PT5.S3.Q20 - a certain viral infection

extramedium

I think I understand why B is right, since middle ear infections are not defined as being bacterial infections in the stimulus. Probably just assumed this on my first read, which led me to pick A or D. I can't remember. I've drilled this question at least twice.

Answers C and E are easily disqualified. However, A and B all seem to provide about the same level of explanation as each other.

D is wrong, I suppose, because, again, ear infections are not defined as bacterial infections in the stimulus. To me, A provides just as much support as B though. They're both similarly vague and do not really do much to explain the discrepancy.

Why is B right?

BenjaminSF

Here is the takeaway for me from the stim: The author never says that the virus itself is what causes the middle ear infections, just that children develop middle ear infections. Since the antibiotics, which aren't effective on virii, clear up the infection often, we can conclude that the cause of the middle ear infection must be caused by something other than the virus directly.

(A) Irrelevant to the stimulus. We are not talking about different antibiotics. The stimulus implies that all antibiotics are equally ineffective against the virus and that all antibiotics clear up the middle ear infection.

(B) Bingo. If the virus means that they are more susceptible to another cause of the infection, this leaves room for explaining why antibiotics treat it.

C,D,E all are way off mark for me, and they don't even feel relevant.

I can see why (D) could be an attractive answer choice, but it only makes sense in the context of answer (B). Nowhere in the stimulus are bacterial infections noted. This is simply a statement that one can take at face value, but it does nothing to actually resolve the conflict until you explain the relationship between the infection and bacteria.

extramedium

@BenjaminSF I was thinking the middle ear infection was more like a side effect, and just because the side effect is cured with antibiotics, it doesn't mean the virus will be cured as well. How did you determine that there must be an alternate cause here?

BenjaminSF

When I think of the word side-effect, I think it relates more to unintended effects of an action.

In this case, the susceptibility to middle ear infections is correlated with the virus, but the author never says "the virus causes middle ear infections". This is the key piece of information that is missing from the stimulus. Since we know that antibiotics clear up the infection, and we know that antibiotics aren't an effective treatment for viral infection, we can assume that there must be a different cause for the infection. If the virus were the sole cause of the middle ear infection, antibiotics would never clear it up, according to the information provided by the author.

Hope this helps!

extramedium

So is this a cause and effect question? I'm not sure how to conclude that the virus is not the direct cause. Doesn't seem to be explicitly stated anywhere. If that was stated, it would make the answer much more reasonable. I understand how that could work. It's not the virus causing the infection. It's the virus creating susceptible conditions for the infection. Even then, it still seems like the virus is an indirect cause. This is a tricky question.

BinghamtonDave

Benjamin already answered this very well but I thought I would add my own understanding:

This is a resolve question. I like to try to get explicitly clear on what the tension really is in these questions. I have memorized the following framework that I have found helpful:

If_______, then how is it that_______? Our answer choice will allow the perceived tension to be alleviated. For this question we have:

If a portion of children who get this virus also end up with an ear infection, then how is it that antibiotics-which are only effective against bacteria- clears up their ear infection?

The perceived tension here is: how can an antibiotic cure something a child got when they had a virus? With (B), this tension goes away: children who get the virus happen to be susceptible to a bacteria, that susceptibility leads a portion of them to get an ear infection and the antibiotic kills that bacteria.

I hope this helps
David

extramedium

Hey @BinghamtonDave

Thanks for your response. I've been thinking about this question for a couple days now weirdly.

Like Benjamin said, that the middle ear infection could be a bacterial infection is never explicitly mentioned in the stimulus. I'm just thinking if the antibiotics did not work on the virus, but the middle ear infections are named as bacteria-related as they are in answer B, and antibiotics work on bacterial infections, then that would resolve the discrepancy.

If antibiotics do not work on viruses but do work on bacterial infections, then how is it that antibiotics did not clear up the virus, but cleared up the middle ear infection? Because the middle ear infection is bacterial. Unfortunately the answer isn't as clear.

Does that make sense? It's actually quite similar to your explanation I think.