it more difficult to match H3N2 viruses. Schaffner said they think it’s because when grown in chicken eggs — as most flu vaccine is — the virus mutates just enough before reproducing to keep it from matching the original virus that infects people during flu season.
Scientists have experimented with growing vaccines in cells rather than eggs, but most flu vaccine still is grown in eggs. Additional vaccines have become available in recent years — one with a stronger dose of vaccine, covered by Medicare for senior citizens who are at particularly high risk with H3N2, and an adjuvant flu vaccine first available last season that has an additive designed to increase immune response — in this case, an oil-in-water emulsion of squalene oil, a plant-derived hydrocarbon. Those vaccines are fairly widely available, Schaffner said, but can be more expensive.
H3N2 harder on old, young
Older people and children younger than 5 are at highest risk for hospitalization and death from H3N2, along with people who have immune systems compromised or who have underlying serious chronic health conditions.
The CDC has long deemed it impossible to track all U.S. deaths from flu complications, but flu-related deaths of children and pregnant women are reported. This season, 20 children so far have died from flu complications, including three in Tennessee. Memphis’ Le Bonheur Children’s Hospital’s emergency department received a record 403 patients, mostly for flu, on Dec. 18, and East Tennessee Children’s Hospital also reports high volumes. The state department of health also confirmed a pregnant woman in Middle Tennessee died of flu complications.
Dr. Stephen Threlkeld, an infectious disease specialist with Baptist Memorial Health Care in Memphis, said this year’s season has been distinguished by a wide variety in the severity of individual flu cases. Some patients feel barely ill, while others, including young and otherwise healthy individuals, have gotten so gravely sick that they needed treatment with extracorporeal membrane oxygenation (ECMO) machines, which temporarily take over the functions of lungs, just to survive.
“These are people who are living productive lives, and they would’ve been snuffed out” without the ECMO machines, Threlkeld said.
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At UT Medical Center, however, Rasnake said though the number of patients is much higher than usual, most are in regular rooms, not intensive care.
“Fortunately for us, we’re not seeing a severe flu and haven’t had any deaths of flu yet,” Rasnake said.
In the Tri-Cities, where at least one older patient has died of flu, Mountain States Health Alliance and Wellmont Health System have increased visitation restrictions at all hospitals to try to slow a surge in cases. Patients may have a maximum of two adult visitors, neither of whom can have any symptoms of illness, and no children are allowed.
“What makes this particularly concerning is that as high as our numbers are locally, they’re even higher in other parts of this country,” said Jamie Swift, director of infection prevention at Mountain States. “Some hospitals in other states are now setting up triage tents outside their emergency rooms to handle the additional volume. This tells us that the possibility exists for our flu cases to surge even higher, so we want to do everything we can to prevent that.”
Flu shot, Tamiflu still of some use
Despite its varying effectiveness, doctors still highly recommend the flu shot, even late in the season. Though it’s not a match for H3N2, it is for the other strains of flu — H1N1, and up to three flu B viruses — and there’s evidence it could lessen the duration and severity of H3N2 infection, even if it doesn’t prevent it.
“Waiting for perfection is the enemy of the good,” Schaffner paraphrased the French philosopher Voltaire. “The vaccine prevents a lot of disease completely. … The lights are on in the research laboratories at night, and maybe we’ll get a better vaccine. It’s a high-priority goal for government labs, industry labs, academic labs.”
The vaccine takes about a week to 10 days to be fully effective, plenty of time before the flu season ends around March, and is still readily available at doctor’s offices, pharmacies and health departments.
Prescription antiviral drugs — the most common being oseltamivir phosphate, or Tamiflu — also can make illness shorter and symptoms lighter, but it must be taken within 48 hours of when flu symptoms start to be effective. Schaffner said some doctors recommend high-risk patients like the elderly, or those most likely to end up hospitalized if they get flu, keep a prescription filled. Some who are at particularly high risk take the drug all during flu season, though the research is still out on that strategy. But Schaffner said the CDC recommends nursing homes or assisted-living facilities who get a flu case to give Tamiflu to all residents as a preventive measure.
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“We recommend all our patients who are sick enough to be hospitalized be treated with Tamiflu,” Rasnake said.
Beyond that, stay home if you’re sick, he said — if not for yourself, than for others you might infect.
“We don’t want people who are still running fevers, still coughing, to go to work, or school, or church,” Rasnake said. “We want to them to stay home so that it doesn’t spread to even more people.”
All about flu
Mild symptoms: Runny nose or stuffiness, low-grade fever for fewer than three days, mild headache, body ache or nausea. Go to doctor, clinic.
Severe symptoms: Difficulty breathing, pain or pressure in their chests or stomachs, sudden dizziness, confusion, severe or persistent vomiting, or flu-like symptoms that improve but return with fever and worse cough. Go to hospital.
In children: Take children to emergency room if they have fast breathing, trouble breathing, bluish skin, are not waking up or interacting, are not drinking or urinating, are so irritable they don’t want to be held, have a fever with rash, can’t eat, or have flu-like symptoms that improve but return with fever and worse cough.
Higher-risk: 65 or older, pregnant women, and people with certain medical conditions, including asthma, chronic lung disease, heart disease, HIV and diabetes.
If you’re sick: Stay home for at least 24 hours after your fever is gone without using Tylenol or other fever-reducing medicines. If you must go out — to go to a clinic, for example — wear a face mask or cover your cough and sneezes with tissues. Most healthy adults can infect other people a day before symptoms develop up to seven days after becoming sick. It takes one to four days after infection for symptoms to show up — so you may be able to pass on the flu to someone else before you even know you are sick.