Thursday, January 2, 2020

Disease Post: Influenza

I had a few days off around the holidays and I was going to finish this and post it. But I didn't plan on not having access to internet for about six days. Insert facepalm here. So I apologize since I swore I would have this posted in December and ended up not being able to finish and post it until January. It is still relevant though, so I hope you can forgive me.

It's the right time of the year for this post--flu season!

There are a ton of misconceptions about the flu and the flu shot (influenza vaccination). So I will try to clear a bit of that up.


Influenza (or the "flu") is caused by a virus from the Orthomyxoviridae family. It is an RNA virus but the RNA is segmented into smaller pieces. This is an important feature that we will discuss in a bit.

There are four types of flu virus: A, B, C, and D. C and D cause little to no disease in humans. While humans can get C and D, they are more common in different animals and are usually very mild if a human catches it. A and B are more important for people so we will focus on those.

Influenza B has no subtypes. According to the WHO, there are different lineages and they are traced that way.

Influenza A is the type you will hear the most about. The WHO states, "Only influenza type A viruses are known to have caused pandemics." There are subtypes of this virus determined by proteins on the virus capsid. There are two main glycoproteins: hemagglutinin (or HA) and neuraminidase (NA). Each of these proteins has different forms and each is coded for on a different segment of RNA. There are 18 known HA subtypes and 11 known NA subtypes. And they can be combined in just about any way. This is how they are labeled, and you’ve probably seen or heard the short hand, like H1N1. Those are the HA and NA subtypes. As you can imagine, this allows for all sorts of recombinations and helps explain why the flu changes so much.

Basically, if two flu viruses infect the same host, they can recombine their genomes to create a new flu strain. This is aided by the fact that the genome is in smaller segments. Or if major mutations occur, the HA or NA can change completely. This reassortment or mutation of genes is called “antigenic shift.”

The following image is one taken from a book I have, sorry for the poorer quality. But this shows how recombination can occur with influenza A viruses.
Image from Medical Microbiology 6th Edition by Patrick R. Murray, Ken S. Rosenthal, and Michael A. Pfaller

To make things worse, the influenza A viruses are not very genetically stable and their genomes can go through smaller mutations very easily. This is called “antigenic drift.” Even small changes can alter the HA or NA enough for someone's immune system to not recognize it.

These things mean that even if you are only talking about H3N1, H3 is the variation of HA antigen and there are even different variations of H3. The flu viruses are always changing and that makes it very difficult to keep up with them. It is also why the vaccines have to be updated constantly.

An influenza type A virion. Image from the CDC.

How is it spread?

Influenza is a respiratory disease, though the "flu" has often been incorrectly used by people for other respiratory and stomach diseases, like the "stomach flu." Since it is a respiratory disease, it makes sense that it is spread in the air and infects the nose, throat, and/or lungs. When someone is sick with the flu, they cough or sneeze or speak and droplets that contain the virus are released into the air and another person inhaling the infected droplets can then get the flu.

It is also recommending that anyone who is sick should wash their hands frequently. If they sneeze or cough into their hands, flu can spread that way, too.

The CDC says that people are most contagious in the first three or four days of the illness, but estimate that they can be contagious from one day before symptoms appear and can remain contagious from five to seven days after becoming sick. The CDC also states that, "Some people, especially young children and people with weakened immune systems, might be able to infect others for an even longer time."


In general, the flu does not have a very long incubation time, meaning that people will start to feel sick pretty quickly after getting it. According to the CDC, the incubation period is about one to four days, with two days being the average.

Symptoms include a fever (but not everyone presents with a fever), chills, cough, sore throat, body aches, congestion, fatigue, and headaches. Rarely, flu can cause vomiting and/or diarrhea, but mostly in children, according to the CDC.

Story time: I got the flu, the actual flu, when I was a senior in high school. I felt a little off for a couple of days, then one day I had a mild fever, and then it hit me like a truck. My fever increased. I couldn't lift my arms to take my hair down. I couldn't stand long enough to shower for a week and when I was getting better, my mom had to put a chair in the shower so I could sit down. I lost my voice and my throat hurt so badly that I couldn't eat and could barely drink. I was completely miserable. It took a good week to start feeling better and another week to get back to my normal energy levels. This is pretty typical of the flu. And I was a young, healthy person. Just think how much worse it would be to be too young or old to have a good immune system. Or to be immunocompromised. That is why these people are usually the most at-risk. A huge part of flu shots is to help protect those at-risk people.

The flu may not sound very serious, but people die from the flu every year. Mostly the people who die are in the at-risk groups. But some flu strains kill people with healthy immune systems, like in the flu pandemic of 1918. Then it was usually the healthy people dying. The flu is no joke.

