A Boy Named Flu

0:01 I know it's fall now because I came home and every surface of my house that was like three feet and lower was covered in construction paper, arts and crafts. I guess just from your kids bringing home stuff from school? Yes, they just make stuff here too.

0:17 And I even asked the youngest one if I could like put it into a frame and bring it up to my office and she just like screamed, NO! And like grabbed it off the wall and ran to her room with it. Wait, she took it?

0:27 Like from you? Yeah, it's like her personal art. She didn't just say no? Yeah, she just like ran off with it. Okay. Um, I don't remember any like real crafts from when I was younger. I do have like one really big elementary school like memory.

0:42 And that was Roxaboxan. So Roxaboxan like was a book about these children in this town that they would go and they made their own like pretend town on the top of the hill using like the pebbles and rocks from their town. And they'd get like the parents cardboard boxes and like build houses.

0:57 And they just had this like play pretend town where they like merchants and like had lives and stuff. And so I remember from my school, we read the book and then we had like this big Roxaboxan day for like multiple grades. And so we would like all go outside and make our own pretend like society.

1:13 And I remember I loved it so, so much. And I would like anticipate it days in advance and I would even collect the little, we use like little black pebbles as currency. And so I remember like days in advance, I would like collect them and hide them on the playground so I could have plenty of currency for when Roxaboxan day was.

1:30 Kind of all I remember about it now. I remember I loved it so, so much. But also it was kind of at the beginning of like fall when we're starting to get cold, which is coincidentally when the flu season begins. I'm Dr. Dustin Edwards.

1:42 And I'm Faith Cox. Welcome to Germomics where we go to be from the A in the most roundabout way, a mix of microbiology and history. In this series, we connect different aspects of modern life in society to microbes through seemingly unconnected natural events, discoveries, and inventions.

1:57 Today's Columbus date. And I remember only a few things from kindergarten and first grade, but I do remember this. And I think everybody remembers this from indoctrination. In 1492, Columbus sailed the ocean blue. Yeah, I remember that too. You said it the other day and it brought it from like the depths of my memories.

2:17 It was, it was far in there. Christopher Columbus was an Italian navigator who was financed by Spain that launched a viable sailing route from Europe to the Americas. This initiated European expeditions to the Caribbean, Central America, and South America for the conquest and settlement by Europeans.

2:33 He sailed a total of four voyages on the first voyage that began on August 3rd, 1492. And he had three ships, the Santa Maria, the Santa Clara, who was also known as the Nina, and then the Pinta. And that one's original name was Law, so we only know it by its nickname now.

2:52 The original island that he landed on was one of the Bahamas. They don't really know which one he landed on first. They should know it was one of them. And when there, he found the Tinos, the indigenous people of the Caribbean. And he took some of them prisoner like right off the bat and demanded that they tell him where their gold was because he noticed they're wearing gold jewelry.

3:12 He then very quickly after that decided their war tools were too primitive and as such would be really easy to conquer. And he like made note of that in his diary. If there was ever an evil villain, this is just like sets that up.

3:25 Oh yeah, no, he was like really just mean right off the bat. He also noticed that they were like really good and like curious and so he'd like say a word to them and they would repeat it back. And so he took that in his head and he's like, you know what?

3:38 This means they make really good slaves. He also left some of his own men behind with the group and then took some of the islanders prisoner with him. In total of the Tinos, he kidnapped about 10 to 15 people. And then only 7 to 8 made it back to Spain alive after that first voyage.

3:57 So then on subsequent voyages, he continued to take advantage of the indigenous populations. And then he even began exporting them from their homes across the Atlantic to be enslaved. And then he started to bring settlers and colonists over from Spain to colonize the new world.

4:12 And as comes with like bringing new people to a new area, he also brought disease. So I think a lot of people are vaguely familiar with Columbus bringing smallpox, but it's also theorized that he brought influenza over. On his second voyage specifically, that's when historians believe that he started to bring like the highly pathogenic diseases over.

4:32 Smallpox was believed to kill around 90% of the inhabitants. But before smallpox outbreaks, they had a big flu outbreak in 1493 that affected the Isle of Santa Domingo. So we obviously still have the flu today, but what is the flu and how is it different from the common cold?

