why does rabies cause the so-called “hydrophobia” and how does the virus benefit from this symptom?

Question

I vaguely remember something about this, like it’s somehow a way for the virus to defend itself. But that’s it. Thanks in advance!

In: Biology

Answer 1

I don’t think it is to benefit the virus, I think it is just a side effect of the virus.

Rabies infects the nervous system, which is why it is so deadly. Part of that is it can cause twitching and muscle spasms. Including muscle spasms in the throat, especially when swallowing.

This means that ingrained fear of choking expands to a fear of water, because attempting to drink water will cause muscle spasms in the throat, leading to choking. Doing that a few times and now the victim will want nothing to do with water for fear of choking again.

Now, one possible benefit to the virus is that rabies is often spread through the saliva, through bites. And if the victim is afraid to ever swallow, guess what happens to all that saliva? It builds up in the mouth and the victim starts to drool, meaning a whole bunch of rabies is sat there ready to be spread.

Answer 2

The virus ‘benefits’ because rabies reproduces in salivary glands and is transmitted via saliva, and if less saliva gets swallowed then more is available to transmit the virus.

Answer 3

I read that it’s beneficial to the virus because it keeps high viral load in saliva. This helps the virus get transmitted to a new host since it’s a fatal disease.