Reduction in mortality from HIV-related CNS infections in routine care in Africa (DREAMM): a before-and-after, implementation study

BACKGROUND: Four decades into the HIV epidemic, CNS infection remains a leading cause of preventable HIV-related deaths in routine care. The Driving Reduced AIDS-associated Meningo-encephalitis Mortality (DREAMM) project aimed to develop, implement, and evaluate pragmatic implementation interventions and strategies to reduce mortality from HIV-related CNS infection. METHODS: DREAMM took place in five public hospitals in Cameroon, Malawi, and Tanzania. The main intervention was a stepwise algorithm for HIV-related CNS infections including bedside rapid diagnostic testing and implementation of WHO cryptococcal meningitis guidelines. A health system strengthening approach for hospitals was adopted to deliver quality care through a co-designed education programme, optimised clinical and laboratory pathways, and communities of practice. DREAMM was led and driven by local leadership and divided into three phases: observation (including situational analyses of routine care), training, and implementation. Consecutive adults (aged ≥18 years) living with HIV presenting with a first episode of suspected CNS infection were eligible for recruitment. The primary endpoint was the comparison of 2-week all-cause mortality between observation and implementation phases. This study completed follow-up in September, 2021. The project was registered on ClinicalTrials.gov, NCT03226379. FINDINGS: From November, 2016 to April, 2019, 139 eligible participants were enrolled in the observation phase. From Jan 9, 2018, to March 25, 2021, 362 participants were enrolled into the implementation phase. 216 (76%) of 286 participants had advanced HIV disease (209 participants had missing CD4 cell count), and 340 (69%) of 494 participants had exposure to antiretroviral therapy (ART; one participant had missing ART data). In the implementation phase 269 (76%) of 356 participants had a probable CNS infection, 203 (76%) of whom received a confirmed microbiological or radiological diagnosis of CNS infection using existing diagnostic tests and medicines. 63 (49%) of 129 participants died at 2 weeks in the observation phase compared with 63 (24%) of 266 in the implementation phase; and all-cause mortality was lower in the implementation phase when adjusted for site, sex, age, ART exposure (adjusted risk difference –23%, 95% CI –33 to –13; p<0·001). At 10 weeks, 71 (55%) died in the observation phase compared with 103 (39%) in the implementation phase (–13%, –24 to –3; p=0·01). INTERPRETATION: DREAMM substantially reduced mortality from HIV-associated CNS infection in resource-limited settings in Africa. DREAMM scale-up is urgently required to reduce deaths in public hospitals and help meet Sustainable Development Goals. FUNDING: European and Developing Countries Clinical Trials Partnership, French Agency for Research on AIDS and Viral Hepatitis. TRANSLATIONS: For the French and Portuguese translations of the abstract see Supplementary Materials section

Development and validation of quantitative PCR assays for HIV-associated cryptococcal meningitis in sub-Saharan Africa: a diagnostic accuracy study

