Clinical Microbiology Laboratories: The Backbone of InfectionControl

May 1, 2002

Clinical Microbiology Laboratories: The Backbone of InfectionControl

By Kelly M. Pyrek

One of the most critical--yet frequently overlooked--healthcare partnershipsis that between the infection control practitioner (ICP) and the clinicalmicrobiology laboratory (CML). According to the Infectious Diseases Society ofAmerica (IDSA), CMLs are the backbone of infection control programs and providecrucial hospital-specific surveillance information for the management ofinfectious diseases, the prevalence of infectious agents and theirsusceptibility to therapeutic products.1 In an era of managed care,however, healthcare organizations have been cutting costs by restructuring andconsolidating hospital-based laboratory services into larger groups that servemultiple facilities and retain fewer professionals with microbiology expertise.

Infectious disease specialists are concerned this consolidation is takingplace at a time when mortality from infectious diseases is increasing. From 1980to 1992, infectious diseases rose from the fifth to the third leading cause ofdeath in the United States, a 58 percent increase.2 According toLance R. Peterson, MD, at Northwestern University Medical School,"Microbiology laboratories are the first lines of defense for detection ofnew antibiotic resistance, outbreaks of foodborne infection and a possiblebioterrorism event. Maintaining high-quality clinical microbiology laboratorieson the site of the institution they serve is the current best approach formanaging today's problems of emerging infectious diseases and antimicrobialagent resistance by providing good patient outcomes that actually savemoney."3

Many believe that moving CMLs offsite is problematic for several reasons.First, it makes frequent and direct interaction between ICPs and lab staffdifficult, if not impossible. Second, this practice is not conducive to much ofinfectious disease testing because it is driven by equipment capabilities ratherthan by disease-based expertise; centralization of CMLs often results in a staffcomprised of generalists instead of microbiology specialists.4

Researchers Peterson and colleagues point to a 1999 survey of CML directorsquerying them about the effects of consolidation.5 While respondentsacknowledged inherent cost reductions for healthcare organizations, thedrawbacks 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 betweenlab personnel and ICPs or infectious disease specialists could affectpatient-care outcomes -- one of the most important reasons for hospitals not toconsolidate CMLs. Northwestern Memorial Hospital discovered that, after fullystaffing and equipping its CML and reporting its surveillance data to theCenters for Disease Control and Prevention (CDC) as part of a comprehensiveinfection control program, it achieved a significant annual reduction innosocomial infections. The program trimmed nearly $2 million in the costsassociated with hospital-acquired infections and avoided nearly 300 infectionsthat 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 theircommunication with lab personnel.

"ICPs must realize lab personnel are part of an important team,"says Paula Denlick, MPH, SM(ASCP), CIC, an epidemiologist and clinicalmicrobiology laboratory consultant in San Diego. "The CML will give ICPsthe answers they need to manage the safety and health of their patients and plantheir course of treatment. It makes it easier for everyone if the ICP and thelab can have an effective two-way conversation about surveillance data. Isuspect things break down when the ICP sends specimens to the lab with nocommunication ahead of time or poor documentation on the lab requisition andmicrobiologists work up the specimens according to routine procedures. Theresults will come back and the ICP will say, 'This isn't what I wanted,' but thelab didn't receive any special requests or instructions. Or the lab, due toconstraints of their own, may not able to accommodate something the ICP needs,and if communication doesn't exist, both could be disappointed by theprocess."

Denlick believes ICPs would be well served by reviewing standard proceduresfor 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 ofgenerating a lab requisition, the paperwork that accompanies the sample. Thepaperwork provides all patient demographic information and can include specialrequests such as, 'rule out acute hepatitis A infection, suspect outbreaksituation.' This is an important step because once the requisition form arrivesat 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 therequisition is not detailed enough, many things can go wrong."

Denlick emphasizes that establishing a good rapport with a facility's CML iskey to reducing the chance for errors, delays and miscommunication.

"Most labs are part of a bigger organization these days, and if it's agiant group where the lab you deal with has to call the main lab, it can bedifficult to develop a rapport at a local level," she says. "It'sworth the effort, however, especially when you have a special request. If it's abig lab group, often the ICP will deal with client services, and all they do ispull up the results on a computer screen and read them off. The ICP needs to getpast this department and talk to the microbiologist doing the actualtesting."

Knowing which department of a CML handles specific kinds of testing can helpsmooth a relationship with the lab, Denlick adds. "Each area of thelaboratory is specialized, so you don't want to pester hematology formicrobiology results. That might be something nurses are not aware of, and itcould be a source of frustration for lab personnel. Conversely, it's frustratingfor nurses to be on the phone and get transferred all over the lab when theyneed an answer quickly."

