HIV-Associated Cryptococcal Meningitis: Bridging the Gap Between Developed and Resource-Limited Settings.

Cryptococcal meningitis is a major cause of HIV-associated morbidity and mortality worldwide. Most cases occur in low-income countries, where over half of patients die within 10 weeks of diagnosis compared to as few as 10 % of patients from developed countries. A host of factors, spanning the HIV care continuum, are responsible for this gap in treatment outcomes between developed and resource-limited settings. We explore factors responsible for this outcomes gap and describe low-cost, highly effective measures that can be implemented immediately to improve outcomes in resource-limited settings. We also explore health-system challenges that must be addressed to reduce mortality further, recent research in disease prevention, and novel short-course treatment regimens that, if efficacious, could be implemented in resource-limited settings where the cost of standard treatment regimens is currently prohibitive

High Mortality in HIV-Associated Cryptococcal Meningitis Patients Treated With Amphotericin B-Based Therapy Under Routine Care Conditions in Africa.

BACKGROUND: Cryptococcal meningitis (CM) causes 10%-20% of HIV-related deaths in Africa. Due to limited access to liposomal amphotericin and flucytosine, most African treatment guidelines recommend amphotericin B deoxycholate (AmB-d) plus high-dose fluconazole; outcomes with this treatment regimen in routine care settings have not been well described. METHODS: Electronic national death registry data and computerized medical records were used to retrospectively collect demographic, laboratory, and 1-year outcome data from all patients with CM between 2012 and 2014 at Botswana's main referral hospital, when recommended treatment for CM was AmB-d 1 mg/kg/d plus fluconazole 800 mg/d for 14 days. Cumulative survival was estimated at 2 weeks, 10 weeks, and 1 year. RESULTS: There were 283 episodes of CM among 236 individuals; 69% (163/236) were male, and the median age was 36 years. All patients were HIV-infected, with a median CD4 count of 39 cells/mm3. Two hundred fifteen person-years of follow-up data were captured for the 236 CM patients. Complete outcome data were available for 233 patients (99%) at 2 weeks, 224 patients (95%) at 10 weeks, and 219 patients (93%) at 1 year. Cumulative mortality was 26% (95% confidence interval [CI], 20%-32%) at 2 weeks, 50% (95% CI, 43%-57%) at 10 weeks, and 65% (95% CI, 58%-71%) at 1 year. CONCLUSIONS: Mortality rates following HIV-associated CM treated with AmB-d and fluconazole in a routine health care setting in Botswana were very high. The findings highlight the inadequacies of current antifungal treatments for HIV-associated CM and underscore the difficulties of administering and monitoring intravenous amphotericin B deoxycholate therapy in resource-poor settings

Laboratory Evaluation of the VISITECT® Advanced Disease Semi-quantitative Point-of-care CD4 Test.

BACKGROUND: Advanced HIV disease (AHD; CD4 counts <200 cells/µL) remains common in many low- and middle-income settings. An instrument-free point-of-care test to rapidly identify patients with AHD would facilitate implementation of the World Health Organization (WHO) recommended package of care. We performed a laboratory-based validation study to evaluate the performance of the VISITECT® CD4 Advanced Disease assay in Botswana. SETTING: A laboratory validation study. METHODS: Venous blood samples from people living with HIV having baseline CD4 testing in Gaborone, Botswana, underwent routine testing using flow cytometry, followed by testing with the VISITECT® CD4 Advanced Disease assay by a laboratory scientist blinded to the flow cytometry result with a visual read to determine if the CD4 count was below 200 cells/µL. A second independent investigator conducted a visual read blinded to the results of both flow cytometry and the initial visual read. The sensitivity and specificity of the VISITECT® for detection of AHD were determined using flow cytometry as a reference standard, and inter-rater agreement in VISITECT® visual reads assessed. RESULTS: 1053 samples were included in the analysis. The VISITECT test correctly identified 112/119 samples as having a CD4 count <200 cells/µL, giving a sensitivity of 94.1% (95% confidence interval [CI] 88.3-97.6%) and specificity of 85.9% (95% CI 83.5-88.0%) compared to flow cytometry. Inter-rater agreement between the two independent readers was 97.5%, Kappa 0.92 (p<0.001). CONCLUSIONS: The VISITECT® CD4 Advanced Disease reliably identified individuals with low CD4 counts and could facilitate implementation of the WHO recommended package of interventions for AHD

Translating evidence into global impact: lessons for HIV research and policy development from the AMBITION trial

Commen

Prevalence and Sequelae of Cryptococcal Antigenemia in Antiretroviral Therapy-Experienced Populations: An Evaluation of Reflex Cryptococcal Antigen Screening in Botswana.

