Clinical Microbiology Laboratories: The Backbone of Infection Control
By Kelly M. Pyrek
One of the most critical--yet frequently overlooked--healthcare partnerships is that between the infection control practitioner (ICP) and the clinical microbiology laboratory (CML). According to the Infectious Diseases Society of America (IDSA), CMLs are the backbone of infection control programs and provide crucial hospital-specific surveillance information for the management of infectious diseases, the prevalence of infectious agents and their susceptibility to therapeutic products.1 In an era of managed care, however, healthcare organizations have been cutting costs by restructuring and consolidating hospital-based laboratory services into larger groups that serve multiple facilities and retain fewer professionals with microbiology expertise.
Infectious disease specialists are concerned this consolidation is taking place at a time when mortality from infectious diseases is increasing. From 1980 to 1992, infectious diseases rose from the fifth to the third leading cause of death in the United States, a 58 percent increase.2 According to Lance R. Peterson, MD, at Northwestern University Medical School, "Microbiology laboratories are the first lines of defense for detection of new antibiotic resistance, outbreaks of foodborne infection and a possible bioterrorism event. Maintaining high-quality clinical microbiology laboratories on the site of the institution they serve is the current best approach for managing today's problems of emerging infectious diseases and antimicrobial agent resistance by providing good patient outcomes that actually save money."3
Many believe that moving CMLs offsite is problematic for several reasons. First, it makes frequent and direct interaction between ICPs and lab staff difficult, if not impossible. Second, this practice is not conducive to much of infectious disease testing because it is driven by equipment capabilities rather than by disease-based expertise; centralization of CMLs often results in a staff comprised of generalists instead of microbiology specialists.4
Researchers Peterson and colleagues point to a 1999 survey of CML directors querying them about the effects of consolidation.5 While respondents acknowledged inherent cost reductions for healthcare organizations, the drawbacks nearly outnumbered the benefits by almost 2-to-1. These include:
- Poor communication between clinicians and laboratory personnel
- Recurrence of serious problems with timely specimen transport
- Lack of report standardization at patient-care sites resulted in time-consuming customized reporting by the lab
- Impaired gram stain analysis resulting from initial smears read by generalists at rapid-response labs
- Compromised infection control surveillance resulting from a lack of personal interaction between hospital staff and lab personnel
The survey findings underscore the concern that loss of communication between lab personnel and ICPs or infectious disease specialists could affect patient-care outcomes -- one of the most important reasons for hospitals not to consolidate CMLs. Northwestern Memorial Hospital discovered that, after fully staffing and equipping its CML and reporting its surveillance data to the Centers for Disease Control and Prevention (CDC) as part of a comprehensive infection control program, it achieved a significant annual reduction in nosocomial infections. The program trimmed nearly $2 million in the costs associated with hospital-acquired infections and avoided nearly 300 infections that would have resulted in at least 10 deaths.6
In their fight to keep CMLs onsite and protect surveillance quality, clinicians are attempting to improve the quality and the frequency of their communication with lab personnel.
"ICPs must realize lab personnel are part of an important team," says Paula Denlick, MPH, SM(ASCP), CIC, an epidemiologist and clinical microbiology laboratory consultant in San Diego. "The CML will give ICPs the answers they need to manage the safety and health of their patients and plan their course of treatment. It makes it easier for everyone if the ICP and the lab can have an effective two-way conversation about surveillance data. I suspect things break down when the ICP sends specimens to the lab with no communication ahead of time or poor documentation on the lab requisition and microbiologists work up the specimens according to routine procedures. The results will come back and the ICP will say, 'This isn't what I wanted,' but the lab didn't receive any special requests or instructions. Or the lab, due to constraints of their own, may not able to accommodate something the ICP needs, and if communication doesn't exist, both could be disappointed by the process."
Denlick believes ICPs would be well served by reviewing standard procedures for filling out lab requisitions.
"Suppose an ICP suspected an outbreak of hepatitis A in her facility. She would need to collect a blood sample and then start the process of generating a lab requisition, the paperwork that accompanies the sample. The paperwork provides all patient demographic information and can include special requests such as, 'rule out acute hepatitis A infection, suspect outbreak situation.' This is an important step because once the requisition form arrives at the lab, the first person who looks at it will tell the people on the bench -- those who actually run the tests -- what to do with the sample. If the requisition is not detailed enough, many things can go wrong."
Denlick emphasizes that establishing a good rapport with a facility's CML is key to reducing the chance for errors, delays and miscommunication.
"Most labs are part of a bigger organization these days, and if it's a giant group where the lab you deal with has to call the main lab, it can be difficult to develop a rapport at a local level," she says. "It's worth the effort, however, especially when you have a special request. If it's a big lab group, often the ICP will deal with client services, and all they do is pull up the results on a computer screen and read them off. The ICP needs to get past this department and talk to the microbiologist doing the actual testing."
