The impact of COVID-19 pandemic on AIDS-related mycoses and fungal neglected tropical diseases: Why should we worry?

Epidemiology of coccidioidomycosis in Argentina, an update

The National Reference Laboratory in Clinical Mycology of Argentina conducted a retrospective review of human coccidioidomycosis cases diagnosed by the National Mycology Laboratory Network of Argentina between 2010 and 2022 to determine the burden of the disease in the country. A total of 100 human coccidioidomycosis cases were documented, with a higher prevalence in male patients (male-to-female ratio of 1.9:1), with a median age of 41 years. Comparing the number of cases between two 10-year periods (2000-2009 and 2010-2019), the increase was 36.51% (from 63 to 86 cases). Among the 100 recorded cases, 79 tested positive using the double immunodiffusion test. Spherules were observed in 19 cases through histopathology or direct microscopic examination and the fungus was isolated in 39 cases. Thirty-six isolates were identified as Coccidioides posadasii through partial sequencing of the Ag2/PRA gene. Catamarca province had the highest number of cases, comprising 64% of the total, with an incidence rate above 1.0-2.5/100,000 inhabitants until 2018. However, there has been a recent downward trend in the region from 2018 to 2022. It is concerning that more than half of diagnosed cases were chronic pulmonary or disseminated forms, indicating a lack of early disease detection. To rectify this issue, it is imperative to conduct targeted training programs for healthcare personnel and enhance public awareness within the endemic area. This will contribute to a better understanding of the true burden of coccidioidomycosis and enable the implementation of appropriate sanitary control measures.

S, V. SD, Duvvur NR. An Experience in Laboratory Diagnosis of Fungal Infections in COVID -19 Patients

Introduction  Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has cast a gloom spell on healthcare worldwide, infecting millions of people. Objective  The aim of the present study is to determine the prevalence and review the contributing comorbidities and the precipitating factors leading to the emergence of the fungal infections in COVID-19-affected patients. To assess the utility of different laboratory techniques for confirmation of fungal infections. To assess the strengths and limitations of the diagnostic methods. Methods  We have studied 252 clinical samples obtained from 121 COVID-positive patients. Results  Among the 121 patients clinically diagnosed with fungal infections, 88 had diabetes and were given steroids for treatment ( p -value = 0.001). Ninety-five patients (78.5%) had a positive laboratory diagnosis (either culture positive, potassium hydroxide [KOH]-positive or positive histopathology report). Fungal culture was positive in 75 (61.9%) patients and histopathology report was positive in 62 (51.2%). Histopathology was positive in 7 (5.8%) patients in whom culture and KOH were negative. Conclusion  Aggressive treatment methods, administration of immune suppressants, and antibiotics, with an intention to salvage, have made patients susceptible to the benign fungus, causing it to evade the host immunity, thus leading to invasive infections. Applying different laboratory modalities would not only aid in providing fast and valuable information but also help in understanding the pathology which would assist the clinician in selecting the correct treatment for the patient.

Emergomycosis in Africa: Time to Pay Attention to This Emerging Deadly Fungal Infection

Emergomycosis is an emerging deadly infectious disease caused primarily by a little-known airborne pathogen Emergomyces africanus, which can cause clinical management challenge especially in patients with advanced HIV disease. This minireview describes Es. africanus as the main cause of emergomycosis in Africa as well as considers contributing factors to the difficulties encountered in managing this infection. Emergomycosis is common in HIV-positive persons with low CD4 lymphocyte count and has an estimated fatality of 50%. The infection exhibits airborne transmission with pulmonary and extrapulmonary manifestations leading to skin lesions. However, the pathogenesis of Es. africanus is still poorly understood. The management of the infection is complicated due to lack of defined diagnostic and therapeutic guidelines. Limited expertise, poor research funding, and lack of awareness and national surveillance are thought to impact the recognition and prioritisation of the infection. These factors may ultimately assign emergomycosis a 'neglected infection status' even as it is suspected to be prevalent in more African countries than previously recognised. Increased awareness and integrated and targeted strategies such as mobilising manpower in clinical mycology are of paramount importance in managing emergomycosis in Africa and beyond.

