Sunday, February 23, 2020

Disease Post: Brucellosis

This is one of my favorite "bugs!"

Bucellosis is caused by a bacteria from the genus Brucella. There are a few different species that cause disease in animals and humans. For humans, the three species that usually cause disease are suis, abortus, and melitensis.
Brucella colonies on blood agar. Image from Pixnio.

Brucella species are small, anaerobic, gram negative coccobacilli, meaning that they do not require oxygen and do not have peptidoglycan in their cell walls and stain red/pink on a gram stain (bacteria that stain purple are gram positive). Coccobacilli describes the shape--they are between cocci (round) and baccili (rod-shaped).

They are facultative intracellular organisms, which means that they have to be inside another cell for part of their life cycle, but can also live outside of another cell. In the case of Brucella species, the cell they tend to invade is the macrophage. Macrophages are important cells in your immune system. Briefly, they usually "eat" things that are dangerous, like bacteria, and break it up into pieces. Then they take those pieces and display them on the surface of their cells using special cell receptors that will signal other immune cells to look for them. That way, the rest of your immune system can respond to the invaders. Brucella bacteria hiding in these cells, it makes it much more difficult for your body to find and fight off.

How is it spread?
Humans usually get this disease either by being in close contact with an infected animal or by eating contaminated animal products. Namely unpasteurized milk, which is contaminated with the bacteria when an animal is infected (this is why drinking unpasteurized milk is so dangerous). The bacteria can cause infection if inhaled, ingested, or through the skin. Most commonly, it infects via mucous membranes (for example: the eyes, throat, or respiratory tract).

According to the CDC, person-to-person spread is rare, but is most common if a mother is infected, she can infect her breastfeeding infant.

This disease is most worrisome in animals, both wild and agricultural. It is also found world-wide.

The bacteria are not especially hardy, they don't form spores and they can be killed with heat. However, they manage to survive in the environment for several years, if the conditions are right.

The incubation period for this bacteria is about two to four weeks, so there can be quite a delay between getting infected and showing symptoms.

Many of the symptoms are flu-like: fatigue, fever, sweating, headache, body aches, anorexia, nausea, and malaise (generally not feeling well). According to the CDC, some symptoms can be recurring or persist for a longer period of time. Most commonly these symptoms are: recurrent fever, arthritis, swelling of the heart, neurological problems, chronic fatigue, swelling of the male reproductive system (namely the testes and scrotum), and swelling of the spleen and/or liver.

The good news is that brucellosis is rarely fatal in humans, but it is still considered a potential bioweapon because it can be easily spread and incapacitate people.

The chronic symptoms that are so common with this microbe are due to a couple things: incomplete antibiotic treatment, which causes relapses, and persistent infection by the bacteria in tissues (like bone, spleen, liver, et cetera). It can be difficult to get rid of.

Brucella colonies on serum dextrose. Credit: Royal Veterinary College and Wellcome Collection

Prevention and Treatment:
One way to prevent human infection is by pasteurizing milk and other dairy products. Eating under-cooked meat is not recommended as it could be contaminated with Brucella. There is also a vaccine for herd animals to B. abortus.

People who work with animals like cattle, pigs, goats, and sheep should wear protective clothing, like gloves and goggles.

Because the bacteria hides inside cells, antibiotic treatments can last a long time (often 6 weeks) and often more than one antibiotic is needed. Doxycycline with with rifampicin can be used, or doxycycline with gentamicin. Trimethoprim-sulfamethoxazole can be used for women who are pregnant or for young children.

Miscellaneous Information:
What I find super interesting about this bacteria is that it causes abortion (and infertility), which can lead to further infections in animals. It almost plays off of the maternal instinct. For example, if a cow is infected and it causes the cow to have an abortion, the cow may survive. However, the aborted fetus is infectious. Other cows may come into contact with the aborted fetus as they inspect it and then the bacteria can infect the new animal. A bit evil and fascinating.

Brucellosis is known by many other names, including: Malta fever, Mediterranean fever, Cyprus fever, goat fever, Gibralter fever, to name a few.

