flu

The Weird and Interesting Life of a Flu Virus

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shutterstock_87645001The first description we have of the influenza virus was from Hippocrates (my hero!) 2400 years ago. He dealt with it every winter, endlessly, just as we do now. Nowadays it makes between 3 and 5 million people sick each year, and kills 250 to 500 thousand people annually. In the US we average 200 thousand hospitalizations and 36 thousand deaths yearly. Persistent, nasty little bugger.

Influenza gets its name from the Italian word for influence, because people initially thought it was caused by the influence of the stars, and later by the influence of the cold. Now we know better.

The Anatomy of a Flu Virus:

The influenza  virus is a tiny spherical particle, only 80-120 nanometers in size. It would take a million of them standing in a row to make a 1 centimeter line. Its core is made of 8 separate segments of RNA (we humans have DNA). This core is surrounded by protective proteins and an envelop with 2 types of “glycoproteins”–the famous Hs and Ns you hear about when people talk about which type of flu is causing problems each year: Hemagglutinins and Neuraminidases.

NPR has a very cool video of the flu virus invading a cell here. The “key” in the video is the hemagglutinin.

How the Virus Works:

The Hemagglutinins (Hs) bind to target cells in your body and inject the virus particle into your cells. How contagious the flu is, what symptoms it gives you, and how sick it can make you depends on the Hs. An H that can bind to cells in your eyes, nose, and mouth is more contagious than one that can only bind to your throat. An H that can bind to a cell deep in your lung is much more serious than one that can only bind to a cell in your throat.

The Neuraminidases (Ns) release the progeny of that prolific particle from that cell so that the little critters can spread further through your body.

How we Fight it:

The Hs and Ns are the molecules our immune systems build antibodies against, whether we catch the flu or just get exposed to the dead virus in the annual vaccine. The Hs and Ns are also the targets for antiviral drugs. There are 16 different Hs and 9 different Ns. Humans are usually infected with H 1, 2, or 3 and N 1 and 2.

There are three groups (genera) of flu viruses in the family Orthomyxoviridae. (I love that word: Ortho-myxo-vir-i-dae.) The three groups are simply labeled A, B, and C. We frequently call the flu by which animal is its main host. Human, bird, and swine are the most common strains we humans catch.

Flu A has the most serogroups (Hs and Ns), infects the most different animals, and is the most virulent. It also mutates 2-3 times faster than B. The critters it infects are mostly aquatic birds, but it can infect many other species.

Flu B has only one serogroup and is almost exclusive to humans. It tends to be less severe and less common. Since it only has one serogroup and mutates slowly, many people develop a degree of immunity to it.

Flu C is even less common and less severe.

What makes Flu unique among viruses:

Viruses enter cells so that they can make copies of themselves and spread. As they make those copies they sometimes make mistakes, creating mutations. They average one mistake per copy, so mutation is constant– what we call antigenic drift. That’s why we never get immune to Flu A–it changes every year.

There is one really cool thing about the flu virus that makes it different from most viruses: its RNA is split into 8 segments. (Most viruses have one long piece of RNA.)

This means that if your local pig catches 2 different strains of flu at the same time, these strains can trade segments. When that happens we get antigenic shifts– much larger changes for which people have no immunity. These larger shifts can create a pandemic, like the Spanish flu in 1918 that killed an estimated 21 million people. We average 3 pandemics each century. We worry a lot about pandemics.

So, those are the ABCs of the flu virus. If you crave something more useful, like what you can do about it, check out my post on colds and flu or info on fever.

Now wash those little hands with soap, keep them away from noses and mouths, break out the bleach, and go get those flu shots! The shots cover an H1N1 and H3N2 Flu A, and two strains of B.

Why Can’t the Doc Fix My Kids’ Cold?

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Adorable Child Dressed As Doctor Playing With Toy Over White

Happy cold and flu season!

How many times have you taken your child to the doctor and been told, “It’s just a virus. Rest, push fluids, and they’ll feel better in about 10 days”?

Sadly, it’s true. There are hundreds of different viruses that cause colds, from the most common rhinovirus through the ever-unpleasant adenovirus to the rather pretty coronavirus (it has a corona, or crown).

coronavirus-01

Coronavirus

We can’t fix any of them.

All of them are contagious. All you have to do to catch one is breathe around someone who has one, or touch a surface that someone infectious has recently touched and then rub your nose or eyes. After a 2 or 3 day incubation period you will wake up to a scratchy throat and headache and you too will be infectious (mostly for the first 3 days).

Children catch an average of 8-10 colds during the first two years of their lives; they average 6-8 colds per year during their school years. Since most colds occur from October through March, this means 1-2 colds per month, lasting 10 days each. If it seems like your children are sick all the time, it’s because… they are sick all the time.