COVID-19 in patients with paracoccidioidomycosis

INTRODUCTION

In 2020, we reported the first patient with concomitant COVID-19 and paracoccidioidomycosis (PCM). Since then, no other cases have been recorded in the literature. We aim to update information on the occurrence of COVID-19 in patients with PCM followed at a reference center for infectious diseases at Rio de Janeiro, Brazil.

METHODS

We reviewed the medical records from patients diagnosed with PCM who presented with clinical symptoms, radiological findings, and/or laboratory diagnosis of COVID-19 at any time during their acute or follow-up care. The clinical profiles of these patients were described.

RESULTS

Between March 2020 and September 2022, we identified six individuals with COVID-19 among the 117 patients with PCM evaluated. The median age was 38 years and the male to female ratio 2:1. Most patients (n = 5) presented for evaluation due to acute PCM. The severity of COVID-19 ranged from mild to severe in acute PCM and only the single patient with chronic PCM died.

CONCLUSIONS

There is a range of disease severity in COVID-19 and PCM co-infection and concomitant disease may represent a severe association, especially in the chronic type of the mycosis with pulmonary involvement. As COVID-19 and chronic PCM share similar clinical aspects and PCM is neglected, it is probable that COVID-19 has been hampering simultaneous PCM diagnosis, which can explain the absence of new co-infection reports. With the continued persistence of COVID-19 globally, these findings further suggest that more attention by providers is necessary to identify co-infections with Paracoccidioides.

An Overlooked and Underrated Endemic Mycosis-Talaromycosis and the Pathogenic Fungus Talaromyces marneffei

Talaromycosis is an invasive mycosis endemic in tropical and subtropical Asia and is caused by the pathogenic fungus Talaromyces marneffei. Approximately 17,300 cases of T. marneffei infection are diagnosed annually, and the reported mortality rate is extremely high (~1/3). Despite the devastating impact of talaromycosis on immunocompromised individuals, particularly HIV-positive persons, and the increase in reported occurrences in HIV-uninfected persons, diagnostic and therapeutic approaches for talaromycosis have received far too little attention worldwide. In 2021, scientists living in countries where talaromycosis is endemic raised a global demand for it to be recognized as a neglected tropical disease. Therefore, T. marneffei and the infectious disease induced by this fungus must be treated with concern. T. marneffei is a thermally dimorphic saprophytic fungus with a complicated mycological growth process that may produce various cell types in its life cycle, including conidia, hyphae, and yeast, all of which are associated with its pathogenicity. However, understanding of the pathogenic mechanism of T. marneffei has been limited until recently. To achieve a holistic view of T. marneffei and talaromycosis, the current knowledge about talaromycosis and research breakthroughs regarding T. marneffei growth biology are discussed in this review, along with the interaction of the fungus with environmental stimuli and the host immune response to fungal infection. Importantly, the future research directions required for understanding this serious infection and its causative pathogenic fungus are also emphasized to identify solutions that will alleviate the suffering of susceptible individuals worldwide.

Advancing disease genomics beyond COVID-19 and reducing health disparities: what does the future hold for Africa?

The COVID-19 pandemic has ushered in high-throughput sequencing technology as an essential public health tool. Scaling up and operationalizing genomics in Africa is crucial as enhanced capacity for genome sequencing could address key health problems relevant to African populations. High-quality genomics research can be leveraged to improve diagnosis, understand the aetiology of unexplained illnesses, improve surveillance of infectious diseases and inform efficient control and therapeutic methods of known, rare and emerging infectious diseases. Achieving these within Africa requires strong commitment from stakeholders. A roadmap is needed to guide training of scientists, infrastructural development, research funding, international collaboration as well as promote public–private partnerships. Although the COVID-19 pandemic has significantly boosted genomics capacity in Africa, the continent still lags other regions. Here, we highlighted key initiatives in genomics research and efforts to address health challenges facing the diverse and fast-growing populations on the continent. We explore the scalability of genomic tools and techniques to tackle a broader range of infectious diseases in Africa, a continent that desperately requires a boost from genomic science.

