Drug-resistant TB

[Almo]

http://www.bbc.co.uk/news/health-16592199

This is kind of scary:

Doctors in Mumbai said 12 patients had a "totally drug resistant" form of the infection, and three have died.

The doctors at the Hinduja National Hospital in Mumbai who discovered it said they had treated patients for up to two years with a battery of drugs, to no avail.

On an evolutionary scale, we've had a relatively small amount of time to enjoy the ascendancy of our drugs against such diseases. Maybe our unique ability to evolve our technology without waiting for the slow (due to our longer life cycles) procession of genes will keep us ahead of the relative speed of bacterial evolution.

But I'm not really counting on it at this point.

 

[Acleron]

Patients who do not finish their lengthy course of treatment also present the bacterium with the perfect environment for developing further resistance.

It was only time.

 

[joesixpack]

Patients who do not finish their lengthy course of treatment also present the bacterium with the perfect environment for developing further resistance.

It's always alarmed me how doctors still fail to stress this. And it's also alarming how few people understand it. I remember learning this in health class in 7th grade.

Cuts to education can have serious consequences, I guess.

 

[Acleron]

It's always alarmed me how doctors still fail to stress this. And it's also alarming how few people understand it. I remember learning this in health class in 7th grade.

Cuts to education can have serious consequences, I guess.

AFAIR the symptoms recede long before the bugs are completely eliminated. The patient feels better so they stop taking the medicine. In some countries, cost may also factor in.

 

[Dymanic]

As far as this particular strain of TB is concerned, well, TB really isn't all that contagious. If you feel the need to dedicate some anxiety units to fretting about the possibly of catching a potentially fatal airborne disease, I'd go with influenza.

Your central point, however, is well taken: Heavy reliance on the use of certain drugs to control pathogens is ultimately doomed to fail unless we can (or maybe it's better to say "because we can't") continue to develop new ones as fast as the pathogens can develop resistance. (This also applies to the pesticides and herbicides we use on our crops, by the way). True, sloppy use of antibiotics contributes to the problem, but sooner or later the pathogens are going to aquire resistance anyway.

We have a high regard for our knowledge and our technology, but the most sophisticated biological engineering on the planet always has been that which takes place inside the cells of microbes. I think it was Stephen Jay Gould who said something to the effect that while we talk about "The Age of the Dinosaurs" and "The Age of Man" and all that, what this really is is the Age of Bacteria. Always has been; always will be.

Sometimes all you can do is take life one day at a time.

 

[bookworm]

It's always alarmed me how doctors still fail to stress this. And it's also alarming how few people understand it. I remember learning this in health class in 7th grade.

Cuts to education can have serious consequences, I guess.

You are right on with this! I can remember doctors always saying "Finish all of this medicine even if you feel better!" But they never said why. That leads people to ignore the instruction because they think the only thing at risk is that they'll get a little sick again. So what. They really need to tell people in no uncertain terms that they must finish the medicine because if they don't the bacteria will strengthen! People often need an explanation for why they are doing what they're doing.

 

[Travis]

AFAIR the symptoms recede long before the bugs are completely eliminated. The patient feels better so they stop taking the medicine. In some countries, cost may also factor in.

But this is why I always took my antibiotics for as long as prescribed for regardless of how good I thought I felt.

 

[Skeptic Ginger]

We're back to TB sanatoriums for this pathogen. Not good.

Drug-resistant TB patients set to be isolated in Maharashtra

MUMBAI: The state government has decided to shift patients with totally drug-resistant tuberculosis (TDR-TB) to a sanatorium in Jaysingpur near Maharashtra's Sangli. A central team of TB experts will assess the patients on Monday before they leave the city.

The move taints India's glorious public health moment: a year without a single polio case. State doctors were busy on Saturday working out quarantine plans to contain one of the worst health disasters-the emergence of totally drug resistant tuberculosis (TDR-TB) in Mumbai.

MDR TB
XDR TB
and now
TDR TB

It was inevitable.

 

[Skeptic Ginger]

As far as this particular strain of TB is concerned, well, TB really isn't all that contagious. If you feel the need to dedicate some anxiety units to fretting about the possibly of catching a potentially fatal airborne disease, I'd go with influenza.

Your central point, however, is well taken: Heavy reliance on the use of certain drugs to control pathogens is ultimately doomed to fail unless we can (or maybe it's better to say "because we can't") continue to develop new ones as fast as the pathogens can develop resistance. (This also applies to the pesticides and herbicides we use on our crops, by the way). True, sloppy use of antibiotics contributes to the problem, but sooner or later the pathogens are going to aquire resistance anyway.

We have a high regard for our knowledge and our technology, but the most sophisticated biological engineering on the planet always has been that which takes place inside the cells of microbes. I think it was Stephen Jay Gould who said something to the effect that while we talk about "The Age of the Dinosaurs" and "The Age of Man" and all that, what this really is is the Age of Bacteria. Always has been; always will be.

Sometimes all you can do is take life one day at a time.

Depends on how you look at risk. TB is in control in wealthy countries because we have significant public health infrastructure to deal with it. But it is expensive. Recently in this county our PHD put up people in an apartment complex to provide DOT (direct observed therapy) for transients and homeless with active TB. This is at the same time the PHD has closed all its vaccine clinics and severely cut the budget for things like preventing people with inactive TB from developing active TB.

And there are not many new drugs to treat TB in the pipeline. The cat's out of the bag. It travels by air. it can spread from a coughing high school student to class mates. It can spread in ED waiting rooms if a coughing patient is not properly triaged. And it spreads in jails where even innocent people are occasionally incarcerated.

