Predictive factors for disseminated histoplasmosis in AIDS patients with fever admitted to a reference hospital in Brazil

Histoplasmosis in non-immunosuppressed patients from an endemic area in Northeastern Brazil

Differently from immunocompromised patients, very little information is available in the literature regarding the clinical presentation, epidemiology, and outcomes of histoplasmosis in non-immunosuppressed individuals living in endemic areas. This retrospective case series study was carried out by reviewing the medical records of non-immunocompromised patients with histoplasmosis, residents in a hyperendemic area in northeastern Brazil, between 2011 and 2022. Thirty HIV-negative patients were identified with histoplasmosis, and 19 cases met the inclusion criteria: three had acute, five subacute and one chronic pulmonary forms; two with mediastinal picture and eight had disseminated disease (two with severe symptoms). The median age of our sample was 32.7 years old [interquartile range: 24-45]. Most of the patients were male (male-to-female ratio = 15:4) and resided in the state capital (n = 9). The majority had a previous history of exposure to well-known risk factors for Histoplasma infection. Pulmonary nodules were observed in all subacute form, two patients (acute and subacute forms) were initially treated empirically for pulmonary tuberculosis; one death was registered in the subacute form. The chronic pulmonary form of histoplasmosis was diagnosed in one patient only after the symptoms persisted despite specific treatment. The primary clinical manifestations of the moderate form of DH were enlarged lymph nodes, with histopathology being the main diagnostic method. The cases were detected as isolated occurrences and not as an outbreak, suggesting that exposure to Histoplasma can be more widespread than presumed. Despite the self-limiting nature of the disease, death can occur even in previously heathy patients.

Histoplasmosis: A systematic review to inform the World Health Organization of a fungal priority pathogens list

Histoplasmosis, a significant mycosis primarily prevalent in Africa, North and South America, with emerging reports globally, poses notable health challenges, particularly in immunocompromised individuals such as people living with HIV/AIDS and organ transplant recipients. This systematic review, aimed at informing the World Health Organization's Fungal Priority Pathogens List, critically examines literature from 2011 to 2021 using PubMed and Web of Science, focusing on the incidence, mortality, morbidity, antifungal resistance, preventability, and distribution of Histoplasma. We also found a high prevalence (22%-44%) in people living with HIV, with mortality rates ranging from 21% to 53%. Despite limited data, the prevalence of histoplasmosis seems stable, with lower estimates in Europe. Complications such as central nervous system disease, pulmonary issues, and lymphoedema due to granuloma or sclerosis are noted, though their burden remains uncertain. Antifungal susceptibility varies, particularly against fluconazole (MIC: ≥32 mg/l) and caspofungin (MICs: 4-32 mg/l), while resistance to amphotericin B (MIC: 0.125-0.16 mg/l), itraconazole (MICs: 0.004-0.125 mg/l), and voriconazole (MICs: 0.004-0.125 mg/l) remains low. This review identifies critical knowledge gaps, underlining the need for robust, globally representative surveillance systems to better understand and combat this fungal threat.

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.

Evidence of Histoplasma capsulatum seropositivity and exploration of risk factors for exposure in Busia county, western Kenya: Analysis of the PAZ dataset

BACKGROUND

Despite recognition of histoplasmosis as a disease of national public health concern in Kenya, the burden of Histoplasma capsulatum in the general population remains unknown. This study examined the human seroprevalence of anti-Histoplasma antibody and explored associations between seropositivity and demographic and environmental variables, in Busia county, western Kenya.

METHODOLOGY

Biobanked serum samples and associated data, from a previous cross-sectional survey, were examined. Latex agglutination tests to detect the presence of anti-Histoplasma antibody were performed on serum samples from 670 survey respondents, representing 178 households within 102 sub-locations. Potential epidemiologic risk factors for H. capsulatum exposure were explored using multi-level multivariable logistic regression analysis with household and sub-location included as random effects.

PRINCIPAL FINDINGS

The apparent sample seroprevalence of anti-Histoplasma antibody was 15.5% (n = 104/670, 95% Confidence Interval (CI) 12.9-18.5%). A multivariable logistic regression model identified increased odds of H. capsulatum seropositivity in respondents reporting rats within the household within the previous 12 months (OR = 2.99 90% CI 1.04-8.55, p = 0.04). Compared to respondents aged 25-34 years, the odds of seropositivity were higher in respondents aged 15-24 years (OR = 2.70 90% CI 1.04-6.97, p = 0.04).

