A novel involving (what else!) a dangerous virus or bacterium...

[EventHorizon]

Hello, everyone!

 

First of all, I wish to apologize for stepping into a place where only the medical minds reside. To my relief, though, I’ve noticed that similar events have already occurred on these forums – that is, cases in which a question was asked by a layperson writing a novel with plot points involving viruses or bacteria. That is what I am doing, and I greatly wish to make this plot point seem plausible. I’m not sure if it is possible to mix this particular concept with the rest of the plot to such a point where a biologist would wave it off as actually acceptable… but, hopefully, at least to the point of not having said biologist angrily throw the book across the room.

 

Predictably, the question involves that ever-popular concept in fiction – a dangerous pathogen. Fast, lethal, durable – or, since I’m assuming that nothing of the sort (fortunately) exists, a realistic approximation of the idea.

 

Since the concept is so far very flexible and as distant from being set in stone as can be, I have taken some of the thoughts I’ve had so far, and made them into several questions.

 

- Could a chimera virus, or a chimera bacterium, ever appear naturally, rather than be created artificially? I’m specifically thinking of the viability of having a particularly lethal virus or bacterium that also possesses considerable durability and longevity. (In other words, it would be much like the old “ultimate biological weapon” trope in fiction, except that it would not have been bio-engineered, as the novel needs to take place some 300 years ago… and in a genre where there would be no aliens, time travelers, etc., to conveniently provide sufficiently advanced technology.)

 

- Would you consider the idea of a virus being able to survive dormant for decades as too far-fetched and annoying (especially if it concerned a filovirus)?

 

- In fact, are there viruses or bacteria that could survive for such a lengthy period outside the host (it would be primarily in a permanently hot, humid and dark environment, more or less sealed from the outside)?

 

- Similarly, would you possibly allow for an idea of a natural mutation of a virus / bacterium as an explanation for its extreme longevity, durability, resistance, etc., or would you see it as too cartoonish?

 

- Would you consider the (admittedly often used due to its popular recognition) hemorrhagic fever as the (and hopefully the expression will not be out of place) “pinnacle of fear”, when it comes to the impression it would have on the general, non-scientific population? (Particularly, 300 years ago…) In a nutshell, I’m wondering about a pathogen that would have a devastating psychological effect on laymen witnessing its effects on someone else (in addition to quickly wreaking havoc on them after the exposure, of course) – i.e. it would have a very short incubation period, manifesting itself quickly after the exposure, and it would be terrifyingly destructive. Essentially, something that could be considered more or less realistic, while having the effect of that old cliché of “a man pricks his finger, starts coughing a minute later, and literally falls apart in ten more minutes” on the reader.

 

So… a pathogen that can long stay dormant, yet still infect a character who has been exposed to it. One lethal, but showing its symptoms quickly. Ideally, one that allows for the idea of another character possessing immunity. But is there such a pathogen – or could a fictitious one be justified?

 

[CharonY]

 

 

Could a chimera virus, or a chimera bacterium, ever appear naturally, rather than be created artificially?

 

Depends on what you mean with chimera. Genetic exchange is very common in bacteria and especially viruses (they are essentially mobile genetic elements themselves).

 

 

 

I’m specifically thinking of the viability of having a particularly lethal virus or bacterium that also possesses considerable durability and longevity.

 

This does not require chimeras of any sorts. The problem with viruses is that that are generally nucleic acids packed in proteins. Their advantage is that they do not really live and as such have no requirements such as other organisms in terms of metabolism. On the other hand their simple structure only offers so much protection from environmental influences and they generally degrade fairly quickly in the environment. Bacteria on the other hand can be extremely resilient buggers and in dormant states (e.g. spores) they can survive almost anything.

Though generally bacteria that are adapted to the life within hosts (which include pathogens) tend to be on the soft side, as they are generally not exposed to such extreme conditions.

 

 

 

 

- Would you consider the idea of a virus being able to survive dormant for decades as too far-fetched and annoying (especially if it concerned a filovirus)?

In well conserved tissues decades should be feasible. In soil not so much, for example.

 

 

 

- In fact, are there viruses or bacteria that could survive for such a lengthy period outside the host (it would be primarily in a permanently hot, humid and dark environment, more or less sealed from the outside)?

Bacteria have no issue with that. In fact, you will be hard pressed to find any patch of anything that does not contain bacteria.

Remember, most bacteria are actually not living within hosts. The only exception is probably very arid areas, and even there they may be laying dormant. But then most are not pathogenic (but in a novel they may very well be). Viruses again are a different matter.

 

 

 

- Similarly, would you possibly allow for an idea of a natural mutation of a virus / bacterium as an explanation for its extreme longevity, durability, resistance, etc., or would you see it as too cartoonish?

We call it "adaptation" and again, that is why bacteria are everywhere (and again, viruses are tied to hosts).

 

 

 

 

In a nutshell, I’m wondering about a pathogen that would have a devastating psychological effect on laymen witnessing its effects on someone else (in addition to quickly wreaking havoc on them after the exposure, of course) – i.e. it would have a very short incubation period, manifesting itself quickly after the exposure, and it would be terrifyingly destructive.

It is not very likely for something like that to happen. Damage by viruses is generally caused because they hijack host cells to multiply, which takes some time and only after a number of cycles do they start creating symptoms (i.e. incubation periods is within days). Also note that many early symptoms such as fever are not so much caused due to damages by pathogens per se, but it is a reaction of our immune system to them. Think of allergies as an analogy.

 

 

To make it more complicated many pathogenic bacteria are not pathogenic all the time, only when multiple parameters, which may include cell density, immune deficiencies and lesions come together do they suddenly become harmful.

 

Think of the plague. The bacterium responsible is Yersinia pestis, the causative agent for the plague. Would it surprise you that you can find them in many soil samples? However they are present in such low amounts that they cannot really infect any hosts. It is simply not very competitive compared to other soil bacteria (usually only very sensitive methods allow their detection in the first place). Only when a lot of things come together do they successfully infect potential hosts.

 

So to summarize, persistence for bacteria is not an issue (viruses are a totally different matter). However those well-adapted to hosts tend to be a bit on the weak side outside (but nothing that some artistic freedom cannot tweak). Quick symptoms are the really odd things. A few cells simply cannot wreak havoc on much larger organisms in such a short time (otherwise we would have much more trouble). However considering that symptoms are what our immune system does to ourselves one can go down that route. Poor misunderstood bacterium triggers immune system to such extent that it kills off the body it is supposed to protect.

 

 

Also note that pathogens are not dangerous because they are persistent per se but rather when we a) do not have a suitable immune response to them and b) medications do not work.

Edited July 9, 2013 by CharonY

[EventHorizon]

Thank you! This is quite helpful indeed - I'm most grateful! If I may, I will keep lurking on the forum for a while, to read up and educate myself further.