Molecular Dx Significance 7/10

TaqMan Array Card Tests CSF for 21 Meningitis Pathogens in a Single 2.5-Hour Run

A 21-pathogen TaqMan array card for cerebrospinal fluid was developed and validated for simultaneous detection of bacterial, viral, and parasitic causes of CNS infection. The card tested eight samples in parallel within 2.5 hours post-extraction, achieving 85.6% sensitivity and 96.7% specificity versus individual real-time PCR, while detecting two additional positive samples missed by standard testing. The platform is particularly valuable for outbreak investigation and surveillance in resource-limited settings.

The original study

Evaluation of a TaqMan Array Card for Detection of Central Nervous System Infections.

Authors
Onyango CO, Loparev V, Lidechi S, Bhullar V, Schmid DS, Radford K, et al.
Journal
Journal of clinical microbiology
Type
Journal Article, Validation Study
PMID
28404679
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Original abstract

Infections of the central nervous system (CNS) are often acute, with significant morbidity and mortality. Routine diagnosis of such infections is limited in developing countries and requires modern equipment in advanced laboratories that may be unavailable to a number of patients in sub-Saharan Africa. We developed a TaqMan array card (TAC) that detects multiple pathogens simultaneously from cerebrospinal fluid. The 21-pathogen CNS multiple-pathogen TAC (CNS-TAC) assay includes two parasites (Balamuthia mandrillaris and Acanthamoeba), six bacterial pathogens (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Mycoplasma pneumoniae, Mycobacterium tuberculosis, and Bartonella), and 13 viruses (parechovirus, dengue virus, Nipah virus, varicella-zoster virus, mumps virus, measles virus, lyssavirus, herpes simplex viruses 1 and 2, Epstein-Barr virus, enterovirus, cytomegalovirus, and chikungunya virus). The card also includes human RNase P as a nucleic acid extraction control and an internal manufacturer control, GAPDH (glyceraldehyde-3-phosphate dehydrogenase). This CNS-TAC assay can test up to eight samples for all 21 agents within 2.5 h following nucleic acid extraction. The assay was validated for linearity, limit of detection, sensitivity, and specificity by using either live viruses (dengue, mumps, and measles viruses) or nucleic acid material (Nipah and chikungunya viruses). Of 120 samples tested by individual real-time PCR, 35 were positive for eight different targets, whereas the CNS-TAC assay detected 37 positive samples across nine different targets. The CNS-TAC assays showed 85.6% sensitivity and 96.7% specificity. Therefore, the CNS-TAC assay may be useful for outbreak investigation and surveillance of suspected neurological disease.