CONCLUSIONS

The seroprevalence result provides a baseline for sample size approximations for future epidemiologic studies of the burden of H. capsulatum exposure in Busia county. The final model explored theoretically plausible risk factors for H. capsulatum exposure in the region. A number of factors may contribute to the complex epidemiological picture impacting H. capsulatum exposure status at the human-animal-environment interface in western Kenya. Focussed H. capsulatum research is warranted to determine the contextual significance of identified associations, and in representative sample populations.

Pulmonary Histoplasmosis

Histoplasmosis is one of the most frequent causes of fungal respiratory infection in endemic regions, has a broad spectrum of clinical manifestations and can present in several forms. The extent of disease is determined by the number of conidia inhaled, the immune response of the host and the integrity of the respiratory tract. From an initial and most benign form, acute pulmonary histoplasmosis (an influenza-like illness that is typically asymptomatic or mild in persons without prior immune compromise), histoplasmosis can become a lifethreatening progressive disseminated infection (PDH) that affects mainly immunocompromised patients, with high morbidity and mortality. Chronic pulmonary histoplasmosis is an uncommon manifestation of Histoplasma infection, with features similar to pulmonary tuberculosis, and if it remains undiagnosed or untreated it also can cause significant morbidity. Some rare but serious complications may also occur that are produced by an excessive immune response, such as mediastinal fibrosis, histoplasmoma and broncholithiasis. Histoplasmosis is highly endemic in regions of North, Central and South America as well as being reported in parts of Asia and Africa. The risk of histoplasmosis is greatest in patients with HIV infection, especially those with CD4⁺ counts of <200 cells/μL. We review clinical manifestations, radiological findings and treatment options according to the clinical form (induction therapy and maintenance therapy), as well as different diagnosis tools and new laboratory tests that have been recently developed and validated and are becoming widely available. These should have an impact in reducing time for diagnosis and starting therapy and in reducing morbidity and mortality, especially in patients with HIV infection, where histoplasmosis is currently estimated to be responsible for 5-15% of AIDS-related deaths.

Symptoms in blastomycosis, coccidioidomycosis, and histoplasmosis versus other respiratory illnesses in commercially insured adult outpatients, United States, 2016-2017

BACKGROUND

Blastomycosis, coccidioidomycosis, and histoplasmosis cause various symptoms and syndromes, which may present similarly to other infections such as bacterial or viral community-acquired pneumonia, influenza, and tuberculosis.

METHODS

We used the IBM® MarketScan® Research Databases to identify adult outpatients with International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) diagnosis codes during 2016-2017 for blastomycosis; coccidioidomycosis; histoplasmosis; pneumonia (viral, bacterial, Streptococcus pneumoniae, and unspecified pneumonia); influenza; tuberculosis; and other lower and upper respiratory infections. We compared symptoms on and in the 90 days before diagnosis between patients with these diagnosis codes.

RESULTS

Fever was less common in blastomycosis (2.6%), histoplasmosis (5.3%) and coccidioidomycosis (9.4%) than in influenza (18.5%) or pneumonia (12.6%-16.3%) patients. Fungal diseases resembled bacterial, viral, and unspecified pneumonias for many pulmonary symptoms. However, cough was more common with coccidioidomycosis (31.4%) and less common with histoplasmosis (14.0%) and blastomycosis (13.1%) vs. influenza (20.2%). Although less frequent, solitary pulmonary nodule (5.2%-14.4%), enlarged lymph nodes (3.7%-9.0%), hyperhidrosis (<2%), and erythema nodosum (<2%) were particularly suggestive of fungal diseases.

CONCLUSIONS

Despite limitations inherent in administrative coding, this analysis of symptom codes across disease types suggests that fungal diseases may be difficult to clinically distinguish from other causes of pneumonia except when certain uncommon symptoms are present. Healthcare providers caring for patients with pneumonia, especially if non-responsive to conventional treatment, should consider fungal diseases as possible etiologies.

The life-threatening eruption in HIV and immunosuppression

Immunosuppressed patients frequently have skin diseases of mild to moderate intensity. Diagnosis as well as treatment should be performed early to avoid important complications for these patients. Skin eruptions are among these problems. Life-threatening eruptions in HIV and other types of immunosuppression range from acute retroviral syndrome to drug eruptions; immune reconstitution inflammatory syndrome; infection by virus, protozoan, bacteria, or fungi; inflammatory and immune dermatoses; and neoplasia. All of these are discussed in this group of patients.

