Bacteria That Killed Nevada Patient Resisted All Antimicrobial Drugs Currently Available

The Centers for Disease Control and Prevention (CDC) have confirmed that the death of a Nevada woman that occurred this past September was due to Klebsiella pneumoniae, a carbapenem-resistant Enterobacteriaceae (CRE) that resisted a total of 26 different antimicrobial drugs — all that are currently available for use on this type of infection in the United States. Due to the patient’s recent return from India and previous hospitalization in that country, the Washoe County Health District acute care hospital placed her in a single room under “contact precautions,” meaning that healthcare workers were instructed to wear personal protective equipment while in the room with the patient and that the hospital took particular care with either sterilizing or disposing of medical instruments and devices as well as frequently cleaning and disinfecting the room itself. After the patient was hospitalized, the CDC tested an isolate collected from a wound specimen and confirmed that she had been infected by a pan-resistant bacterium, New Delhi metallo-beta-lactamose (NDM).

The patient had recently returned to the United States after an extended visit to India, where she had been hospitalized repeatedly for a right femur fracture and subsequent complications related to that injury and its treatment. She had been hospitalized in India as recently as June 2016. When she was admitted to acute care in Reno, Nevada, in August 2016, she was given a primary diagnosis of systemic inflammatory response syndrome. She developed septic shock and died in early September 2016 after failing to respond to 26 different antibiotic regimens, including all aminoglycosides and polymyxins. The infection was “intermediately resistant to tigecycline,” the CDC noted. Although CDC testing indicated that the isolate had relatively low fosfomycin MIC of 16 μg/mL, the patient did not receive this treatment as it is only approved in oral form to treat uncomplicated cystitis in the United States. In other countries, it can be administered intravenously.

Most people have some levels of Enterobacteriaceae in their gastrointestinal tracts, and these organisms are among the most common human pathogens. They can cause a number of health problems, including urinary tract infections, septicemia, pneumonia, and other infections ranging from relatively minor to very severe. These bacteria can be spread hand-to-hand as well as through consumption of contaminated food and water. Researchers speculate that these bacteria are developing antibiotic resistance not only due to high exposures to antibiotic medications, but also possibly from exposure to disinfectant products.

According to the CDC, there have been more than 250 CRE isolate reports collected as part of the Emerging Infections Program (EIP). About 80% of those collected were susceptible to at least one aminoglycoside and nearly 90% were susceptible to tigecycline. “When [CRE] are identified, facilities should ensure that appropriate infection control contact precautions are instituted to prevent transmission and that healthcare contacts are evaluated for evidence of transmission,” a CDC spokesperson said.

Given that the patient in this case had inpatient healthcare exposure in India before receiving care in the United States, the CDC also recommends “healthcare facilities... obtain a history of healthcare exposures outside their region upon admission and consider screening for CRE when patients report recent exposure outside the United States or in regions of the United States known to have a higher incidence of CRE.”