The pathobiology of human fungal infections.

Human fungal infections are a historically neglected area of disease research, yet they cause more than 1.5 million deaths every year. Our understanding of the pathophysiology of these infections has increased considerably over the past decade, through major insights into both the host and pathogen factors that contribute to the phenotype and severity of these diseases. Recent studies are revealing multiple mechanisms by which fungi modify and manipulate the host, escape immune surveillance and generate complex comorbidities. Although the emergence of fungal strains that are less susceptible to antifungal drugs or that rapidly evolve drug resistance is posing new threats, greater understanding of immune mechanisms and host susceptibility factors is beginning to offer novel immunotherapeutic options for the future. In this Review, we provide a broad and comprehensive overview of the pathobiology of human fungal infections, focusing specifically on pathogens that can cause invasive life-threatening infections, highlighting recent discoveries from the pathogen, host and clinical perspectives. We conclude by discussing key future challenges including antifungal drug resistance, the emergence of new pathogens and new developments in modern medicine that are promoting susceptibility to infection.

Candida parapsilosis: A systematic review to inform the World Health Organization fungal priority pathogens list.

Candida parapsilosis is globally distributed and recognised for causing an increasing proportion of invasive Candida infections. It is associated with high crude mortality in all age groups. It has been particularly associated with nosocomial outbreaks, particularly in association with the use of invasive medical devices such as central venous catheters. Candida parapsilosis is one of the pathogens considered in the WHO priority pathogens list, and this review was conducted to inform the ranking of the pathogen in the list. In this systematic review, we searched PubMed and Web of Science to find studies between 2011 and 2021 reporting on the following criteria for C. parapsilosis infections: mortality, morbidity (hospitalisation and disability), drug resistance, preventability, yearly incidence, and distribution/emergence. We identified 336 potentially relevant papers, of which 51 were included in the analyses. The included studies confirmed high mortality rates, ranging from 17.5% to 46.8%. Data on disability and sequelae were sparse. Many reports highlighted concerns with azole resistance, with resistance rates of >10% described in some regions. Annual incidence rates were relatively poorly described, although there was clear evidence that the proportion of candidaemia cases caused by C. parapsilosis increased over time. While this review summarises current data on C.parapsilosis, there remains an urgent need for ongoing research and surveillance to fully understand and manage this increasingly important pathogen.

Features and global impact of invasive fungal infections caused by Pneumocystis jirovecii: A systematic review to inform the World Health Organization fungal priority pathogens list.

This systematic review evaluates the current global impact of invasive infections caused by Pneumocystis jirovecii (principally pneumonia: PJP), and was carried out to inform the World Health Organization Fungal Priority Pathogens List. PubMed and Web of Science were used to find studies reporting mortality, inpatient care, complications/sequelae, antifungal susceptibility/resistance, preventability, annual incidence, global distribution, and emergence in the past 10 years, published from January 2011 to February 2021. Reported mortality is highly variable, depending on the patient population: In studies of persons with HIV, mortality was reported at 5%-30%, while in studies of persons without HIV, mortality ranged from 4% to 76%. Risk factors for disease principally include immunosuppression from HIV, but other types of immunosuppression are increasingly recognised, including solid organ and haematopoietic stem cell transplantation, autoimmune and inflammatory disease, and chemotherapy for cancer. Although prophylaxis is available and generally effective, burdensome side effects may lead to discontinuation. After a period of decline associated with improvement in access to HIV treatment, new risk groups of immunosuppressed patients with PJP are increasingly identified, including solid organ transplant patients.

Lived experience of people with cryptococcal meningitis: A qualitative study.

Background: The high burden of cryptococcal meningitis (CM) among people living with HIV persists despite widespread access to antiretroviral therapy. Efforts to prevent CM among people living with HIV could be hindered by a limited understanding of their lived experiences of CM and its diagnosis. Objectives: To explore and describe the experiences of people diagnosed with HIV-associated CM in routine care. Two public healthcare facilities in Johannesburg, South Africa. Method: This was a qualitative-methods exploratory, descriptive, phenomenological study. We conducted semi-structured, individual in-depth interviews with nine purposively sampled participants (comprising 5 men and 4 women). Data were analysed using the Moustakas phenomenological approach. Results: Five themes and several sub-themes emerged from the data. Participants described their experiences of being diagnosed, which were marked by intense headaches. Diagnosis of CM led to reduced quality of life, fear of death, and loss of income. Participants described their CM treatment experience and health-seeking behaviour including self-medication, seeking help from traditional healers and general practitioners and utilising public health facilities as a last resort. Barriers to care included negative healthcare workers' attitudes, unhealthy lifestyles, and poor knowledge of CM. Conclusion: People with HIV-associated CM face negative impacts prior to and after diagnosis. These patients struggled to access timely quality healthcare. Patients starting or restarting antiretroviral therapy, and thus at risk for CM, should receive CM education as part of HIV counselling.