Prevention and Treatment:

Every year a new flu shot is developed and it is recommended that everyone six months or older should get it, unless you have a medical condition that does not allow you to get the vaccine (ie: if you are immunocompromised or you have an egg allergy).

It is new every year because of how much the flu viruses mutate. We don't often see the exact same flu viruses, espcially with influenza A. The WHO and others spend all year monitoring the flu all over the world. They track which strains are present, where, and for how long. They predict where and how far the strains will spread and they develop the vaccines based on that data. Which means that, yes, sometimes the viruses included in the vaccine are not the ones that people will encounter. But most of the time, that is not the case. The flu vaccine in the US usually covers four different flu strains. It used to be three until recently and there have been the odd year where the number will be different.

The flu shot is the best way to prevent the flu.

There is not a cure for the flu. Generally, care focuses on trying to relieve the symptoms and on hydration until your body can fight it off.

According to the WHO, there are neuraminidase inhibitos (like oseltamivir) available that help, but that many strains resistant to some other antiviral treatments.

And I want to talk briefly about the myths of the flu vaccine.
  • You CANNOT get the flu from the flu shot. The flu shot contains inactivated virus, they cannot cause an infection. Some people may feel a little feverish for a day after a flu shot. This is not the flu. This is your immune system reacting to the vaccine. It is actually a good thing, it means that your body is creating a strong immune reaction and studies generally show that a robust immune response gives you better protective immunity in the future. (Side note, this is why many vaccines use adjuvants. An adjuvant is something added to a vaccine like a protein that causes your body to give a better response. When you body responds to the adjuvant, it will respond to the vaccine better, too. It's like a way of making your immune system pay more attention to what is in the vaccine.)
  • You can still catch the flu if it is not one of the strains in the vaccine.
  • A bad cold is not the same as the flu.
  • Vaccines do not cause autism.
I hope that about covers it. Please reach out if you have questions! Thanks!

Medical Microbiology 6th Edition by Patrick R. Murray, Ken S. Rosenthal, and Michael A. Pfaller
World Health Organization (WHO): Influenza
Centers for Disease Control (CDC): Influenza 
The Great Influenza by John M. Barry

Wednesday, January 1, 2020

December 2019 and Year 2019 Wrap Up

We made it through December and into 2020!

2019 was sort of a crazy year for me. I don't feel like I accomplished very much and still feel a little stuck in my life and unsure what to do about it. I am adjusting to living in a new state and trying to find ways to make friends and find places to go. Mostly I end up being a complete home-body and never doing much of anything!

As for my New Years Resolutions for 2019 did not go over so well.
  • I did not manage to read my goal of 75 books (I got to 72). 
  • I was trying to figure out what I want to do with my life, especially where medical school was concerned. I read some books to help study for the MCAT, but I haven't made any other progress. I am still so torn because I would still need to do so much and I'm already 32. But I keep reminding myself that the time will pass anyway.
  • Lastly was to get my blog back up and running. This one I have mostly done! I haven't done anything crafty to document. I've been on some trips, and pictures can be found on my Instagram, but I stopped posting that stuff here long ago. But I did start disease posts, which is great (even if I am not consistent about posting them).

So how about for 2020?
  • Read at least 75 books
  • Get involved in a local book club
  • Keep making progress on my blog
  • Look into classes

That seems like an OK set of goals to have.

And now on to books read in December!

Title: Together at Midnight
Author: Jennifer Castle
Narrators: Arielle DeLisle and James Fouhey

Synopsis: Kendall and Max are both in a spot where they are trying to figure out where they fit and what they want from their lives. By chance, they both end up in New York City after Christmas and witness a tragic accident. While they wrestle with their mutual feelings of guilt and thoughts about courage and kindness, they set out to do random acts of kindness before the New Year to try and make a difference.

Thoughts: I gave this book a much higher rating than it may have deserved for one big reason: it showed how hard it can be to be brave and to do the right thing. It made me think a ton about this topic and even made me cry. That was pretty huge to me and is what stuck with me the most. I want to recommend it just for that, because being brave takes a special kind of courage and not everyone can manage it. And then how you feel about it afterwards can be so difficult to reconcile. I also liked being able to see how their acts of kindness worked on the people they helped.

Rating: 3 1/2 out of 5 stars

Title: Let it Snow
Author: Nancy Thayer
Narrator: Joyce Bean

Synopsis: Christina is a Nantucket native with her own little shop and circle of friends. But her unpleasant landlord raises the rent on her shop and the shops of her friends. It's enough that none of them will be able to stay in business once the holiday season is over. Meanwhile, Christina makes friends with her landlord's granddaughter, Wink, and her uncle (a handsome, wealthy, single man and the son of her miserly landlord). As their lives become more entwined, can she and Wink thaw her landlord's icy heart?

