CRE Infection (Carbapenem-Resistant Enterobacteriaceae Infection)

The signs and symptoms of a CRE infection depend upon the organs infected.

• Enterobacteriaceae is a family of bacteria.
• There are a number of bacteria in this family, including some that commonly cause infections in humans (Salmonella, Escherichia coli, Yersinia pestis, Klebsiella, Shigella, Proteus, Enterobacter, Serratia, and Citrobacter).
• While a number of these bacteria exist in the gut (called enteric bacteria) of humans, not all of these bacteria live in the bowels. Also, these bacteria can infect many different organs, including the lungs and urinary tract.

Carbapenem antibiotics are broad-spectrum antibiotics that treat serious infections that are commonly resistant to many other antibiotics. Commonly used carbapenem antibiotics include imipenem (Primaxin), meropenem (Merrem, Meronem), ertapenem (Invanz), and doripenem (Doribax).

Carbapenem-resistant Enterobacteriaceae (CRE) infection is a condition in which the Enterobacteriaceae bacteria produce enzymes that break down carbapenem antibiotics and make them ineffective against the infection.

CRE infections usually do not occur in healthy individuals. They are more common in people living in nursing homes and in recently hospitalized people. These people have immune systems that weakened by other infections and illnesses. Many times, these people are on other antibiotics prior to developing the resistant infection with CRE. CRE infections also occur more commonly in those on ventilators or who have urinary bladder or intravenous catheters.

CRE infections are contagious and can spread from person to person. Transmission can occur when health care workers fail to wash their hands or use appropriate gowns and gloves when caring for patients infected with CRE. Not only can the patient transmit the infection, but the bacteria may also live on beds, blood pressure cuffs, and thermometers. There have also been cases of infections spread by improperly disinfected endoscopes (used to do colonoscopies).

Risk factors for CRE infection include admission from a long-term care facility (nursing home), use of antibiotics (especially fluoroquinolones and cephalosporins), undergoing an invasive procedure with a scope (laparoscope or endoscope), and prior hospitalization. Although there are concerns of pregnant nurses being exposed to patients with CRE infection, there are no studies showing increased risk of acquiring CRE while pregnant.

The signs and symptoms of CRE infections vary depending on which organs are infected. Many patients will have a fever and signs of overwhelming infection (sepsis). When sepsis is present, symptoms can include low blood pressure, rapid heart rate, and fast respirations. Those with infections in their lungs may have cough or respiratory failure. Abdominal pain may be present in the cause of abdominal infections.

There is no defined incubation period for CRE infections. However, almost one-third of those affected are still colonized (have the bacteria in their body without signs of infection) one year after being treated for CRE.

To diagnose the type of infection that a patient has, medical professionals will order blood, urine, and sputum cultures. If bacteria grow from these cultures, then the laboratory does sensitivity testing. Based on this sensitivity testing, the laboratory can tell if the bacteria are sensitive or resistant to certain antibiotics. If the bacteria are resistant to carbapenem antibiotics, they are CRE.

When a patient is infected, there are very limited options for treatment. No single therapy has been shown to be universally effective. Most physicians try a combination of multiple antibiotics. The exact treatment will be determined by the hospital based on local resistance patterns.

According to the United States Centers for Disease Control and Prevention (CDC), about half of patients who have an infection with CRE will die despite all therapy.

Prevention of CRE is the key. Hospitals need to make sure that patients who are infected or even colonized (have the bacteria in their body but not causing an infection) with CRE are placed in isolation. Standard precautions to prevent hospital-acquired infections, like CRE, include hand washing, use of personal protective equipment, safe infection practices, and safe handling of contaminated equipment. Hospitals must do a better job at making all hospital personnel wash their hands before and after caring for all patients. Environmental cleaning between patients is critical. Some hospitals may not adequately disinfect rooms after a patient is discharged, which puts the next patient at risk of an infection. Hospitals also need to limit the use of antibiotics (antibiotic stewardship), especially the use of fluoroquinolones and cephalosporins.