Genomic Approaches to Antifungal Drug Target Identification and Validation

The last several decades have witnessed a surge in drug-resistant fungal infections that pose a serious threat to human health. While there is a limited arsenal of drugs that can be used to treat systemic infections, scientific advances have provided renewed optimism for the discovery of novel antifungals. The development of chemical-genomic assays using Saccharomyces cerevisiae has provided powerful methods to identify the mechanism of action of molecules in a living cell. Advances in molecular biology techniques have enabled complementary assays to be developed in fungal pathogens, including Candida albicans and Cryptococcus neoformans. These approaches enable the identification of target genes for drug candidates, as well as genes involved in buffering drug target pathways. Here, we examine yeast chemical-genomic assays and highlight how such resources can be utilized to predict the mechanisms of action of compounds, to study virulence attributes of diverse fungal pathogens, and to bolster the antifungal pipeline.

Coinfection of fungi with SARS-CoV-2 is a detrimental health risk for COVID-19 patients

Background

Notable fungal coinfections with SARS-CoV-2 in COVID-19 patients have been reported worldwide in an alarming way. Mucor spp. and Rhizopus spp. were commonly known as black fungi, whereas Aspergillus spp. and Candida spp. were designated as white fungi implicated in those infections. In this review, we focused on the global outbreaks of fungal coinfection with SARS-CoV-2, the role of the human immune system, and a detailed understanding of those fungi to delineate the contribution of such coinfections in deteriorating the health conditions of COVID-19 patients based on current knowledge.

Main body

Impaired CD4 + T cell response due to SARS-CoV-2 infection creates an opportunity for fungi to take over the host cells and, consequently, cause severe fungal coinfections, including candidiasis and candidemia, mucormycosis, invasive pulmonary aspergillosis (IPA), and COVID-19-associated pulmonary aspergillosis (CAPA). Among them, mucormycosis and CAPA have been reported with a mortality rate of 66% in India and 60% in Colombia. Moreover, IPA has been reported in Belgium, Netherlands, France, and Germany with a morbidity rate of 20.6%, 19.6%, 33.3%, and 26%, respectively. Several antifungal drugs have been applied to combat fungal coinfection in COVID-19 patients, including Voriconazole, Isavuconazole, and Echinocandins.

Conclusion

SARS-CoV-2 deteriorates the immune system so that several fungi could take that opportunity and cause life-threatening health situations. To reduce the mortality and morbidity of fungal coinfections, it needs immunity boosting, proper hygiene and sanitation, and appropriate medication based on the diagnosis.

Potential of Triterpenic Natural Compound Betulinic Acid for Neglected Tropical Diseases New Treatments

Neglected tropical diseases are one of the most important public health problems in many countries around the world. Among them are leishmaniasis, Chagas disease, and malaria, which contribute to more than 250 million infections worldwide. There is no validated vaccine to prevent these infections and the treatments available are obsolete, highly toxic, and non-effective due to parasitic drug resistance. Additionally, there is a high incidence of these diseases, and they may require hospitalization, which is expensive to the public health systems. Therefore, there is an urgent need to develop new treatments to improve the management of infected people, control the spread of resistant strains, and reduce health costs. Betulinic acid (BA) is a triterpene natural product which has shown antiparasitic activity against Leishmania, Trypanosoma cruzi, and Plasmodium. Here, we review the main results regarding the in vitro and in vivo pharmacological activity of BA and its derivatives against these parasites. Some chemical modifications of BA have been shown to improve its activities against the parasites. Further improvement on studies of drug-derived, as well as structure–activity relationship, are necessary for the development of new betulinic acid-based treatments.

