So, I'm thinking about catching cholera...

and I begin to wonder why certain pathogens only wreck havoc with certain body systems. Cholera, for instance, is a disease of the gatrointestinal system. Is that only because the method of transmission is by eating or drinking something in which the pathogens are floating around? If you inhaled cholera germs would you get infected and develop “bloody flux” of the lungs?

Syphillis is a bacterial infection that at first is concentrated in the genitourinary organs but, left untreated, can then damage other systems (I recall that Al Capone died of tertiary syphillis that pretty much ate his brain into swiss cheese). This leads me to believe that the answer may depend upon the organism, but I’m wondering if that’s really the case.


But I think the thread title might be putting people off (?)

IANAD, but what I read about cholera is that the bacterium that causes it can only be transmitted through food or water. So you have to ingest it. You can’t inhale it.

If you think you do have cholera, lay off the Rolaids or Tums. Antacids prolong the infection.

You may be right. Moderator, please change the title of the thread to “Pubic Shaving Techniques Illustrated.” I’ll have a million hits inside 5 minutes.

I think it depends on the bug and the bug’s habitat and how it spreads. For instance, tuberculosis is systemic. It usually starts in the lungs, but then spreads to other organs in the body.

A quick net search on cholera says it is only transmitted by food or water, so it is not airborn. The disease causes diarrhea, which leads to dehydration and loss of minerals (salts), which is how it kills. If a person consumes enough liquids and salts they can survive even without antibiotics. Antibiotics lessen the illness time and make it less severe.

I realize you probably aren’t interested so much in cholera itself, but rather the overall process. Some bugs only infect where they get into you, some are systemic, and spread. I don’t know enough about how or why this happens to be more help.

The answer is : it depends on the bug. Some, like the bacterium responsible for black plague, will infect almost any membrane it can penetrate, hence the one organism leads to pneumonic plague, bubonic plague and a whole range of interesting side infections as well.
Syphillis has a very hard time because the bacterium reponsible has an extremely low oxygen tolerance, and so is confined to naturally anearobic areas (ie the genitals and anus). It can infect the central nervous system due to the interesting blood barrier that impedes oxygen flow directly into the CNS. For this organism the lungs are simply not an option.
Cholera is caused by a bacterium that can use oxygen or not as it sees fit. However it needs to reach fairly high levels to cause any noticeable symptoms. If it alighted in the lungs the natural defenses, particularly macrophages, present would destroy it before it could establish. Added to this the lungs aren’t exactly nutrient rich, making it difficult for a colony to establish. In the intestine however there are no immune defenses and a whole bunch of nutrients just sloshing around. This allows the bacteria to multiply to the stage where they can start digesting you from the inside out.
So basically the area of effect of a bacterium depends on its nutrient requirements and ability to cope with the conditions found in any potentail infection site.
Viruses become even more specific, since they are often only capable of binding to the surface protiens on one type of cell, say neurons, and can’t infect any other area of the body.

Cholera’s effects are also confined to the intestine because of the action of its toxin. It’s the toxin that makes you sick, not the bacteria, in cholera’s case. The cholera toxin is an A-B toxin, which means it’s an A protein attached to several (5, IIRC) B proteins. The B proteins attach to the cell surface and get the A protein into the cell. There, the A protein adds ADP-ribose, well, to make a long story short, it causes the cell to pump water and nutrients out of the cell instead of into it, thus causing diarrhea.

I don’t recall offhand whether the receptor for the toxin is known or if it’s confined to instestinal cells, but even if it could infect other cell types, they’d be less able to extrude water, since they’re less able to absorb water. It’s the same machinery - just in reverse.

I’ve seen people with cholera shit 40 Litres of water in a day. Are you sure you don’t want to catch beaver fever instead?

Cholera was just the first example of a pathogen having a very specific effect - if you get cholera YOU KNOW you’re going to have trouble in your guts. I couldn’t really think of other pathogens that so severly effected a specific organ system.

Given my druthers, I die from exhaustion brought on by non-stop hoo-ha (see The Brazillian thread).