Biology and human behavior have converged to create a dangerous condition within hospitals — health-care-associated infections.
The phrases we read and hear — “flesh-eating bacteria,” “super-bugs,” “multi-antibiotic-resistant bacteria” and “MRSA” — are frightening. Unlike some problems that seem distant in beautiful Stowe, Vt., this one concerns every human being who might ever be hospitalized.
Understanding the components of this problem will help demystify the terminology and, ideally, decrease our sense of vulnerability regarding these types of infections.
What are these organisms? How did they become so powerful? What can we do to stay safe in and out of hospitals? Is this problem worsening or improving?
These are some of the issues I will address in this monthly column.
Survival is a competitive endeavor for any organism, large or small. From single-cell bacteria to multi-system mammals, food and space are finite resources that are fought over. Darwin summarized the outcome of this struggle: “Survival of the fittest.”
In a hospital, humans with illnesses or injuries are competing with bacteria, viruses and fungi. The human strives to leave the hospital in better health than when admitted. The bacteria on and in our bodies are trying to survive their encounter with human medical intervention.
An increasing number of people in the world have immune systems that are at a disadvantage, or compromised, in fighting infections. This includes those of us who are very old, very young, on chemotherapy, have HIV, are born with a compromised immune system, have a transplanted organ, or are treated for a variety of conditions with certain kinds of medications.
This can also include people who are simply sick or have had surgery — the reasons we are admitted to a hospital.
Immuno-compromised individuals either inherit or acquire this problem. For example, inheriting a single mutant gene can predispose people to severe infections. Most immune-compromised conditions, however, are acquired.
In 2006, the World Health Organization estimated that 39.5 million people were living with human immunodeficiency virus, HIV. This virus targets immune system cells that are needed to fight infections caused by fungi and parasites.
In addition to people with HIV, many others have immune systems which, either temporarily or permanently, are impaired. For example, pregnant women are slightly immuno-compromised by necessity. The fetus is a foreign body and would be rejected by a robust maternal immune system.
Organs such as kidneys, hearts, livers and lungs transplanted from genetically non-identical people are recognized as foreign bodies. The recipients of these transplants take medication to prevent their immune systems from attacking and destroying the donor organs.
People on chemotherapy for cancer treatment are often immuno-suppressed because chemotherapy kills rapidly growing cells while sparing the slower-growing normal cells. Our immune cells are often multiplying rapidly, especially when fighting an infection, making them targets for chemotherapy medications.
Some people have autoimmune disorders, where their immune system mixes up their own cells with foreign ones and mounts an attack. These autoimmune disorders are frequently treated with drugs to suppress the attack and minimize the damage; however, this suppression also decreases the person’s ability to fight true foreign objects such as bacteria and viruses.
Bacteria and antibiotics
Where did the first antibiotics come from? From microorganisms themselves! One type of bacteria or fungus produces a substance to kill other microorganisms, resulting in less competition for nutrients — chemical warfare at the single-cell scale.
The first widely used antibiotic, penicillin, is a toxin derived from the penicillium mold. Alexander Fleming observed in 1939 that a mold contaminating his laboratory dish of bacteria actually killed the bacteria. Thus, one of the first antibiotics was harnessed and later produced in large quantities for patient use.
A human taking antibiotics creates a war zone for bacteria. In addition to competition for nutrients, these microorganisms are bombarded with toxic chemicals aimed to eradicate them. In this hostile milieu, there might be a survivor — a single mutant bacterial cell unaffected by the toxin, which replicates to produce exact copies of itself. For example, penicillin (naturally occurring at first) inhibits bacterial cell wall repair. Bacteria that produced an enzyme that inactivated the penicillin soon became prevalent.
Next, humans added a chemical to paralyze the bacterial enzyme, then bacteria using a different repair process evolved. So the battle continued.
The speed of bacterial mutation, which enables their survival despite antibiotic treatment, has exceeded the speed at which humans can invent new types of antibiotics. In 1967, the surgeon general of the U.S. declared, “We have won the war on bacteria with the development of synthetic antibiotics.” Have we, or has our “solution” worsened the problem exponentially?
The bacterial phenomena of mutating and reproducing, despite the presence of toxins (antibiotics), is the process called antibiotic resistance. The growth of resistance microorganisms has since proceeded extremely rapidly.
Four years after drug companies began mass-producing penicillin in 1943, microbes that could resist the drug became evident. This resistance has increased a thousand-fold in the last 20 years in the U.S., from 0.02 percent in 1987 to more than 20 percent in 2004. From 1974 to 2004, the prevalence of methicillin-resistant staphylococcus aureus (MRSA) climbed from 2 percent to more than 50 percent in many U.S. hospitals.
Pharmacologists specializing in infectious disease have determined that a single dose of antibiotics leads to a greater risk of resistant organisms to that antibiotic in the person for up to a year. Are these bacterial dynamics of fighting for survival any different from human endeavors to preserve whatever is important to each of us?
Putting it all together
Hospitals in the United States are dangerous places to be, according to the Journal of the American Medical Association. More than twice as many people die every year from health-care-associated infections as in car accidents — 80,000 deaths compared to 34,000.
Divided by the number of admissions, one of every 370 people admitted to a hospital dies due to preventable medical errors. That is equivalent to approximately one 747 crashing every day for 200 days per year in the U.S.
As human beings and potential patients, we need to be aware of the competitive biological forces in hospitals so that we and our loved ones don’t undergo needless suffering.
Each of us has the ability to speak up if we notice behavior in the hospital or doctor’s office that seems unsafe or unclean. The time for hoping that someone else will take responsibility for adequate hygiene practices in health-care facilities has passed.
Next month, I will write about some of the forces in health care that make disclosure of medical errors and complications very difficult for the caregivers.