The Centers for Disease Control: Brucellosis
Microorganisms and Bioterrorism edited by Burt Anderson, Herman Friedman, and Mauro Bendinelli
Emerging Infectious Diseases by Lisa A. Beltz
Medical Microbiology 6th edition by Patrick R. Murray, Ken S. Rosenthal, and Michael A Pfaller

Saturday, February 1, 2020

January 2020 Wrap Up

Well the first month of 2020 is over.

My January had several ups and downs. I've been missing my friends and family back home and probably not dealing with it as well as I normally would because, well, my support system is back in Colorado.

I did attend my first meeting at a local book club at the beginning of the month. It seems like a good group and I managed to meet a couple of ladies who are also scientists. I plan to keep going as long as my work schedule allows. They give a choice of two books each month and are very laid back and nonjudgmental. So you can read one book, or both books, or neither! For January the books were The Paper Magician or Feast Your Eyes. I re-listened to the Paper Magician, but did not read the other one. For the February meeting, the options are the Book Thief (which I re-read) or Red at the Bone, which I tried to get to and didn't. Even though I probably can't go to the February meeting due to tutoring...

This month, Kevin and I went to a museum exhibit all about Jim Henson, which was wonderful. And it was fun to see the puppets and read the stories. Of course, the Labyrinth section was my very favorite. I was so excited to see the ballroom outfits! Here are a few of my favorites from the exhibit:

In other exciting news, Kevin surprised me (late Christmas gift) with a trip to India later this year! I am still working out the details with my work place to make sure that I can work it in since I don't really have that much vacation time. But I was very surprised and I think it will be amazing.

On top of that, he usually works nearly all of the time, which leaves me alone the majority of the time. This doesn't bother me really, since I like alone time, but can be hard because I don't have friends here. So one night a week, he will come home on time and we will have a date night. We put together a bunch of different date ideas so that we won't ever be scrambling for things to do or places to go. We have been doing this for the last few weeks and its been lovely. I am glad that he suggested it.

And now for the books I read in January:

Title: The Autobiography of Santa Claus
Author: Jeff Guinn

Synopsis: This is just what the title implies: the true story of how Santa became the figure we all know and love. From his early days as a local gift-giver to his adventures around the world and his famous helpers.

Thoughts: I liked the history parts and some of the ideas were cute, but I did not love this book. I remember Kevin asked me about it and I said that I liked parts of it, but I hoped it would get better. It wasn't bad, it just didn't knock my socks off. I don't really know how to describe it.

Rating: 2 out of 5 stars

Title: The Paper Magician
Author: Charlie N. Holmberg
Narrator: Amy McFadden

Synopsis: After Ceony finishes her year as a student of magic, she enters her apprenticeship to a paper magician. Her dream was to be a Smelter (magician that enchants metal), but she has been forced into being a Folder against her will. To her surprise, her mentor, Magician Thane, is a young, eccentric, good man and she begins to enjoy Folding. Until a dangerous Excisioner (those who practice illegal magic on people) appears and steals Magician Thane's heart. It is up to Ceony to rescue him.

Thoughts: I read this series several years ago and remember thinking it was OK. I re-read this one for my book club. It isn't great. I think some of the magic system is creative and interesting, but mostly the story seemed contrived or strange. It might go over better with a younger audience.

Rating: 2 1/2 stars out of 5

Title: Red, White, and Royal Blue
Author: Casey McQuiston

Synopsis: First Son of the United States is a well-loved public figure. His mother is the first woman president and her family is incredibly supportive and active in politics. In fact, Alex's dream is to be a great politician on day, much like his mom. However, following a confrontation with his self-proclaimed nemesis, Prince Henry at Henry's brother's wedding, he has to embark on a damage control mission to pretend that he and Henry are actually best friends. This means photo sessions, joint charity work, and spending time together. But as Alex gets to know Henry better, he finds that he actually likes him. And Henry likes him back. Now they have to keep their real relationship a secret. And Alex's mom is up for re-election. What could go wrong?

