Flu Season

Is It Too Late to Get a Flu Shot? Because the Flu Season Isn’t Over Yet

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Asking for the procrastinators among us.
too-late-for-flu-shot

Flu season has been especially severe this year, which is why, if you haven’t gotten the flu, you might feel like you managed to dodge a bullet now that it’s basically allergy season already. Well, we hate to break it to you, but flu season isn’t over yet. In fact, a new surveillance report from the Centers for Disease Control and Prevention (CDC) shows that a different influenza virus is becoming more prevalent.

Flu season can actually last all the way through May, according to the CDC, so we’ve got some time before this thing is really over.

Since October 2017, over 70 percent of flu cases overall have been influenza A. But during the week ending March 17, only about 42 percent of flu cases were influenza A, and nearly 58 percent were influenza B, per the new report. That suggests that influenza B has overtaken influenza A, which was the predominant type of flu this season until recently.

The CDC data also notes that the proportion of outpatient visits for flu-like illness is 2.7 percent, which is still above the national baseline of 2.2 percent. That means that although we’re past peak flu season, the overall amount of flu cases nationwide still remains “elevated.”

We tend to think that influenza B isn’t as severe as influenza A, but that’s not necessarily true. The major influenza A strain this year, H3N2 (aka the “Aussie flu“), is notoriously severe and tends to result in complications more often than some other strains. But that doesn’t mean all influenza A strains are universally awful—or that all influenza B strains are a walk in the park. In fact, results of a CDC study released last year found that influenza B viruses caused “equally severe disease outcomes” as influenza A viruses.

This “second wave” is actually normal flu activity, partly because people let up on other flu prevention strategies thinking they can’t get sick this late in the season.

Influenza B is usually the most prominent strain that circulates late in flu season, William Schaffner, M.D., an infectious disease specialist and professor at the Vanderbilt University School of Medicine, tells SELF. So, while you’re probably already a little nervous about the flu, this news doesn’t mean that mutant flu strains are popping up everywhere—this isn’t all that unusual.

But it is important to realize that you can still get the flu now, Alan Taege, M.D., an infectious disease specialist at the Cleveland Clinic, tells SELF. “What tends to happen too often is people reach this point in the flu season where the number of cases are dropping and they aren’t as careful,” he says. “People start developing symptoms and say, ‘I can’t get the flu now,’ but they can.”

So following good hand hygiene (and trying to avoid touching your mouth or eyes with your hands) is still important. This should help you ride out the remainder of the season in good health, Amesh A. Adalja, M.D., senior scholar at the John’s Hopkins Center for Health Security, tells SELF.

For those people who haven’t gotten their flu shot yet, don’t assume you’ve missed the boat.

If you procrastinated getting your flu shot up until this point, you should still should go, Richard R. Watkins, M.D., an infectious disease physician in Akron, Ohio, and an associate professor at the Northeast Ohio Medical University, tells SELF. “Everyone not vaccinated since the fall until now needs one,” he says.

The CDC estimates that this year’s vaccine is 36 percent effective at preventing the flu, but the number is better for influenza B strains specifically. This year’s shot is 42 percent effective against influenza B and just 25 percent effective against influenza A. So it may be even more helpful this late in the season when B strains dominate. (Also, it’s worth pointing out that it’s possible to catch the flu outside of flu season.)

Dr. Taege agrees: “If people are at risk of influenza and they’ve not had the shot yet, they should still obtain it,” he says. “It’s not too late and it’s still worth it.” That’s especially true if you have an underlying health condition or other issue that puts you at an increased risk for complications from the flu, which can be deadly.

Worth noting: Even if you already got the flu (oof, sorry), you should still get your flu shot. Having the flu twice in one season would suck—and it’s actually possible. If you’ve had the flu already, that does provide some protection against the one strain you got, but you’re still vulnerable to every other strain out there, Scientific American explains. So, again, it’s worth thinking about getting the vaccine.

But keep in mind for next year: You’ll get more protection the earlier you get your flu shot.

“The flu season is winding down and should end soon,” Dr. Adalja says. Because it takes two weeks for the shot to give protection, getting the vaccine now isn’t as urgent as it was at the beginning of the season. Though, again, that’s not necessarily reason to skip it if you haven’t gotten it.

You also may have trouble actually locating the flu shot, given that many pharmacies and doctor’s offices may have depleted their supplies by now, Dr. Schaffner says. So you might have to call around to a few pharmacies or use the CDC’s Vaccine Finder before getting your shot.

