Evaluation of Fingerstick Cryptococcal Antigen Lateral Flow Assay in HIV-Infected Persons: a Diagnostic Accuracy Study (original) (raw)
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East African Medical Journal, 2018
Background : HIV-associated cryptococcal meningitis carries a high case-fatality-rate in sub-Saharan Africa. Diagnostic delays partly contribute to this. Rapid point-of-care tests may facilitate speedy diagnosis. This study aimed to determine the sensitivity and specificity of urine, serum and cerebrospinal fluid (CSF) cryptococcal antigen lateral flow assay for the diagnosis of HIV-associated cryptococcal meningitis compared with the gold standard CSF culture. Methods : A cross-sectional study was conducted in the medical wards of Moi Teaching and Referral Hospital, Eldoret, Kenya. Adult (≥18years) HIV-infected in-patients suspected to have meningitis had paired samples of urine, serum and CSF collected and tested real time using the cryptococcal antigen lateral flow assay (rapid point of care test). CSF cultures were also conducted. Data were analyzed using STATA ® (Statacorp Texas USA®). Descriptive statistics were used to summarize demographic, clinical and laboratory parameters...
BMC Research Notes, 2019
Objectives: The objective of this study was to evaluate the performance of lateral flow immunoassay (LFA) against latex agglutination (LA), India ink and culture in point-of-care diagnosis of cryptococcus meningitis (CM). We conducted cross-sectional study among HIV-positive patients with suspected CM at Mbagathi Hospital, Nairobi, April-July 2017. Results: Of 124 capillary blood and serum and 99 cerebrospinal fluid (CSF) samples, LFA and LA had a concurrence on serum of 94.4%, kappa (0.88), sensitivity (100%) and specificity (91%). LFA and LA on CSF, was 97.9%, kappa (0.96), sensitivity (100%) and specificity (96%). LFA and India ink was 96.9%, kappa (0.94), sensitivity (100%) and specificity (94.1%). On CSF culture, concurrence was 72.7%, kappa (0.43), sensitivity (100%) and specificity (64%) and of LFA on capillary blood, serum and CSF was 100% with kappa (1.00), sensitivity and specificity of 100%.
Scientific Reports
Since rapid cryptococcal antigen lateral flow assays (CrAg LFA) may expedite treatment of HIVassociated cryptococcal infections, we sought to validate clinic-based CrAg LFA testing. Among newly-diagnosed HIV-infected adults in South Africa, a trained nurse performed clinic-based testing of urine, fingerprick capillary and venous whole blood with rapid CrAg LFA (Immy Diagnostics, Norman, USA). We performed matched laboratory-based serum cryptococcal antigen testing with an enzyme immunoassay (EIA). We assessed diagnostic accuracy using EIA as the gold-standard, and performed additional validation testing on serum and among hospitalized adults with cryptococcal meningitis. Among 5,618 participants enrolled, 1,296 were HIV-infected and screened for cryptococcal antigenemia. Overall CrAg prevalence by serum EIA was 3.6% (95% CI 2.0-6.0%) for adults with CD4 < 200 cells/mm 3 , and 5.7% (95% CI 2.8-10.2%) for adults with CD4 < 100 cells/mm 3. Using expanded screening guidelines (CD4 < 200 cells/mm 3), CrAg LFA testing of venous whole blood, fingerprick capillary blood, and urine had diagnostic sensitivities of 46% (95% CI 19-75%), 38% (95% CI 14-68%), and 54% (95% CI 25-81%), and specificities of 97%, 97%, and 86%, respectively. When tested on serum samples, CrAg LFA had sensitivity of 93% (95% CI 66-100%) and specificity of 100% (95% CI 88-100%). All venous and fingerprick whole blood CrAg LFA tests were positive among 30 hospitalized adults with cryptococcal meningitis. Two independent readers had strong agreement for all LFA results (p < 0.0001). When performed at the point-of-care by trained nurses, CrAg LFA testing was feasible, had the highest accuracy on serum specimens, and may accelerate treatment of HIV-associated cryptococcal infections.
Indian Journal of Sexually Transmitted Diseases and AIDS, 2021
Background: Cryptococcal meningitis (CM) is the initial acquired immunodeficiency syndrome (AIDS) defining illness in 2% of patients with CD4 levels <100/μL and a leading cause of mortality in AIDS in the developing world. It is the most common opportunistic infection of the central nervous system in AIDS in various Indian studies. Detection of serum cryptococcal antigen (SCRAG) is the most widely used diagnostic method for cryptococcosis. The presence of cerebrospinal fluid cryptococcal antigen (CSF CRAG) is diagnostic of CM. CRAG can be determined by latex agglutination (LAT), enzyme-linked immunosorbent assay and now, by lateral flow (LFA)immunoassay. LFA is a point of care test that rapidly detects CRAG. Aims and Objectives: This study compares LAT and LFA for the detection of serum CRAG and diagnosing CM. Materials and methods: Two hundred and ten patients of HIV/AIDS were submitted to SCRAG LFA by dipstick. A sample was also sent to laboratory for SCRAG by LAT. CSF examinat...
Revista do Instituto de Medicina Tropical de São Paulo, 2015
SUMMARYAIDS-related cryptococcal meningitis continues to cause a substantial burden of death in low and middle income countries. The diagnostic use for detection of cryptococcal capsular polysaccharide antigen (CrAg) in serum and cerebrospinal fluid by latex agglutination test (CrAg-latex) or enzyme-linked immunoassay (EIA) has been available for over decades. Better diagnostics in asymptomatic and symptomatic phases of cryptococcosis are key components to reduce mortality. Recently, the cryptococcal antigen lateral flow assay (CrAg LFA) was included in the armamentarium for diagnosis. Unlike the other tests, the CrAg LFA is a dipstick immunochromatographic assay, in a format similar to the home pregnancy test, and requires little or no lab infrastructure. This test meets all of the World Health Organization ASSURED criteria (Affordable, Sensitive, Specific, User friendly, Rapid/robust, Equipment-free, and Delivered). CrAg LFA in serum, plasma, whole blood, or cerebrospinal fluid is...
