vaccine - curious question

[IslandTractor]

The tetanus organism (Clostridium tetani) does not really cause a recognizable infection at the site of innoculation. It does not behave like a typical staph infection. Despite relatively little or no evidence of infection, the organism releases a toxin that causes the symptoms of the clinical illness "Tetanus". All the symptoms relate to muscle as the toxin blocks normal nerve function by binding to critical sites on the nerve-muscle connection. That gives you "lock jaw" and other severe muscular spasms. As Soundguy pointed out, it is rarely fatal in the US because we can support patients through the 2-3 week illness and it is self limited. Worldwide tetanus is a different story and it accounts for quite a large number of deaths. Neonatal tetanus occurs when infants of unimmunized mothers are infected, usually due to non sterile cutting of the umbilical cord (or the bizarre practice of packing the new umbilical cord in cow dung ). Infants have muscular spasms that prevent them from breathing and they often die, especially in parts of the world without neonatal intensive care (which happens to be the same parts of the world where mother's do not receive tetanus immunization unfortunately).

I don't know anything about boosting of antibody except with repeat vaccination (booster shots). I kinda doubt injuring yourself with the proverbial rusty nail does much for boosting though in theory it could if the rusty nail had tetanus spores on it. Not a recommended practice however.

Any penetrating injury (as opposed to bug bite, scrape, cut etc) where there is contamination of soil introduced deep enough into your tissue to form an anaerobic environment could result in a tetanus infection as the organism is actually quite common. The type of injury (punture usually, not an open cut) and luck (presence of the organism) as well as absence of immunity are what combine to give you tetanus. If you have had a tetanus shot within 5 years you are set. 10 years is the normal interval but just to be sure docs will give you a booster if you are more than 5 years from your last shot if you have the type of injury that increases risk.

 

[Soundguy]

I've got a ? technical / theory question for you. For '1st world'.. or otherwise medically modern countries, It seems likely that prudent 'typical' treatment of a dirty puncture wound may actually be a two-fold attack vs tetanus.

For instance. patient steps on the proverbial rusty nail. Goes to doctor, gets wound cleaned if not already, and then almost definately gets a tetanus shot, and probably an antibiotic.

Seems like tetanus shot prevents the problems with the toxins... so that angle is covered, even if a tetanus infection did / was to occur.

Now, on the flip side, it seems like the antibiotics that were prescribed, to prevent / control ? staph? infection, might also limit or prevent the initial tetanus infection.. ( or many other bacterial infections.. etc. ).

Seems like that is a two fold treatment.. and probbaly why it works so well. Am I on the right track.. or off down the wrong path here on this one.

Soundguy

 

[IslandTractor]

Good thoughts but I don't think there is evidence that the antibiotic is important. There are at least two issues with these tetanus infections that are important reasons why routine care doesn't help much. First is that the puncture wound does tissue damage and tissue damage means there is not good blood flow to the damaged area which in turn sets up an anerobic environment which is what the tetanus spores need to grow. A damaged area with poor or no blood flow (even just a small area) does not get good antibiotic levels as antibiotics ultimately are delivered by blood flow to the site of infection. Also, as the tetanus infection is not the typical pus and inflammation producing type of infection, the body inflammatory mechansims that increase blood flow and therefore antibiotic delivery to infected areas does not function. The tetanus organsim is pretty easy to kill with penicillin and many other antibiotics but as prophylactic antibiotics are usually only given for a short course the infection can start up after the antibiotics stop too.

The other reason that the doctor's visit doesn't help too much (other than vaccine booster) is that with a puncture wound it is very hard (impossible) to actually clean out the wound. By definition the injury is deep and there is usually only a small (perhaps already sealed over) entrance wound so it is very difficult to clean it out. That is also why animal bites are such a problem. Lacerations (cuts) are much easier to clean properly and are also less likely to set up an anaerobic environment so that type of cut is less likely to result in tetanus. This is probably where the "rusty nail" business got started because a rusty nail (or any nail contaminated with dirt) is likely to cause a puncture wound.

Not to get off topic but Bird's injury with a puncture wound through a sneaker is a classic example of a different special type of infection (which he dodged): pseudomonas osteomyelitis. In this case an organism that is actually not a very effective pathogen in healthy individuals (pseudomonas aeruginosa) is innoculated by the puncture into the boney part of the foot. Again the tissue damage and innoculation allows the organism to slowly grow causing osteomyelitis. The classic story is of a young boy running who steps on a nail while wearing grungy old sneakers (anything moist and warm will evenually have some psuedomonas in it). The nail goes through the sneaker sole, picks up the pseudomonas from the foam innersole and is then innoculated into the foot. Classically, if the injury is appropriately managed (with or without antibiotics) and the kid initially gets better, then will start limping about 3-4 weeks later. The organism cannot be treated with antibiotics alone usually and oddly, once surgery is done to debride (remove dead tissue) then antibiotics are probably not even necessary for recovery (but we use them anyway).

 

[SkyPup]

Many years ago at our Veterinary Animal Disease Diagnostic Laboratory, we once had Doyle Conner, the Department of Agriculture Commissioner, come to our lab with a dozen dead Charolais steers. He wanted to know what killed all of them?

Upon necropsy, all flesh and organs appeared fine, except for a little necrosis at the site of their recent castrations. However, I took 10 milliliters of blood out of the heart of one, spun down the serum, and make a serial dilution out to 1:10,000,000.

Later than morning, I took 0.1 milliliters of the diluted 1:1,000,000 and 1:10,000,000 serum and injected same subcutaneously into a couple of white mice.

Within the four hours, all the mice were dragging their rear ends and within 6 hours, all the mice were moribund, at the end of the day they were all dead.

Upon questioning the Agriculture Commissioner about the castration of his steers, he pulled out his pocket knife and stated that he had personally castrated all the Charolais himself with the knife.

I asked him if he disinfected the knife between castrations.

"Nope, my father and my grandfather never did that, and neither do I."

"Whelp," I said, "then you can take full responsibility for the destruction of your $75,000 worth of cattle here, your entire calf crop, since they all died of Tetanus toxemia!"


Diagnosis was later confirmed by Fluorescent Antibody agains Clostridia tetani in the scrotal histopath sections.

Each cow had enough toxin in it to kill over 1,000,000 people.......

 

[AndyMA]

I don't recall where I heard this but here goes...
If you get cut once in a while by rusty metal or get dirt in the cut then you are getting "vaccinated" by being exposed to the rather common bacteria that caused tetanus.
So, no booster shot needed in this case and no worry of getting harmed.
Anyone heard this before?

No and I wouldn't count on it. Seems like an old wives tale. I wouldn't want to be exposed to 10 pieces of metal with no tenanus on it and then the one which "locks my jaws"

Andy

 

[rback33]

I ams ure Bird will be disappointed to hear that there is no sign of infection in my leg. No pus oozing out or any reason to amputate. dang the luck...

 

[Bird]

I ams ure Bird will be disappointed to hear that there is no sign of infection in my leg. No pus oozing out or any reason to amputate. dang the luck...

That's OK; one good laugh per customer's enough.