This flu season has now reached pandemic levels (but it’s not technically a pandemic)

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This flu season is turning out to be so intense that the number of people seeking care at doctors’ offices and emergency rooms has surged to levels not reported since the peak of the 2009 swine flu pandemic, federal officials said Friday.

For yet another week, the flu continues to get worse. “We were hoping to have better news,” said Anne Schuchat, acting director of the Centers for Disease Control and Prevention.

“This does not mean we’re having a pandemic,” Schuchat said. “But it is a signal of how very intense the flu season has been. We may be on track to break some recent records.”

Pandemics occur when there is a new strain of virus for which people have no previous exposure. That’s not the case here, because the seasonal strains that are circulating this year are not new. But the predominant one, H3N2, is a particularly nasty strain that is associated with more complications, hospitalizations and deaths, especially among children, those older than 65 and people with certain chronic conditions.

Another 10 children died in the week ending Feb. 2, bringing the total number of child deaths since this flu season began to at least 63. This is the number of reported deaths and probably does not include all children who have died. States are not required to report adult flu deaths.

Flu activity is still widespread across the country, the latest data show. Overall hospitalizations are also now significantly higher than what officials have normally seen this time of year since CDC began using this tracking system in 2010, Schuchat said. In particular, officials are seeing unusually high levels of hospitalizations in non-elderly adults, with the rates for 50-to-64-year-olds significantly higher than what they were at the same period in the severe 2014-2015 season with the same predominant flu strain.

The latest weekly report shows 1 out of every 13 doctor visits last week was for fever, cough and other symptoms of the flu, matching the peak levels during the 2009 swine flu pandemic. It was higher than any other seasonal flu season since 2003, when officials changed the way flu is tracked.

“We don’t have any signs of hospitalizations leveling off yet,” Schuchat said in a telephone briefing for reporters.

Concern over the deadly flu season was one reason Sen. John McCain delayed his return to Washington during key legislative deliberations, his daughter Meghan said Wednesday.

In an interview with Politico’s “Women Rule” podcast, the Arizona Republican’s daughter said her father, recovering from chemotherapy for aggressive brain cancer and a viral infection in December, is taking precautions that are keeping him in Arizona.

While the H3N2 strain, a type of influenza A virus, continues to dominate, officials are now also seeing increases in the proportion of influenza B viruses in this 11th week of the flu season.

One reason for this unusually intense flu season is probably the vaccine’s lower effectiveness against the predominant strain. Canadian researchers recently suggested the H3N2 component of the vaccine is about 17 percent effective in preventing infection.

“I wouldn’t be surprised to see something like that” for the vaccine’s effectiveness against the H3N2 in the United States, Schuchat said. But she and others have said the vaccine performs better against other strains, and is about 55 percent effective against influenza B viruses that are on the rise. Flu shots also reduce the severity of illness. CDC is expected to soon release a preliminary analysis of this season’s vaccine effectiveness.

Officials say it is not too late to get a flu shot. They don’t know how long this season will last — it has yet to reach its peak — and it is possible to get infected by flu more than once.

Angie Barwise, a 58-year-old mother and grandmother from Fort Worth, was diagnosed with the flu twice this season and died last week following complications from the illness. She had been diagnosed around the holidays with the flu, along with bronchitis and strep, her family told Fox affiliate KDFW. Her family said she had not received the vaccine.

Doctors gave her antibiotics and the antiviral medication Tamiflu, and she started to bounce back. But almost exactly a month later, her family said, she was in the emergency room with a different strain of the virus. But this time, KDFW reported, Barwise also had pneumonia and went into in septic shock, a life-threatening medical condition and a known complication of the virus, according to CDC.

On Saturday — a week after her second bout of the flu began — she died.

“I’ve outlived my own daughter,” her mother, Eileen Smith, told the news station this week. “I’m 83 years old, and I’ve outlived her. It shouldn’t be that way.”

As health-care professionals scramble to combat the virus and care for people seeking treatment, there continue to be local shortages of antiviral medication, officials said. Unlike most years when flu activity starts and ends at different times and at different places across the country, virtually the entire country has been slammed with intense levels of flu at the same time, so there are more prescriptions for antiviral drugs than previous years, Schuchat said.

CDC officials are working with pharmacies, health plans and others in the health-care system to have pharmacies stock larger amounts of medicine and allow brand-name drugs to be substituted for generics, which often carry lower out-of-pocket costs for consumers.

Still, the cost of prescription antivirals has led some patients to hesitate using them, with tragic consequences.

