Diagnostic capacity for invasive fungal infections in advanced HIV disease in Africa: a continent-wide survey

Global incidence and mortality of severe fungal disease

Current estimates of fungal disease incidence and mortality are imprecise. Population at risk denominators were used to estimate annual incidence for 2019-21. Extensive literature searches from 2010 to 2023 were combined with over 85 papers on individual country and global disease burden. Crude and attributable mortality were estimated using a combination of untreated mortality, the proportion of patients who are treated, and percentage survival in treated patients. Awareness, guidelines, and accessibility of diagnostics and therapies informed the ratio of treated to untreated cases. Estimates do not include influenza or COVID-19 outbreaks. Data from more than 120 countries were included. Annually, over 2 113 000 people develop invasive aspergillosis in the context of chronic obstructive pulmonary disease, intensive care, lung cancer, or haematological malignancy, with a crude annual mortality of 1 801 000 (85·2%). The annual incidence of chronic pulmonary aspergillosis is 1 837 272, with 340 000 (18·5%) deaths. About 1 565 000 people have a Candida bloodstream infection or invasive candidiasis each year, with 995 000 deaths (63·6%). Pneumocystis pneumonia affects 505 000 people, with 214 000 deaths (42·4%). Cryptococcal meningitis affects 194 000 people, with 147 000 deaths (75·8%). Other major life-threatening fungal infections affect about 300 000 people, causing 161 000 deaths (53·7%). Fungal asthma affects approximately 11·5 million people and might contribute to 46 000 asthma deaths annually. These updated estimates suggest an annual incidence of 6·5 million invasive fungal infections and 3·8 million deaths, of which about 2·5 million (68%; range 35-90) were directly attributable.

Advanced HIV disease and associated factors among young people aged 15-24 years at a tertiary hospital in Sierra Leone: a cross-sectional study

BACKGROUND

Advanced HIV disease (AHD) in young people living with HIV (PLHIV) is an increasingly pressing public health issue in sub-Saharan Africa. Despite global progress in early HIV testing and reducing HIV-related deaths, many youths experience increased rates of HIV disease progression in sub-Saharan Africa. This study describes the burden, clinical manifestations, and factors for disease progression among young PLHIV aged 15 - 24 years seeking medical services at a major public hospital in Sierra Leone.

METHODS

We performed a cross-sectional analysis of routinely collected data for PLHIV patients aged 15 to 24 seen at Connaught Hospital in Sierra Leone between September 2022 and March 2023. We estimated the proportion of AHD in young PLHIV and performed logistic regression modelling to explore predictors of AHD. The statistical significance level was set at 0.05 for all statistical tests.

RESULTS

Of the 581 PLHIV that were reported, 238 (40.9%) were between the ages of 15 and 24 years, with a median age of 22 (20-24), and 151 (63.5%) were females. On review, 178 (74.8%) has initiated antiretroviral therapy regimen (ART); 117 (65.7%) were actively on ART for ≤ 6 months, while 114 (64%) had interruptions with their ART treatment. The overall prevalence of AHD was 41.6% (99/238); 46.7% (35/68) of young PLHIV at the HIV clinic, and 39.3% (64/163) of admission. Sex-Female (OR, 0.51; 95% CI, 0.28-0.94; p = 0.030), and Tertiary Education level (OR, 0.27; 95% CI, 0.10 - 0.78; p = 0.015) have significantly lower odds of AHD in the entire study population. While for inpatients, Age (young Adults) of PLHIV (OR, 1.23; 95% CI, 1.00-1.52; p = 0.047) had 1.23 times the odds of AHD compared to adolescents, and being female (OR, 0.27; 95% CI, 0.08-0.84; p = 0.024), Overweight-Body mass index (OR, 0.10; 95% CI, 0.01-0.77; p = 0.028), Tertiary Education level (OR, 0.08; 95% CI, 0.01-0.52; p = 0.008) have significantly lower odds of AHD. Common conditions reported for the AHD group in the medical wards are tuberculosis (13.58%), hepatitis B (6.13%), Kaposi sarcoma (3.07%), and oesophagal candidiasis (2.45%).

CONCLUSION

We reported a high prevalence of advanced HIV among young patients in a tertiary Hospital in Sierra Leone. One in two young PLHIV aged 15 to 24 years reported AHD, emphasizing the need to strengthen public health measures that address access to and retention of HIV services.

N-Butylphthalide Potentiates the Effect of Fluconazole Against Drug-Resistant Candida glabrata and Candida tropicalis. Evidence for Its Mechanism of Action

Objective

To define the antifungal activity of n-butylphthalide alone or in combination with fluconazole in Candida glabrata and Candida tropicalis.