Optimizing the Treatment of Invasive Candidiasis-A Case for Combination Therapy.

Invasive candidiasis is a rising global health threat with increasing incidence, persistently high mortality, and diminishing treatment options. Antifungal resistance has rapidly emerged and spread, with multidrug-resistant species deemed an urgent and serious threat. While acknowledging the key role of antifungal stewardship and infection control in curbing spread, we examine the role of antifungal monotherapy in driving resistance and the potential for combination therapy to prevent stress adaptation and emergence of drug resistance. In addition to its role in mitigating resistance, combination treatment may improve drug penetration, expedite fungal clearance, and allow lower, less toxic doses of individual drugs to be used. A growing body of laboratory-based evidence suggests that antifungal combinations can yield synergistic activity against Candida spp., including against frequently multidrug-resistant Candida auris. It is imperative to test these combinations in clinical trials, incorporating resistance end points as a marker of success.

Prospective antimicrobial stewardship interventions by multidisciplinary teams to reduce neonatal antibiotic use in South Africa: The Neonatal Antimicrobial Stewardship (NeoAMS) study.

BACKGROUND: Hospitalized neonates are vulnerable to infection and have high rates of antibiotic utilization. METHODS: Fourteen South African neonatal units (seven public, seven private sector) assembled multidisciplinary teams involving neonatologists, microbiologists, pharmacists, and nurses to implement prospective audit and feedback neonatal antimicrobial stewardship (NeoAMS) interventions. The teams attended seven online training sessions. Pharmacists conducted weekday antibiotic prescription reviews in the neonatal intensive care unit and/or neonatal wards providing feedback to the clinical teams. Anonymized demographic and NeoAMS interventions data were aggregated for descriptive purposes and statistical analysis. FINDINGS: During the 20-week NeoAMS intervention in 2022, 565 neonates were enrolled. Pharmacists evaluated seven hundred antibiotic prescription episodes; rule-out sepsis (180; 26%) and culture-negative sepsis (138; 20%) were the most frequent indications for antibiotic prescription. For infection episodes with an identified pathogen, only 51% (116/229) of empiric treatments provided adequate antimicrobial coverage. Pharmacists recommended 437 NeoAMS interventions (0·6 per antibiotic prescription episode), with antibiotic discontinuation (42%), therapeutic drug monitoring (17%), and dosing (15%) recommendations most frequent. Neonatal clinicians' acceptance rates for AMS recommendations were high (338; 77%). Mean antibiotic length of therapy decreased by 24% from 9·1 to 6·9 days (0·1 day decrease per intervention week; P = 0·001), with the greatest decline in length of therapy for culture-negative sepsis (8·2 days (95% CI 5·7-11·7) to 5·9 days (95% CI 4·6-7·5); P = 0·032). INTERPRETATION: This neonatal AMS programme was successfully implemented in heterogenous and resource-limited settings. Pharmacist-recommended AMS interventions had high rates of clinician acceptance. The NeoAMS intervention significantly reduced neonatal antibiotic use, particularly for culture-negative sepsis. FUNDING: A grant from Merck provided partial support.

Invasive candidiasis.

Invasive candidiasis is an important fungal disease caused by Candida albicans and, increasingly, non-albicans Candida pathogens. Invasive Candida infections originate most frequently from endogenous human reservoirs and are triggered by impaired host defences. Signs and symptoms of invasive candidiasis are non-specific; candidaemia is the most diagnosed manifestation, with disseminated candidiasis affecting single or multiple organs. Diagnosis poses many challenges, and conventional culture techniques are frequently supplemented by non-culture-based assays. The attributable mortality from candidaemia and disseminated infections is ~30%. Fluconazole resistance is a concern for Nakaseomyces glabratus, Candida parapsilosis, and Candida auris and less so in Candida tropicalis infection; acquired echinocandin resistance remains uncommon. The epidemiology of invasive candidiasis varies in different geographical areas and within various patient populations. Risk factors include intensive care unit stay, central venous catheter use, broad-spectrum antibiotics use, abdominal surgery and immune suppression. Early antifungal treatment and central venous catheter removal form the cornerstones to decrease mortality. The landscape of novel therapeutics is growing; however, the application of new drugs requires careful selection of eligible patients as the spectrum of activity is limited to a few fungal species. Unanswered questions and knowledge gaps define future research priorities and a personalized approach to diagnosis and treatment of invasive candidiasis is of paramount importance.