Heather Holland, a schoolteacher from Willow Park, Tex., was recently diagnosed with the flu and prescribed the generic form of Tamiflu. But her husband, Frank, told the Wall Street Journal that once she discovered it cost her $116 under her insurance plan, she decided against it.

“It’s principle with her. She’s a very frugal person in general, always has been,” he said.

Frank Holland told the Journal that when he found out that his wife had refused to fill the prescription, he did it. “I made her start taking it,” he told the newspaper.

But Holland was not able to fight the flu — her family said she died Feb. 4, less than a week after she first started to experience symptoms of the virus.

Worst Flu Season Since 2009 Hitting Boomers Hard

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The flu has sent more people to the doctor this year than in any season since the 2009 pandemic, health officials said Friday as they warned that this flu season was shaping up to be active and severe.

man getting vaccine

While the hospitalization rates are highest among adults 65 and older, health officials said baby boomers — adults ages 50 to 64 — were the next most likely to be hospitalized.

“This is a change,” said Dan Jernigan, MD, director of the CDC’s Influenza Division. Young children are typically the second most likely to be hospitalized with flu.

Included in the updated numbers this week was news of seven more flu deaths among kids. So far this season, 37 children have died of the flu.

Flu activity has been higher in the U.S. for 9 weeks. Flu seasons typically last 16 to 20 weeks, putting the nation at the halfway point of its feverish and aching misery.

Jernigan pointed to a couple of reasons that middle-aged adults might be more likely to get the flu this season: biology and behavior.

How a person responds to the circulating flu depends, in part, on the first flu strains they were exposed to as children — an immune phenomenon called imprinting. Jernigan suspects that the flu strains that imprinted on baby boomers years ago are very different from the kinds that are going around now, making boomers more vulnerable.

They’re also less likely to get vaccinated. A 2015 study found that while almost three-quarters of adults over 65 get an annual flu shot, less than half of middle-aged adults do.

“It has been a tough flu season so far this year. While flu activity is starting to go down in some areas, it remains high in much of the U.S. and in some areas is still rising,” Jernigan said.

He said there were signs in California and some Western states — where the flu has packed hospitals — that the epidemic was slowing. In New York, on the other hand, there were indications that the season was just gaining steam.

Jernigan said that this season was tracking much like the 2014-2015 season, which hospitalized nearly three quarters of a million Americans.

“We would expect, at the end of this season, to have somewhere around this number,” he said.

If you are a healthy adult, meaning that you don’t have another medical condition like asthma or diabetes or pregnancy, you’re probably OK dealing with the flu at home, says William Schaffner, MD, an infectious disease specialist at Vanderbilt University in Nashville.

“Take lots of fluid. Force yourself to sit up every 15 or 20 minutes and sip on some water,” he says. “It’s very, very important, because as you become dehydrated and you’re horizontal, you’re more likely to develop the complication of pneumonia.”

Adults 65 and older; those who have a medical condition like heart disease or diabetes; pregnant women; and children under 5 should get to the doctor within 48 hours of their first symptoms. Doctors can prescribe antiviral medications that can lessen the chance of severe complications.

Symptoms that should send anyone — children or adults — for immediate medical attention include:

  • Shortness of breath
  • Difficulty breathing
  • Chest pain
  • A temperature of 103 F or higher and a fever that doesn’t come down over time or with medication.
  • Ear pain (sometimes a sign in kids of a viral infection)

Schaffner says he would add another sign to the list: Flu causes a dry cough. If you instead develop a wet cough that begins to bring up green, yellow, or blood-streaked phlegm, it’s time to get to the hospital, since that can be a sign of pneumonia.

CDC Director Brenda Fitzgerald, MD, urged people with any symptoms of the flu, including headache, body aches, cough, and fever, to stay home. She also urged people to wash their hands frequently, especially if they’re caring for someone who’s sick, to prevent the spread of the virus.

The CDC recommends antiviral medications that can shorten how long the flu lasts and blunt its symptoms, especially when they are given at the first sign of illness. Health officials said they are aware that some of the medications are in short supply in some areas. Jernigan said it’s worth calling ahead to your pharmacy to make sure they’re in stock.

Big Pharma Has the Flu

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Flu vaccines make pharma companies $3 billion a year and aren’t very effective. Without a Manhattan Project-style initiative to modernize immunizations, things aren’t going to get any better.

A week ago, the Centers for Disease Control and Prevention confirmed what people have been suspecting: This flu season is one of the worst in recent memory. It’s on track to match the 2014-2015 season in which 34 million Americans got the flu, and about 56,000 people—including 148 children—died.

