Which HAIs Pose the Highest Risk for Special Populations?

Michael Calderwood, MD, MPH, previously assistant hospital epidemiologist and associate director of antimicrobial stewardship at Brigham and Women’s Hospital, discusses healthcare associated infections that special populations, such as those who are immunocompromised, are most susceptible to.

Interview Transcript (slightly modified for readability)

“[For] patients [who acquire] infections in a healthcare [setting], first thing you want to think about is [whether this] is something they brought in from the community. Patients who come in from the community, regardless of [if] they’re immunocompromised or not, are still at highest risk for infections with common pathogens. [So we have to consider] if they have a pneumonia, such as streptococcus pneumoniae, or if they have a urinary tract infection, things like E. coli or other gram negatives.

Once [the patients] are hospitalized, often because of a more prolonged exposure to the healthcare system, they are at risk for certain drug-resistant pathogens that are circulating in the hospital setting. We think about things such as MRSA- and VRE-resistant gram negatives.

In addition to that, these patients are susceptible to bacteria, viruses and fungi, [sometimes] from environmental exposure, [that] the rest of us, due to having an in-tact immune system would be fine coming in contact with, but can cause significant invasive disease when one has an impaired immune system. We have to begin to think about things that might be in the air or in the water. We think about water systems and the risk for Legionella; we [also] think about building construction and the risk for various aerosolized spores.

Then, we think about viral risk. Many times that’s a reactivation that someone may have been exposed to in the past, but now because of an impaired immune system, they are at risk for. But they can also pick up the virus from others they come in contact with in the hospital.”