Symptoms of a cold include fever, red watery eyes, congestion, cough, tiredness and decreased appetite. Your child’s ears might feel plugged up. Watery nasal discharge can turn thick and green after a day or two (this doesn’t mean they have a sinus infection, it’s just part of what a virus does).

So how do we keep them as healthy as possible? You probably already know the basics:

  • Wash their hands frequently. Keep those hands away from their eyes, nose and mouth! No nail chewing!
  • Cover their mouths when they sneeze or cough. Elbows or facial tissues work.
  • Disinfect surfaces.
  • Look for small daycares and classes whenever possible (I know, but we can dream).
  • Do what you can to boost their young immune systems. Breastfeeding your infant will make me poor–all that wonderful grown-up immunity transferred to your little one. Never smoke in air your child will inhale. Really. Never. It will destroy their immune system. And yours, by the way. Take probiotics like Acidophilus (in yogurt) or Lactobacillis.
  • Make sure they get enough sleep. If they are sleepy during the day, move their bedtimes up. Tired people get sick.
  • Offer them healthy food, and throw out all the unhealthy food so they will have fewer options when they get hungry.
  • Have lots of fluids available, because hydration is necessary for your body’s defenses to work. And no, I don’t mean soda. Water, dilute juice or milk please.

When your children get sick, treat their symptoms so that they will feel better. We have nothing that cures colds–antibiotics do not kill viruses. Salt water (saline) nose sprays are safe. Tylenol or ibuprofen will help with fever and pain. Over the counter cold meds will suppress some of the symptoms in children over 6 years of age, although they’ve never been proven to work well for younger kids.

Call your doctor if the fever lasts more than three days, if your child is lethargic or unusually cranky, or if they have an earache or breathing problems.

Make them rest and drink fluids, and they’ll feel better in about 10 days.

Why Can’t the Doc Fix My Kid’s Cold?

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sneezing boy-01Happy cold and flu season! How many times have you taken your child to the doctor and been told, “It’s just a virus. Rest, push fluids, and they’ll feel better in about 10 days”?

Sadly, it’s true. There are hundreds of different viruses that cause colds, from the most common rhinovirus through the ever-unpleasant adenovirus to the rather pretty coronavirus (it has a crown…).

We can’t fix any of them.

All of them are contagious. All you have to do to catch one is breathe around someone who has one, or touch a surface that someone infectious has recently touched and then rub your nose or eyes. After a 2 or 3 day incubation period you will wake up to a scratchy throat and headache and you too will be infectious (mostly for the first 3 days).

Children catch an average of 8-10 colds during the first two years of their lives; they average 6-8 colds per year during their school years. Since most colds occur from October through March, this means 1-2 colds per month, lasting 10 days each. If it seems like your children are sick all the time, it’s because… they are sick all the time.

Symptoms of a cold include fever, red watery eyes, congestion, cough, tiredness and decreased appetite. Your child’s ears might feel plugged up. Watery nasal discharge can turn thick and green after a day or two (this doesn’t mean they have a sinus infection, it’s just part of what a virus does).

So how do we keep them as healthy as possible? You probably already know the basics:

  • Wash their hands frequently. Keep those hands away from their eyes, nose and mouth! No nail chewing!
  • Cover their mouths when they sneeze or cough. Elbows or facial tissues work.
  • Disinfect surfaces.
  • Look for small daycares and classes whenever possible (I know, but we can dream).
  • Do what you can to boost their young immune systems. Breastfeeding your infant will make me poor–all that wonderful grown-up immunity transferred to your little one. Never smoke in air your child will inhale. Really. Never. It will destroy their immune system. And yours, by the way. Take probiotics like Acidophilus (in yogurt) or Lactobacillis.
  • Make sure they get enough sleep. If they are sleepy during the day, move their bedtimes up. Tired people get sick.
  • Offer them healthy food, and throw out all the unhealthy food so they will have fewer options when they get hungry.
  • Have lots of fluids available, because hydration is necessary for your body’s defenses to work. And no, I don’t mean soda. Water, dilute juice or milk please.

When your children get sick, treat their symptoms so that they will feel better. We have nothing that cures colds–antibiotics do not kill viruses. Salt water (saline) nose sprays are safe. Tylenol or ibuprofen will help with fever and pain. Over the counter cold meds will suppress some of the symptoms in children over 6 years of age, although they’ve never been proven to work for younger kids.

Call your doctor if the fever lasts more than three days, if your child is lethargic or unusually cranky, or if they have an earache or breathing problems.

Make them rest and drink fluids, and they’ll feel better in about 10 days.

