Think again about infections
Antibiotics are losing the battle with harmful bacteria
Thursday, October 27, 2005
Or is it?
Since they hit the market about 50 years ago, we have relied on antibiotics to take care of bacterial infections. Yet, as soon as we began using antibiotics, the stage was set for bacteria to find ways to evade them.
Drug-resistant bacteria, sometimes called superbugs, are now a major health care challenge that is likely to get worse in the coming decades. Infections now considered routine may become serious health threats. And children are among the highest risk groups for resistant staph infections.
This is frightening new territory for parents. The threat of drug-resistant infections requires extra vigilance from parents and a concerted effort from society as a whole. But as with any problem, you have to understand it before you can do anything about it.
Bacteria fight back
While resistance is a natural survival mechanism, it is also now considered a major public health threat. According to the Centers for Disease Control and Prevention, "Nearly all significant bacterial infections in the world are becoming resistant to the most commonly prescribed antibiotic treatments."
At the American Society for Microbiology meeting last June, the World Health Organization General Assembly named antimicrobial resistance one of the top three global health threats. According to the World Health Organization, "Most alarming of all are diseases where resistance is developing for virtually all current available drugs, thus raising the specter of a post-antibiotic era."
The first and most famous antibacterial drug, penicillin, provides a good example of bacteria’s drug resistance. Penicillin damages the cell wall of certain kinds of bacteria. When exposed to penicillin, the bacteria either adapt or die.
At first they died. But later they adapted. A genetic mutation in one cell allowed it to produce a substance called penicillinase, which destroys penicillin. This one cell spread the useful new gene to its progeny and to nearby bacteria in a process that allows cells to quickly develop resistance to a single drug.
Bacterial infections once easily cured by penicillin now require different antibiotics. For example, methicillin was the first semi-synthetic penicillin designed to kill bacteria that were no longer harmed by penicillin. But as scientists devise new antibacterial drugs, bacteria find new ways to evade them.
At this point, most resistant strains are still treatable, but only with powerful antibiotics. So, someone infected with a resistant strain of bacteria not only faces the consequences of a prolonged illness, hospitalization and a greater risk of death but also drugs that are more expensive and more toxic than first-line treatments, according to Kathleen Mullane, an infectious disease specialist at the University of Chicago.
People at highest risk for catching drug-resistant infections are hospital patients or those with weakened immune systems, such as people with HIV. Hospital-acquired infections have been a problem for decades. But now an alarming number of cases are transmitted from one person to another in the community—affecting otherwise healthy people, Mullane says. Resistant staph infections are a good example and a serious problem in kids.
Staphlococcus aureus, sometimes called "staph," is usually harmless and found on the skin or in the noses of about a third of all people. But it can cause infections, ranging from minor pimples to potentially life-threatening skin or bloodstream infections.
Staph that resists methicilllin is common in hospitals, according to the Alliance for the Prudent Use of Antibiotics, a Boston-based nonprofit organization.
But "a newer form of [this staph] is now circulating in the community," says Dr. Maskit Bar-Meir, a specialist in infectious disease at Children’s Memorial Hospital. "We see these infections in healthy children."
About 12 percent of all drug-resistant staph victims are people who have not been hospitalized recently or undergone an invasive medical procedure. About 20 percent of those cases are serious enough to require hospitalization, according to the alliance.
These infections "are not necessarily more severe than typical staph infections, but they can be more challenging to treat," Bar-Meir says.
This superbug is usually spread through close skin-to-skin contact, contact with cuts or contact with contaminated items. This puts children and athletes at higher risk.
One drug—intravenous vancomycin—still is successful in treating this superbug, but perhaps not for long. The CDC first reported vancomycin-resistant strains of staph in 2002.
The best ways to prevent infection are:
• Wash hands regularly with soap and water or an alcohol-based gel.
• Keep scrapes and cuts covered and clean.
• Avoiding contact with other people’s wounds and bandages.
• Don’t share towels.
• Wipe sports and exercise equipment clean when one person is done.
The culprit: antibiotic overuse
Scientists accept that overuse and misuse of antibiotics is creating these superbugs at least partly because of their use in agriculture.
In North America and Europe, about half of antibiotics are given to healthy cattle and poultry to increase growth or prevent future infection, according to the World Health Organization. As a result, the animals—and the bacteria they carry—are regularly exposed to antibiotics even when they aren’t sick.