BACKGROUND: Evidence to inform cryptococcal antigen (CrAg)-screening guidelines among ART-experienced populations is lacking. We performed a study evaluating the utility of reflex CrAg screening in Gaborone, Botswana. METHODS: CD4 count data were collected from the HIV reference laboratory from 2014-2016. CrAg screening was performed on samples with CD4 ?100 cells/µL beginning January 2015. The proportion of CD4 counts ?100 cells/µL was determined and the frequency of repeat CrAg testing described. Analyses ascertained the impact of ART status on CrAg prevalence and outcomes, and whether CrAg titers could be used for risk stratification. RESULTS: Overall, 5.6% (3335/59 300) of individuals tested had CD4 ?100 cells/?L; 2108 samples with CD4 ?100 cells/?L from 1645 unique patients were CrAg tested. Over half of samples were from ART-experienced individuals: 40.9% (863) on ART and 12.1% (255) defaulters; 22% (463) of CrAg tests were on repeat samples. CrAg prevalence was 4.8% (72/1494; 95% CI, 3.8-6.0%) among outpatients and 21.9% (32/151; 95% CI, 15.3-28.5%) among inpatients. CrAg prevalence rates did not differ by ART status, but 6-month mortality was significantly lower in CrAg-positive individuals on ART at screening. Ten CrAg positives were identified through repeat testing. A CrAg titer cutoff ?1:80 provided the best discrimination for 6-month survival. CONCLUSIONS: CrAg-positivity rates in an ART-experienced population were comparable to those seen in ART-naive populations. Repeat screening identified individuals who seroconverted to CrAg positivity and were at risk of cryptococcal disease. CrAg titers ?1:80 can help identify the individuals at highest risk of death for more intensive management

Evaluation of a Novel Semiquantitative Cryptococcal Antigen Lateral Flow Assay in Patients with Advanced HIV Disease.

Higher cryptococcal antigen (CrAg) titers are strongly associated with mortality risk in individuals with HIV-associated cryptococcal disease. Rapid tests to quantify CrAg levels may provide important prognostic information and enable treatment stratification. We performed a laboratory-based validation of the IMMY semiquantitative cryptococcal antigen (CrAgSQ) lateral flow assay (LFA) against the current gold standard CrAg tests. We assessed the diagnostic accuracy of the CrAgSQ in HIV-positive individuals undergoing CrAg screening, determined the relationship between CrAgSQ scores and dilutional CrAg titers, assessed interrater reliability, and determined the clinical correlates of CrAgSQ scores. A total of 872 plasma samples were tested using both the CrAgSQ LFA and the conventional IMMY CrAg LFA, of which 692 were sequential samples from HIV-positive individuals undergoing CrAg screening and an additional 180 were known CrAg-positive plasma samples archived from prior studies. Interrater agreement in CrAgSQ reading was excellent (98.17% agreement, Cohen's kappa 0.962, P?<?0.001). Using the IMMY CrAg LFA as a reference standard, CrAgSQ was 93.0% sensitive (95% confidence interval [CI] 80.9% to 98.5%) and 93.8% specific (95% CI, 91.7% to 95.6%). After reclassification of discordant results using CrAg enzyme immunoassay testing, the sensitivity was 98.1% (95% CI, 90.1% to 100%) and specificity 95.8% (95% CI, 93.9% to 97.2%). The median CrAg titers for semiquantitative score categories (1+ to 4+) were 1:10 (interquartile range [IQR], 1:5 to 1:20) in the CrAgSQ 1+ category, 1:40 (IQR, 1:20 to 1:80) in the CrAgSQ 2+ category, 1:640 (IQR, 1:160 to 1:2,560) in the CrAgSQ 3+ category, and 1:5,120 (IQR, 1:2,560 to 1:30,720) in the CrAgSQ 4+ category. Increasing CrAgSQ scores were strongly associated with 10-week mortality. The IMMY CrAgSQ test had high sensitivity and specificity compared to the results for the IMMY CrAg LFA and provided CrAg scores that were associated with both conventional CrAg titers and clinical outcomes

Tracking cryptococcal meningitis to monitor HIV program success during the Treat-All era: an analysis of national data in Botswana.

