Monday, June 14, 2010
Superbug by Maryn McKenna
The case studies in this book are frightening and might be especially so for those who have had staphylococcus infections like boils, strange forms of cellulitis which only responded IV antibiotics or have spent abnormal amounts of time recovering from surgery for unknown reasons. Such was the rising sense of panic in my breast as I read along, it took me several days to get through the first chapter of this book. As the story of each new case of anti-biotic resistant staph infection ( Methicillin-Resistant Staphylococcus Aureus- MRSA) unfolded , along with a recognition of how things might have been, I had to put the book aside and reach for something a little less personal and discomforting. Never-the-less, by my indomitable will always to learn something no matter horrible the subject, I prevailed and completed the book.
We are all colonized by various types and strains of staphylococcus bacteria. In fact, such is the evolutionary adaptability of this bacteria, it is safe to say that most of us are even colonized by antibiotic resistant types and strains of it, even if we'd never used an antibiotic or been near a hospital. We have it but it has not yet made us ill.
Bacteria have an array of strategies for evolving- surviving - altering their DNA. Everybody thinks of mutation but this is a random process and slow; the genetic equivalent of waiting for all the cherries to line up in a slot machine. Bacteria have faster strategies. They can trade entire DNA segments by opening their membranes to each other ( conjugation). They can receive them via phages, viruses that infect bacteria ( transduction) or they can pick up, from their environments, free DNA released by other bacteria that have died or broken open (transformation). Thus, so far, they have been able to defeat every counter-measure modern science in its infinite wisdom has thrown against them. They can do it so quickly that during the last twenty years big Pharma has cut back its investment to discover new types and strains of antibiotics. Since each new anti-biotic is overcome by resistant bacteria in short order, their applicability rapidly deteriorates, along with the profits to be gained from selling them. Drugs like Viagra or any number of pain-killers and anti-depressants are far more marketable.
At this stage there is no point in going off the deep end. Many anti-biotics still work against many of the common strains of staphylococcus, even against most MRSA, albeit in higher doses and longer courses of treatment. And medicine doesn't quit just because the “wonder” of antibiotics has worn off. It has its surgical interventions which, though it may be costly and mutilating, used along with various life-support systems, buys time and the chance for numerous combinations of antibiotics and the miracle of the body's own mysterious healing powers to work their magic. Gradually, over the years, Medicine has also developed some useful preventive strategies, however much the fragmentation, lack of communication and the dumb persistence of old habits in American medical practice has made this so difficult.
One preventive strategy has been an attempt to get doctors to quit prescribing antibiotics for conditions that cannot be cured by them, like most of the earaches and sore-throats of children, which are usually viral in nature. Doctors are also advised to curtail prescribing powerful, broadly acting antibiotics when weaker, more narrowly focused ones might do just as well. This slows down staph's ability to mutate, transduce and transform their resistance. The monitoring of initial campaigns to this effect showed some effects- doctors prescribed less- but progress was hard to maintain. Many doctors tend to give their patients what they expect and , furthermore, conservative treatments which require follow-ups tend to be time consuming and costly. Quantifying results in terms of fewer MRSA infections is also difficult in the short term.
Three are three basic types of MRSA: those that are generated in hospitals, those that are generated in the community and those associated with animal husbandry, especially pigs, but also horses and chickens. MRSA appeared first in hospitals, in their most destructive strains, since that was where antibiotics were used most extensively ( the more they are used the more rapidly the bacteria evolve). MRSA then began to appear, principally in populations of poor people, among prisoners and in schools and athletic facilities. The deadly, virtually untreatable “Superbug” of the title of this book is “a cross" between the in-hospital and in-community strains of MRSA. Although there is clear evidence that some MRSA-like strains jump from factory farmed animals to human beings, gathering a sufficient amount to overcome the objections of that powerful interest has been difficult.
Some of the most effective measures for preventing the spread of MRSA in hospitals, besides identifying and keeping an accurate, published record of their presence- not at all a universal practice- is pre-screening and isolation. Many patients and medical personnel arrive at the hospital colonized by MRSA though it may not be effecting their health in the least. It is actually possible to de-colonize these patients with short courses of anti-biotic treatment and re-colonize them with more benign forms of staph which thus replace beleaguered MRSA. Patients with MRSA can also be isolated by various procedures to keep them from infecting other patients and staff. Thorough and routine sterilization of hospital rooms, equipment and supplies is vital. Imposing rigorous standards of hand-washing among nurses, staff and physicians is an extremely effective preventive measure but, as experience has shown, often very difficult and costly to impose consistently, either in terms of overcoming habits, normal patterns of inattention in all human behavior and labor-hours consumed. Although it does not de-colonize its patients, the biggest single endorser of screening and isolation is the Veterans Health Administration, the most socialized health care system in the U.S.A.. Its record of success is similar to some systems in Scandinavia.
Dangerous outbreaks of MRSA have occurred in association with contact sports. Although organizations like the NFL have the means to take very effective countermeasures- using anti-bacterial surfaces in their locker-rooms, super-heating their laundry, restricting the sharing of equipment, spraying and pre-screening, most public schools lack this ability. It is amazing the extent to which kids these days do not use the shower facilities in their schools athletic facilities, how poorly maintained these facilities and regular bathrooms are, often lacking even soap or sanitary towels. However, in some districts, where prior victims MRSA or their surviving relatives have become active, improvements have been made.
Poor neighborhoods , nursing homes and prisons remain among the most intractable environments for transmission of MRSA. These populations are often composed of individuals whose health is already comprised, are crowded together and have very little access to any ( or the best sorts of ) health care. For some this might actually be an encouraging situation since they are healthy, are not crowded together and have access to health care. Therefore, it would seem, they are much less likely to contract a MRSA infection. Frankly, these facts ( along with the fact that I am assiduous hand-washer) helped to calm the fear I experienced when I first started to read the case studies in this book. But ( I now proceed entirely in the author's own words)...
For a very long time, no one wondered what the effect might be of so many prisoners picking up MRSA in jail and carrying with them when they are released. In 2006, though, a group of epidemiologists at the University of Maryland became interested in a vast increase in MRSA in the main jail in Baltimore and wondered what its impact on the surrounding city might be. They used a measure called “epidemiological weight,” a calculation that assesses how much risk an outbreak in a self-contained group poses to its larger setting, based on how many people join the group, become infected without receiving treatment, and exit the group, as well as how fast or slowly that churning happens. Because hospitals have hundreds of patients staying for weeks, while jails have thousands of people staying for years, the researchers assumed that hospitals would feed the larger epidemic, while prison outbreaks would harm only those inside. Their calculations revealed that assumption to be wrong.
MRSA in correctional facilities affects a wider segment of the population than prisoners, and reaches neighborhoods far beyond the ones where the former prisoners lived. About 750,000 people go in and go out of correctional institutions in the United States every day. They are administrators, guards, cleaners, and cooks, and they have enough close contact with prisoners to be vulnerable to their infections, as well. Jails and prisons are “superspreaders”, seeding MRSA into society at large. Of course reforming health care in our jails and prisons is not a high priority, and often a matter of lengthy and contentious lawsuits.
Superbug; The Fatal Menace of MRSA by Maryn McKenna; Free Press, 2010