Case Report of Nasal Rhinosporidiosis in South Africa.

We describe a classic case of nasal rhinosporidiosis in a woman who resided in Johannesburg, South Africa, but originated from a rural area in Eastern Cape Province. We confirmed histologic diagnosis using PCR testing and compared details with those from records on 17 other cases from South Africa.

Global guideline for the diagnosis and management of cryptococcosis: an initiative of the ECMM and ISHAM in cooperation with the ASM.

Cryptococcosis is a major worldwide disseminated invasive fungal infection. Cryptococcosis, particularly in its most lethal manifestation of cryptococcal meningitis, accounts for substantial mortality and morbidity. The breadth of the clinical cryptococcosis syndromes, the different patient types at-risk and affected, and the vastly disparate resource settings where clinicians practice pose a complex array of challenges. Expert contributors from diverse regions of the world have collated data, reviewed the evidence, and provided insightful guideline recommendations for health practitioners across the globe. This guideline offers updated practical guidance and implementable recommendations on the clinical approaches, screening, diagnosis, management, and follow-up care of a patient with cryptococcosis and serves as a comprehensive synthesis of current evidence on cryptococcosis. This Review seeks to facilitate optimal clinical decision making on cryptococcosis and addresses the myriad of clinical complications by incorporating data from historical and contemporary clinical trials. This guideline is grounded on a set of core management principles, while acknowledging the practical challenges of antifungal access and resource limitations faced by many clinicians and patients. More than 70 societies internationally have endorsed the content, structure, evidence, recommendation, and pragmatic wisdom of this global cryptococcosis guideline to inform clinicians about the past, present, and future of care for a patient with cryptococcosis.

Bacterial and Candida Colonization of Neonates in a Regional Hospital in South Africa.

BACKGROUND: Neonatal colonization with multidrug-resistant (MDR) Enterobacter spp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterococcus faecium (ESKAPE) and Candida spp. often precedes invasive hospital-acquired infections. We investigated the prevalence and dynamics of neonatal ESKAPE and Candida spp. colonization from hospital admission until discharge (or death) and followed up for invasive disease. METHODS: Prospective longitudinal surveillance for neonatal ESKAPE and Candida spp. colonization was conducted over 6 months at a South African regional hospital. Neonates enrolled at birth had swabs (nasal, 2× skin and rectal) collected within 24 hours and every 48-96 hours thereafter, until discharge or death. ESKAPE and Candida spp. were cultured for and antimicrobial susceptibility was performed on bacterial isolates. Whole-genome sequencing was undertaken on paired samples with the same bacterial species from colonizing and invasive disease episodes in the same child. RESULTS: Of 102 enrolled neonates, 79% (n = 81) were colonized by ≥1 ESKAPE organism by time of discharge or death. Forty-four percent (36/81) were colonized within 24 hours of birth. Common colonizers were K. pneumoniae (70%; n = 57) and Enterobacter spp. (43%; n = 35). Almost all MDR organisms (93%) were Gram-negative. Forty-two (45%, 42/93) newborns acquired Candida spp. (skin only) colonization, commonly Candida parapsilosis (69%; n = 29). For 2 children with K. pneumoniae colonization and sepsis, the bloodstream and colonizing isolates were genetically different, whereas the single A. baumannii colonizing and blood isolate pair were genetically identical. CONCLUSIONS: We report a high prevalence of MDR ESKAPE and Candida spp. colonization in a regional neonatal unit. Interventions to reduce the high incidence of hospital-acquired neonatal infections should include reducing high colonization rates.

The pathogenesis of experimental Emergomycosis in mice.