Methods

The antifungal activity of n-butylphthalide alone and in combination with fluconazole was investigated by the classical broth microdilution method and the time-killing curve method. The QRT-PCR method was used to determine gene expressions changes of mitochondrial respiratory chain enzymes, drug efflux pumps and drug target enzymes in Candida glabrata and Candida tropicalis after n-butylphthalide treatment.

Results

The MIC values of n-butylphthalide against Candida glabrata and Candida tropicalis ranged from 16 to 64 μg·mL-1. The FICI value of the combination of n-butylphthalide and fluconazole against drug-resistant Candida glabrata and Candida tropicalis ranged from 0.5001 to 0.5315 with partial synergism. Time-killing curves showed that 256 μg·mL-1 n-butylphthalide significantly inhibited the growth of drug-resistant colonies of Candida glabrata and Candida tropicalis, and 128 μg·mL-1 n-butylphthalide combined with 1 μg·mL-1 fluconazole had an additive effect. N-butylphthalide could alter the expression of mitochondrial respiratory chain enzymes COX1, COX2, COX3, and CYTB genes in Candida glabrata and Candida tropicalis (P< 0.05) and downregulate the expression of the drug efflux pump genes CDR1 and CDR2 in drug-resistant Candida glabrata to 3.36% and 3.65%, respectively (P<0.001), but did not affect the drug target enzyme ERG11 in drug-resistant Candida tropicalis.

Conclusion

N-butylphthalide had antifungal activity against Candida glabrata and Candida tropicalis. N-butylphthalide improved the activity of fluconazole against drug-resistant Candida glabrata by affecting the expression of mitochondrial respiratory chain enzyme genes and reversing the high expression of drug efflux pump genes CDR1 and CDR2.

Frequency of fungal pathogens in autopsy studies of people who died with HIV in Africa: a scoping review

BACKGROUND

Fungal infections are common in HIV-infected individuals and significantly contribute to mortality. However, a substantial number of cases are undiagnosed before death.

OBJECTIVE

To determine the frequency of fungal pathogens in autopsy studies of people who died with HIV in Africa.

METHODS

We conducted a scoping review of autopsy studies conducted in Africa.

DATA SOURCES

PubMed, Scopus, Web of Science, Embase, Google Scholar, and African Journal Online.

STUDY ELIGIBILITY CRITERIA

The review encompasses studies published from inception to September 2023, and no language restrictions were imposed during the search process. We included studies that reported histopathological or microbiological evidence for the diagnosis of fungal infections and other pathogens.

DATA SYNTHESIS

Data were summarized using descriptive statistics and no meta-analysis was performed.

RESULTS

We examined 30 articles reporting studies conducted between 1991 and 2019, encompassing a total of 13 066 HIV-infected decedents across ten African countries. In five studies, the autopsy type was not specified. Among those studies with specified autopsy types, 20 involved complete diagnostic autopsies, whereas 5 were categorized as partial or minimally invasive autopsies. There were 2333 pathogens identified, with 946 (40.5%) being mycobacteria, 856 (36.7%) fungal, 231 (3.8%) viral, 208 (8.9%) parasitic, and 92 (3.9%) bacterial. Of the 856 fungal pathogens identified, 654 (28.0%) were Cryptococcus species, 167 (7.2%) Pneumocystis jirovecii, 16 (0.69%) Histoplasma species, 15 (0.64%) Aspergillus species, and 4 (0.17%) Candida species. Other major non-fungal pathogens identified were cytomegalovirus 172 (7.37%) and Toxoplasma gondii 173 (7.42%).

CONCLUSIONS

Invasive fungal infections occur in over one-third of people who succumb to HIV in Africa. In addition to cryptococcosis and Pneumocystis jirovecii pneumonia, integrating other priority fungal pathogen detection and management strategies into the broader framework of HIV care in Africa is recommended. This involves increasing awareness regarding the impact of fungal infections in advanced HIV disease and strengthening diagnostic and treatment capacity.

Targeting Fks1 proteins for novel antifungal drug discovery

Fungal infections are a major threat to human health. The limited availability of antifungal drugs, the emergence of drug resistance, and a growing susceptible population highlight the critical need for novel antifungal agents. The enzymes involved in fungal cell wall synthesis offer potential targets for antifungal drug development. Recent studies have enhanced our focus on the enzyme Fks1, which synthesizes β-1,3-glucan, a critical component of the cell wall. These studies provide a deeper understanding of Fks1's function in cell wall biosynthesis, pathogenicity, structural biology, evolutionary conservation across fungi, and interaction with current antifungal drugs. Here, we discuss the role of Fks1 in the survival and adaptation of fungi, guided by insights from evolutionary and structural analyses. Furthermore, we delve into the dynamics of Fks1 modulation with novel antifungal strategies and assess its potential as an antifungal drug target.