Background: HIV-associated cryptococcal meningitis is the second leading cause of AIDS-related deaths, with a 10-week mortality rate of 25–30%. Fungal load assessed by colony-forming unit (CFU) counts is used as a prognostic marker and to monitor response to treatment in research studies. PCR-based assessment of fungal load could be quicker and less labour-intensive. We sought to design, optimise, and validate quantitative PCR (qPCR) assays for the detection, identification, and quantification of Cryptococcus infections in patients with cryptococcal meningitis in sub-Saharan Africa. Methods: We developed and validated species-specific qPCR assays based on DNA amplification of QSP1 (QSP1A specific to Cryptococcus neoformans, QSP1B/C specific to Cryptococcus deneoformans, and QSP1D specific to Cryptococcus gattii species) and a pan-Cryptococcus assay based on a multicopy 28S rRNA gene. This was a longitudinal study that validated the designed assays on cerebrospinal fluid (CSF) of 209 patients with cryptococcal meningitis at baseline (day 0) and during anti-fungal therapy (day 7 and day 14), from the AMBITION-cm trial in Botswana and Malawi (2018–21). Eligible patients were aged 18 years or older and presenting with a first case of cryptococcal meningitis. Findings: When compared with quantitative cryptococcal culture as the reference, the sensitivity of the 28S rRNA was 98·2% (95% CI 95·1–99·5) and of the QSP1 assay was 90·4% (85·2–94·0) in CSF at day 0. Quantification of the fungal load with QSP1 and 28S rRNA qPCR correlated with quantitative cryptococcal culture (R2=0·73 and R2=0·78, respectively). Both Botswana and Malawi had a predominant C neoformans prevalence of 67% (95% CI 55–75) and 68% (57–73), respectively, and lower C gattii rates of 21% (14–31) and 8% (4–14), respectively. We identified ten patients that, after 14 days of treatment, harboured viable but non-culturable yeasts based on QSP1 RNA detection (without any positive CFU in CSF culture). Interpretation: QSP1 and 28S rRNA assays are useful in identifying Cryptococcus species. qPCR results correlate well with baseline quantitative cryptococcal culture and show a similar decline in fungal load during induction therapy. These assays could be a faster alternative to quantitative cryptococcal culture to determine fungal load clearance. The clinical implications of the possible detection of viable but non-culturable cells in CSF during induction therapy remain unclear. Funding: European and Developing Countries Clinical Trials Partnership; Swedish International Development Cooperation Agency; Wellcome Trust/UK Medical Research Council/UKAID Joint Global Health Trials; and UK National Institute for Health Research

Development and validation of quantitative PCR assays for HIV-associated cryptococcal meningitis in sub-Saharan Africa: a diagnostic accuracy study

Background: HIV-associated cryptococcal meningitis is the second leading cause of AIDS-related deaths, with a 10-week mortality rate of 25–30%. Fungal load assessed by colony-forming unit (CFU) counts is used as a prognostic marker and to monitor response to treatment in research studies. PCR-based assessment of fungal load could be quicker and less labour-intensive. We sought to design, optimise, and validate quantitative PCR (qPCR) assays for the detection, identification, and quantification of Cryptococcus infections in patients with cryptococcal meningitis in sub-Saharan Africa. Methods: We developed and validated species-specific qPCR assays based on DNA amplification of QSP1 (QSP1A specific to Cryptococcus neoformans, QSP1B/C specific to Cryptococcus deneoformans, and QSP1D specific to Cryptococcus gattii species) and a pan-Cryptococcus assay based on a multicopy 28S rRNA gene. This was a longitudinal study that validated the designed assays on cerebrospinal fluid (CSF) of 209 patients with cryptococcal meningitis at baseline (day 0) and during anti-fungal therapy (day 7 and day 14), from the AMBITION-cm trial in Botswana and Malawi (2018–21). Eligible patients were aged 18 years or older and presenting with a first case of cryptococcal meningitis. Findings: When compared with quantitative cryptococcal culture as the reference, the sensitivity of the 28S rRNA was 98·2% (95% CI 95·1–99·5) and of the QSP1 assay was 90·4% (85·2–94·0) in CSF at day 0. Quantification of the fungal load with QSP1 and 28S rRNA qPCR correlated with quantitative cryptococcal culture (R2=0·73 and R2=0·78, respectively). Both Botswana and Malawi had a predominant C neoformans prevalence of 67% (95% CI 55–75) and 68% (57–73), respectively, and lower C gattii rates of 21% (14–31) and 8% (4–14), respectively. We identified ten patients that, after 14 days of treatment, harboured viable but non-culturable yeasts based on QSP1 RNA detection (without any positive CFU in CSF culture). Interpretation: QSP1 and 28S rRNA assays are useful in identifying Cryptococcus species. qPCR results correlate well with baseline quantitative cryptococcal culture and show a similar decline in fungal load during induction therapy. These assays could be a faster alternative to quantitative cryptococcal culture to determine fungal load clearance. The clinical implications of the possible detection of viable but non-culturable cells in CSF during induction therapy remain unclear

The Nairobi Declaration 2023: A commitment to address deadly yet neglected fungal diseases in Africa.