When humans or animals ingest antibiotics, 80 to 90 percent is not broken down during digestion; it passes through the body and eventually finds it way to soil and water, which means resistant genes can develop in the bacteria found in the ground and water.
In fact, the U.S. Department of Health and Human Services, the National Institutes of Health, the U.S. Food and Drug Administration, the CDC and other government agencies formed a task force in 1999 to address the problem. Two years later, the groups issued an action plan setting guidelines for antibiotic use, urging public education about the misuse of antibiotics, stressing the need for regulating antibiotic use in agriculture and for developing new drugs to combat resistant strains.
On the horizon
Even with public health organizations on high alert and making plans, the problem is likely to get worse before it gets better.
People who believe in the healing power of antibiotics want them—regardless of the implications of overuse, the World Health Organization notes in its report.
In addition, the report says, pharmaceutical companies are not moving quickly to develop new superdrugs to take on the superbugs.
Mullane says: "Antibiotics have such a short market life that pharmaceutical manufacturers are not developing them. … It is too expensive for the drug companies to develop a drug that has a finite use due to mutations in the bacteria."
The World Health Organization report says, "Even if the pharmaceutical industry were to step up efforts to develop new replacement drugs immediately, current trends suggest that some diseases will have no effective therapies in 10 years."
The good news, according to Mullane, is that where antibiotics are failing, vaccines may succeed. The Haemophilus type b (Hib) conjugate vaccine, for example, has essentially wiped out the potentially fatal infections that cause one-third to one-half of all cases of bacterial meningitis in children under age 5 and up to one-quarter of all cases of severe pneumonia in young children. A full complement—three doses—of the vaccine reduces the risk of Hib disease in young children by more than 90 percent.
"We are hoping to get the same result with the pneumococcal vaccine," which protects children from about 80 percent of the types of viruses that can cause meningitis, bloodstream infection, pneumonia and middle ear infections, Mullane says. A vaccine for drug-resistant staph is being tested and may someday be used to prevent resistant infections—that is, until that bacteria fights back too.
Parents can combat resistance
Misuse and overuse of antibiotics is recognized as the primary driver of bacterial resistance. Parents can combat the problem in these ways:
• Use antibiotics responsibly. Use antibiotics for bacterial infections only and use them exactly as directed by the doctor. (Colds, the flu, runny noses, most coughs and most sore throats are from viruses; antibiotics won’t help.) Don’t keep unused antibiotics. Don’t take antibiotics prescribed for someone else.
• Prevention is key. Wash your hands regularly with soap and water and practice safe food handling.
• Be vigilant about infections. If a bacterial infection worsens or does not improve after about three doses of an antibiotic, return to the doctor immediately. Says Dr. Maskit Bar-Meir of Children’s Memorial Hospital, "If the trend is not toward improvement within 48 hours, see the doctor. This has always been true, but it is especially true with more resistant bacteria in the community." Culture any skin infections that are draining to check if the bacteria is a resistant strain.
• Buy meats raised without antibiotics. Make a statement that you oppose unnecessary antibiotic use.
Antibacterial soap is controversial
Hundreds of products, including soaps, detergents, sponges, kitchen utensils, toys and even fabrics claim they are antibacterial. Translation? These products contain long-acting residues—such as triclosan, triclocarban and benzalkonium—that kill bacteria.
But you don’t need these residues. Cleaning products with alcohol, chlorine and peroxides have been used for years. They rapidly kill germs, then quickly disappear through evaporation or by chemical breakdown. So, they are not believed to promote bacterial resistance.
The Alliance for the Prudent Use of Antibiotics says:
• When you use residue-producing antibacterials, you risk creating resistant bacteria.
• Even low-level concentrations with long-term use can promote the development of resistant bacteria.
• They attack bacteria indiscriminately and, in the process, disrupt the body’s normal bacteria that act as barriers against invading disease-causing bacteria, potentially creating an opening for those pathogens.
• Cleaner is not always better. Some scientists—and this is controversial—have shown overly hygienic homes may prevent the normal development of a young child’s immune system and may be linked to the appearance of allergies later in life.
Tracy Binius is the mom of two boys and a writer living in Oak Park.