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.

Standard of care in advanced HIV disease: review of HIV treatment guidelines in six sub-Saharan African countries

BACKGROUND

The World Health Organization (WHO) recommends an evidence-based package of care to reduce mortality and morbidity among people with advanced HIV disease (AHD). Adoption of these recommendations by national guidelines in sub-Saharan Africa is poorly documented. We aimed to review national guidelines for AHD management across six selected countries in sub-Saharan Africa for benchmarking against the 2021 WHO recommendations.

METHODS

We reviewed national guidelines from six countries participating in an ongoing randomized controlled trial recruiting people with AHD. We extracted information addressing 18 items of AHD diagnosis and management across the following domains: [1] Definition of AHD, [2] Screening, [3] Prophylaxis, [4] Supportive care, and [5] HIV treatment. Data from national guideline documents were compared to the 2021 WHO consolidated guidelines on HIV and an agreement score was produced to evaluate extent of guideline adoption.

RESULTS

The distribution of categories of agreement varied for the national documents. Four of the six countries addressed all 18 items (Malawi, Nigeria, Sierra Leone, Uganda). Overall agreement with the WHO 2021 guidelines ranged from 9 to 15.5 out of 18 possible points: Malawi 15.5 points, Nigeria, and Sierra Leone 14.5 points, South Africa 13.5 points, Uganda 13.0 points and Botswana with 9.0 points. Most inconsistencies were reported for the delay of antiretroviral therapy (ART) in presence of opportunistic diseases. None of the six national guidelines aligned with WHO recommendations around ART timing in patients with tuberculosis. Agreement correlated with the year of publication of the national guideline.

CONCLUSION

National guidelines addressing the care of advanced HIV disease in sub-Saharan Africa are available. Besides optimal timing for start of ART in presence of tuberculosis, most national recommendations are in line with the 2021 WHO standards.

Prevalence and factors associated with advanced HIV disease among young people aged 15 - 24 years in a national referral hospital in Sierra Leone: A cross-sectional study

Background

Advanced HIV in young people living with HIV is an increasingly pressing public health issue in sub-Saharan Africa. Despite global progress in early HIV testing and reducing HIV-related deaths, many young people with HIV continue to experience HIV disease progression in sub-Saharan Africa. This study provides an overview of the prevalence, clinical manifestations, and factors associated with advanced HIV in young people seeking medical services in a major hospital in Sierra Leone.

Methods

We used a cross-sectional design to collect data from HIV patients aged 15 to 24 years at a major hospital in Sierra Leone between September 2022 and March 2023. Advanced HIV was defined as (i) CD4+ below 200 cells/mm3 or (ii) WHO clinical stage 3 or 4. Logistic regression models determined the association between observable independent characteristics and advanced HIV. The statistical significance level was set at 0.05 for all statistical tests.

Results

About 40% (231/574) of patients were recruited; 70.6% (163/231) were inpatients, and 29.4% (68/231) were outpatients. The mean age was approximately 21.6 years (SD ±2.43). The overall prevalence of advanced HIV was 42.9% (99/231), 51.5% (35/68) of outpatients, and 39.3% (64/163) of inpatients. Age of inpatients (OR, 1.23; 95% CI, 1.00-1.52; p= 0.047) was associated with a higher risk. Female sex (OR, 0.51; 95% CI, 0.28-0.94; p= 0.030), higher education (OR, 0.27; 95% CI, 0.10 - 0.78; p= 0.015), and Body Mass (OR, 0.10; 95% CI, 0.01-0.77; p= 0.028) were at lower risk of advance HIV. Common conditions diagnosed in this population are tuberculosis (13.58%), hepatitis B (6.13%), Kaposi sarcoma (3.07%), and esophageal candidiasis (2.45%).

Conclusion

We reported a high prevalence of advanced HIV among young patients in a referral Hospital in Sierra Leone. This emphasises the need to strengthen public health measures and policies that address challenges of access to HIV services.

HIV and fungal priority pathogens

The burden of invasive fungal infections associated with opportunistic fungal pathogens is a persistent challenge, particularly among people with advanced HIV disease. In October, 2022, WHO published the Fungal Priority Pathogens List (FPPL)-the first global effort to systematically prioritise fungal pathogens. Of the 19 pathogens in the WHO FPPL, four opportunistic pathogens in particular cause invasive diseases in people living with HIV: Cryptococcus neoformans, Histoplasma spp, Pneumocystis jirovecii, and Talaromyces marneffei. These four fungal pathogens are major causes of illness and death in people with advanced HIV and overwhelmingly affect those in low-income and middle-income countries. Access to diagnostics, improved surveillance, targeted support for innovation, and an enhanced public health focus on these diseases are needed in the effort to reduce HIV-associated deaths.

