Combining urine antigen and blood polymerase chain reaction for the diagnosis of disseminated histoplasmosis in hospitalized patients with advanced HIV disease

Systematic Review of Prevalence of Histoplasma Antigenuria in Persons with HIV in Latin America and Africa

Histoplasmosis is a fungal disease associated with substantial mortality rates among persons with advanced HIV disease. Our systematic review synthesized data on the global prevalence of Histoplasma--caused antigenuria in persons with HIV. We searched PubMed/Medline, Embase, and Scopus databases on January 3, 2023, to identify cross-sectional and cohort studies evaluating Histoplasma antigenuria prevalence among adults with HIV infection. We calculated point estimates and 95% CIs to summarize prevalence. Of 1,294 studies screened, we included 15. We found Histoplasma antigenuria among 581/5,096 (11%; 95% CI 11%-12%) persons with HIV and 483/3,789 persons with advanced HIV disease (13%; 95% CI 12%-14%). Among persons with HIV and symptoms consistent with histoplasmosis, Histoplasma antigenuria prevalence was 14% (95% CI 13%-15%; 502/3,631 participants). We determined that persons with advanced HIV disease, inpatients, and symptomatic persons might benefit from a systematic approach to early detection of histoplasmosis using urine antigen testing.

Tackling Histoplasmosis Infection in People Living with HIV from Latin America: From Diagnostic Strategy to Public Health Solutions

Histoplasmosis, caused by the thermally dimorphic fungus Histoplasma spp., is a disease with a broad clinical spectrum, presenting from asymptomatic/flu-like symptoms to progressive disseminated disease in people with immunosuppression. In recent years, the concept of histoplasmosis as a disease restricted to the American continent has changed, as now histoplasmosis is reported in many regions around the world. In Latin America, histoplasmosis represents a threat, especially in people with advanced HIV disease (AHD). Diagnosis of histoplasmosis in people living with HIV (PLHIV) is challenging due to the low index of suspicion of the disease, non-specificity of signs and symptoms, and limited access to specific laboratory testing, while the diagnostic delay is significantly associated with mortality. In the last decade, novel diagnostic tests have been developed for the rapid detection of histoplasmosis, such as commercial kits for antigen detection. Furthermore, advocacy groups were created that presented histoplasmosis as a public health problem, with emphasis on patients at risk of progressive disseminated disease. This review aims to discuss the impact of histoplasmosis associated with AHD in Latin America and the strategies employed to tackle histoplasmosis, from the implementation of laboratory testing to disease advocacy and public health interventions.

Histoplasmosis at a Reference Center for Infectious Diseases in Southeast Brazil: Comparison between HIV-Positive and HIV-Negative Individuals

Objectives: Histoplasmosis is a systemic mycosis, present globally. We aimed to describe cases of histoplasmosis (Hc) and to establish a risk profile associated with Hc in HIV-infected patients (HIV+). Methods: This was a retrospective study of patients with a clinical laboratory diagnosis of Hc. Data were fed into REDCap, and statistical analysis was performed with R. Results: We included 99 records, 65 HIV+ and 34 HIV-. Average age was 39 years. Median time from onset to diagnosis was 8 weeks in HIV- and 22 weeks in HIV+. Disseminated histoplasmosis occurred in 79.4% of HIV+, vs. 36.4% of HIV- patients. Median CD4 count was 70. Co-infection with tuberculosis was present in 20% of HIV+ patients. Blood cultures were positive in 32.3% of HIV+ vs. 11.8% of HIV- (p = 0.025) patients; bone marrow culture was positive in 36.9% vs. 8.8% (p = 0.003). Most HIV+ patients (71.4%) were hospitalized. On univariate analysis, anemia, leukopenia, intensive care, use of vasopressors and mechanical ventilation were associated with death in HIV+ patients. Conclusions: Most of our patients with histoplasmosis were HIV+, presenting advanced AIDS. Diagnosis was late in HIV+ patients, and they frequently presented disseminated Hc, required hospitalization, and died. Early screening for Hc in HIV+ and drug-induced immunosuppressed patients is crucial.

