Virulence

I remember a few years back when H1N1 (the swine flu) hit. Our ED volumes were through the roof. H1N1 affected middle and high school aged kids more than older populations. It was one time that perhaps the elderly were not as affected (perhaps because of years and years of flu shots and being exposed to other viruses.)

I was working with a PICU intensivist who was moonlighting in the ER. These are doctors who work in the Pediatric ICU. He was wicked smart, managed ED volumes well, had an awesome bedside personality and was great with the nursing staff. If you work in healthcare you’d realize these things ALL together in one physician are rare.

H1N1 Influenza Virus

There was becoming a concern about resources. If H1N1 hit as bad as was thought– this is what he said, “There won’t be enough ventilators to take care of everyone.”

That’s not funny.

Have you heard of coronavirus or the one that’s in the news a lot lately: MERS-CoV that’s affecting people near and around Saudi Arabia.

So far there has been 81 confirmed cases and 45 deaths— that’s about a 56% death rate.

That’s high. In medical terms, this would be considered a highly virulent bug. Imagine you’re told you have this virus and you have more than a 50% chance of dying.

MERS-CoV is a member of the coronavirus family. If you remember SARS from a few years back that affected South China and Hong Kong — this is a member of the same family. Consider it a cousin. Death rate from SARS was around 10%.

See what I mean?

Transmission of MERS is from close contact. This generally means you have to be within six feet of someone for prolonged periods of time to contract the bug– like living in the same household or being a medical person caring for a patient.

People present with symptoms of a URI (upper respiratory infection) which would be fever, cough and shortness of breath.

Thus far– there have been no cases in the US.

However, coronaviruses are common but usually not fatal. In fact, the CDC website says most people will be infected at some point in their life. They were first identified in the 1960s.

Interestingly, the SARS virus mentioned above hasn’t been seen since 2004. Where is it hiding? Will it come back?

The coronavirus family is a good example of the gamut viruses can run that are related. From mild infection to death.

Have you heard of the Saudi Arabian MERS virus? Did you know it had such a high death rate?

To read more about MERS: check out this post.

Here is Part I of the series.

There’s nothing like a good pathogen story line for medical thriller authors. It might be considered a mandatory novel requirement if you’re in the genre. Hmm . . . guess I better start developing a virus-run-amok story line.

Great examples would be Robin Cook’s Outbreak and the unrelated movie Outbreak that starred Dustin Hoffman. Recent film examples would be Contagion.

I was talking with a physician co-worker of mine after the movie Contagion was released and she said she’d applied for work at the CDC but they were overwhelmed by applications as a result of the movie. Personally, that movie would have quelled my desire to study virulent pathogens up close and personal but I guess if you like to hang over the edge of the cliff like that go right ahead . . . I’d rather write books.

When picking a pathogen there’re a couple of principles to keep in mind when you choose your microorganism of destruction.

First– what is a pathogen? A pathogen is a microorganism that causes disease. It can be one of four things: bacteria, virus, fungus or prion. Each has a different level of virulence.

Virulence is how deadly a pathogen is. Generally– medical thrillers pick bugs that have high virulence (hence the dramatic part.) This is the concern with the new SARS like virus (MERS-CoV) in Saudi Arabia that has a death rate of 60%. That’s scary. I’ll blog about that later this week.

Next thing to consider is how will the pathogen spread or what is its route of transmission? If you’re talking medical thriller– airborne transmission is generally preferred because of it’s ease and spread of transmission.

Pathogens can be spread person to person through touch (common cold), contaminated blood (HIV, Hepatitis C), saliva (rabies), and air (measles.)

Pathogens can also be spread through food, water, insects and fomites (non-living objects such counter tops).

Another thing to consider is the incubation period which is the time between exposure and development of symptoms and surprisingly they vary widely depending on what agent is involved. For instance, Mad Cow disease could have up to a 30 year incubation period whereas a staph infection can have an incubation period as short as one hour.

Here a list to peruse of different pathogens and some of these principles.