CI 5.2 - Specimen Collection and Handling for Dianogsis of Infectious Diseases (BODY FLUIDS)

CSF is most likely to diagnose what?

meningitis or encephalitis

most common cause of infectious meningitis

enteroviruses

Organisms found in Neonates - 3 months old

Group B streptococcus, Escherichia coli, Listeria monocytogenes

Organisms found in 4 months - 6 years old

Streptococcus pneumoniae

Organisms found in 6-45 years old

Neisseria meningitidis, Streptococcus pneumoniae

Organisms found in older than 45 years old

Streptococcus pneumoniae, Listeria monocytogenes, Group B streptococcus

<24 hours onset of duration

acute syndrome meningitis

1-7 days onset of duration

subacute syndrome meningitis

persisting at least 4 weeks onset of duration

chronic syndrome meningitis

probable pathogens for acute syndrome meningitis

Pyogenic bacteria

probable pathogens for Subacute syndrome meningitis

Enteroviruses, pyogenic bacteria

probable pathogens for Chronic syndrome meningitis

M. tuberculosis, T. pallidum, Brucella spp., L. interrogans, B. burgdorferi, C. neoformans, C. immitis, H. capsulatum

Order of filling for CSF

1 - Chemistries

2 - Microbiology

3 - Hematology

4 - Cytology

Why is the second tube for microbiology?

less contaminated with blood and normal flora

procedure for CSF collection

Lumbar tap / spinal tap / lumbar puncture

What can be tested with the first tube in Chemistry?

glucose and protein

What can be tested with the third tube in hematology?

cell count

What specific cell are you trying to look for if there is possible infection in the CSF?

white blood cells

ideal specimen volume for CSF for microbiology testing?

adequate volume?

5 - 10 mL

0.5 - 1.0 mL

how to store CSF if there are delays

room temperature; NEVER or freeze REFRIGERATE

main clue that we have a possible infection

marked decrease of glucose; utilized by the organism (bacterial)

psychologic testing for bacterial meningitis

check WBCs, especially polymorphonuclear cells

T/F

glucose is affected in viral menigitis

F

routine bacterial culture process

Concentration (sediment), smear, culture

used for molecular techniques

CSF supernatant

Brucellosis CSF handling

media is incubated for 2-3 weeks

Leptospirosis CSF handling

culture and NAAT testing; specific treponemal tests

Lyme disease (Borrelia burgdorferi) CSF handling

Serologic testing

Mycobacteria CSF handling

culture, smear, NAAT

C. neoformans CSF handling

latex agglutination, ELISA, india ink

initial treponemal test

VDRL

Is VDRL a specific or non-specific test?

Non-specific, however since the specimen is CSF the sensitivity and specificity of the test increases.

If VDRL is really negative and we are suspecting meningitis what should we do?

Proceed to specific treponemal tests such as FTA-ABS.

2 types for rapid testing for C. neoformans

1 - Latex agglutination and ELISA

2 - india ink

detects capsular antigen

Latex agglutination and ELISA

non-specific test; shows capsular morphology

India ink

Almost always performed in viral infections.

NAAT

the most prominent/ notorious amoeba in CSF

Naegleria fowleri

(another is Acanthamoeba spp.)

free-living amoeba is detected through ?

wet smear and culture