Septic shock, hyperferritinemic syndrome, and multiple organ dysfunction without respiratory failure in a patient with disseminated histoplasmosis and advanced HIV disease

AIDS-related disseminated histoplasmosis (DH) can cause septic shock and multiorgan dysfunction with mortality rates of up to 80%. A 41-year-old male presented with fever, fatigue, weight loss, disseminated skin lesions, low urine output, and mental confusion. Three weeks before admission, the patient was diagnosed with HIV infection, but antiretroviral therapy (ART) was not initiated. On day 1 of admission, sepsis with multiorgan dysfunction (acute renal failure, metabolic acidosis, hepatic failure, and coagulopathy) was identified. A chest computed tomography showed unspecific findings. Yeasts suggestive of Histoplasma spp. were observed in a routine peripheral blood smear. On day 2, the patient was transferred to the ICU, where his clinical condition progressed with reduced level of consciousness, hyperferritinemia, and refractory septic shock, requiring high doses of vasopressors, corticosteroids, mechanical ventilation, and hemodialysis. Amphotericin B deoxycholate was initiated. On day 3, yeasts suggestive of Histoplasma spp. were observed in the bone marrow. On day 10, ART was initiated. On day 28, samples of peripheral blood and bone marrow cultures revealed Histoplasma spp. The patient stayed in the ICU for 32 days, completing three weeks of intravenous antifungal therapy. After progressive clinical and laboratory improvement, the patient was discharged from the hospital on oral itraconazole, trimethoprim-sulfamethoxazole, and ART. This case highlights the inclusion of DH in the differential diagnosis of patients with advanced HIV disease, septic shock and multiorgan dysfunction but without respiratory failure. In addition, it provides early in-hospital diagnosis and treatment and comprehensive management in the ICU as determining factors for a good outcome.

Validation and Concordance Analysis of a New Lateral Flow Assay for Detection of Histoplasma Antigen in Urine

Histoplasmosis is a major cause of mortality in people living with HIV (PLHIV). Rapid methods to diagnose Histoplasma capsulatum disease could dramatically decrease the time to initiate treatment, resulting in reduced mortality. The aim of this study was to validate a MiraVista^® Diagnostics (MVD) Histoplasma urine antigen lateral flow assay (MVD LFA) for the detection of H. capsulatum antigen (Ag) in urine and compare this LFA against the MVista^® Histoplasma Ag quantitative enzyme immunoassays (MVD EIA). We assessed the MVD LFA using a standardized reference panel of urine specimens from Colombia. We tested 100 urine specimens, 26 from PLHIV diagnosed with histoplasmosis, 42 from PLHIV with other infectious diseases, and 32 from non-HIV infected persons without histoplasmosis. Sensitivity and specificity of the MVD LFA was 96%, compared with 96% sensitivity and 77% specificity of the MVD EIA. Concordance analysis between MVD LFA and the MVD EIA displayed an 84% agreement, and a Kappa of 0.656. The MVD LFA evaluated in this study has several advantages, including a turnaround time for results of approximately 40 min, no need for complex laboratory infrastructure or highly trained laboratory personnel, use of urine specimens, and ease of performing.

Disseminated Histoplasmosis in an Immunocompetent Patient After COVID-19 Pneumonia

Disseminated histoplasmosis can occur in immunocompromised patients such as in HIV disease and patients with medication-induced immunosuppression. Most of these patients present with fever, weight loss, hepatosplenomegaly, lymphadenopathy, and pancytopenia. There are increasing reports of coronavirus disease 2019 (COVID-19) pneumonia associated with fungal infections including aspergillus and mucormycosis. It is not typical for immunocompetent patients to present with disseminated fungal disease. We herein report a case of a 50-year-old immunocompetent male with a recent recovery from COVID-19 pneumonia who presented with fever and pancytopenia. Chest computed tomography (CT) demonstrated new-onset right upper lobe lung mass, subcarinal lymphadenopathy, and splenomegaly. Mediastinal lymph nodes and bone marrow biopsies were performed, and the patient was diagnosed with disseminated histoplasmosis. The association between COVID-19 pneumonia and fungal infections is increasingly reported. Diagnosis requires a high index of suspicion, especially in immunocompetent patients.