Skip to main content

Massachusetts Medical Society's Physician Focus

December 2016


The Threat of Infection


  • “Superbugs” are microbes - germs, bacteria, fungi, parasites - that become resistant to the medications intended to kill them.
  • While most microbes are harmless and some are even beneficial, some cause disease.
  • All types of microbes have the ability to develop resistance to the drugs created to destroy them.
  • The single biggest factor leading to antibiotic resistance is the use of antibiotics.

Recent years have seen the rise of “superbugs” – germs, bacteria, or parasites that become resistant to the medications intended to kill them. Each year in the United States, two million people become infected with drug-resistant bacteria and some 23,000 people die as a result.

“The parasites, bacteria, and viruses that infect us exist in large numbers and reproduce quickly,” says Alfred DeMaria Jr., M.D., “and they have genes for resistance that exist naturally.”

“What’s changed with superbugs is the exposure of the organisms that actually cause infection in people to antibiotics,” DeMaria says.

He explains that the microorganisms that are exposed to these drugs select for the resistance organisms within the population of organisms. While some are killed, others survive, and the next time around, those that survive become even more resistant.

Dr. DeMaria, the Medical Director and State Epidemiologist of the Bureau of Infectious Disease and Laboratory Sciences for the Massachusetts Department of Public Health, appears on the December edition of Physician Focus to discuss the rise of “superbugs,” how serious a threat they are, what public health officials are doing to combat them, and what patients can do to protect themselves. Hosting this edition is primary care physician Bruce Karlin, M.D.

According to the U.S. Centers for Disease Control, the biggest factor leading to antimicrobial resistance is the use of antibiotics. These drugs are among the most frequently prescribed in medicine, but are prescribed inappropriately almost half the time and are often prescribed when not needed. In addition, they are used in animals that produce food to promote growth.

“The goal,” says Dr. DeMaria, “is to use antibiotics appropriately, in appropriate dosages, for the appropriate duration of treatment.”

Dr. DeMaria says that using low levels of antibiotics is what leads to resistant organisms.

If a patient with an infection takes the full dosage that’s prescribed, very few of the organisms are going to survive.

“But if you forget to take your pills,” he says, “or only take half your dose, or only take it for half the time, you have low levels of antibiotics, so whatever bacteria are around are going to have a better chance of escaping that low dose. And that brings bacteria that are more resistant than the original bacteria, and that can happen over and over again.”

“Superbugs” have been around for decades, Dr. DeMaria notes, but were confined to hospitals for the most part, because patients would stay in the hospital until their infections were under control.

Now, he says, people are leaving the hospital sooner, or going to rehabilitation centers or to long-term care facilities, so the infections that were once confined behind the walls of the hospital are now spreading into the community.

As a result, Dr. DeMaria says, we’re now seeing “superbugs” that are “really opportunistic infectious agents,” appearing where we would have never seen them before.

Antibiotic use in the community is also driving “superbugs,” he adds, because if people don’t take the full dose of the drugs for the full duration they are allowing resistance to increase.

What about the development of new drugs to fight the superbugs?

“Over time,” says Dr. DeMaria, “no matter how many new antibiotics we’re going to get, organisms are still going to become resistant. That’s why we have to be smart about how we use antibiotics. Antibiotics are great when used appropriately, but can have bad effects when used inappropriately.”

Watch the video above, for more conversation, including what public health officials are doing to combat the superbugs and what prescribers and patients can do to reduce the spread of these diseases.

MMS/Richard Gulla

Massachusetts Department of Public Health

Centers for Disease Control

National Institute of Health

World Health Organization

Antimicrobial Resistance (WHO)

Left to right; Bruce Karlin, M.D. (l), Alfred DeMaria Jr., M.D.
hi-res photo
promo slide