Methods of Rapid Diagnosis for the Etiology of Meningitis in Adults

Abstract

Infectious meningitis may be due to bacterial, mycobacterial, fungal or viral agents. Diagnosis of meningitis must take into account numerous items of patient history and symptomatology along with regional epidemiology and basic cerebrospinal fluid testing (protein, etc.) to allow the clinician to stratify the likelihood of etiology possibilities and rationally select additional diagnostic tests. Culture is the mainstay for diagnosis in many cases, but technology is evolving to provide more rapid, reliable diagnosis. The cryptococcal antigen lateral flow assay (Immuno-Mycologics) has revolutionized diagnosis of cryptococcosis and automated nucleic acid amplification assays hold promise for improving diagnosis of bacterial and mycobacterial meningitis. This review will focus on a holistic approach to diagnosis of meningitis as well as recent technological advances.

Improved diagnostic sensitivity for tuberculous meningitis with Xpert<SUP>®</SUP> MTB/RIF of centrifuged CSF

“…Cerebrospinal fluid (CSF) smear microscopy for acid fast bacilli (AFB) has abysmal sensitivity (~15%), and mycobacterial culture is too slow to be clinically meaningful. 1 Due to the HIV epidemic, TBM has emerged as the second most common cause of adult meningitis in Africa. 2–7 The Xpert MTB/RIF (Xpert, Cepheid, Sunnyvale, CA) test, a fully automated, cartridge-based PCR assay is now available worldwide, with FDA approval for pulmonary TB diagnosis.…”

State-of-the-Art Microbiologic Testing for Community-Acquired Meningitis and Encephalitis

“…Testing for M. tuberculosis and fungi, such as Cryptococcus neoformans, is usually limited to patients with recognized risk factors or immunocompromising conditions (6,22). Cryptococcus gattii occurs occasionally without obvious risk factors.…”

“…Bacterial meningitis is rare in healthy vaccinated populations but increased in infants and older adults and patients with persistent CSF leaks or basilar skull fractures, terminal complement deficiencies, and other immunocompromising conditions (4,18). Agents that primarily affect immunocompromised patients and rarely cause meningitis in immunocompetent persons include Cryptococcus spp., cytomegalovirus (CMV), VZV, human herpesvirus-6 (HHV-6), and Epstein-Barr virus (EBV), among others (22,23). Mycobacterium tuberculosis infections occur in patients with risk factors such as recent tuberculosis infection, prior residence in a region of endemicity, or immune-compromising condition (e.g., HIV infection).…”

Diagnostic accuracy of Xpert MTB/RIF Ultra for tuberculous meningitis in HIV-infected adults: A prospective cohort study

“…5 Cerebrospinal fluid (CSF) smear microscopy for acid-fast bacilli has poor sensitivity (≤15%) in routine care. 5 Although mycobacterial culture has higher sensitivity (50-60%), culture is too slow to be clinically useful. 5 In 2013, WHO endorsed the Xpert MTB/RIF assay (Cepheid, Sunnyvale, CA, USA) as the preferred initial test to investigate tuberculous meningitis after a systematic review of 13 studies.…”

“…5 Although mycobacterial culture has higher sensitivity (50-60%), culture is too slow to be clinically useful. 5 In 2013, WHO endorsed the Xpert MTB/RIF assay (Cepheid, Sunnyvale, CA, USA) as the preferred initial test to investigate tuberculous meningitis after a systematic review of 13 studies. [6][7][8] The Xpert is cartridge-based fullyautomated PCR test.…”