The Current and Future States of Diagnostic Tests for Histoplasmosis with a Focus on People with HIV and Disseminated Histoplasmosis

Histoplasmosis is caused by Histoplasma capsulatum and, although endemic in large parts of the world, is often underrecognized in many locations. In addition to underrecognition, inadequate availability of diagnostic tests is a major contributor to poor outcomes in disseminated disease in people with HIV. For those with advanced HIV and disseminated disease, antibody testing is less useful. Culture and histopathology can be useful in this situation, but each has limitations, including variable sensitivity by site and, in the case of culture, the need for a biosafety level three laboratory and a long period of growth. Antigen testing has proven useful for disseminated histoplasmosis due to the excellent sensitivity of urine. Yet, turnaround is slower than ideal due to use in a limited number of centers. The development of lateral flow assays has the potential to make for true rapid point-of-care assays for histoplasmosis, but in order to meet that promise, the tests must be widely available and affordable.

Discovery and development of novel substituted monohydrazides as potent antifungal agents

Novel substituted monohydrazides synthesized for this study displayed broad-spectrum activity against various fungal strains, including a panel of clinically relevant Candida auris strains. The activity of these compounds was either comparable or superior to amphotericin B against most of the fungal strains tested. These compounds possessed fungistatic activity in a time-kill assay and exhibited no mammalian cell toxicity. In addition, they prevented the formation of fungal biofilms. Even after repeated exposures, the Candida albicans ATCC 10231 (strain A) fungal strain did not develop resistance to these monohydrazides.

A multicentre external quality assessment: A first step to standardise PCR protocols for the diagnosis of histoplasmosis and coccidioidomycosis

BACKGROUND

In-house real-time PCR (qPCR) is increasingly used to diagnose the so-called endemic mycoses as commercial assays are not widely available.

OBJECTIVES

To compare the performance of different molecular diagnostic assays for detecting Histoplasma capsulatum and Coccidioides spp. in five European reference laboratories.

METHODS

Two blinded external quality assessment (EQA) panels were sent to each laboratory that performed the analysis with their in-house assays. Both panels included a range of concentrations of H. capsulatum (n = 7) and Coccidioides spp. (n = 6), negative control and DNA from other fungi. Four laboratories used specific qPCRs, and one laboratory a broad-range fungal conventional PCR (cPCR) and a specific cPCR for H. capsulatum with subsequent sequencing.

RESULTS

qPCR assays were the most sensitive for the detection of H. capsulatum DNA. The lowest amount of H. capsulatum DNA detected was 1-4 fg, 0.1 pg and 10 pg for qPCRs, specific cPCR and broad-range cPCR, respectively. False positive results occurred with high concentrations of Blastomyces dermatitidis DNA in two laboratories and with Emergomyces spp. in one laboratory. For the Coccidioides panel, the lowest amount of DNA detected was 1-16 fg by qPCRs and 10 pg with the broad-range cPCR. One laboratory reported a false positive result by qPCR with high load of Uncinocarpus DNA.

CONCLUSION

All five laboratories were able to correctly detect H. capsulatum and Coccidioides spp. DNA and qPCRs had a better performance than specific cPCR and broad-range cPCR. EQAs may help standardise in-house molecular tests for the so-called endemic mycoses improving patient management.

Clinical Manifestations of Human Exposure to Fungi

Biological particles, along with inorganic gaseous and particulate pollutants, constitute an ever-present component of the atmosphere and surfaces. Among these particles are fungal species colonizing almost all ecosystems, including the human body. Although inoffensive to most people, fungi can be responsible for several health problems, such as allergic fungal diseases and fungal infections. Worldwide fungal disease incidence is increasing, with new emerging fungal diseases appearing yearly. Reasons for this increase are the expansion of life expectancy, the number of immunocompromised patients (immunosuppressive treatments for transplantation, autoimmune diseases, and immunodeficiency diseases), the number of uncontrolled underlying conditions (e.g., diabetes mellitus), and the misusage of medication (e.g., corticosteroids and broad-spectrum antibiotics). Managing fungal diseases is challenging; only four classes of antifungal drugs are available, resistance to these drugs is increasing, and no vaccines have been approved. The present work reviews the implications of fungal particles in human health from allergic diseases (i.e., allergic bronchopulmonary aspergillosis, severe asthma with fungal sensitization, thunderstorm asthma, allergic fungal rhinosinusitis, and occupational lung diseases) to infections (i.e., superficial, subcutaneous, and systemic infections). Topics such as the etiological agent, risk factors, clinical manifestations, diagnosis, and treatment will be revised to improve the knowledge of this growing health concern.