One reason behind the high toll is a mismatch between one of the flu viruses infecting people and one of the viral strains chosen almost a year ago for the global vaccine recipe, which gets rewritten every year. The dominant strain this winter is one called H3N2, which historically causes more severe illness, hospitalizations, and deaths than other strains. When the flu swept through Australia last summer, the effectiveness of the H3N2 component of the vaccine was only about 10 percent. The CDC doesn’t yet have a hard estimate for effectiveness in the United States but thinks it might be near 30 percent.

That mismatch is a bad piece of biological luck. But we should consider it a warning.

We’ve long known that our flu vaccines aren’t built to last, or to tackle every strain. But pharma companies don’t have an incentive to research drugs that will make them less money—not while current vaccines are good enough to make them $3 billion a year. To drive those new vaccines forward, medicine needs a Manhattan Project-style investment, pulling on resources outside the drug industry to force a new generation of vaccines into existence.

It’s well-known inside medicine, and little appreciated outside it, that flu vaccines aren’t as protective as most people assume. In January, the CDC collated data on flu-vaccine effectiveness from 2004 up through last year. There was no flu season in which the vaccine protected more than 60 percent of recipients. In the worst season, 2004-2005, effectiveness sank to 10 percent. That’s very different from childhood vaccines. As Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, lamented at a meeting last summer: “The measles, mumps, and rubella vaccine is 97 percent effective; yellow fever vaccine is 99 percent effective.”

The flu virus itself is to blame. The measles virus that threatens a child today is no different from the one that circulated 50 years ago, so across those 50 years, the same vaccine formula has worked just fine. But flu viruses—and there are always a few around at once—change constantly, and each year vaccine formulators must race to catch up.

The dream is to develop a “universal flu vaccine,” one that could be given once or twice in toddlerhood like an MMR vaccine, or boosted a few times in your life as whooping-cough shots are. That is a substantial scientific challenge because the parts of the flu virus that don’t change from year to year—and thus could evoke long-lasting immunity—are hidden away in the virus, masked by the parts that change all the time.

A handful of academic teams are competing to build such a new shot. They’re tinkering with the proteins that protrude from the virus, trying to take off their ever-changing heads so the immune system can respond to their conserved, unchanging stalks. They’re creating chimeric viruses from several proteins fused together, and they’re emptying out viral envelopes or engineering nanoparticles to provoke immunity in unfamiliar ways. Several of those strategies look promising in animal studies but haven’t been tested in humans. There are substantial hurdles to putting any formula into a human arm—including the fundamental one of figuring out what level of immune reaction signals that a new formula is protective enough.

And then, of course, there’s the fact that creating a new vaccine is expensive. It includes not just the cost of research and development, clinical trials, and licensing—generally accepted, across the pharma industry, to take 10 to 15 years and about $1 billion—but also the price tag for building a new manufacturing facility, which can top $600 million. Contrast that to the expenses of making the current vaccines, which use equipment and processes not changed in decades. A 2013 World Health Organization analysis pegged each manufacturers’ cost of refreshing the annual vaccine at $5 million to $18 million per year.

Now consider this: Right now, millions of people, roughly 100 million just in the United States, receive the flu vaccine every year. If those shots were converted to once or twice or four times in a lifetime, manufacturers would lose an enormous amount of sales and would need to price a new vaccine much higher per dose to recoup.

“What’s the business model here? Am I going to spend more than $1 billion to make a vaccine when I can only sell $20 million worth of doses?” Michael Osterholm asks.

The founder of the University of Minnesota’s Center for Infectious Disease Research and Policy, and a former adviser to the Secretary of Health and Human Services, Osterholm has been pushing for years to get people to notice that the market structure for the flu vaccine works against innovation. “Think about this,” he told me. “If you get a licensed product, which can take billions of dollars to achieve, how are you going to get a return on investment unless you are able to charge an exorbitant amount?”

This isn’t a hypothetical. Take the case of FluMist: As Osterholm’s CIDRAP group revealed in a 2012 report, The Compelling Need for Game-Changing Influenza Vaccines, the vaccine manufacturer MedImmune expended more than $1 billion to develop the novel nasal-spray flu vaccine. In 2009, its first year on the market, FluMist earned just $145 million. And in 2016 and 2017, a CDC advisory body recommended against using the spray at all, saying its rate of effectiveness had sunk to 3 percent.

Examples such as FluMist, Osterholm’s group wrote in their report, make it unlikely that any manufacturer will embark on a new flu vaccine or that VCs will fund them. “We could find no evidence that any private-sector investment source, including venture capital or other equity investors or current vaccine manufacturers, will be sufficient to carry one, yet alone multiple, potential novel-antigen influenza vaccines across the multiyear expenses of production,” they wrote.

