Drug-Resistant Klebsiella Spread Silently in an Arizona Nursing Facility’s Ventilator Unit

Carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CP-CRE) are multidrug-resistant bacteria usually found in people who have had health care. Invasive infections kill about half of patients — and only 31%–63% of people who carry them without symptoms are found through clinical cultures, so silent carriers can spread them.

The cluster

On August 2, 2018, the Maricopa County (Arizona) Department of Public Health identified two isolates of carbapenemase-producing Klebsiella pneumoniae (KPC-KP), from urine collected on July 17 and 23 from two residents of a ventilator-capable unit in a skilled nursing facility.

• Both had urinary catheters and urinary tract infections, lived in neighboring rooms and depended on staff for daily care; one was on a ventilator.
• The Antibiotic Resistance Laboratory Network's Mountain Region lab in Austin, Texas, found the two isolates indistinguishable by pulsed-field gel electrophoresis (PFGE) — pointing to spread within the facility.

The facility had 192 beds, 48 (25%) in the ventilator unit, and an average stay of 14 days.

Screening

Residents who had spent 3 or more days in the unit alongside either patient were offered rectal-swab screening on August 13:

Five (19%) of those screened, with no symptoms, carried KPC-KP — and three of them had the same strain as the first two patients.

What investigators saw

On September 6, county and Arizona Department of Health Services staff visited the facility and saw missed hand hygiene before and after touching residents and lapses in sterile technique during routine procedures. They recommended:

• housing residents with CP-CRE together, in the same ward or room when possible;
• contact precautions with room restriction for infected residents who are ventilated, have tracheostomies or have uncontained body fluids;
• alcohol-based hand sanitizer before and after every contact, with more dispensers;
• training staff on common sterile procedures.

Did it work?

On November 5, 28 eligible residents who had never tested positive were identified for rescreening; 9 declined and 19 agreed. All 19 tested negative. Both original patients were treated with antibiotics and survived; one later showed signs of ongoing urinary colonization.

Takeaway

Finding three additional carriers of the same strain confirmed health care–associated spread. Following CDC guidance — housing infected residents together, better hand hygiene, gowns and gloves for residents on ventilators or with tracheostomies, and contact precautions for uncontained body fluids — can help prevent it.

Sources

Based on Scott SE, Matthews J, Hobbs KC, et al., "Notes from the Field: Carbapenemase-Producing Klebsiella pneumoniae in a Ventilator-Capable Skilled Nursing Facility — Maricopa County, Arizona, July–November 2018," Morbidity and Mortality Weekly Report, Centers for Disease Control and Prevention; a work of the United States government in the public domain.