BACKGROUND: Cryptococcal meningitis causes substantial mortality in high-HIV prevalence African countries despite advances in disease management and increasing antiretroviral therapy coverage. Reliable diagnosis of cryptococcal meningitis is cheap and more accessible than other indicators of AHD burden such as CD4 testing or investigation for disseminated tuberculosis; therefore, monitoring cryptococcal meningitis incidence has the potential to serve as a valuable metric of HIV programmatic success. METHODS: Botswana national meningitis surveillance data from 2015 to 2022 were obtained from electronic health records. All electronic laboratory records from cerebrospinal fluid samples analysed within government healthcare facilities in Botswana were extracted from a central online repository. Adjustments for missing data were made through triangulation with prospective cohort study datasets. Cryptococcal meningitis case frequency was enumerated using a case definition and incidence calculated using national census data. RESULTS: A total of 1,744 episodes of cryptococcal meningitis were identified; incidence declined from 15.0 (95% CI 13.4-16.7) cases/100,000 person-years in 2015 to 7.4 (95% CI 6.4-8.6) cases/100,000 person-years in 2022. However, the rate of decline slowed following the introduction of universal treatment in 2016. The highest incidence was observed in men and individuals aged 40-44. The proportion of cases diagnosed through cryptococcal antigen testing increased from 35.5% to 86.3%. CONCLUSION: Cryptococcal meningitis incidence has decreased in Botswana following expansion of ART coverage but persists at a stubbornly high incidence. Most cases are now diagnosed through the cheap and easy-to-use cryptococcal antigen test highlighting the potential of using cryptococcal meningitis as key metric of programme success in the Treat All era

Epidemiology of adult meningitis during antiretroviral therapy scale-up in southern Africa: Results from the Botswana national meningitis survey.

OBJECTIVES: Data on meningitis epidemiology in high HIV-prevalence African settings following antiretroviral therapy scale-up are lacking. We described epidemiology of adult meningitis in Botswana over a 16-year period. METHODS: Laboratory records for adults undergoing lumbar puncture (LP) 2000-2015 were collected, with complete national data 2013-2014. Cerebrospinal fluid (CSF) findings and linked HIV-data were described, and national incidence figures estimated for 2013-2014. Temporal trends in meningitis were evaluated. RESULTS: Of 21,560 adults evaluated, 41% (8759/21,560) had abnormal CSF findings with positive microbiological testing and/or pleocytosis; 43% (3755/8759) of these had no confirmed microbiological diagnosis. Of the 5004 microbiologically-confirmed meningitis cases, 89% (4432/5004) were cryptococcal (CM) and 8% (382/5004) pneumococcal (PM). Seventy-three percent (9525/13,033) of individuals undergoing LP with identifiers for HIV registry linkage had documented HIV-infection. Incidence of LP for meningitis evaluation in Botswana 2013-2014 was 142.6/100,000 person-years (95%CI:138.3-147.1); incidence of CM was 25.0/100,000 (95%CI:23.2-26.9), and incidence of PM was 2.7/100,000 (95%CI:2.4-3.1). In contrast to previously reported declines in CM incidence with ART roll-out, no significant temporal decline in pneumococcal or culture-negative meningitis was observed. CONCLUSIONS: CM remained the predominant identified aetiology of meningitis despite ART scale-up. A high proportion of cases had abnormal CSF with negative microbiological evaluation

Mortality in adult patients with culture-positive and culture-negative meningitis in the Botswana national meningitis survey: a prevalent cohort study.