As it happens, another sector of medicine is grappling with a similar problem. Since about 2000, pharma manufacturers have largely abandoned antibiotics because of a similar mismatch between investment and reward. Like vaccines, antibiotics are priced low and used for short amounts of time—unlike the lucrative cardiovascular or cancer drugs you’ll see advertised on TV and in magazines.

One answer to the funding gap has been a public-private research accelerator, CARB-X. It was founded in 2016 to dispense $455 million from the US government and a matching amount from the Wellcome Trust in England to support risky early stage research into new antibiotic compounds. Another proposal, put forward by the British Review on Antimicrobial Resistance but not yet enacted, would give roughly $1 billion in no strings “market entry rewards” to companies that get new compounds all the way through trials to licensure, counting on the cash grant to repay R&D expenses.

Osterholm thinks flu vaccines need research support, market rewards, sales guarantees, and more—a matrix of investment in research, manufacturing, and research leadership that he likens to the Manhattan Project, the all-in federal effort to build atomic bombs to bring an end to World War II. Only governments have the power to organize that scale of project, he thinks, and only private philanthropy, on the scale of the Gates Foundation or the Wellcome Trust, has the resources and the flexibility.

And he may be right. What’s clear is that the current flu vaccine market is broken. It’s important to think about that now, because this flu season marks the 100th anniversary of the worst flu known to history: The world-spanning 1918 influenza, which killed an estimated 100 million people in little more than a year. Flu pandemics arrive irregularly, and no one has been able to predict when the worst of them will come again. It would be smart of us to fix the vaccine problem before it arrives.

This Flu Season, Don’t Forget About Tamiflu

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Despite recent controversies about its effectiveness, clinicians should not forget about using the antiviral, oseltamivir (Tamiflu), to help shorten the course of influenza among patients during the coming flu season. In this exclusive MedPage Today video, Arnold Monto, MD, of the University of Michigan School of Public Health in Ann Arbor, discusses how antivirals may be more important than ever this flu season — both in adult and pediatric populations — with an influenza vaccine that may not be as effective.

Following is a transcript of his remarks:

What’s happening is that we are about to have an influenza outbreak, or it’s already starting. We know that this influenza outbreak in the U.S. is mainly H3N2, which is the one that’s the most severe in terms of causing severe morbidity and mortality.

We also know that the vaccine doesn’t work as well against this kind of influenza, and what we really need to remember is that we should be using Tamiflu as the one licensed antiviral that we have which is commonly available. We have others that are a little harder to get a hold of, but they will shorten the duration of illness and prevent complications. We should not hesitate to use what we’ve got because these drugs are not super drugs.

We know that we need better antivirals, and there are new ones in the pipeline, but they are not currently available. The CDC is very strong in their recommendation in certain risk groups that the antivirals — mainly oseltamivir, Tamiflu — be used in the appropriate situations.

I think the CDC has spoken — as have various other organizations like the Infectious Diseases Society, pediatric groups — [about] appropriate use of antivirals, and we need to remember to use them during the coming flu season because we expect the vaccine to work, but not as well as we would like.

There has been controversy between two journals in terms of how they view Tamiflu, which is very strange because we are all science-based and we should really go on the evidence.

We published an article in Lancet looking at the clinical trials of Tamiflu, and we are now about to publish a paper in Clinical and Infectious Diseases that looks at the effect of Tamiflu in pediatrics. We find that it not only shortens the duration of influenza, but also prevents complications [like] otitis media, which is an important complication that occurs after a case of influenza.

4 Vaccine Myths Busted by Science.

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You don’t have to look far to find vaccine myths and misconceptions.

With flu season upon us — and with outbreaks of dangerous yet preventable diseases on the rise — now is the perfect time to rethink these myths, and what science tells us about them.

Vaccine needle

Myth No. 1: Vaccines cause autism

This autism myth has roots in research from 1998. However, the researcher behind it has since been barred from practicing medicine and found guilty of serious scientific misconduct for falsifying information and concealing bias. Dozens of groups have tried to repeat his findings with no success. Science has not validated a link between vaccines and autism.

Still, the myth persists. Emails, blogs and websites that cite “scientific research” or “clinical studies” often provide misleading or incorrect information. Some may even try to sell you “all natural” alternatives to prevent the disease. It’s understandable for parents to be afraid and seek alternatives — but pay close attention to the source of all scientific information.

