Microscopic Examination and Broth Culture of Cerebrospinal Fluid in Diagnosis of Meningitis

April 2, 2019 at 6:15 pm

Journal of Clinical Microbiology June 1998 V.36 N.6 P.1617-1620

Dunbar SA et al

We reviewed the results of microscopic Gram stain examination and routine culture for 2,635 cerebrospinal fluid (CSF) samples processed in an adult hospital microbiology laboratory during 55 months. There were 56 instances of bacterial or fungal meningitis (16 associated with central nervous system [CNS] shunt infection), four infections adjacent to the subarachnoid space, four cases of sepsis without meningitis, and an additional 220 CSF specimens with positive cultures in which the organism isolated was judged to be a contaminant. Because 121 of these contaminants were isolated in broth only, elimination of the broth culture would decrease unnecessary work. However, 25% of the meningitis associated with CNS shunts would have been missed by this practice. The most common cause of meningitis was Cryptococcus neoformans, followed by Streptococcus pneumoniaeand Neisseria meningitidis. In 48 of 56 (88%) of cases, examination of the Gram-stained specimen revealed the causative organism. If patients who had received effective antimicrobial therapy prior to lumbar puncture are excluded, the CSF Gram stain is 92% sensitive. Microscopic examination incorrectly suggested the presence of organisms in only 3 of 2,635 (0.1%) CSF examinations. Thus, microscopic examination of Gram-stained, concentrated CSF is highly sensitive and specific in early diagnosis of bacterial or fungal meningitis.

Bacterial meningitis is a life-threatening infection. Although patients typically present with fever, headache, stiff neck, and altered mental status, these symptoms may be subtle in elderly or immunocompromised persons (1, 6, 7,18). Early implementation of appropriate antimicrobial therapy requires prompt identification of the infecting pathogen. Although culture is considered to be the definitive diagnostic test, microscopic examination of a Gram-stained specimen of cerebrospinal fluid (CSF) may provide immediate information about the causative microorganism. Previous studies have suggested that the sensitivity of this technique ranges from 60 to 90% and the specificity approaches 100% (1, 5,6, 8, 12, 18). Scheld concludes that the overall sensitivity is only 75% (14). It is often unclear whether earlier studies have stratified patients based upon their having received prior antimicrobial therapy. Further, the role of semiquantitative assessment of leukocytes (WBC) by microscopic examination as an indicator of infection (8, 12) is uncertain. The value of using broth culture in various populations is also questionable (9, 10,17). In the present study, we reviewed the results of microscopic examination and routine culture of 2,635 CSF specimens to establish the predictive value of the cytocentrifuged Gram stain and the usefulness of broth culture in a veteran population.

FULL TEXT

https://jcm.asm.org/content/36/6/1617

PDF

https://jcm.asm.org/content/jcm/36/6/1617.full.pdf

Advertisements

Entry filed under: Antimicrobianos, Bacterias, Bacteriemias, Biología Molecular, BIOMARCADORES, Epidemiología, FIEBRE en el POSTOPERATORIO, Infecciones del SNC, Inmunizaciones, Metodos diagnosticos, REPORTS, Resistencia bacteriana, Sepsis, Update.

Predictive Value of Cerebrospinal Fluid (CSF) Lactate Level vs CSF-Blood Glucose Ratio for the Diagnosis of Bacterial Meningitis Following Neurosurgery 2017 WSES and SICG guidelines on acute calcolous cholecystitis in elderly population


Calendar

April 2019
M T W T F S S
« Mar   May »
1234567
891011121314
15161718192021
22232425262728
2930  

Most Recent Posts


%d bloggers like this: