Matthew B. Crist

Evolutionary dynamics and genomic features of the Elizabethkingia anophelis 2015 to 2016 Wisconsin outbreak strain

An atypically large outbreak of Elizabethkingia anophelis infections occurred in Wisconsin. Here we show that it was caused by a single strain with thirteen characteristic genomic regions. Strikingly, the outbreak isolates show an accelerated evolutionary rate and an atypical mutational spectrum. Six phylogenetic sub-clusters with distinctive temporal and geographic dynamics are revealed, and their last common ancestor existed approximately one year before the first recognized human infection. Unlike other E. anophelis, the outbreak strain had a disrupted DNA repair mutY gene caused by insertion of an integrative and conjugative element. This genomic change probably contributed to the high evolutionary rate of the outbreak strain and may have increased its adaptability, as many mutations in protein-coding genes occurred during the outbreak. This unique discovery of an outbreak caused by a naturally occurring mutator bacterial pathogen provides a dramatic example of the potential impact of pathogen evolutionary dynamics on infectious disease epidemiology.

Notes from the Field: Hepatitis C Transmission from Inappropriate Reuse of Saline Flush Syringes for Multiple Patients in an Acute Care General Hospital — Texas, 2015

In October 2015, the Texas Department of State Health Services (DSHS) was notified that a hospital telemetry unit nurse had been reusing saline flush prefilled syringes in the intravenous (IV) lines of multiple patients, a risk factor for patient-to-patient transmission of bloodborne pathogens (1).* This practice was discovered through an investigation undertaken by the hospital after the nurse was observed to frequently leave a partially filled syringe near a computer work station. State, regional, and local health departments, with consultation from CDC, collaborated with the hospital to investigate infection prevention lapses, assess risk to patients, perform patient notification, and provide bloodborne pathogen testing.† Upon interview, the nurse reported reusing syringes during the previous 6 months, erroneously believing that this was a safe, cost-saving measure if no fluids were withdrawn into the syringe before injection of the saline flush (1,2). The nurse had been working in this unit for 18 months, had not worked at another health care facility before or during employment at the hospital, and reported that this practice was not taught by the hospital. The hospital voluntarily notified patients and offered bloodborne pathogen screening to patients who might have been cared for by the nurse during employment from April 2014 to October 2015, when the practice was recognized and corrected (3). Because all telemetry unit patients were required to have IV access, all patients cared for on the unit during shifts worked by the nurse were included in the notification. During October 2015, notification letters were sent to patients via both certified and registered mail to inform them of a possible bloodborne pathogen exposure and a need for laboratory testing for Hepatitis B (HBV), Hepatitis C (HCV), and human immunodeficiency virus (HIV). The notification included locations where testing would be offered, a laboratory order form, and a 24-hour hospital hotline number for questions and concerns. The hospital provided testing free of charge through a commercial laboratory that coordinated testing at many satellite locations. Recommended laboratory testing consisted of a baseline screening test and a follow-up

A multistate investigation of health care–associated Burkholderia cepacia complex infections related to liquid docusate sodium contamination, January-October 2016

Background: Outbreaks of health care–associated infections (HAIs) caused by Burkholderia cepacia complex (Bcc) have been associated with medical devices and water‐based products. Water is the most common raw ingredient in nonsterile liquid drugs, and the significance of organisms recovered from microbiologic testing during manufacturing is assessed using a risk‐based approach. This incident demonstrates that lapses in manufacturing practices and quality control of nonsterile liquid drugs can have serious unintended consequences. Methods: An epidemiologic and laboratory investigation of clusters of Bcc HAIs that occurred among critically ill, hospitalized, adult and pediatric patients was performed between January 1, 2016, and October 31, 2016. Results: One hundred and eight case patients with Bcc infections at a variety of body sites were identified in 12 states. Two distinct strains of Bcc were obtained from patient clinical cultures. These strains were found to be indistinguishable or closely related to 2 strains of Bcc obtained from cultures of water used in the production of liquid docusate, and product that had been released to the market by manufacturer X. Conclusions: This investigation highlights the ability of bacteria present in nonsterile, liquid drugs to cause infections or colonization among susceptible patients. Prompt reporting and thorough investigation of potentially related infections may assist public health officials in identifying and removing contaminated products from the market when lapses in manufacturing occur.

Multistate Outbreak of Burkholderia cepacia Complex Bloodstream Infections After Exposure to Contaminated Saline Flush Syringes — United States, 2016–2017

Background Burkholderia cepacia complex (Bcc) has caused healthcare-associated outbreaks, often in association with contaminated products. The identification of four Bcc bloodstream infections (BSIs) in patients residing at a single skilled nursing facility (SNF) within one week led to an epidemiological investigation to identify additional cases and the outbreak source. Methods A case was initially defined as a blood culture yielding Bcc in a SNF resident receiving intravenous therapy after August 1, 2016. Multistate notifications were issued to identify additional cases. Public health authorities performed site visits at facilities with cases to conduct chart reviews and identify possible sources. Pulsed-field gel electrophoresis (PFGE) was performed on isolates from cases and suspect products. Facilities involved in manufacturing suspect products were inspected to assess possible root causes. Results An outbreak of 162 Bcc BSIs across 59 nursing facilities in 5 states occurred during September 2016-January 2017. Isolates from patients and pre-filled saline flush syringes were closely related by PFGE, identifying contaminated flushes as the outbreak source and prompting a nationwide recall. Inspection of facilities at the saline flush manufacturer identified deficiencies which might have led to the failure to sterilize a specific case containing a partial lot of product. Conclusions Communication and coordination among key stakeholders, including healthcare facilities, public health authorities, and state and federal agencies, led to the rapid identification of an outbreak source and likely prevented many additional infections. Effective processes to ensure the sterilization of injectable products are essential to prevent similar outbreaks in the future.