4:51 So the flu is only caused by influenza viruses. Colds can have multiple causes and their infections are usually much more mild than the flu. And so colds generally don't result in serious health problems. Both colds and flu infections are acute infections, meaning you get sick and your body either quickly clears the infection or you don't and die.

5:14 There's really only two options there. Yeah, you either like get over it or you don't. There's like not an alternative path. Also with acute infections, one single virion or infectious agent doesn't cause an infection that repeatedly manifests, like herpes simplex virus where you get infected and then you can like have cold sores for the rest of your life.

5:34 With acute infections, like I said, you get it and then you clear it. However, you can catch it again with a different strain or a different actual infection. So the flu manifests with abrupt symptom onset, often a fever, aches, chills, and fatigue or general weakness.

5:51 It's also really common to have sneezing, a stuffy nose, chest discomfort, coughing, a sore throat, and a headache. I know my mom always taught me that if I was achy, it was probably more likely to be the flu than a cold. Yes, that's the main symptom difference between cold and flu is that if you have the flu, you definitely have body aches.

6:11 Yeah, I was reading that. I've never had the flu, but I was reading that some people get it like so bad they can't get out of bed. Yeah, I think I only had the flu once when I was a child and I was just laid out on the couch for like three days.

6:23 So influenza viruses, like all known viruses, are obligate intracellular pathogens, meaning that they have to use a host cell to replicate in and then they destroy them to exit. Influenza viruses are RNA viruses, meaning they have an RNA-based genome. Influenza viruses are divided into four groups, influenza A, B, C, and D.

6:46 If you're familiar with influenza but haven't heard of D, it's because it was first isolated in 2011 and then was only given its own family in 2016. Influenza A viruses are the most virulent human pathogens among the four and cause the most severe manifestations.

7:02 Wild aquatic birds are the natural host for type A and occasionally the virus is transmitted to other avian species, such as domestic poultry, and then may infect their handlers and give rise to a human pandemic. This group can be further subdivided based on the proteins on the outside of the virus.

7:19 The virus contains hemagglutinin, which is like the key to get into the lock to enter into the cell. And then there is also neuraminidase, which after you make new viruses and they start to leave the cell, neuraminidase cuts it so that they don't clump up on the surface.

7:35 Hemagglutinin and neuraminidase are what you hear about on the news when you hear like different strains of like H1N1 or H3N2. Several human pandemics, which is a worldwide outbreak of massive proportions, have been caused by influenza A viruses. There was H1N1, which caused the Spanish flu or the flu of 1918 and the swine flu in 2009.

8:00 There's also H3N2, which caused the Hong Kong flu in 1968. H5N1 caused the bird flu in 2004 and H7N1 was rated in 2018 to have the greatest pandemic potential by the CDC. Influenza B almost exclusively infects humans and is less common than type A.

8:21 Just as a fun fact though, it also infects seals and ferrets. Influenza B is, however, less likely to cause a pandemic because it mutates at a much slower rate than type A. And because it's only in one main species, it can't jump hosts as easily and that limits its genetic diversity.

8:40 There's also influenza C, which infects humans, dogs, and pigs. And this one can be severe, but it's less common and actually usually only causes mild illness in children. There's also influenza D, and it infects humans and cattle. It has the potential to infect humans, but there has not yet been a reported case.

8:58 Influenza virion, which is an individual virus particle, is made up of a viral envelope surrounding a protein capsid that encloses a central core. And that contains the RNA genome and other viral proteins. The virions have two main proteins on the outside of the virion.

9:14 They have hemagglutinin, which mediates the binding of the virion to host cells and the entry of the viral genome into the cell. And then also neuraminidase, which plays a role in the release of the daughter viruses from the infected cells by cutting up the sugars that help hold a cell together.

9:30 So they open it up enough for the virus to leave. Both of these proteins play a really big role with flu infection, and so as such, they are targets for antiviral therapies. Influenza replicates inside of host cells in a multi-step process. They bind to and enter the host cell, and they deliver the genome to the replication site.

9:50 The cells that influenza replicate in are often the respiratory tract, so the nose, the throat, and the lungs of mammals, and then the intestines of birds. Because of that, it can be transmitted through the aerosolization of respiratory droplets from coughing or sneezing. And direct transmission, so like shaking hands with someone who coughed in their hand and they have the flu and they're touching your nose.

