Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (1333 page)

   Limitations

   
Brucella
may be difficult to detect by Gram stain in primary specimens.

   
Common pitfalls:
Because brucellosis may present after a prolonged incubation period, or present with nonspecific symptoms and an indolent onset, the diagnosis may not be considered until progression into the chronic phase of illness. Clinicians may fail to request specific cultures for brucellosis, or alert the laboratory of their clinical suspicion.

   Other Considerations

   Brucellosis is a reportable disease. Patients with a diagnosis of brucellosis must be reported to the local department of health.

CEREBROSPINAL FLUID (CSF) CULTURE

   Definition and Use

   CSF culture is used for specific diagnosis of bacterial meningitis. Patients commonly present with severe headache, fever, neck stiffness, and meningeal signs, mental status changes, and signs of systemic toxicity.

   Method

   CSF is inoculated onto sheep blood and chocolate agar, incubated aerobically. Broth media may be inoculated. Special media or culture conditions may be used for non–community-acquired meningitis, such as infections associated with trauma and prosthetic implants.

   
Turnaround time:
Cultures are incubated for 96 hours. Additional time is required for isolate identification, susceptibility testing, and further characterization, as needed.

   Special Collection and Transport Instructions

   CSF is collected by needle aspiration after preparation of the puncture site in a manner consistent with a surgical site preparation.

   Fluid is transported in a sterile container or tube with a tight-fitting lid.