Denlick says knowing the inner workings of the CML is another way ICPs cancreate harmonious working relationships with microbiologists. "Cliniciansoften don't realize labs are under the duress of numerous time constraints andrigid reporting times. If clinicians can understand or appreciate what theprocess is, they can avoid creating headaches for everyone. All they have to dois ask what time results are normally reported, so the ICP won't waste timecalling for them repeatedly. If you know that gram stain results aren't reportedout until the next day and you need those reports in six hours, you need to puta 'stat' request on the requisition so the microbiologist will get to it rightaway. Otherwise, all samples that come to the lab may be unpacked and enteredinto the computer system, but they're processed in batches because it's moreefficient that way. Again, it comes down to good communication. If you needsomething done more quickly than the routine, you need to say so. Inmicrobiology, 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 12hours. You could say, 'Could you process this stat, but other than that, youcan't make it grow any faster than it's normally going to grow. That's notsomething most ICPs would consider, but it's a fact to keep in mind and isuseful when developing a good rapport with the lab."

CMLs provide the information that is incorporated into epidemiology reportsby the ICP or hospital epidemiologist. Denlick says ICPs can request specificdata from microbiology, including patient demographic information and lists ofall cultures on patients for particular time periods--a service that isparticularly critical during a suspected outbreak within a facility. "Youcan call the CML and ask for data on all the cultures on a particular ward forthe last month. Many are printed out by ward or unit, so if there's aparticularly resistant bacteria isolated from certain wards, you can see thepattern within the facility."

Most CMLs establish guidelines as to what results carry red flags and must bereported to the facility as well as to the state health department and othercollectors of surveillance data such as the CDC. "CMLs have additionalreporting requirements related to public health reporting guidelines,"Denlick says. "For example, if a California facility sends in a stoolculture and the lab isolates Salmonella, state rules mandate that the labmust notify the public health department (PHD). There's a long list ofreportable bacteria and viruses that the lab must contact the PHD about, such asShigella and hepatitis A and B... it's part of the process of trying tocircumvent an outbreak."

If an outbreak is suspected, Denlick says ICPs should contact the CML to knowwhat samples to collect for testing. "You think you have a methicillinresistant Staph aureus (MRSA) outbreak, so you call the lab and say, 'Ihave all these wound infections that have been resistant to treatment and Idon't know what's causing them. I suspect MRSA, so can you help me?' The labwill ask, 'Do you want us to just rule out MRSA on these wound cultures?' andthe ICP should say yes, instead of asking the lab to culture for whateverbacteria it can find. Otherwise, the lab will simply report, 'We grew X, Y and Zbacteria,' when you really want to know, 'Do I have a MRSA outbreak?' It saveseveryone time and the lab can set up special media to isolate just for MRSA. Soif you suspect an outbreak, you should talk to a microbiologist and ask whatkind of specimen should be collected, and how it should be done. Themicrobiologist will instruct you to take a swab culture for a wound or collect aurine sample for a urine culture, and walk you through the appropriate steps toensure a quality sample. It's critical to pay attention to environmentalcontrols, 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 properoutbreak investigation is to get the CML involved from the start; if you don'tcollect the proper specimen, you will lose your window of opportunity todetermine the infectious agent and treat the patient. You'll lose informationfrom your first few cases, making it harder to go back and establish whichpatient presented as the first outbreak case and how bacteria was transmitted toother patients. It's like a puzzle; if you're missing the first piece, or somepieces, it's hard to put it all together."

The role that CMLs play in infection control programs is significant. Earlystudies on the effectiveness of these kinds of programs have shown they canreduce infections by 30 percent,7 and CMLs provide the infrastructureneeded to produce critical surveillance information.

"With national attention focused on an increase in infectious diseasesand the goal of improving the quality of healthcare outcomes, a consensus mustbe reached as to what threat infectious diseases pose and what resources areneeded to improve microbiology laboratory infrastructure so that the laboratorycan deal with them," writes Peterson in a position paper for the IDSA."On the basis of our current knowledge, it appears the management ofinfectious diseases will be best accomplished by the maintenance of clinicalmicrobiology laboratories on the same campus as the healthcare institutions theyserve, to provide the public and they clinicians who care for them with thenecessary diagnostic testing, means of epidemiological detection and futureinnovation required in an era of emerging and re-emerging infectiousdiseases."

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