Lab tests key to identifying, treating infectious diseases

A new guide developed by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM) will help physicians appropriately and accurately use laboratory tests for the diagnosis of infectious diseases. Laboratory test results drive approximately two-thirds of physicians' medical decisions.

Published today in the journal Clinical Infectious Diseases, the recommendations provide guidance regarding which lab tests are valuable and should be used in specific contexts; which add little or no value; and how to appropriately collect and manage specimens.

Laboratory diagnoses directly affect patient care and outcomes, as well as hospital infection control, patients' length of stay in the hospital, costs and laboratory efficiency.

“Getting the right diagnosis is contingent upon laboratory results that are accurate and clinically relevant,” says Ellen Jo Baron, PhD, who worked with J. Michael Miller, PhD, to shepherd the guide to completion after its inception by Gary Doern, PhD. “Physicians, their staff and microbiologists must communicate and work together to ensure the best outcome for patients, and this guide aims to help facilitate this collaboration.”

Divided into sections on anatomic systems (including infections of the bloodstream, cardiovascular system, central nervous system, eyes, soft tissue of the head and neck, upper and lower respiratory system, gastrointestinal tract, abdomen, bone and joints, urinary tract, genitals and skin and soft tissues) and etiologic agent groups (tickborne infections, viral syndromes, blood and tissue and parasite infections), the guide helps physicians decide what tests to request when they suspect specific agents are causing disease. It also provides targeted recommendations and precautions regarding selecting and collecting specimens, detailing what is required for various cultures and tests, as well as the appropriate collection device, temperature and ideal transport time.

The guide suggests 10 tenets of specimen management that everyone involved – from physician to nurse to laboratory scientist – should follow for good patient care. These include:

Specimens of poor quality must be rejected or results could be compromised.
Physicians should not demand a report of “everything that grows” as this could result in an inaccurate diagnosis.
Avoiding contamination of specimens is key, and careful collection is crucial.
The laboratory requires a specimen, not a swab of a specimen, which may not hold enough infected material to ensure an accurate diagnosis and may be easily contaminated.
The laboratory must follow its procedure manual or face legal challenges.
A specimen should be collected prior to administration of antibiotics, presence of which could lead to misleading results.

Susceptibility testing should be performed on clinically significant isolates, not all microorganisms in the culture.

Lab results should be accurate, significant and clinically relevant.
The laboratory – not the medical staff – should be allowed to set technical policy. Good communication and mutual respect will lead to collaborative policies.

Specimens must be labeled accurately and completely (for example: dog bite wound, right forefinger).

Guidance provided in the document is not intended to take the place of a doctor's judgment, but rather to support the decision-making process, which must be individualized according to each patient's circumstances.

The guide was conceived, organized, and initially managed by Gary Doern, PhD, and the 18-member author panel represents specialists with a variety of expertise, including infectious diseases, pathology and microbiology. In addition to Dr. Baron, the panel includes: J. Michael Miller, PhD; Melvin P. Weinstein, MD; Sandra S. Richter, MD; Peter H. Gilligan, PhD; Richard B. Thomson Jr., PhD; Paul Bourbeau, PhD; Karen C. Carroll, MD; Sue C. Kehl, PhD; W. Michael Dunne, PhD; Barbara Robinson-Dunn, PhD; Joseph D. Schwartzman, MD; Kimberle C. Chapin, MD; James W. Snyder, PhD; Betty A. Forbes, PhD; Robin Patel, MD; Jon E. Rosenblatt, MD; and Bobbi S. Pritt, MD.

IDSA has published more than 50 treatment guidelines on various conditions and infections, ranging from HIV/AIDS to Clostridium difficile, which can be found on the IDSA website at http://www.idsociety.org.

Note: For an advance copy of A Guide to Utilization of the Microbiology Laboratory for Diagnosis of Infectious Diseases: 2013 Recommendations by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM), which will be published in Clinical Infectious Diseases, please contact Jerica Pitts at (312) 558-1770 or jpitts@pcipr.com. The guide is embargoed until 12:01 a.m. EDT on July 11, 2013.

AT A GLANCE

A new guide to help physicians make the most appropriate use of laboratory tests to diagnose infectious diseases has been published by the Infectious Diseases Society of America (IDSA) and American Society for Microbiology (ASM).
An estimated 60 to 70 percent of physicians' diagnosis and treatment decisions are based on lab test results, research suggests.
Lab test results directly affect patient care and outcomes: inappropriate or poorly performed tests can lead to incorrect diagnoses, inappropriate treatment and increased costs.

The guide provides a resource for physicians and lab technicians regarding what tests should be used under which conditions and how specimens should be collected and managed.

Founded in 1979, Clinical Infectious Diseases publishes clinical articles twice monthly in a variety of areas of infectious disease, and is one of the most highly regarded journals in this specialty.

The Infectious Diseases Society of America (IDSA) is an organization of physicians, scientists, and other health care professionals dedicated to promoting health through excellence in infectious diseases research, education, patient care, prevention, and public health. The Society, which has nearly 10,000 members, was founded in 1963 and is based in Arlington, Va. For more information, see http://www.idsociety.org.

The American Society for Microbiology (ASM) is the largest single life science society, composed of over 39,000 scientists and health professionals. ASM's mission is to advance the microbiological sciences as a vehicle for understanding life processes and to apply and communicate this knowledge for the improvement of health and environmental and economic well-being worldwide. For more information, see http://www.asm.org.