Emergomyces africanus is a recently identified thermally-dimorphic fungal pathogen that causes disseminated infection in people living with advanced HIV disease. Known as emergomycosis, this disseminated disease is associated with very high case fatality rates. Over the last decade, improved diagnostics and fungal identification in South Africa resulted in a dramatic increase in the number of reported cases. Although the true burden of disease is still unknown, emergomycosis is among the most frequently diagnosed dimorphic fungal infections in Southern Africa; and additional species in the genus have been identified on four continents. Little is known about the pathogenesis and the host's immune response to this emerging pathogen. Therefore, we established a murine model of pulmonary infection using a clinical isolate, E. africanus (CBS 136260). Both conidia and yeast forms caused pulmonary and disseminated infection in mice with organisms isolated in culture from lung, spleen, liver, and kidney. Wild-type C57BL/6 mice demonstrated a drop in body weight at two weeks post-infection, corresponding to a peak in fungal burden in the lung, spleen, liver, and kidney. An increase in pro-inflammatory cytokine production was detected in homogenized lung supernatants including IFN-γ, IL-1ß, IL-6, IL12-p40 and IL-17 at three- and four-weeks post-infection. No significant differences in TNF, IL-12p70 and IL-10 were observed in wild-type mice between one and four-weeks post-infection. Rag-1-deficient mice, lacking mature T-and B-cells, had an increased fungal burden associated with reduced IFN-γ production. Together our data support a protective T-helper type-1 immune response to E. africanus infection. This may provide a possible explanation for the susceptibility of only a subset of people living with advanced HIV disease despite hypothesized widespread environmental exposure. In summary, we have established a novel murine model of E. africanus disease providing critical insights into the host immune components required for eliminating the infection.

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.

This review presents the current state of the art in medical mycology in Africa discussed at the first scientific meeting of the Pan African Mycology Working Group, an affiliate of the International Society for Human and Animal Mycology (ISHAM) held in Nairobi, Kenya on May 30th and 31st, 2023.

Fungal diseases in Africa: Closing the gaps in diagnosis and treatment through implementation research and advocacy.

Fungal diseases impose an escalating burden on public health in Africa, exacerbated by issues such as delayed diagnosis, inadequate therapy, and limited access to healthcare resources, resulting in significant morbidity and mortality. Effectively tackling these challenges demands a comprehensive approach encompassing research, training, and advocacy initiatives. Recent clinical mycology surveys conducted by Global Action for Fungal Infection (GAFFI) and the European Confederation of Medical Mycology/International Society for Human and Animal Mycology (ECMM/ISHAM) have underscored gaps in fungal diagnostics and the availability and accessibility of antifungal therapy in Africa. The World Health Organization (WHO) Fungal Priority Pathogens List (FPPL) identifies fungi of critical or high importance to human health, providing a roadmap for action and highlighting the urgent need for prioritizing fungal diseases and developing targeted interventions within the African context. To enhance diagnosis and treatment, it is imperative to invest in comprehensive training programs for healthcare workers across all levels and disciplines. Equipping them with the necessary knowledge and skills will facilitate early detection, accurate diagnosis, and appropriate management of fungal infections. Moreover, implementation science research in medical mycology assumes a pivotal role in bridging the gap between knowledge and practice. By identifying the barriers and facilitators that influence the adoption of diagnostic techniques and public health interventions, tailored strategies can be formulated to improve their implementation within healthcare settings. Advocacy plays a critical role in raising awareness regarding the profound impact of fungal diseases on public health in Africa. Engaging policymakers, healthcare providers, researchers, industry experts and communities underscore the importance of addressing these diseases and galvanize efforts for change. Substantial investment in surveillance, research and development specifically focused on fungal diseases is indispensable for advancing our understanding of local epidemiology, developing effective interventions, and ultimately improving patient outcomes. In conclusion, closing the gaps in diagnosing and treating fungal diseases in Africa demands concerted research and advocacy initiatives to ensure better healthcare delivery, reduced mortality rates, and improved public health outcomes.

Federation of infectious diseases societies of southern Africa guideline: Recommendations for the detection, management and prevention of healthcare-associated candida auris colonisation and disease in South Africa

Candida auris has been detected at almost 100 South African hospitals, causing large outbreaksinsome facilities, and this pathogen now accounts for approximately 1 in 10 cases of candidaemia. The objective of this guideline is to provide updated, evidence-informed recommendations outlining a best-practice approach to prevent, diagnose and manage C.auris disease in public- and private-sector healthcare settings in South Africa. The 18 practical recommendations cover five focus areas: laboratory identification and antifungal susceptibility testing, surveillance and outbreak response, infection prevention and control, clinical management and antifungal stewardship