On May 30th and 31st, 2023, delegates representing various African subregions, together with global representatives from the International Society of Human and Animal Mycology (ISHAM), the European Confederation of Medical Mycology (ECMM), the United States Centre for Disease Control and Prevention (CDC), and Global Action for Fungal Infections (GAFFI), convened in Nairobi, Kenya under the aegis of the Pan African Mycology Working Group, a working group of ISHAM. The meeting objectives were, amongst others, to deliberate on a continental response to the World Health Organisation Fungal Priority Pathogen List and facilitate interaction between global and regional leaders. Country delegates and international speakers addressed Africa's fungal disease burden; capacity for diagnosis and management; ongoing surveillance; knowledge gaps and trends in invasive fungal diseases such as Candida auris, mucormycosis, aspergillosis, and Acquired Immune Deficiency Syndrome (AIDS)-related mycoses; and current laboratory practice. During the technical sessions, expert panels deliberated on establishing and financing of national/regional surveillance networks for mycoses; establishing and sustaining African-led collaborations; expanding on existing laboratory and point-of-care diagnostic capacity as well as planning a mycology reference laboratory service and network in Africa. The meeting also highlighted successful African-led collaborations, capacity building, and clinical trial initiatives. The meeting conclusions informed the resolutions of the Nairobi Declaration calling for improved awareness; strong collaborations between clinical and laboratory teams across Africa; improved fungal disease surveillance within the continent; access to antifungals and diagnostics; and leveraging qualified human resources for mycology present within and outside Africa to facilitate trainings, collaborations, and exchanges

Titan cells formation in Cryptococcus neoformans is finely tuned by environmental conditions and modulated by positive and negative genetic regulators.

The pathogenic fungus Cryptococcus neoformans exhibits morphological changes in cell size during lung infection, producing both typical size 5 to 7 μm cells and large titan cells (> 10 μm and up to 100 μm). We found and optimized in vitro conditions that produce titan cells in order to identify the ancestry of titan cells, the environmental determinants, and the key gene regulators of titan cell formation. Titan cells generated in vitro harbor the main characteristics of titan cells produced in vivo including their large cell size (>10 μm), polyploidy with a single nucleus, large vacuole, dense capsule, and thick cell wall. Here we show titan cells derived from the enlargement of progenitor cells in the population independent of yeast growth rate. Change in the incubation medium, hypoxia, nutrient starvation and low pH were the main factors that trigger titan cell formation, while quorum sensing factors like the initial inoculum concentration, pantothenic acid, and the quorum sensing peptide Qsp1p also impacted titan cell formation. Inhibition of ergosterol, protein and nucleic acid biosynthesis altered titan cell formation, as did serum, phospholipids and anti-capsular antibodies in our settings. We explored genetic factors important for titan cell formation using three approaches. Using H99-derivative strains with natural genetic differences, we showed that titan cell formation was dependent on LMP1 and SGF29 genes. By screening a gene deletion collection, we also confirmed that GPR4/5-RIM101, and CAC1 genes were required to generate titan cells and that the PKR1, TSP2, USV101 genes negatively regulated titan cell formation. Furthermore, analysis of spontaneous Pkr1 loss-of-function clinical isolates confirmed the important role of the Pkr1 protein as a negative regulator of titan cell formation. Through development of a standardized and robust in vitro assay, our results provide new insights into titan cell biogenesis with the identification of multiple important factors/pathways

The Nairobi Declaration 2023: A Commitment to Address Deadly Yet Neglected Fungal Diseases in Africa

International audienceOn May 30th and 31st, 2023, delegates representing various African subregions, together with global representatives from the International Society of Human and Animal Mycology (ISHAM), European Confederation of Medical Mycology (ECMM,) United States Centre for Disease Control and Prevention (CDC) and Global Action for Fungal Infections (GAFFI), convened in Nairobi, Kenya under the aegis of the Pan African Mycology Working Group, a working group of ISHAM. The meeting objectives were, amongst others, to deliberate on a continental response to the World Health Organization Fungal Priority Pathogen List and facilitate interaction between global and regional leaders. Country delegates and international speakers addressed Africa’s fungal disease burden; capacity for diagnosis and management; ongoing surveillance; knowledge gaps and trends in invasive fungal diseases such as Candida auris, mucormycosis, aspergillosis and Acquired Immune Deficiency Syndrome (AIDS)-related mycoses; and current laboratory practice. During the technical sessions, expert panels deliberated on establishing and financing of national/regional surveillance networks for mycoses; establishing and sustaining African-led collaborations; expanding on existing laboratory and point of care diagnostic capacity as well as planning a mycology reference laboratory service and network in Africa. The meeting also highlighted successful African-led collaborations, capacity building and clinical trial initiatives. The meeting conclusions informed the resolutions of the Nairobi Declaration calling for improved awareness; strong collaborations between clinical and laboratory teams across Africa; improved fungal disease surveillance within the continent; access to antifungals and diagnostics; and leveraging qualified human resources for mycology present within and outside Africa to facilitate trainings, collaborations and exchanges