“Vaccines have saved countless lives in the past. In the future, they’ll save even more — but only if people get the vaccinations they need.”

Paul DiCorleto

Paul DiCorleto, PhD

Lerner Research Institute

Myth No. 2: Measles and whooping cough have been eradicated

An effective vaccine for whooping cough has been available since the 1940s. Yet a 2010 outbreak killed 10 infants and sickened many more in California. New research suggests the outbreak was caused by many parents refusing to vaccinate their kids.

Similarly, measles outbreaks in several states have brought the disease back into the spotlight, 13 years after it was declared “eliminated” by the United States. Twenty-one people recently caught the measles at a church in Texas. Most had not been vaccinated.

When groups of people are vaccinated, a “community immunity” develops. By controlling the spread of disease, vaccination not only protects the healthy members of a group, but also those with weakened immune systems, such as the elderly, and those who cannot receive certain vaccines, such as infants or pregnant women.

Refusing vaccines puts you — and others — at risk.

Myth No. 3: The flu shot doesn’t work

The influenza virus is notorious for its ability to mutate and evade the immune system. However, researchers are constantly monitoring and analyzing how it spreads. They collect thousands of samples and use sophisticated models to predict which strains will be most important from year to year. This information helps them design the next seasonal flu vaccine.

The Centers for Disease Control and Prevention estimate that last year’s vaccine reduced flu-related trips to the doctor by one-half for one strain of flu and two-thirds for another. While not perfect, the benefits of flu vaccination far outweigh the inconvenience and minor side effects, especially for those at high risk.

Myth No. 4: There is nothing new in vaccine research

Actually, immunotherapy is a hot area of research right now. Immunotherapy harnesses the power of the body’s own immune system to fight diseases such as cancer, malaria and even Alzheimer’s disease.

Our immune system normally fights cancerous cells, but tumors develop when these cells grow uncontrollably and overpower the system. Researchers study ways to give our immune systems a “memory” of cancer. Then our bodies are conditioned to keep cell growth in check. Several therapeutic cancer vaccines are in clinical trials or in research now.

For example, Qing Yi, MD, PhD, Chair of the Department of Cancer Biology at Cleveland Clinic, is working on a vaccine for multiple myeloma, a type of blood cancer. And in two years, enrollment will begin for a clinical trial testing the world’s first preventive breast cancer vaccine, based on the research of Vincent K. Tuohy, PhD, Department of Immunology.

Vaccines have saved countless lives in the past. In the future, they’ll save even more — but only if people get the vaccinations they need.

ACIP Publishes Recommendations for 2012–2013 Influenza Vaccination.

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The Advisory Committee on Immunization Practices has published its influenza vaccine recommendations for the 2012–2013 season in MMWR.

The change from 2011 is that children aged 6 months through 8 years who have never received influenza vaccine or who have not received two or more doses of seasonal influenza vaccine since July 2010 should receive two doses of 2012–2013 vaccine (given at least 4 weeks apart).

ACIP does not expect the recently approved quadrivalent flu vaccine (FluMist Quadrivalent) to be available until the 2013–2014 flu season.

Source: MMWR article

 

Pandemic (H1N1) 2009: a clinical spectrum in the general paediatric population.

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This retrospective case series describes the clinical spectrum of 43 children with pandemic (H1N1) 2009 admitted to a single hospital in Australia during the peak winter flu season. Clinical features, diagnoses, length of hospitalisation and complications were reviewed in children up to 17 years of age with proven pandemic (H1N1) 2009 by RT-PCR. The median age was 6 years, 42% had a pre-existing medical condition. The most common presentation was fever and cough, and 88% of patients met our criteria for flu-like illness. Consolidation on chest x ray was the most common diagnosis (n=20, 46%), followed by dehydration (n=13, 30%). Three (7%) had encephalopathy and two (5%) had diabetic ketoacidosis. There were two intensive care admissions and no deaths. Pandemic (H1N1) 2009 flu has a wide range of presentation in the paediatric population. The diagnosis should be considered during the current pandemic in any child with fever, or who is unwell.

Introduction

Since being identified in Mexico in April 2009, human influenza A (H1N1) virus has spread across the world and has widespread community transmission in many countries. The World Health Organization escalated the pandemic to alert phase 6 in early June 2009.1 The outbreak coincided with Australia’s flu season resulting in 35 579 confirmed cases of pandemic (H1N1) 2009 and 161 deaths, in Australia as of 7 September 2009.2 An early report of 18 hospitalised patients of the initial outbreak in Mexico showed that the pandemic (H1N1) 2009 virus caused severe illness and death in previously healthy young to middle-aged persons.3 Despite this, it has been found that the majority of patients continue to experience mild illness.