Journal of Clinical Microbiology, 2021
A newly developed cryptococcal antigen (CrAg) semiquantitative (SQ) lateral flow assay (LFA) provides a semiquantitative result in a rapid one-step test instead of performing serial dilutions to determine CrAg titer. We prospectively compared the diagnostic performance of the CrAgSQ assay (IMMY) with the CrAg LFA (IMMY) on cerebrospinal fluid (CSF) samples collected from persons with HIV-associated meningitis. The CrAgSQ grades (11 to 51) were compared with CrAg LFA titers and quantitative CSF fungal cultures. Among 87 participants screened for HIV-associated meningitis, 60 had cryptococcal meningitis (59 CrAg positive [CrAg 1 ] by LFA and 1 false negative due to prozone with CrAg LFA titer of 1:1,310,000 and culture positivity), and 27 had no cryptococcal meningitis by CrAg LFA or culture. The CrAgSQ on CSF had 100% (60/60) sensitivity and 100% specificity (27/27
Performance of Cryptococcal Antigen Lateral Flow Assay Using Saliva in Ugandans with CD4 <100
PLoS ONE, 2014
Cryptococcal meningitis is the most common cause of opportunistic meningitis in HIVinfected patients in Brazil and causes unacceptable high mortality rates. In this study, HIVinfected patients with a first episode of culture-proven cryptococcal meningitis in cerebrospinal fluid (CSF) were prospectively included in order to evaluate sensitivity of cryptococcal antigen (CrAg) lateral flow assay (LFA) in serum, CSF, whole blood (fingerstick), and fresh urine. In addition, HIV-infected patients with other neurological confirmed diseases were included in order to evaluate the specificity of CrAg LFA in serum. Twenty patients with cryptococcal meningitis were included and in 19 of them, CrAg LFA in CSF, serum, and whole blood were positive (95% sensitivity). In 18 patients, India ink test was positive in CSF (90% sensitivity), and in 16 cases, CrAg LFA was positive in urine (80% sensitivity). Thirty-six HIV-infected patients with other neurological diseases had negative results of CrAg LFA in serum (100% specificity). In conclusion, CrAg LFA in serum, CSF, and whole blood showed high sensitivity and specificity. Whole blood CrAg LFA seems to be a good and reliable strategy to improve AIDS-related cryptococcal meningitis diagnosis in Brazil.
2015
Background: Cryptococcal meningitis is a fatal opportunistic infection in immunecompromised patients. Lack of simple, affordable, rapid and specific methods for diagnosis in many government health facilities in Kenya has aggravated patients’ conditions. Objective: This study was aimed at determining the performance of India ink (Microscopy), latex agglutination test (LAT) and enzyme immunoassay (EIA) in the diagnosis of cryptococcal meningitis in a Kenyan population. Design: Laboratory based cross-sectional study. Setting: A high-volume government health facility based in Nairobi. Subjects: One hundred and thirteen CSF samples from HIV positive patients with signs and symptoms of cryptococcal meningitis sent to the laboratory for routine analysis. Methodology: The study was approved by the KEMRI Scientific Committee/Ethics Review Committee and informed consent sought from the patients. The test for the agreement between the test methods and the gold standard (Culture) was calculated...
Tropical medicine & international health : TM & IH, 2016
To determine the prevalence of asymptomatic cryptococcal antigen (CRAG) using lateral flow assay (LFA) in hospitalized HIV-infected patients with CD4 counts < 200 cells/μL. Hospitalized HIV-infected patients were prospectively recruited at Instituto de Infectologia Emilio Ribas, a tertiary referral hospital to HIV-infected patients serving the São Paulo State, Brazil. All patients were >18 years old without prior cryptococcal meningitis, without clinical suspicion of cryptococcal meningitis, regardless of antiretroviral (ART)-status, and with CD4 counts <200 cells/μL. Serum CRAG was tested by LFA in all patients and whole blood CRAG was tested by LFA in positive cases. We enrolled 163 participants of whom 61% were men. The duration of HIV diagnosis was a median of 8 (range, 1-29) years. 26% were antiretroviral (ART)-naïve, and 74% were ART- experienced. The median CD4 cell count was 25 (range, 1-192) cells/μL. Five patients (3.1%; 95%CI, 1.0 to 7.0%) were asymptomatic CRAG-...
Introduction: Infections of the central nervous system are a considerable basis of mortality in people living with Human immunodeficiency virus (HIV), with progression to cryptococcal meningitis documented at around 15% of HIV‐associated mortality globally, with nearly three‐quarters occurring in the sub-Saharan Africa. Discoveries from previous studies preluded that mortality amid cryptococcal antigen (CrAg) positive persisted to be elevated than in CrAg negative persons. One feasible interpretation of this could be due to undiagnosed cryptococcus. Laboratory investigations towards prompt identification of cryptococcal disease prior to cryptococcal meningitis has progressed to point-of-care testing with high sensitivity and specificity as seen with the CrAg lateral flow assay screening to expedite treatment. The aim of the study is to map and translate evidence on CrAg infection among HIV-infected persons in sub-Saharan Africa (SSA).Methodology: The proposed scoping review will be ...