Genes affected by SNPs or Indels in the different H99 strains.

<p>Genes affected by SNPs or Indels in the different H99 strains.</p

<i>In vitro</i> titan cells generation is dependent on the negative regulator <i>PKR1</i> and <i>TSP2</i>.

<p><b><i>(A)</i></b><i>PKR1</i> is a repressor of titan cells formation in KN99α background and (<b>B</b>) in H99 background. (<b>C</b>) in galactose mimimal medium (galactose MM), GAL7 promoter upstream of the <i>PKA1</i> and <i>PKR1</i> genes induced an increased titan cells formation for PKA1 and a decreased titan cells formation for PKR1 (<b>D</b>) In minimal medium with glucose (glucose MM)), GAL7 promoter induced a repression of titan cells formation for PKA1 and an induction of titan cells formation for PKR1. (<b>E</b>) Tetraspanin 2 (<i>TSP2</i>) is a repressor of titan cells formation. Complementation of the deletion mutants restored the phenotype of KN99α. The ratio to H99 or KN99α, used as a calibrator in each experiment, was calculated for each strain (panel A to E) and results expressed as mean ± SD. Experiments A to G were done in triplicate. To compare the experimental conditions to H99O, Khi2 analysis was performed (*p<0.0001 vs control H99 or KN99α or appropriate mutants).</p

Alignment and SNP statistics of sequenced isolates using H99 as a reference.

<p>Alignment and SNP statistics of sequenced isolates using H99 as a reference.</p

Dynamics of titan cells generation <i>in vitro</i>.

<p>(<b>A</b>) Cell body size was measured from samples of H99O culture (step 3 of the protocol) withdrawn at specific times (H0 to H120) using pictures taken in bright field and measured with the ICY software (mean number of yeasts counted ± SD = 219 ± 67, representative of three experiments). Cell size increased starting at H8 with some cells reaching the threshold of 10 μm (grey dashed line). Each dot represents a single cell and the bars represent median and IQR; (<b>B</b>) Titan cells generation started between H8 and H12 and reached a plateau at H24. Each dot represents the proportion of titan cells in the corresponding sample (3 independent experiments); (<b>C</b>) Pictures (x400 magnification) taken overtime showing the progressive increase in cell body size and the appearance of a vacuole typical of titan cells in a large cell at H8 (white arrow) (scale bar 10 μm); (<b>D</b>) Time lapse imaging of titan cells generation over 12 h showing that titan cells swelled progressively from a small cell and produced daughter cells after having increased their size. (<b>E</b>) Cells stained with calcofluor (CFW) at 0.1 μg/mL prior to incubation using our protocol. CFW fluorescent intensity is analyzed by flow cytometry in the initial (H0) and the resulting FSC/SSC^high (titan cells) and FSC/SSC^low (typical cells) observed at H24. The initial (H0) (green line) and the H24 FSC/SSC^high (blue line) populations harbored a high CFW fluorescence suggesting that they are mother cells, with a higher fluorescence for the FSC/SSC^high, while two populations of high and low (black star) CFW fluorescence intensity were observed for the H24 FSC/SSC^low cells (Left panel). The right panel shows the size (FSC) and CFW fluorescence intensity of the yeast populations at H0 (black content lines) and H24 (yellow content lines). The initial population (CFW^high/FSC^low) evolved in two populations, one corresponding to daughter cells (typical cells, CFW^low/FSC^low, white arrow), and the other one corresponding to titan cells (CFW^high/FSC^high, black arrow).</p