BACKGROUND: CNS infections are a leading cause of HIV-related deaths in sub-Saharan Africa, but causes and outcomes are poorly defined. We aimed to determine mortality and predictors of mortality in adults evaluated for meningitis in Botswana, which has an estimated 23% HIV prevalence among adults. METHODS: In this prevalent cohort study, patient records from 2004-15 were sampled from the Botswana national meningitis survey, a nationwide audit of all cerebrospinal fluid (CSF) laboratory records from patients receiving a lumbar puncture for evaluation of meningitis. Data from all patients with culture-confirmed pneumococcal and tuberculous meningitis, and all patients with culture-negative meningitis with CSF white cell count (WCC) above 20 cells per μL were included in our analyses, in addition to a random selection of patients with culture-negative CSF and CSF WCC of up to 20 cells per μL. We used patient national identification numbers to link CSF laboratory records from the national meningitis survey to patient vital registry and HIV databases. Univariable and multivariable Cox proportional hazards models were used to evaluate clinical and laboratory predictors of mortality. FINDINGS: We included data from 238 patients with culture-confirmed pneumococcal meningitis, 48 with culture-confirmed tuberculous meningitis, and 2900 with culture-negative CSF (including 1691 with CSF WCC of up to 20 cells per μL and 1209 with CSF WCC above 20 cells per μL). Median age was 37 years (IQR 31-46), 1605 (50%) of 3184 patients were male, 2188 (72%) of 3023 patients with registry linkage had documentation of HIV infection, and median CD4 count was 139 cells per μL (IQR 63-271). 10-week and 1-year mortality was 47% (112 of 238) and 49% (117 of 238) for pneumococcal meningitis, 46% (22 of 48) and 56% (27 of 48) for tuberculous meningitis, and 41% (1181 of 2900) and 49% (1408 of 2900) for culture-negative patients. When the analysis of patients with culture-negative CSF was restricted to those with known HIV infection, WCC (0-20 cells per μL vs >20 cells per μL) was not predictive of mortality (average hazard ratio 0·93, 95% CI 0·80-1·09). INTERPRETATION: Mortality from pneumococcal, tuberculous, and culture-negative meningitis was high in this setting of high HIV prevalence. There is an urgent need for improved access to diagnostics, to better define aetiologies and develop novel diagnostic tools and treatment algorithms. FUNDING: National Institutes of Health, President's Emergency Plan for AIDS Relief, National Institute for Health Research

Causes of Pediatric Meningitis in Botswana: Results From a 16-Year National Meningitis Audit.

BACKGROUND: Central nervous system infections are an important cause of childhood morbidity and mortality in high HIV-prevalence settings of Africa. We evaluated the epidemiology of pediatric meningitis in Botswana during the rollout of antiretroviral therapy, pneumococcal conjugate vaccine and Haemophilus influenzae type B (HiB) vaccine. METHODS: We performed a cross-sectional study of children (<15 years old) evaluated for meningitis by cerebrospinal fluid (CSF) examination from 2000 to 2015, with complete national records for 2013-2014. Clinical and laboratory characteristics of microbiologically confirmed and culture-negative meningitis were described and incidence of Streptococcus pneumoniae, H. influenzae and cryptococcal meningitis was estimated for 2013-2014. RESULTS: A total of 6796 unique cases were identified. Median age was 1 year [interquartile range 0-3]; 10.4% (435/4186) of children with available HIV-related records were known HIV-infected. Overall, 30.4% (2067/6796) had abnormal CSF findings (positive microbiologic testing or CSF pleocytosis). Ten percent (651/6796) had a confirmed microbiologic diagnosis; including 26.9% (175/651) Cryptococcus, 18.9% (123/651) S. pneumoniae, 20.3% (132/651) H. influenzae and 1.1% (7/651) Mycobacterium tuberculosis. During 2013-2014, national cryptococcal meningitis incidence was 1.3 cases per 100,000 person-years (95% confidence interval, 0.8-2.1) and pneumococcal meningitis incidence 0.7 per 100,000 person-years (95% confidence interval, 0.3-1.3), with no HiB meningitis diagnosed. CONCLUSIONS: Following HiB vaccination, a marked decline in microbiologically confirmed cases of H. influenzae meningitis occurred. Cryptococcal meningitis remains the most common confirmed etiology, demonstrating gaps in prevention-of-mother-to-child transmission and early HIV diagnosis. The high proportion of abnormal CSF samples with no microbiologic diagnosis highlights limitation in available diagnostics