The purpose of this study was to describe the clinical spectrum of pandemic (H1N1) 2009 virus in the general paediatric population. The Gold Coast Hospital serves a population of over 455 000 people. Our case series describes the epidemiological characteristics, clinical features, range of diagnoses and length of hospitalisation in 43 children positive for pandemic (H1N1) 2009 admitted to the Gold Coast Hospital.

Methods

This retrospective study was conducted by review of medical charts, laboratory and radiological findings of all children admitted to the Gold Coast Hospital with confirmed pandemic (H1N1) 2009. The study period was from the 25 May 2009 to the 16 August 2009, coinciding with Australia’s flu season. During this period, all children admitted into hospital with a febrile or respiratory illness were tested for pandemic (H1N1) 2009 by two Taqman based real-time RT-PCR methods, designed locally in Australia. The two assays, H1-PCR and N1-PCR, were designed targeting the pandemic (H1N1) 2009 virus haemagglutinin and neuraminidase genes, respectively. These RT-PCR methods are found to be sensitive and specific for pandemic (H1N1) 2009 RNA.4 The tests were done at the closest tertiary centre 1 h away and took 2 h to complete. In the peak of the pandemic, due to the overwhelming number of samples, it took 48 h for results to return. Specimens were collected from nasal pharyngeal aspirates or nasal pharyngeal swabs. These specimens were also tested with a multiplex PCR assay for a select respiratory viral panel including influenza A, influenza B, respiratory syncytial virus, parainfluenza types 1, 2 and 3, adenovirus and human metapneumovirus.

Epidemiological characteristics observed were age, gender and pre-existing medical conditions. Pre-existing medical conditions were obtained from the initial history and chart review. These were then categorised according to physiological system. Asthmatic patients were included if they were, at the time of admission, on preventive treatment for asthma. Due to variable documentation of obesity or indigenous background in the medical charts, these factors were not examined in our study.

Clinical features were obtained from findings documented by the treating physician. Based on Queensland Health’s pandemic (H1N1) 2009 case definition, children had flu-like illness if they presented with a fever of at least 38°C, or a history of fever, with one symptom of cough, sore throat or rhinorrhoea.5

Diagnosis was based on history and examination findings documented by the admitting physician, laboratory and radiological findings. In our study, respiratory diagnoses were divided into three groups namely, asthma, bronchiolitis and consolidation on chest x ray. Asthma was defined as the presence of wheezing and/or chest retraction in those with a past history of asthma, without evidence of consolidation on chest x ray. Bronchiolitis was defined as the presence of wheezing and/or chest retraction in those <1 year of age without evidence of consolidation on chest x ray. Due to the difficulty in differentiating consolidation caused by pneumonia or asthma, those with bilateral or unilateral consolidation on chest x ray were analysed in one group called consolidation. Febrile convulsion was defined as a seizure associated with a fever, or history of recent fever, with no previous history of afebrile seizures or evidence of central nervous infection or metabolic abnormality. Dehydration was defined according to the admitting physician’s initial assessment based on history of fluid loss, or poor oral intake, clinical signs including tachycardia, dry mucous membranes, poor central capillary refill, poor urine output and laboratory findings. Encephalopathy was defined as altered mental status lasting greater than 24 h. Diabetic ketoacidosis was defined by biochemical criteria of a blood glucose greater than 11 mmol/litre and evidence of metabolic acidosis (venous pH <7.3 and/or plasma bicarbonate <15 mmol/litre).

Patients were treated with the antiviral, oseltamivir, at the discretion of the admitting physician. Factors considered when commencing treatment were based on the joint position statement published by the Australasian Society for Infectious Diseases (ASID) and the Thoracic Society of Australia and New Zealand (TSANZ).6 These recommendations included treatment for children with risk factors for severe disease, particularly children <5 years of age, those with immunosuppression or chronic disease like asthma, cardiorespiratory disease, diabetes and renal failure. In children with no risk factors for severe disease, oseltamivir was recommended in those who presented within 48 h of onset of symptoms. Oseltamivir was not recommended in those <1 year of age due to limited safety data. Oseltamivir was given to those hospitalised with severe flu infection even after 48 h of symptom onset.