The Blogger's Pit Stop

The Weird and Interesting Life of a Flu Virus

Posted by

13

sick-kid-01The first description we have of the influenza virus was from Hippocrates (my hero!) 2400 years ago. He dealt with it every winter, endlessly, just as we do now. Nowadays it makes between 3 and 5 million people sick each year, and kills 250 to 500 thousand people annually. In the US we average 200 thousand hospitalizations and 36 thousand deaths yearly. Persistent, nasty little bugger.

Influenza gets its name from the Italian word for influence, because we initially thought it was caused by the influence of the stars, and later by the influence of the cold. Now we know better.

The influenza  virus is a tiny spherical particle, only 80-120 nanometers in size. It would take a million of them standing in a row to make a 1 centimeter line. Its core is made of 8 separate segments of RNA (we humans have DNA). This core is surrounded by protective proteins and an envelop with 2 types of “glycoproteins”–the famous Hs and Ns you hear about when people talk about which type of flu is causing problems each year: Hemagglutinins and Neuraminidases. NPR has a very cool video of the flu virus invading a cell. The “key” in the video is the hemagglutinin.

The Hemagglutinins (Hs) bind to target cells in your body and inject the virus particle into your cells. How contagious the flu is, what symptoms it gives you, and how sick it can make you depends on the Hs. An H that can bind to cells in your eyes, nose, and mouth is more contagious than one that can only bind to your throat. An H that can bind to a cell deep in your lung is much more serious than one that can only bind to a cell in your throat.

The Neuraminidases (Ns) release the progeny of that prolific particle from that cell so that the little critters can spread further through your body.

The Hs and Ns are the molecules our immune systems build antibodies against, whether we catch the flu or just get exposed to the dead virus in the annual vaccine. The Hs and Ns are also the targets for antiviral drugs. There are 16 different Hs and 9 different Ns. Humans are usually infected with H 1,2, or 3 and N 1 and 2.

There are three groups (genera) of flu viruses in the family Orthomyxoviridae. (I am a nerd–I love that word. Ortho-myxo-vir-i-dae. It would make a killer rap song.) The three groups are simply labeled A, B, and C. Nerds have no creativity. A, B, and C. Sad.

  • Flu A has the most serogroups (Hs and Ns), infects the most different animals, and is the most virulent. It also mutates 2-3 times faster than B. The critters it infects are mostly aquatic birds, but it can infect many other species. We frequently call the flu by which animal is its main host. Human, bird, and swine are the most common strains we humans catch.
  • Flu B has only one serogroup and is almost exclusive to humans. It tends to be less severe and less common. Since it only has one serogroup and mutates slowly, many people develop a degree of immunity to it.
  • Flu C is even less common and less severe.

Flu viruses enter cells so that they can make copies of themselves and spread. As they make those copies they sometimes make mistakes, creating mutations. They average one mistake per copy, so mutation is constant– what we call antigenic drift. That’s why we never get immune to Flu A–it changes every year.

What makes Flu unique: There is one really cool thing about the flu virus that makes it different from most viruses: its RNA is split into 8 segments. Most viruses have one long piece of RNA. This means that if your local pig catches 2 different strains of flu at the same time, these strains can trade segments. When that happens we get antigenic shifts– much larger changes for which people have no immunity. These larger shifts can create a pandemic, like the Spanish flu in 1918 that killed an estimated 21 million people. We average 3 pandemics each century. We worry a lot about pandemics.

So, those are the ABCs of the flu virus. If you crave something more useful, like what you can do about it, check out my post on colds and flu or info on fever.

Now wash those little hands with soap, keep them away from noses and mouths, break out the alcohol (not the drinkable kind) and bleach, and go get those flu shots! This year’s shot covers Flu A H1N1 and H3N2, and two strains of B.

DomesticatedMomster
The Blogger's Pit Stop

Just a Cold? Or is it the Flu?

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sick kid-01Any given year, between 5% and 20% of the US population will catch the flu.

Influenza, or the flu, is a virus spread in tiny drops of fluid that an infected person has sneezed or coughed out. Your children can inhale these, or rub droplets contacted from surfaces–or other people–onto their eyes, nose, or mouth. After a 1-4 day incubation period, your child becomes sick.

The initial symptoms of flu include a sudden, high spiking fever, chills, headache, tiredness, and body aches. From there it progresses through sore throat and congestion. Symptoms generally last about ten days, with the worst occurring during the first three days.

Children can be sick for longer than adults, and have more complications.

Complications of the flu commonly include things like pneumonia, ear infections, and sinusitis. Less common complications include fever seizures, encephalopathy, inflammation of the heart, and death.

Serious complications are more common in children with underlying health conditions, but even healthy children can become severely ill. During the 2014-2015 season, more than 145 children died, and more than 200,000 kids were hospitalized with flu complications. Generally about 43% of hospitalized kids have no predisposing health problems.