Histoplasma capsulatum and Pneumocystis jirovecii coinfection in hospitalized HIV and non-HIV patients from a tertiary care hospital in Mexico

BACKGROUND

Histoplasma capsulatum and Pneumocystis jirovecii are respiratory fungal pathogens that principally cause pulmonary disease. Coinfection with both pathogens is scarcely reported. This study detected this coinfection using specific molecular methods for each fungus in the bronchoalveolar lavage (BAL) of patients from a tertiary care hospital.

MATERIALS AND METHODS

BAL samples from 289 hospitalized patients were screened by PCR with specific markers for H. capsulatum (Hcp100) and P. jirovecii (mtLSUrRNA and mtSSUrRNA). The presence of these pathogens was confirmed by the generated sequences for each marker. The clinical and laboratory data for the patients were analyzed using statistical software.

RESULTS

The PCR findings separated three groups of patients, where the first was represented by 60 (20.8%) histoplasmosis patients, the second by 45 (15.6%) patients with pneumocystosis, and the last group by 12 (4.2%) patients with coinfection. High similarity among the generated sequences of each species was demonstrated by BLASTn and neighbor-joining algorithms. The estimated prevalence of H. capsulatum and P. jirovecii coinfection was higher in HIV patients.

Accuracy of Buffy Coat in the Diagnosis of Disseminated Histoplasmosis in AIDS-Patients in an Endemic Area of Brazil

The buffy coat is obtained routinely for disseminated histoplamosis (DH) diagnosis in Ceará, Brazil. The aim of this study is to describe the accuracy of staining smears for Histoplasma in the buffy coat of AIDS-patients with DH. From 2012-2013, all results of stained buffy coat smears and culture for fungi performed at São José Hospital were recorded. In total, 489 buffy coats of 361 patients were studied; 19/361 (5.3%; 95%CI = 2.9-7.6%) had positive direct examination stained smears for Histoplasma and 61/361 (16.9%; 95%CI = 13.0-20.8%) had growth in culture. For those with positive Histoplasma cultures, the CD4 count was significantly lower (139.3 vs. 191.7cells/µL; p = 0.014) than others, and death was 18%. The sensitivity and specificity of stained smears was 25.9% and 100%, respectively. A second test, performed up to 36 days from the first one, increased the sensitivity of stained smears to 32.2%. Stained smears of buffy coat have low accuracy; nonetheless, they are easy to perform and can give a quick diagnosis in low-resource endemic areas. Despite the decrease in mortality, it is not yet to the low levels observed in areas that have better and more efficient methods.

Histoplasmosis, An Underdiagnosed Disease Affecting People Living With HIV/AIDS in Brazil: Results of a Multicenter Prospective Cohort Study Using Both Classical Mycology Tests and Histoplasma Urine Antigen Detection

Background

Histoplasmosis is highly endemic in the American continent. This condition is associated with a high mortality, particularly in people living with HIV/AIDS (PLWHA). Diagnosis of histoplasmosis is usually late in South America, as Histoplasma antigen detection is rarely available. Here we determined the prevalence, risk factors, and outcome of histoplasmosis in PLWHA in Brazilian hospitals.

Methods

This was a prospective cohort study (2016-2018) involving 14 tertiary medical centers in Brazil. We included hospitalized PLWHA presenting with fever and additional clinical findings. Patients were investigated at each participant center with classical mycology methods. Also, Histoplasma antigen detection was performed in urine samples (IMMY). Probable/proven histoplasmosis was defined according to European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group/National Institute of Allergy and Infectious Diseases Mycoses Study Group criteria.

Results

From 616 eligible patients, 570 were included. Histoplasmosis was identified in 21.6% (123/570) of patients. Urine antigen testing increased the diagnostic yield in 53.8%, in comparison with standard mycology methods. Variables independently associated with histoplasmosis were CD4+ count <50 cells/mm³, use of an antiretroviral (protective effect), and sample collection in the Northeast region of Brazil. Dyspnea at presentation was independently associated with death. Histoplasmosis was more frequent than tuberculosis in patients with low CD4+ counts. Overall 30-day mortality was 22.1%, decreasing to 14.3% in patients with antigen-based diagnosis.

Conclusions

Histoplasmosis is a very frequent condition affecting PLWHA in Brazil, particularly when CD4+ counts are lower than 50 cells/mm³. Antigen detection may detect earlier disease, with a probable impact on outcomes. Access to this diagnostic tool is needed to improve clinical management of PLWHA in endemic countries.