Results

In the period from the end of May to mid-August 2009, a total of 683 children were admitted to hospital. Of these 130 children were screened, via nasopharyngeal swab or aspirate, for pandemic (H1N1) 2009 influenza virus and other common respiratory viruses on our respiratory viral PCR panel. Forty-three children were proven to have pandemic (H1N1) 2009. The characteristics of the patients with pandemic (H1N1) 2009 are listed in table 1.

Fever was the most common presenting symptom (n=41, 95%) followed by cough (n=40, 93%). Other common symptoms were vomiting (n=21, 49%), rhinorrhoea (n=19, 44%) and respiratory distress (n=16, 37%). Headache, myalgia, sore throat, lethargy, abdominal pain, diarrhoea, confusion and seizures were other symptoms reported at presentation. Two (5%) patients did not have a fever or history of fever. Both had pre-existing medical conditions. Thirty-eight (88%) patients fulfilled our criteria for flu-like illness.

The most common diagnosis was consolidation on chest x-ray, with a total of 20 (46%) patients. Thirteen (30%) patients were clinically dehydrated, and four (9%) patients had an exacerbation of asthma. Encephalopathy was diagnosed in three (7%) patients and two (5%) were admitted with diabetic ketoacidosis. Febrile convulsion, bronchiolitis and abdominal pain each occurred in one (2%) patient.

Overall, the median length of stay was 2 days. Those with consolidation had a median length of stay of 2 days while asthma, bronchiolitis, clinical dehydration and febrile convulsion had a median length of 1 day. Patients with encephalopathy and diabetic ketoacidosis had a median length of stay of 4 and 5 days, respectively. Those who were previously healthy had a median stay of 1 day while those who had a pre-existing medical condition had a median stay of 2 days. Twenty-nine (67.4%) patients were treated with oseltamivir.

Of the 43 patients, there were no deaths. Two patients (4.6%) required intensive care; both had pre-existing disorders. One patient had severe bilateral pneumonia and respiratory distress requiring non-invasive ventilation with a background of Retts syndrome. The other patient was admitted to intensive care in severe diabetic ketoacidosis. Five patients (11.6%) were readmitted with complications, including secondary pneumonia, ongoing confusion and exacerbation of asthma. Three of these patients had been treated initially with oseltamivir.

Discussion

Our case series of 43 paediatric patients with proven pandemic (H1N1) 2009 admitted to hospital during the peak of Australia’s flu season demonstrates the wide range of presentations in the paediatric population. All paediatric age groups were affected and almost half of those admitted had an underlying medical problem.

During this study period, there was a low clinical threshold to obtain pandemic (H1N1) 2009 identification. It became apparent that children were being admitted with a wide range of presentations. Fever and cough were present in almost all our cases. Screening only with our criteria for flu-like illness would have missed 12% of children with pandemic (H1N1) 2009 in contrast to a similar report in the UK which found it would have missed 40% of cases using their case definition which required fever and two other symptoms.7 This same report found that 19% of cases did not have a temperature of at least 38ºC or history of fever in contrast to our study which found only 5%. A full screening study of all admissions may be warranted in the future. This was unable to be done due to the significant impact it would have on the testing laboratory during a pandemic.

Consolidation on chest x ray was the most common diagnosis followed by clinical dehydration requiring rehydration in hospital. Interestingly three patients had encephalopathy. Similar neurological complications have been documented in patients with pandemic (H1N1) 2009 in Dallas, Texas as well as in other seasonal flu epidemics.8 In one case, a 16-year-old boy with no previous medical or psychological disorder, had hallucinations and paranoid delusions for 7 days. The other two cases, 2 and 9 years of age, had seizures and altered mental status. Two patients were admitted with diabetic ketoacidosis, one with known diabetes and the other their first presentation.

Conclusion

Pandemic (H1N1) 2009 in the general paediatric population can have a wide range of presentation. Respiratory illness was the most common presentation, there were however, less typical presentations like encephalopathy and diabetic ketoacidosis. There were no deaths and two admissions to intensive care in which both patients had pre-existing medical conditions. Pandemic (H1N1) 2009 should be considered as a diagnosis in any child with fever or who is unwell, even without fever.

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Source: BMJ.

 

 

 

 

 

Flu Season Off to Slow Start .

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Flu season has finally begun in the U.S., according to one measure used by the CDC.

For the first time this season, the proportion of respiratory specimens that tested positive for influenza nationally reached 10.5% for the week ending February 4. Passing the 10% mark is one indication that flu season has begun.

Other markers of influenza activity are also off to a slow start this year, the CDC reports, but the agency says it expects activity to pick up. To date, the circulating viruses have been well matched to this year’s influenza vaccine.

Source:CDC