Knowing which department of a CML handles specific kinds of testing can help smooth a relationship with the lab, Denlick adds. "Each area of the laboratory is specialized, so you don't want to pester hematology for microbiology results. That might be something nurses are not aware of, and it could be a source of frustration for lab personnel. Conversely, it's frustrating for nurses to be on the phone and get transferred all over the lab when they need an answer quickly."
Denlick says knowing the inner workings of the CML is another way ICPs can create harmonious working relationships with microbiologists. "Clinicians often don't realize labs are under the duress of numerous time constraints and rigid reporting times. If clinicians can understand or appreciate what the process is, they can avoid creating headaches for everyone. All they have to do is ask what time results are normally reported, so the ICP won't waste time calling for them repeatedly. If you know that gram stain results aren't reported out until the next day and you need those reports in six hours, you need to put a 'stat' request on the requisition so the microbiologist will get to it right away. Otherwise, all samples that come to the lab may be unpacked and entered into the computer system, but they're processed in batches because it's more efficient that way. Again, it comes down to good communication. If you need something done more quickly than the routine, you need to say so. In microbiology, the lab will often see a request to run a urine culture run stat; you can't do so because it has to be incubated overnight or for at least for 12 hours. You could say, 'Could you process this stat, but other than that, you can't make it grow any faster than it's normally going to grow. That's not something most ICPs would consider, but it's a fact to keep in mind and is useful when developing a good rapport with the lab."
CMLs provide the information that is incorporated into epidemiology reports by the ICP or hospital epidemiologist. Denlick says ICPs can request specific data from microbiology, including patient demographic information and lists of all cultures on patients for particular time periods--a service that is particularly critical during a suspected outbreak within a facility. "You can call the CML and ask for data on all the cultures on a particular ward for the last month. Many are printed out by ward or unit, so if there's a particularly resistant bacteria isolated from certain wards, you can see the pattern within the facility."
Most CMLs establish guidelines as to what results carry red flags and must be reported to the facility as well as to the state health department and other collectors of surveillance data such as the CDC. "CMLs have additional reporting requirements related to public health reporting guidelines," Denlick says. "For example, if a California facility sends in a stool culture and the lab isolates Salmonella, state rules mandate that the lab must notify the public health department (PHD). There's a long list of reportable bacteria and viruses that the lab must contact the PHD about, such as Shigella and hepatitis A and B... it's part of the process of trying to circumvent an outbreak."
If an outbreak is suspected, Denlick says ICPs should contact the CML to know what samples to collect for testing. "You think you have a methicillin resistant Staph aureus (MRSA) outbreak, so you call the lab and say, 'I have all these wound infections that have been resistant to treatment and I don't know what's causing them. I suspect MRSA, so can you help me?' The lab will ask, 'Do you want us to just rule out MRSA on these wound cultures?' and the ICP should say yes, instead of asking the lab to culture for whatever bacteria it can find. Otherwise, the lab will simply report, 'We grew X, Y and Z bacteria,' when you really want to know, 'Do I have a MRSA outbreak?' It saves everyone time and the lab can set up special media to isolate just for MRSA. So if you suspect an outbreak, you should talk to a microbiologist and ask what kind of specimen should be collected, and how it should be done. The microbiologist will instruct you to take a swab culture for a wound or collect a urine sample for a urine culture, and walk you through the appropriate steps to ensure a quality sample. It's critical to pay attention to environmental controls, such as keeping a sample at room temperature or refrigerating it, depending on what bacteria you are trying to isolate. The way to start a proper outbreak investigation is to get the CML involved from the start; if you don't collect the proper specimen, you will lose your window of opportunity to determine the infectious agent and treat the patient. You'll lose information from your first few cases, making it harder to go back and establish which patient presented as the first outbreak case and how bacteria was transmitted to other patients. It's like a puzzle; if you're missing the first piece, or some pieces, it's hard to put it all together."
The role that CMLs play in infection control programs is significant. Early studies on the effectiveness of these kinds of programs have shown they can reduce infections by 30 percent,7 and CMLs provide the infrastructure needed to produce critical surveillance information.
"With national attention focused on an increase in infectious diseases and the goal of improving the quality of healthcare outcomes, a consensus must be reached as to what threat infectious diseases pose and what resources are needed to improve microbiology laboratory infrastructure so that the laboratory can deal with them," writes Peterson in a position paper for the IDSA. "On the basis of our current knowledge, it appears the management of infectious diseases will be best accomplished by the maintenance of clinical microbiology laboratories on the same campus as the healthcare institutions they serve, to provide the public and they clinicians who care for them with the necessary diagnostic testing, means of epidemiological detection and future innovation required in an era of emerging and re-emerging infectious diseases."