Children at the highest risk are those with underlying conditions like asthma, a compromised immune system (cancer, HIV/AIDS…), or with chronic diseases (diabetes, seizures…) Also at risk are babies under six months of age, who are not yet old enough to get the vaccine and whose immune systems are not yet adult sized.

We try to make sure high risk kids get their vaccines if they can, but we rely on other people to also get their vaccines to “cocoon” these kids so that they are not exposed. If parents, chid care providers, and the other kids in daycare get their flu shots, then chances are that the cute little baby with heart disease will not catch the flu.

Vaccines rule. Preventing disease is always better and safer than trying to treat it once a child is sick.

Flu vaccines come in two types–shot and inhaled mist. The shot is a dead virus, the inhaled mist is a live attenuated (very weak) virus. Neither can give you the flu or make your child autistic. Since we give the vaccine in the midst of cold and flu season, some people are bound to become ill in the weeks after they get it. It is easy to blame the vaccine. The shot can make your arm red and sore; the mist, since it is live, can give you a mild stuffy nose and a low grade fever. So much better than what the actual flu can do!

Last, what should you do if your child does catch the flu? If he or she has any underlying health conditions or is under two years old, call your doc. We have antiviral meds that, while they taste horrible and are not completely effective, do help.

Then, just like when they have a cold, make them rest, push any sort of fluid they will drink, and treat the symptoms. Ibuprofen will generally work better for the body aches and headaches than acetaminophen. Salt water drops or sprays work for stuffy noses, and for kids over four, cold and cough medicines will help them feel better.

Keep them home, because they are contagious. Adults are contagious for about 5-7 days; kids can be contagious for more than 10 days. Both can be contagious about a day before they have any signs of illness.

Call your doc if your child has any breathing problems, lethargy, fever that persists for more than three days, or isn’t starting to get better after the first few days. Or just if you want to. That’s what we’re here for.

 

 

 

“It’s Just a Cold…”

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Adorable child dressed as doctor playing with toy over white

Happy cold and flu season! How many times have you taken your child to the doctor and been told, “It’s just a virus. Rest, push fluids, and they’ll feel better in about 10 days”?

Sadly, it’s true. There are hundreds of different viruses that cause colds, from the most common rhinovirus through the ever-unpleasant adenovirus to the rather pretty coronavirus (it has a crown…).

We can’t fix any of them.

All of them are contagious. All you have to do to catch one is breathe around someone who has one, or touch a surface that someone infectious has recently touched and then rub your nose or eyes. After a 2 or 3 day incubation period you will wake up to a scratchy throat and headache and you too will be infectious (mostly for the first 3 days).

Children catch an average of 8-10 colds during the first two years of their lives; they average 6-8 colds per year during their school years. Since most colds occur from October through March, this means 1-2 colds per month, lasting 10 days each. If it seems like your children are sick all the time, it’s because… they are sick all the time.

Symptoms of a cold include fever, red watery eyes, congestion, cough, tiredness and decreased appetite. Your child’s ears might feel plugged up. Watery nasal discharge can turn thick and green after a day or two (this doesn’t mean they have a sinus infection, it’s just part of what a virus does).

So how do we keep them as healthy as possible? You probably already know the basics:

  • Wash their hands frequently. Keep those hands away from their eyes, nose and mouth! No nail chewing!
  • Cover their mouths when they sneeze or cough. Elbows or facial tissues work.
  • Disinfect surfaces.
  • Look for small daycares and classes whenever possible (I know, but we can dream).
  • Do what you can to boost their young immune systems. Breastfeeding your infant will make me poor–all that wonderful grown-up immunity transferred to your little one. Never smoke in air your child will inhale. Really. Never. It will destroy their immune system. And yours, by the way. Take probiotics like Acidophilus (in yogurt) or Lactobacillis.
  • Make sure they get enough sleep. If they are sleepy during the day, move their bedtimes up. Tired people get sick.
  • Offer them healthy food, and throw out all the unhealthy food so they will have fewer options when they get hungry.
  • Have lots of fluids available, because hydration is necessary for your body’s defenses to work. And no, I don’t mean soda. Water, dilute juice or milk please.

When your children get sick, treat their symptoms so that they will feel better. We have nothing that cures colds–antibiotics do not kill viruses. Salt water (saline) nose sprays are safe. Tylenol or ibuprofen will help with fever and pain. Over the counter cold meds will suppress some of the symptoms in children over 6 years of age, although they’ve never been proven to work for younger kids.

Call your doctor if the fever lasts more than three days, if your child is lethargic or unusually cranky, or if they have an earache or breathing problems.

Make them rest and drink fluids, and they’ll feel better in about 10 days.

Domesticated Momster