Ralstonia Associated with Vapotherm Oxygen Delivery Device --- United States, 2005

In August 2005, a health-care facility in Pennsylvania reported the occurrence of Ralstonia spp. in six patients aged 21 days to 8 years to the Philadelphia Department of Health and CDC. Preliminary laboratory and epidemiologic investigation identified the Vapotherm 2000i oxygen delivery device (Vapotherm Inc., Stevensville, Maryland) as an associated risk factor for recovery of the organism from blood and respiratory tract samples. Although the source of Ralstonia has not yet been identified, Vapotherm has created new infection-control procedures to reduce the risk for infectious disease transmission among patients using their machines. This report summarizes the initial results of this ongoing investigation and provides recommendations to prevent further spread of Ralstonia species in hospitals.

The Vapotherm device is capable of delivering high concentrations of medical gases, such as oxygen, via nasal cannula. Breathing gas is distributed alongside a discrete water chamber, where it is warmed and humidified and then delivered to the patient. The machine employs a reusable 0.01-µ cartridge filter, which should prevent passage of bacterial microorganisms from the water chamber to the air compartment. Approximately 4,500 Vapotherm units are in service in the United States. Ralstonia species are gram-negative bacilli that grow well in moist environments and are an infrequent cause of colonization and infection in humans. Although ubiquitous in the environment, the organism is rarely found in hospitals. Ralstonia spp. have traditionally exhibited low virulence in humans but have been implicated in several nosocomial outbreaks involving contaminated solutions (1--3).

Surveillance performed through pediatric and neonatology electronic mail listserv groups identified 10 hospitals in seven states that have recovered Ralstonia species from clinical specimens and/or Vapotherm devices. During January--September 2005, a total of 18 pediatric patients with positive Ralstonia respiratory or blood cultures were reported from five hospitals in five states. Investigations to determine which cases represent infections (as opposed to colonization) are ongoing. Seventeen of these patients were exposed to a Vapotherm system before culture specimens were obtained. Four of the 10 hospitals cultured the organism from Vapotherm systems and reusable filter cartridges after they had been disinfected according to the manufacturer's previously recommended reprocessing protocol. Whether the remaining six hospitals followed Vapotherm's recommended reprocessing protocol is unclear. Failure to reprocess the system properly might have allowed development of a biofilm, which the previous reprocessing protocol did not address.

In response to this investigation, Vapotherm has developed new infection-control guidelines. Vapotherm continues to recommend that machines be reprocessed after each patient use or every 30 days if a single patient uses the device. Furthermore, the company now advises that each filter cartridge either be used for a single patient or be subjected to the new high-level disinfection reprocessing protocol. Moreover, the suggested maximum service life of the filter cartridge now is 60 cumulative days. Finally, Vapotherm now recommends use of sterile water in the delivery circuit, instead of following previous guidelines, which allowed use of tap water.

CDC recommends that users of the Vapotherm device follow the manufacturer's recommendations. More information on the new reprocessing protocol is available at http://www.vtherm.com/customers/infectioncontrol.asp. CDC also encourages health-care facilities to adhere to strict infection-control practices while administering respiratory therapy to prevent transmission of organisms such as Ralstonia spp. that thrive in warm, moist environments. Information on appropriate infection-control procedures is available at http://www.cdc.gov/ncidod/hip/pneumonia/default.htm.

Reported by: K Arias, MS, O Bamford, PhD, D Lain, JD, B Niland, B Storey, K Thibodeau, Vapotherm, Inc., Stevensville, Maryland. L Campagna, D Borowitz, MD, Women and Children's Hospital of Buffalo, New York. R Serlen, Shriners Hospital for Children/Temple Univ Children's Medical Center; C Johnson, MD, City of Philadelphia Dept of Health; G Dash, Temple Univ Hospital, Philadelphia; S Coffin, MD, K St. John, MS, A Hedgman, Children's Hospital of Pennsylvania, Philadelphia. J Atkins, MD, B Quattlebaum, P Hudak, C Wahrmund, B Snow, Methodist Children's Hospital of South Texas, San Antonio. B Stein, M McNeal, C Tyndall, Children's Hospital of The King's Daughters, Norfolk, Virginia. M Rotar, Children's Hospital of Wisconsin, Milwaukee. A Srinivasan, MD, D Jernigan, MD, A Peterson, MPH, B Jensen, MMSc, J Noble-Wang, PhD, M Arduino, PhD, Div of Healthcare Quality Promotion, National Center for Infectious Diseases; M Jhung, MD, F Lewis, MD, R Sunenshine, MD, EIS officers, CDC.

References

1. Labarca JA, Trick WE, Peterson CL, et al. A multistate nosocomial outbreak of Ralstonia pickettii colonization associated with an intrinsically contaminated respiratory care solution. Clin Infect Dis 1999;29:1281--6.
2. Maroye P, Doermann HP, Rogues AM, Gachie JP, Megraud F. Investigation of an outbreak of Ralstonia pickettii in a paediatric hospital by RAPD. J Hosp Infect 2000;44:267--72.
3. Moreira BM, Leobons MB, Pellegrino FL, et al. Ralstonia picketti and Burkholderia cepacia complex bloodstream infections related to infusion of contaminated water for injection. J Hosp Infect 2005;60:51--5.

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Date last reviewed: 10/19/2005