- Colorized transmission electron micrograph of the Middle East respiratory syndrome coronavirus (Credit: NIAID via Flickr used under CC license)
In 2002 the first cases of a strange new flu-like illness began appearing in southern China. As case numbers mounted well into 2003, it became clear that this was not the flu. Patients began dying as their lungs filled with fluid and stopped functioning. Researchers rushed to determine what kind of virus was causing this disease before it could spread past hope of containment.
After the hard work of many dedicated individuals, it was determined that this new lethal virus was in fact a coronavirus (later named Sever Acute Respratory Syndrom virus, or SARS-CoV). This was odd, as this kind of virus was not known to cause serious disease in humans before this point. By comparing this new virus to older samples, it was determined that this virus was originally living in bats before jumping to civets, and then finally humans. Thankfully, due to this varied zoonotic background (which means to come from animals), SARS did not have the best person-to-person transmissibility during the early parts of the outbreak and was eventually contained once health care officials new what to look for and quarantine. Once the numbers were tallied it was determined that SARS infected over 8000 people, killing over 700 of the most unfortunate individuals. This would not be the last time a coronaviruses would make a dramatic jump into human hosts. In 2012 we were tested on what we learned during the first SARS outbreak in 2002. Continue reading
For this installment of book club I am happy to introduce The Coming Plague: Newly Emerging Diseases in a World out of Balance by Laurie Garret.
Written in 1994, this is an impressively well researched work on the current microbiological topics of the time. While this book is almost 20 years old, I was very impressed by how many of our current problems in health care were covered in these 620 pages and how well the content has held up to the passage of time.
What is even more impressive is how the author narrates the stories, giving a more human side to the factual recounting of disease outbreaks that most of us in the microbiology community are familiar with.
This book is arranged so that each chapter covers a specific disease or theme. Notable chapters on exotic pathogens include those on Bolivian Hemorrhagic fever, the Ebola virus, Lassa fever, the Legionnaires’ disease outbreak in 1976, and the Hantavirus outbreak in the 4 corners region of the United States. These are all fascinating chapters as many of the people who were present for these events were interviewed and there is a real sense of the fear and confusion that accompanies the outbreak of unknown diseases.
These chapters also show “disease cowboys” in action during these outbreaks, scrambling to find out the causative agent or vector for these diseases. As someone who has just learned how to work in a Biosafety level 3 lab I can only imagine the difficulty involved in doing any kind or research in the field, let alone in with diseases that are known to be highly lethal.
The author does an excellent job of showing how environmental, social, and political factors drive the emergence of disease in human population. No other chapter covers this intersection quite as well as well as her work on the early years of the HIV epidemic. With 30 years separating me from this period in time it is easy to not think about how we got to where we are today with HIV; during my life it has always been here. It was eye-opening to see just how badly the epidemic was handled by politicians of the day or how distinguished scientists could fight so readily over discoveries relating to this new viral plague.
Overall, I highly recommend this book to anyone looking for a more in-depth and extremely well written take on the challenges we face against the invisible armies of microbes that continually surround us.
Poster from before the 1979 eradication of smallpox, promoting vaccination. (Photo credit: Wikipedia)
Why is it that members of the public health community are worried about falling vaccination rates in the US when getting vaccinated is treated as a largely personal choice? Do our personal health decisions for ourselves and our children have an impact on the health of society as a whole?
The answer to this is that yes, our individual decisions do matter to society when it comes to combating the spread of contagious disease.
A large part of this is herd or community immunity; the way in which mass immunity in a population can control the spread of disease among individuals. Herd immunity is a major reason behind why so many deadly diseases have all but disappeared from American society; our vaccination rates protect many of those who are unvaccinated from contagious diseases. However, this is beginning to change in the US and we are beginning to see outbreaks of diseases that have not been of major clinical concern for decades.
Read on to find out more on how herd immunity and how it protects vulnerable members of society. Continue reading
Zombies are after your brains! (Photo credit: Scott Beale)
Maybe it’s the Halloween spirit and all the zombies I’ve been seeing everywhere, but this week I can’t help but write about two very different kinds of microbes that infect the brain. I’ve already covered a virus that causes encephalitis and meningitis, and many bacteria can cause septic meningitis. However, the two organisms in the news this week that are causing fatal brain infections are neither a virus or bacteria, and much less common. The first is Naegleria fowleri, a warm-water dwelling amoeba; the second is Exserohilum rostratum, a nearly ubiquitous fungus found in the soil and on plants. These organisms normally live in very different environments but both have the unusual ability to infect the brain under very specific circumstances with fatal outcomes.
Click through to read more about these miniature brain-invaders and how they got into human brains in the first place. Continue reading
Syphilis is a bacterial disease caused by the spirochete Treponema palladium. While this may be something that most of us have (thankfully!) never encountered there have been multiple reports of this disease in the news and a recent resurgence in infection rates around the globe.
During the month of July and August there was a moratorium in the California pornography community due to an outbreak of syphilis that began with one infected performer1 who forged his most recent test results after it returned positive. This actor then went back to work after treatment but while he was still highly contagious; subsequently infecting nine individuals2. Since this outbreak was discovered all involved persons have been treated and the further spread of this disease has been prevented. However, this outbreak this raises two significant questions about syphilis and what it means to be infected:
- What exactly is syphilis?
- Why is the appearance of syphilis so significant that it required the shutdown of an entire industry?
Read on to find these answers and more…
Deer mouse, Peromyscus maniculatus. Vector for Sin Nombre virus (Photo credit: Wikipedia)
So far in the month of September there have been eight confirmed cases of hantavirus pulmonary syndrome (HPS) and three confirmed deaths due to infections with Sin Nombre virus, a hantavirus contracted at Yosemite national park. Up to 30,000 other people were exposed to this potentially fatal disease, yet before this very few people had heard of Sin Nombre or hantaviruses in general. (Editor’s Note: 230,000 more people who visited Yosemite national park were notified of the virus on September 13th, 2012).
Relatively little is known about this rare disease, but we do know enough about the basic virology and ecology of this virus to take effective steps towards prevention.
Read on to find out more about Sin Nombre virus and what we can do to protect ourselves from infection.