Thoughts: This book has popped up everywhere, it seems. Everyone was raving about it on Instagram and in a book community I follow on Facebook. So when it came up in a Kindle sale, I just had to try it out. And I thought it was cute! I'm not sure what else to say. I enjoyed it, but I can see why some people wouldn't. It was a nice, easy book to read. Parts were definitely funny and charming. I thought the characters were well-written and I felt satisfied with the ending.

Rating: 4 out of 5 stars

Title: The Glass Magician
Author: Charlie N. Holmberg
Narrator: Amy McFadden

Synopsis: Ceony's apprenticeship continues. She likes being a Folder now and she hopes that her growing feelings for Magician Thane are not one-sided. And things would be easier if she weren't being targeted by a couple of evil Excisioners who are threatening her, her friends, and her family if she will not help them.

Thoughts: I wanted to read this after I finished the Paper Magician because I couldn't properly remember the story lines from several years ago. And it was OK overall, but I kind of couldn't wait for it to be over so that I could read something else. I guess that isn't a glowing review...

Rating: 2 out of 5 stars

Title: Girls of Paper and Fire
Author: Natasha Ngan

Synopsis: Lei lives in a small village in a kingdom that treats its lowest citizens (the paper class who have no demon in them) like dirt. Except for the eight most beautiful girls who are sent to the palace every year to serve the king--the Paper Girls. Lei is snatched from her home and family (as her mother was years before) and taken to the palace as a Paper Girl. She is forced into training with the other selected girls, but then she falls in love with someone who she should not love. And there might be a secret plot to help free papers from the evil grasp of the demons.

Thoughts:  I really liked the premise of this book, but I did not enjoy the book as much as I had hoped. To be honest, I really think I wasn't in the mood for this type of book and that affected my feelings towards it. And I nearly stopped reading right at the beginning because of one scene (no spoilers) that really, really bothered me. I am a little interested to follow the characters and see what happens next, even if I didn't love this one.

Rating: 3 out of 5 stars

Title: The Book Thief
Author: Markus Zusak
Narrator: Allan Corduner

Synopsis: This is the story of a young German girl living in Nazi Germany. On the way to her new foster family, her brother dies and she steals her first book.  As Liesel adjusts to her new life, her foster father shows her great kindness and gentleness. And he teaches her to read. Liesel loves words and so begins her unusual ways of collecting books. And her world changes again when her foster parents take in a Jewish man and hide him in their basement.

Thoughts: This was a re-read for me. I loved it the first time I read it and I loved it this time, too. I'm not sure I even have the words to say how beautiful this book is. The style and narration were unique. And it is interesting to see the world from the point of view of a "normal" German girl. And watch her develop into the Word Shaker. There is so much heart and compassion (and some heartbreak) in this book, I highly recommend it.

Rating: 5 out of 5 stars

Title: Thirteenth Child
Author: Patricia Wrede
Narrator: Amanda Ronconni

Synopsis: Set in an alternative early America, this book follows the journey of a girl named Eff, who is an unlucky thirteenth child (so they say). Her twin brother, however, is the seventh son of a seventh son and blessed with luck and strong magic. Due to her fear of her magic and of being an unlucky thirteenth, the development of her own magical abilities is difficult, but she finds some of her own unique strength in the end.

Thoughts: This is a re-read. I have read this trilogy many times. I just love it. And I love it as an audiobook (I'm not sure I would have liked it as much if I read the actual book). But this trilogy is a comfort read for me and I just felt like re-reading them.

Rating: 4 out of 5 stars

Favorite book read this month: The Book Thief. Or Thirteenth Child.

Least favorite book read this month: The Autobiography of Santa Claus

In other literary news, I decided to try participating in a little reading challenge. It is the alphabet challenge. The goal is to read one book that starts with each letter of the alphabet. "The" does not count for any title, including for T. And for X and Z, there needs to be an X or Z somewhere in the title, even if it isn't the first letter.

So this month, I have covered A, B, G, P, R, and T! And I have read seven books towards my annual goal of 75.

I have part of a new disease post written. It is about one of my favorite diseases! But I have had a difficult time finding any good pictures. I will keep trying.

That's about it for January! I hope everyone else had a good month!

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