 

[Almo]

As far as this particular strain of TB is concerned, well, TB really isn't all that contagious. If you feel the need to dedicate some anxiety units to fretting about the possibly of catching a potentially fatal airborne disease, I'd go with influenza.

My real concern is more that just TB; I worry about contagious disease in general. Though you're right to point out that influenza is far more contagious.

But I don't fret on a minute-to-minute basis. I'm not phobic really. It just seems that as a genetically-homogeneous planet-spanning species, we should think about this a bit more as a group.

 

[AlBell]

You are right on with this! I can remember doctors always saying "Finish all of this medicine even if you feel better!" But they never said why. That leads people to ignore the instruction because they think the only thing at risk is that they'll get a little sick again. So what. They really need to tell people in no uncertain terms that they must finish the medicine because if they don't the bacteria will strengthen! People often need an explanation for why they are doing what they're doing.

Even then strong oral antibiotics too often have unfortunate digestive-tract side-effects so people don't want to continue taking them especially if they are feeling better otherwise.

 

[joesixpack]

...

Your central point, however, is well taken: Heavy reliance on the use of certain drugs to control pathogens is ultimately doomed to fail unless we can (or maybe it's better to say "because we can't") continue to develop new ones as fast as the pathogens can develop resistance. ...

Pathogens wouldn't be able to mutate into drug resistant strains if patients took the entire course of their antibiotics. This is not the result of a heavy reliance on certain drugs, it is the result of the drugs not being used as prescribed, or worse, prescribed where not necessary.

 

[rjh01]

I wonder what would happen if all drug manufacturers stopped producing antibiotics for a year or two? I suggest that the drug resistant bacteria would be at a disadvantage and at the end of the year there would be less of it. However many people will die during that year.

 

[Skeptic Ginger]

I wonder what would happen if all drug manufacturers stopped producing antibiotics for a year or two? I suggest that the drug resistant bacteria would be at a disadvantage and at the end of the year there would be less of it. However many people will die during that year.

I don't follow your logic. Care to explain?

 

[Skeptic Ginger]

Pathogens wouldn't be able to mutate into drug resistant strains if patients took the entire course of their antibiotics. This is not the result of a heavy reliance on certain drugs, it is the result of the drugs not being used as prescribed, or worse, prescribed where not necessary.

While the two things you mention contribute to the development of drug resistance, I believe it leaves out the reality of evolution. Unfortunately for we humans. evolution results in drug resistance despite the misuse of antibiotics. Our misuse merely makes the inevitable occur more readily, but evolution would create drug resistant strains even if the use of antibiotics was perfectly orchestrated.

 

[rjh01]

I don't follow your logic. Care to explain?

I always thought that drug resistant bacteria were weaker than similar non drug resistant bacteria. So remove the drug and the non drug resistant bacteria would take over. Or am I wrong?

 

[joesixpack]

While the two things you mention contribute to the development of drug resistance, I believe it leaves out the reality of evolution. Unfortunately for we humans. evolution results in drug resistance despite the misuse of antibiotics. Our misuse merely makes the inevitable occur more readily, but evolution would create drug resistant strains even if the use of antibiotics was perfectly orchestrated.

Yes, but you have to admit that evolution wouldn't be fast enough to matter without the two factors I mentioned.

 

[Dymanic]

Depends on how you look at risk.

Sure. I mean, it might be tempting to try to separate perceived risk from actual risk, but it's not always possible to do that, because the way one looks at risk tends to influence behavior, and the actual degree of risk often depends a lot on how one behaves. For a person who smokes a lot and never exercises and has poor dietary habits and spends a lot of time driving (especially while drinking, texting, or talking on the phone), worrying about drug-resistant TB should probably rank somewhere alongside worrying about being hit by falling meteors.

TB is in control in wealthy countries because we have significant public health infrastructure to deal with it.

Well, it's more than that. TB is associated with crowding, malnutrition, poor quality housing, high HIV rates -- in other words, with poverty in general.

 

[Dymanic]

Pathogens wouldn't be able to mutate into drug resistant strains if patients took the entire course of their antibiotics.

Yes, they would. Devising new ways of out-flanking their competitors is what these microbes do. They were honing their technology by practicing on each other long before we came along and learned how to exploit the process, and have already demonstrated a clear ability to defeat our comparatively crude and amateuristic efforts to thwart them.

This is not the result of a heavy reliance on certain drugs, it is the result of the drugs not being used as prescribed, or worse, prescribed where not necessary.

No. Those practices certainly do speed the process along, but it would happen anyway.

Yes, but you have to admit that evolution wouldn't be fast enough to matter without the two factors I mentioned.

SG doesn't have to admit that, and I doubt if you could get her to do so if you put a gun to her head. I wouldn't admit it either. The shorter generation times and greater mutation rates alone insure that these microbes will evolve exponentially faster than, say, vertebrates -- and that's without even getting into horizontal gene transfer.

 

[Skeptic Ginger]

Yes, but you have to admit that evolution wouldn't be fast enough to matter without the two factors I mentioned.

Yes they would. Did you know that some organisms which are not the target of the antibiotic develop drug resistance then the genes are shared with pathogens?

Were you aware that some bacteria have a mechanism by which when exposed to a toxin like an antibiotic they shut down their genetic repair mechanisms thereby allowing more rapid mutation rates?

Did you know some target organisms are shed in a viable condition before the person has completed the course of antibiotics?

There are many more natural factors involved in the development of drug resistance. I'm not saying misuse and overuse of antibiotics doesn't quicken the development of resistance, clearly it does. But so do natural evolutionary mechanisms all on their own.