S7.1d Reliability of bedside point-of-care tests for Candida neoformans , M. tuberculosis and S. pneumoniae in adults living with HIV presenting with suspected central nervous system infection (CNS) in low- and middle-income settings: Preliminary results from the DREAMM study

Abstract

S7.1 Update in management of fungal infection in adult hematology, September 23, 2022, 10:30 AM - 12:00 PMBackgroundBedside point-of-care (POC) testing, with parallel laboratory testing, represents a unique opportunity to improve and speed up the diagnostic workup of people living with HIV with suspected CNS infection in resource-limited settings.ObjectivesTo assess the agreement between POC tests for Cryptococcus neoformans, Mycobacterium tuberculosis, and Streptococcus pneumoniae performed at the bedside and in the routine laboratory, in African low- and middle-income countries (LMICs).MethodsFrom January 2018 to March 2021, the following POC tests were performed in parallel at the bedside and in the routine laboratory: Cryptococcal antigen lateral flow assay (CrAg LFA, Immy) in blood and cerebrospinal fluid (CSF), tuberculosis lipoarabinomannan (TB-LAM, Alere) in urine, and, where indicated, pneumococcal antigen (Streptococcus pneumoniae (SP), Biosynex) in CSF.Participants: HIV-infected adults (>18 years old) suspected of CNS infection.Setting: The prospective multicenter DREAMM project (Driving Reduced AIDS Meningo-Encephalitis Mortality) in five hospital sites in Cameroon, Malawi, and Tanzania.Primary outcome: Cohen's kappa statistic of agreement between the results of POC tests obtained at the bedside and the routine laboratory.ResultsThe study included 356 consecutive participants (mean age 39.5 +/- 10 years; 68.7% ART-experienced; 46.3% male; median CD4 count 75/mm3; abnormal mental status 75%). In total, 148/355 (41.7%) participants had positive bedside CrAg in blood, 140/315 (44.4%) positive bedside CrAg in CSF, 64/339 (18.9%) positive bedside TB-LAM in urine, and 10/175 (5.7%) positive bedside SP in CSF. Kappa statistics evaluating agreement between bedside and laboratory test results were: 0.98 [95% confidence interval (CI) 0.96-1.00; n = 347] for blood CrAg, 0.99 (95%CI, 0.98-1.00; n = 307) for CSF CrAg, 0.92 (95% CI, 0.87-0.98; n = 330) for urinary TB-LAM, and 0.68 (95%CI, 0.40-0.96; n = 34) for CSF SP.ConclusionsBedside POC tests for Cryptococcus spp. are highly reliable and can be safely performed in parallel to laboratory testing to expedite targeted treatment in people living with HIV with suspected CNS infection in African LMICs. Other bedside POC tests need further evaluation before large-scale implementation.