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

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 ( and ), six bacterial pathogens (e, ,, ,, and ), 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.

Advances in molecular diagnostic testing for central nervous system infections

“…A study evaluating the TaqMan array card demonstrated good results in an initial evaluation of a select number of samples. However in a retrospective study of consecutive patient CSF samples with lower pathogen concentrations, the assay showed poor sensitivity compared to routine testing [6].…”

Exploration of risk factors for ceftriaxone resistance in invasive non-typhoidal Salmonella infections in western Kenya

“…Details of the vaccine trial, the CNS study, and the surveillance program have been described previously [9][10][11]; for background, we briefly summarize these three projects. First, the vaccine trial enrolled 1,696 children aged 6 weeks to 17 months from 2009 through 2013, and participants were followed for up to 53 months.…”

“…Blood culture was performed for participants who were hospitalized or were evaluated for prolonged fever at outpatient clinics [9]. Second, the CNS study enrolled 320 participants aged �6 weeks who were hospitalized and met criteria for evaluation for acute central nervous system infection from November 2011 through December 2013 [10]. Blood and cerebrospinal fluid (CSF) culture were performed for all participants.…”

Building laboratory capacity to detect and characterize pathogens of public and global health security concern in Kenya

“…The Enteric TAC was similarly validated for 15 of the most common enteropathogens detected in the Global Enteric Multicenter Study (GEMS) using 1500 clinical specimens [31,32]. The Encephalitis TAC was developed to detect 21 pathogens (2 parasites, 6 bacteria, 13 viruses) known to cause encephalitis, with an overall sensitivity of 86% and specificity of 97% across tested comparative assays [33]. Because TAC is an effective screening tool for multiple pathogens in a single sample, it can detect co-infections or discover emerging pathogens not routinely tested through national surveillance platforms that frequently have a narrow focus.…”