10:11 Or through fomites, which are inanimate objects that are contaminated, such as a doorknob or a keyboard of a computer. So how bad is the flu and how bad could a flu infection get? Because of its modes of transmission, the flu can be very easily spread.

10:28 Aerosolized droplets can hang in the air. For how long they hang varies based on environmental factors, such as the humidity and UV radiation. Just as a fun fact, decreased humidity and UV radiation are part of why the virus thrives in the winter. One droplet can contain enough virions to cause an active infection.

10:46 Influenza can also persist outside of the host in the environment through fomites, with the virus remaining viable for up to two days on non-porous surfaces, such as plastic or metal. If it's present in mucus, then it can actually remain viable for even longer.

11:00 Apparently, mucus is known to aid in virion stability, and there was a study that showed that influenza remained infectious for 17 days when it mixed with mucus on bank notes or money. So how bad is the flu in the United States? This is preliminary data from the 2018-2019 flu season, which actually only ended in May.

11:20 From October 1, 2018 to May 4, 2019, the Centers for Disease Control and Prevention estimates that there were between 37.4 to 42 .8 million flu infections in the U.S. alone. There were 17.3 to 20.1 million flu medical visits. 531,000 to 647,000 flu hospitalizations.

11:46 And between 36,400 to 61,200 flu -related deaths. Those are all, like I said, just in the U.S. alone, and those numbers are actually an improvement from the 2017-2018 flu season, which had 48.8 million cases of influenza, which is only 12,000 less than what the 2009 H1N1 pandemic caused in the U.S. The 2017-2018 flu season was particularly bad.

12:17 Infections were more severe than usual for all age groups. Influenza burden is normally particularly high in the very young and the very old, but in the 2017-2018 season, all age groups were more severely affected. I just want to sit and think about this for a minute.

12:34 There were 80,000 flu-related deaths. Yes. That's just an enormous number. It's an enormous number. Of mostly preventable deaths. Yeah.

12:49 There were a total of 183 reported and confirmed pediatric deaths in the 2017-2018 flu season. That's the highest number that there's been outside of a pandemic year, and those were the laboratory-confirmed cases. The CDC used a mathematical model to estimate what the likely number of pediatric deaths to be was, because not every child that's dying of the flu has a laboratory-confirmed strain of flu.

13:17 A lot of times, they die of flu -related complications that don't get reported. Using these models, the number of pediatric deaths is estimated to be closer to 600. In 2016 and 2017, influenza and pneumonia were the 8th leading cause of death of adults in America.

13:36 So many people get the flu and recover. How do you know when it's too bad and what can you do to prevent the flu? There are red flags to look for with a flu infection. Anyone who's exhibiting shortness of breath, chest pain, dizziness, confusion, cyanosis, which is when you turn blue from a lack of oxygen, a high fever, an inability to drink fluids, or flu symptoms that improve but then relapse with a high fever and cough are all red flags.

14:06 So that relapse is particularly indicative of a bacterial pneumonia infection, which is a complication of flu. Your best course of action during flu season is just to get the vaccine. The CDC recommends that all those aged 6 months or older that don't have a contradiction get the flu vaccine.

14:24 The main vaccine that's given out contains an inactivated form of the virus, meaning the virus is completely killed. The killed virus is then injected into a patient so that their immune cells learn what the virus looks like and how to neutralize the protein so that it can't enter host cells.

14:41 Your body then remembers the specific virus strains so that when you encounter the virus in the environment, you can better and more quickly respond to the virus. And try to remember that it takes about 2 weeks for the antibodies to be made and ready.

14:54 Even within that 2 weeks, you can still get the flu, so you want to try to get your flu shot before the season peaks. The vaccine each year is based on the strains that are most likely to cause significant human suffering that year, which is why you have to get a new flu vaccine every year because the strains can change.

15:11 Getting the flu shot doesn't necessarily mean that you won't get the flu. However, it does help that if you do get the flu, your symptoms are dramatically less severe, it decreases hospitalizations, it's beneficial to have even if you end up getting the flu.

15:25 If you do get infected with the flu, there is antiviral therapy though. However, these antivirals are prescription based, so you do have to go to a physician and you have to test positive for the flu before being prescribed these. And they're most effective when they're given out within 48 hours of symptom onset, but they're also given out to very severe hospitalized infections.

