Healthcare Infection Prevention

Ambulatory care infections linked to multidose vials

Hepatitis prime concern, but bacteria never sleep

While much of the recently reported infection control problems in ambulatory care have centered on viral hepatitis and reused needles, there may be a comparable level of bacterial infections occurring that are more difficult to detect, investigators report.

"Most of the injection safety issues are predominantly [associated] with bloodborne pathogens," said Dan Jernigan, MD, a medical epidemiologist at the Centers for Disease Control and Prevention, at a recent Healthcare Infection Control Practices Advisory Committee (HICPAC) meeting.

"It is simpler to do that for a number of reasons. I think it is easier to pick up. Hepatitis [cases] in the United States at least are reportable. So when these cases do occur, they do somehow make their way to the public health establishment. There are really are very few reports of outbreaks due to nonviral causes in the United States," he noted.

Jernigan recently reviewed the situation due to increasing interest in improving infection control in outpatient settings. Amid increasing reports of outbreaks due to reused needles and other infection control lapses in ambulatory care, HICPAC has formed a working group to investigate the situation. The primary focus has been on outbreaks of hepatitis B and C virus, but bacterial infections must be addressed as well.

"We wanted to determine if the efforts to address bloodborne viral pathogens will cover issues with bacteria, mycobacteria, and fungi associated with unsafe injection practices," he added. "[The question is] whether something will be missed in terms of bacterial causes if we focus just on the bloodborne pathogens."

In reviewing the reported bacterial outbreaks in outpatient settings, Jernigan found common problems in the preparation of medications and injection practices. "The sharp end of the problem — where the needle goes into the skin — is really only one aspect of what we are looking at here," he said. "There is the dull end — the preparation end of the materials that gets injected, not only into the skin but into IV lines. It is not only injection activity, but also the aseptic techniques that are needed for preparations. We looked at both inpatient and outpatient settings to get a sense of what kinds of bacterial problems you might see, but then sorted that down to outpatient settings alone."

An initial scan of the situation underscores the vast variety and sheer number of injected medications and medical settings. "The outpatient settings that came up most frequently were physician clinic offices, hemodialysis centers, oncology clinics, some outpatient surgery clinics, podiatrist clinic offices, and home care," Jernigan said. "Sources of infection included extrinsic contamination of multidose vial contents or the vial stoppers, and that came from health care workers’ hands [and] the environment from preparation areas."

Jernigan cited an outbreak that occurred in a hemodialysis clinic as a cautionary tale, noting that scavenging leftover medicine to cut costs led to an outbreak of Serratia marcescens.¹ Clinicians were pooling leftover, preservative-free epoetin alfa (EPO) medication taken from single-dose vials.

"This was important because the reimbursement for EPO was done by what was injected into the [patients]," Jernigan said. "So if you have a patient who needs a certain amount and you have a greater amount of that in a single dose vial, you cannot get reimbursed for what remains. So they were taking the EPO from the vials and putting it into other vials. They were pooling that for later use and cost and reimbursement was clearly the driver."

As a result, 10 S. liquefaciens bloodstream infections and six pyrogenic reactions occurred in outpatients at the center. The pathogen was isolated from pooled EPO, empty vials of EPO, antibacterial soap, and hand lotion. All the isolates were identical by pulsed-field gel electrophoresis.

After the practice of pooling EPO was discontinued and the contaminated soap and lotion were replaced, no further S. liquefaciens bloodstream infections or pyrogenic reactions occurred.

Jernigan also found reports of bacterial infections associated with making injectables for vaccine or for oncology clinics. Injectables were sometimes prepared "in the same areas where they were putting their swabs and other infectious materials that were going to be sent to the lab," he said.

Saline and heparin flush solutions also were implicated, as a host of water bugs was present in the list of problem pathogens. "There [were problems with] extrinsic contamination of syringes or inadequate disinfection of the injection site," he added. "In terms of the gram negatives, there were certainly a number of water bugs [e.g., Alcaligenes xyloxidans]. This suggests that perhaps water was being used to clean something but then the apparatus is not adequately disinfected, or [bacteria] are being introduced through contaminated water on the hands of the workers."

Still, the primary problem area appears to be linked to multidose vials — which can save money but carry the risk of becoming contaminated. Key infection control interventions include appropriate use of multidose vials, intravenous fluid administration sets, and flush solutions. (See Learn to give injections without causing infection.)

Preparation and storage must be done following aseptic techniques to prevent bacterial outbreaks. "The control points for intervention clearly include the appropriate use of multidose vials — an area that would be a shared victory for both bacteria and viral [infection prevention]." he said.

The problem is, of course, not so much a lack of infection control guidelines but poor compliance with those already issued for ambulatory settings. "If you focus on the bloodborne pathogens, you are going to be looking at aseptic practices and appropriate needle safety, and there are some benefits that will have for preventing bacterial problems [as well]," Jernigan told HICPAC members.

Reference

1. Grohskopf LA, Roth VR, Feikin DR, et al. Serratia liquefaciens bloodstream infections from contamination of epoetin alfa at a hemodialysis center. N Engl J Med 2001; 344:1,491-1,497.