Posted by Larry Hoover on December 7, 2003, at 19:13:41
In reply to Lar...the parasitologist's dilemma, what say you, posted by stjames on December 7, 2003, at 16:19:47
> My dear friend Val, who is a molecular microbiologist, helped form many of my concepts.
> MMB is where it all happens, it defines biological life. the parasitologist's dilemma is that all emergent conditions like AIDS, Ebola, ect have actually always been here (we have samples of AIDS from 1950-60's) but it is more likly to be made ill
> by the common things. As we cure the common things
> we "flush out" the uncommon. The fact that we a moving into areas that were uninhabited has something to do with this, also. So the invention
> of antibiotics and vaccines has caused, decades later, many uncommon and deadly pathogens to emerge.
>
> However, clearly no one wants polio or septcisis
> from a simple cut. The choice of antibiotics and vaccines is clear. Now we are at the point that we have but one antibiotic between as and all the deadly pathogens. The major deadly pathogens have done a good job sharing their DNA and are resistant to all but
> one antibiotic, vancomycin. Increasing reliance on vancomycin has led to the emergence of vancomycin-resistant enterococci (VRE). By 1993, however, more than 10 percent of hospital-acquired enterococci infections reported to the CDC were resistant to vancomycin. From the discovery of
> antibiotics to this and the last decade we did little to discover new antib's.
>
> So, what say you ? Does toxicology have a dilemma
> such as this ? The parasitologist might say it was always a loosing battle and we just bought time.
> Pathogens are so far ahead of our science; do you see a way out ?I differ from you in one key aspect of your analysis....I think that exposure to pathogens is the key variable....before human culture was so closely linked (there are few real physical gaps between populations any more, and with modern transportation methods, particularly air travel), disease outbreaks were very limited affairs. If e.g. Ebola had come out of the jungle in the past, a tribe might have simply disappeared, but no one else would have been impacted, if they even came to know of the loss. Today, we live in fear that Ebola might be carried to a populated area via e.g. airplane before the infection has been identified. The result would be an epidemic, if not a pandemic.
Then you add in a new variable that comes solely from the high density of creatures in confined areas, cities with agricultural regions nearby, and you get a whole new environmental niche for viral and bacterial hybridizations.... Consider the influenza virus. There are strains that infect ducks. There are strains that infect pigs. The duck strains don't make the ducks too sick. Ditto for the pigs. But, if the duck and pig viruses exchange genetic material (these little beggars are true, err, sluts), novel influenza viruses emerge....ones which can jump to humans (so-called zoonoses), and we get human epidemics. Where are ducks and pigs and people all crammed together? China. I'm not being racist...it's like an influenza orgy going on. It's no coincidence that most influenza strains have oriental names.
That's just one example. Your vancomycin resistance example is another....transfer of plasmids between non-related species of bacteria. A totally uncontrollable phenomenon. Where do we find all sorts of bacteria and all sorts of sick and vulnerable people....in hospitals. You probably could not design better places to breed antibiotic resistance if you tried.
The real opportunities will come from vaccines, IMHO. The net effect of vaccination is to reduce the pool of people who can become infected. If that number drops below a critical threshold, epidemics cannot occur. We got smallpox (virtually) eradicated, and we didn't have to innoculate everyone to do it. We just innoculated enough of the right people....
The other thing, of course, is to find novel antibiotic compounds. I don't think it's a fools game....it's all we've got. However, merely ensuring adequate hand-washing by hospital staff would substantially reduce the unacceptable rate of hospital-acquired infections (about 1 in 7 patients right now).
As TJ says, there's a lot more going on than we realize, vis a vis immune responses to parasites and chronic infections. For example, there is a Pacific island (Tonga?, I'm not sure), where public sanitation initiatives and treatments for parasites eradicated what had been chronic infestations by various worms....and suddenly, whereas there had been zero incidence of allergies and asthma, the islanders took on typical Western prevalence rates of about 1 in 5 with those disorders....so, artificially introducing parasites to asthma sufferers may effect a cure....we evolved with the flukes and worms, and maybe we don't do well without them.
I can ramble on for days.....
Lar
poster:Larry Hoover
thread:287474
URL: http://www.dr-bob.org/babble/alter/20031204/msgs/287518.html