15:48 I remember only having the flu once and that was when I was a kid. And I do remember that I didn't want to do anything. Your body just absolutely hurts. It hurts to try to lift your arm. It hurts trying to stand up off the couch to go to the bathroom.

16:05 It just hurts to do everything. So I can't imagine trying to get yourself into a physician within 48 hours. Yeah, and so I've shadowed physicians that if the patient doesn't get in within that first 48 hours of symptom onset and they test positive for the flu, unless it's like a really severe case, they won't prescribe them an antiviral because at that point they just think the patient should ride it out because they're passed when the drugs would have been most effective.

16:31 For our science and society message today, we wanted to do a little bit of myth busting about the flu shot. So I have some CDC literature here and we're just going to do kind of a top 10 excuses people have. So number one, I'm healthy and I don't need the flu shot.

16:49 So getting the flu shot isn't all about you. Like I said, it's the oldest and the youngest that are most affected by the flu. And when you get your flu shot, you help protect the very young and the very old, the people who are most susceptible to flu infection.

17:03 And people who are immunocompromised who can't get the vaccine. Yeah, and people who are immunocompromised, but then also you get the vaccine and worst case scenarios, you still get the flu, but then you just have dramatically less severe symptoms than you would have had if you had a full blown flu infection.

17:19 Okay, number two, the flu shot can give me the flu. That's just wrong. Yeah, the main flu vaccine that's given out is inactivated, so you can't get it from that. Number three, I got the flu shot last year. So you have to get a new flu shot every year because the strains that are going to be circulating and causing the most significant human suffering change each year just due to genetic mutations and just due to new strains arising.

17:47 Number four, doctor, I have an egg allergy. There is a version of the flu shot that is not made with eggs, so it's safe for people who have egg allergies. You just have to tell your physician. Doctor, I'm also pregnant. So this is still actually a really good time to get your flu shot because getting the flu while you're pregnant can lead to further complications, as well as when you get your flu shot, your antibodies will offer the baby protection for the first six months of life.

18:14 Number six, I don't have time to get a flu shot. If you don't have time to get your flu shot, you definitely don't have time to get the flu because it's going to be a lot more time consuming, but it's also pretty quick now.

18:24 Yes, and as far as the actual time it takes to get the flu vaccine, I got mine recently and it took about 15 minutes total. And that includes waiting in line behind two other people. So you just go in there and you sign the paperwork saying kind of your health conditions at the moment.

18:40 And for a lot of insurance plans, it's actually free. So I got mine super quick too. I was in line behind a couple of people also, but mine was super fast. Mine was also free. But then if you're a university student or you work at a university, a lot of times they have flu shot clinics where you can pay a reduced price to get your flu shot or at your local university clinic that they have all the time.

19:03 And they offer the flu shot again for a reduced price without insurance. You don't have to have insurance to be getting your flu shot each year. Number seven, I waited too long. You can still get your flu shot in December or January. It's recommended to get it in October and that's considered the best time, but it's not really at every point too late to get your flu shot.

19:23 Number eight, I don't like shots. There's a nasal spray that you can get if you don't like shots. So you don't have to do the needle route. You can get the nasal spray. So to recap, we talked about back to school crafts and my childhood memory of Roxaboxan and just going back to school in general and along with that Columbus Day.

19:45 So then we talked a little bit about Columbus and how he brought influenza to the new world. So then we talked about influenza in modern society and the flu season, which still bears a large burden, even in the US, but that burden can be lessened by getting your flu shot, which is out now.

20:02 So if you haven't gotten it yet, now's a really, really good time to get your flu shot. Thank you for listening to episode seven, A Boy Named Flu. Show notes, transcripts, citations, and social media links are available on our website at germomics.com. So I know it's flu season, but it's apparently also the holiday season.

20:21 I went to Walmart today and it is Columbus Day. And despite there being, let's see, number one, Columbus Day, two, Halloween, three, Thanksgiving, four, Christmas. So despite there being so many holidays between now and Christmas, there were Christmas decorations up and also Halloween decorations up.

20:42 So there was actually Santa Claus and Christmas trees up next to wicked witches and skeletons. So was it like you were living a real life nightmare before Christmas?