• Question: If a human gets rabies, why are they afraid of water?

    Asked by sent1vac to Zoe V, Martin M, Erin P, Christie, Alberto G on 7 Mar 2024.
    • Photo: Zoe Vance

      Zoe Vance answered on 7 Mar 2024:

      I don’t work on rabies so had to go and investigate this a bit! But it seems like it’s less a fear of water and more a fear of swallowing liquids. The virus causes very painful spasms (muscle contractions) in the throat if you swallow, so someone who is infected and showing symptoms may seem panicked if presented with something to drink because of the pain. This makes sense from the point of view of the virus because it spreads in saliva from bites etc. – if an infected animal is swallowing their saliva then the viruses aren’t getting to where they want to go!

    • Photo: Erin Pallott

      Erin Pallott answered on 8 Mar 2024:

      Thanks for sending in the question after our chat! Rabies is a very interesting and scary disease, with near 100% fatality once symptoms start. We have effective treatments and vaccinations to use before symptoms.

      Rabies virus spreads from the bite wound to your central nervous system which includes your brain. As it progresses, the virus is also found in the salivary glands and around the mouth, which is the “exit” and the route it can be passed on (through bites). This leads to excess saliva and painful spasms in the jaw and neck muscles. On top of this, there are other symptoms which include paranoia, hallucinations and aggression. Together, it explains how patients show irrational fear and panic responses when presented with water.

      In summary, it’s a combination of the pain that will come from swallowing and the neurological (brain) symptoms.

    • Photo: Martin McCoustra

      Martin McCoustra answered on 8 Mar 2024:

      Interestingly rabies was sometimes called hydrophobia as a result of the fear of water. I believe that people suffering from rabies are hydrophobic as one of the symptoms of the disease is pain in the muscles that makes swallowing water hard.

    • Photo: Alberto Granero

      Alberto Granero answered on 13 Mar 2024: last edited 13 Mar 2024 1:15 pm

      The term hydrophobia literally means “fear of water”. In reality, animals or people affected with rabbis suffer of inflammation in the mouth (as explained by Erin!), which makes drinking difficult and painful. Before this was known/understood (centuries ago) it looked like animals would not want to drink, hence the term “fear of water” was coined.

    • Photo: Christie Waddington

      Christie Waddington answered on 15 Mar 2024:

      The guys have pretty much answered this below – if you want the technical wording, hydrophobia occurs following paroxysmal contractions of the pharynx.

      What’s interesting about rabies is that we have treatment if rabies is caught early on but once it’s moved to the brain, it’s very very difficult to cure as the virus is protected against the blood-brain barrier (layer between the brain and blood vessels in your head).