Genetic analysis of Hsp90 function in Cryptococcus neoformans highlights key roles in stress tolerance and virulence

The opportunistic human fungal pathogen Cryptococcus neoformans has tremendous impact on global health, causing 181,000 deaths annually. Current treatment options are limited, and the frequent development of drug resistance exacerbates the challenge of managing invasive cryptococcal infections. In diverse fungal pathogens, the essential molecular chaperone Hsp90 governs fungal survival, drug resistance, and virulence. Therefore, targeting this chaperone has emerged as a promising approach to combat fungal infections. However, the role of Hsp90 in supporting C. neoformans pathogenesis remains largely elusive due to a lack of genetic characterization. To help dissect the functions of Hsp90 in C. neoformans, we generated a conditional expression strain in which HSP90 is under control of the copper-repressible promoter CTR4-2. Addition of copper to culture medium depleted Hsp90 transcript and protein levels in this strain, resulting in compromised fungal growth at host temperature; increased sensitivity to stressors, including the azole class of antifungals; altered C. neoformans morphology; and impaired melanin production. Finally, leveraging the fact that copper concentrations vary widely in different mouse tissues, we demonstrated attenuated virulence for the CTR4-2p-HSP90 mutant specifically in an inhalation model of Cryptococcus infection. During invasion and establishment of infection in this mouse model, the pathogen is exposed to the relatively high copper concentrations found in the lung as compared to blood. Overall, this work generates a tractable genetic system to study the role of Hsp90 in supporting the pathogenicity of C. neoformans and provides proof-of-principle that targeting Hsp90 holds great promise as a strategy to control cryptococcal infection.

Overview on the Prevalence of Fungal Infections, Immune Response, and Microbiome Role in COVID-19 Patients

Patients with severe COVID-19, such as individuals in intensive care units (ICU), are exceptionally susceptible to bacterial and fungal infections. The most prevalent fungal infections are aspergillosis and candidemia. Nonetheless, other fungal species (for instance, Histoplasma spp., Rhizopus spp., Mucor spp., Cryptococcus spp.) have recently been increasingly linked to opportunistic fungal diseases in COVID-19 patients. These fungal co-infections are described with rising incidence, severe illness, and death that is associated with host immune response. Awareness of the high risks of the occurrence of fungal co-infections is crucial to downgrade any arrear in diagnosis and treatment to support the prevention of severe illness and death directly related to these infections. This review analyses the fungal infections, treatments, outcome, and immune response, considering the possible role of the microbiome in these patients. The search was performed in Medline (PubMed), using the words "fungal infections COVID-19", between 2020-2021.

Acute Pulmonary Histoplasmosis Following COVID-19: Novel Laboratorial Methods Aiding Diagnosis

The acute form of histoplasmosis usually occurs after the exposition of more than one individual to a common environmental source harboring Histoplasma capsulatum. Here, we present two cases of acute pulmonary histoplasmosis seen within two weeks at a reference center for infectious diseases at Rio de Janeiro, Brazil. The patients did not present a common epidemiologic history for histoplasmosis, however both presented COVID-19 before the onset of histoplasmosis symptoms. Due to the difficulties in the diagnosis of acute histoplasmosis, novel laboratory methods such as Western Blot and PCR were included in the investigation of these cases. Both patients presented negative cultures for H. capsulatum and negative urinary galactomannan. However, they presented H and M bands in the Western blot as well as a positive H. capsulatum DNA detection in sputum. These results were available approximately 36 h after sample collection, fastening the beginning of treatment of one patient. Both patients progressed well with itraconazole treatment. These cases suggest that COVID-19 may facilitate the development of acute pulmonary histoplasmosis and, therefore, clinicians must be aware of this differential diagnosis in patients from endemic areas with fever and coughing after recovery from COVID-19.