The "Histoplasmosis Porto Alegre manifesto"-Addressing disseminated histoplasmosis in AIDS

Rapid CD4 cell count determination and Cryptococcus and Histoplasma antigen detection in people living with HIV: Implementation of a package of care strategy in a pilot study, Argentina

Objectives

Despite advancements in HIV diagnosis and treatment, advanced HIV disease (AHD) is still a significant concern worldwide, especially in countries with a high percentage of undiagnosed cases and late-stage diagnoses.

Methods

A prospective pilot study was conducted in Buenos Aires, Argentina to assess the feasibility of implementing a package for people living with HIV, integrating a point-of-care clusters of differentiation (CD4) test, followed by rapid Cryptococcus and Histoplasma antigen (Ag) detection.

Results

A total of 105 people living with HIV were enrolled, during June 2021 to October 2021. The VISITECT CD4 Advanced Disease Lateral Flow Assay (CD4-LFA) (Accubio) classified 98 (93%) patients with AHD. Compared with flow cytometry, the CD4-LFA performed with a high sensitivity (100%) but low specificity (19%) and limited accuracy (47%). In the 98 patients classified with AHD using the CD4-LFA, 16 tested positive for any of the rapid Ag used, including 12 patients positive for the Histoplasma Ag test and four positive for Cryptococcus Ag; all four patients with positive Cryptococcus Ag in sera and were diagnosed with meningitis. In the 30-day follow-up, one death was recorded.

Conclusions

The CD4-LFA correctly classified all patients with CD4 ≤200 cells/µL by flow cytometry, but a high frequency of patients misclassified with AHD was recorded. We also observed a high prevalence of opportunistic fungal infections, as previously observed in the hospital where this pilot study was conducted; however, in contrast with those previous reports, mortality was lower. The study underscores the importance of scaling up comprehensive care strategies and collaborating with governmental and non-governmental partners to enhance access to essential diagnostic tools and treatments for people living with HIV. Further research with larger sample sizes is needed to validate these findings.

Fungal Infections in the Caribbean: A Review of the Literature to Date

The most common fungal infections reported from the Caribbean include dermatophytosis, candidiasis, pneumocystis, aspergillosis, histoplasmosis, and cryptococcosis. The Caribbean is hyperendemic for histoplasmosis, with high population exposures. Fungal infections are a significant public health problem in the Caribbean, with rates varying depending on the specific country or region. In Trinidad and Tobago, the fungal burden accounts for 3.3% of the 1.4 million population, while in Jamaica, with a population of 2.9 million, over 57,600 people suffer from fungal infections each year. A study in the Dominican Republic estimated that approximately 221,027 (2%) of over 10 million people have a serious fungal infection. Fungal infections accounts for 21.9% of all skin infections in Haiti. The diagnosis of fungal infections in the Caribbean can be challenging, as access to laboratory testing and specialized medical services is limited in many areas. Access to antifungal medications can also be a challenge in some areas, and antifungal resistance has been reported.

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.

Comparative Genomics of Histoplasma capsulatum and Prediction of New Vaccines and Drug Targets

Histoplasma capsulatum is a thermodymorphic fungus that causes histoplasmosis, a systemic mycosis that presents different clinical manifestations, ranging from self-limiting to acute lung infection, chronic lung infection and disseminated infection. Usually, it affects severely immunocompromised patients although immunocompetent patients can also be infected. Currently, there are no vaccines to prevent histoplasmosis and the available antifungal treatment presents moderate to high toxicity. Additionally, there are few options of antifungal drugs. Thus, the aim of this study was to predict possible protein targets for the construction of potential vaccine candidates and predict potential drug targets against H. capsulatum. Whole genome sequences from four previously published H. capsulatum strains were analyzed and submitted to different bioinformatic approaches such as reverse vaccinology and subtractive genomics. A total of four proteins were characterized as good protein candidates (vaccine antigens) for vaccine development, three of which are membrane-bound and one is secreted. In addition, it was possible to predict four cytoplasmic proteins which were classified as good protein candidates and, through molecular docking performed for each identified target, we found four natural compounds that showed favorable interactions with our target proteins. Our study can help in the development of potential vaccines and new drugs that can change the current scenario of the treatment and prevention of histoplasmosis.

Correction: The "Histoplasmosis Porto Alegre manifesto"-Addressing disseminated histoplasmosis in AIDS

[This corrects the article DOI: 10.1371/journal.pntd.0010960.].