INTRODUCTION

Clinicians can often recognize specific infectious disease syndromes based on clinical presentation and, based on experience, strongly suspect a particular etiology. For example, cellulitis, skin abscesses, and sinusitis are typically associated with bacteria, whereas measles, chickenpox, zoster, croup, and bronchiolitis are caused by viruses. In many cases, identification of the specific causative microorganism by the microbiology laboratory is very important:

• some infectious disease syndromes such as pneumonia, diarrhea, and sepsis can be caused by various classes of organisms (bacteria, viruses, fungi, parasites)

• identification of the microorganism allows selection of targeted antimicrobial agents, thereby decreasing use of broad-spectrum antibiotics, the occurrence of adverse effects from antimicrobial agents, and the risk that resistant organisms will emerge

• an organism may be resistant to a given antimicrobial therapy, requiring a change in antimicrobial regimen

• an unexpected organism that might not otherwise be treated may be identified, such as Entamoeba histolytica causing diarrhea.

Effective use of the clinical microbiology laboratory requires collection of appropriate specimens and knowledge of the tests offered by the laboratory.

SPECIMEN COLLECTION

General Collection Procedures

1. Refer to laboratory collection guidelines for descriptions of available collection devices and instructions for proper specimen collection.

2. Talk to microbiology laboratory staff about complex cases before collecting specimens.

3. Collect specimens before antimicrobial therapy is started.

4. Because many body sites harbor commensal or normal flora, cleanse lesions with sterile saline or debride wounds before collecting specimens.

5. Clearly label specimens with patient information.

6. The requisition form or computer order should contain the following information: patient name, medical record number, patient age and sex, patient location, ordering physician name with phone or pager number, specific anatomic site, date and time of specimen collection, name of person collecting specimen.

7. […]