Thoughts: I did not love this book. Parts of it were charming and endearing, but it felt pretty contrived and cheesy. And her "inner Christina" could really get annoying. It was alright for a holiday read, but I would not read it again.

Rating: 2 1/2 out of 5 stars

Title: The Christmas Sisters
Author: Sarah Morgan
Narrator: Mandy Weston

Synopsis: It's finally happening, Suzanne's adopted daughters are coming home to Scotland for Christmas. All three of them. And she wants everything to be as perfect as possible. But it won't be that easy. As Suzanne comes down with the flu, Posy is feeling the pressure of her role to step into Suzanne's shoes and make Christmas great and run the coffee shop, even though this doesn't align with her dreams. Beth shows up early after having a huge argument with her husband about her desire to return to work after being a stay-at-home mom for several years. And Hannah, who usually avoids family at all costs, also shows up early and she isn't ready to tell anyone what is going on in her life. She wants to deal with it herself. Maybe the sisters can find their ways back into one anothers' lives.

Thoughts: I wasn't sure I would enjoy this one because I thought the title was cheesy, but a couple people recommended it to me, so I wanted to give it a go. I actually enjoyed it much more than I expected to, though Hannah annoyed me greatly and could really benefit from some therapy. I was most interested in Suzanne's and Beth's stories. And it had Christmas vibes and happy endings. It was a great Christmas-y read.

Rating: 4 out of 5 stars

Title: A Christmas Carol
Author: Charles Dickens
Narrator: Tim Curry

Synopsis: I'm pretty sure everyone knows the story of Scrooge and Tiny Tim and the ghosts of Christmas Past, Present, and Future. I will not re-hash it here.

Thoughts: I listen to this book every year. And while I still picture the characters as mice and ducks (thank you Disney and Mickey's Christmas Carol), I still enjoy it. I think this story is always charming and a good way to remind people to be kind and generous!

Rating: 4 out of 5 stars

Title: Landline
Author: Rainbow Rowell

Synopsis: Georgie knows that her marriage hasn't exactly been happy for a while. Maybe not really ever. She still loves her husband, Neal, but Neal does not love Georgie's career and what it requires of her. They are supposed to go to Omaha to visit Neal's mom for Christmas, but Georgie drops the bomb that she needs to stay for work. So Neal takes their daughters to Omaha without her. Not wanting to stay at her empty house, she basically moves back into her mom's house. While she is at her mom's, she finds her old yellow rotary phone. Neal has been avoiding her calls, but she figures she will try the landline. On the yellow phone. But she ends up talking to Neal from 15 years in the past. From before they were married. From the week where they didn't speak at all and Georgie was convinced he had broken up with her. This can't really be happening, right?

Thoughts: This is one of my very favorite books and I re-read it every year around Christmas. I'm not even sure why I love it so much. When I first discovered Rainbow Rowell, I thought this book sounded stupid, so I didn't read it for a while. But when I did, I was so sad that I had waited. I love the way this book is written. Some of it is clever and funny. But most of it is very honest and touching. I don't always recommend it to people, and I'm not sure why. Like maybe by other people or my friends not liking it, it will ruin the magic? Or maybe I feel so strongly about it that it feels personal, like the book is just for me? Whatever the reason, I don't tend to recommend it. But I love it so much.

Rating: 5 out of 5 stars

Title: The Afterlife of Holly Chase
Author: Cynthia Hand
Narrator: Erin Spencer

Synopsis: On Christmas Eve, Holly Chase was visited by four ghosts: her dead stepmother, and the ghosts of Christmas past, present, and future. And she didn't listen. And then she died. Her punishment (so she thinks) is to work at a company called Project Scrooge as the new Ghost of Christmas Past. They work to save a new "Scrooge" every year. Since she is technically dead, she doesn't age and nothing changes. Until this year, her sixth year working at Project Scrooge.

Thoughts: Several people recommended this book to me this year, too. I'm glad I managed to squeeze it in! It is a pretty unique re-telling of A Christmas Carol. Some parts may have been a little strange and I didn't love the romance aspect, but overall, I really enjoyed it! If you like re-tellings, I highly recommend it.

Rating: 3 1/2 out of 5 stars

Least favorite book read this month: Let it Snow
Favorite book read this month: Besides Landline? Probably the Afterlife of Holly Chase

I suppose that is it for books. December was pretty exciting for me. A couple of my friends came to visit and we went to Carlsbad caverns and hung out in my new home town. Then I got to go to Connecticut with Kevin to visit his family for Christmas. That was very nice and I appreciated the time off. I got to see the new Star Wars movie, which I liked. And I finally saw the new Ghostbusters movie, which was hilarious.

Overall it was a good month. I missed my family and the rest of my friends during my birthday and the holidays, but I'm still happy with the way my month turned out.

What are your goals for next 2020?

Happy New Year everyone!