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

The impact of immune recovery and treatment duration on disseminated histoplasmosis consolidation therapy in AIDS patients

INTRODUCTION

The present study investigated the impact of immune recovery and the duration of antifungal adherence in the consolidation phase of disseminated histoplasmosis (DH) in acquired immune deficiency syndrome (AIDS) patients living in a hyperendemic area in northeastern Brazil.

MATERIAL AND METHODS

Sixty-nine patients with DH/AIDS, admitted to the São José Hospital between 2010 and 2015, who continued histoplasmosis consolidation therapy at the outpatient clinic were studied. The follow-up duration was at least 24 months.

RESULTS

Sixty-eight patients used itraconazole 200-400 mg/day or amphotericin B deoxycholate weekly during the consolidation phase, and six patients relapsed during follow-up. The overall median duration of consolidation antifungal use was 250 days [IQR 101 - 372]. Antifungal withdrawal by medical decision occurred in 41 patients (70.7 %) after a median of 293 days [IQR 128 - 372] of use; 16 patients discontinued by their own decision, with a median of 106 days [IQR 37 - 244] of therapy; three patients had no information available, and nine continued on AF therapy. The median CD4+ T-cell count in the group without relapse was 248 cells/µL [IQR 115-355] within 6 months after admission; conversely, in the relapse group, the median cell count remained below 100 cells/µL. Irregular adherence to highly active antiretroviral therapy (HAART) was the leading risk factor associated with relapse and death (p< 0.01).

DISCUSSION

The regular use of HAART, combined with immune recovery, proved to be highly effective in preventing relapses in DH/AIDS patients, suggesting that long-term antifungal therapy may not be necessary.

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.

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.

Laboratory diagnosis of community-acquired bloodstream infection in therapeutic pathology

Community-acquired bloodstream infections (CBSIs) occur in the out-of-hospital setting (44%) and increase the overall mortality from bloodstream infections (BSIs) by 7.2% per year. The development of CBSIs depends on both comorbid and polymorbid diseases and the patients' age. The causes of CBSIs are: respiratory, hepatobiliary gastrointestinal and urogenital tracts and dental interventions. The etiology of CBSIs is characterized by the isolation of coagulase-negative staphylococci (CNS) (32%), E. coli (27%). To investigate community-acquired bloodstream infection in therapeutic patients. The study included out-of-hospital patients (n=382). 4.5 ml of blood were taken intravenously into a closed vacuum system in order to obtain a buffy coat of blood, which was put on glasses for microscopy and Petri dishes with blood agar for cultivating under aerobic and anaerobic conditions. Microorganisms were identified by mass spectrometry. Microscopy of blood smears was used for rapid diagnosis of infection in the bloodstream. BSI was diagnosed in 183 (48.0%) out of 382 out-of-hospital patients. The etiology of CBSIs was studied on 297 isolated strains of microorganisms. CBSIs rather often complicated the underlying disease in women and young people. The spectrum of CBSI pathogens included aerobic and anaerobic bacteria and fungi. Gram-positive cocci with the leadership of S.epidermidis (25.7%) were more often isolated among bacteria. 70% of all isolated pathogens grew under anaerobic conditions. CBSIs were characterized by polymicrobiality (33.5%) of two to four different microorganisms in one blood culture; the species of associates of polymicrobial blood cultures are shown. Microscopic examination of blood smears revealed microorganisms in 97.1% of cases, including associations of bacteria with fungi (66.9%). CBSIs occurred after contour plastic, in diseases of the respiratory system, genitourinary system, oral cavity, skin and subcutaneous tissue. Microbiological examination of the buffy coat is an alternative microbiological method of CBSIs diagnosis, which includes microscopy and blood cultivating and has a high diagnostic efficiency (97.1% and 48% respectively). It can become an option for replacing imported blood culture automated systems.

Progressive disseminated histoplasmosis in HIV-positive patients

BACKGROUND

Histoplasmosis is the most common endemic mycosis among people living with advanced HIV infection.

PURPOSE

Describe general aspects and challenges of this disease and its association with HIV.

RESEARCH DESIGN

Review of literature.

STUDY SAMPLE

Articles found using different combinations of terms including "disseminated histoplasmosis" and AIDS/HIV or immunosuppression in PubMed, Scopus, WHO Global health library, and Scielo database.

ANALYSIS

We look for information on epidemiology, pathogenesis, diagnosis, and treatment of histoplasmosis in AIDS patients.

RESULTS

Histoplasmosis is caused by Histoplasma capsulatum, a dimorphic fungus encountered throughout the world, mainly in soil enriched with bat and bird excreta. Progressive disseminated histoplasmosis is the main presentation of this mycosis in people living with advanced HIV and is fatal if left untreated. Symptoms include a systemic disease characterized by fever, weight loss, night sweats, skin manifestations, hepatomegaly, splenomegaly, and septic shock. Diagnostic tests include culture, visualization of H. capsulatum by direct and histopathological examination, serology, antigen, molecular, and skin testing. Patients with disseminated disease require aggressive and prolonged treatment to eradicate the pathogen and include amphotericin B and itraconazole. In many low income countries of endemic regions, histoplasmosis in HIV-positive patients is often undiagnosed or misdiagnosed as another opportunistic infection, due to the similarity in clinical manifestations and to the paucity of better diagnostic tests.

CONCLUSION

Histoplasmosis remains a neglected disease. Few studies about the disease and expensive treatments make it difficult to reduce the morbidity and mortality of this condition. Public health services and physicians must be aware of histoplasmosis' burden among the HIV-positive population.

Summary of Guidelines for Managing Histoplasmosis among People Living with HIV

Histoplasmosis is a frequent fungal opportunistic infection in people living with HIV (PLHIV), associated every year to a total of 5% to 15% of AIDS-related deaths among this population. In 2020, the first global guidelines for diagnosing and managing disseminated histoplasmosis among PLHIV was published. This document recommends (1) detection of circulating Histoplasma antigens as the recommended laboratory assay to diagnose histoplasmosis among PLHIV; (2) the use of liposomal amphotericin for induction therapy in severe or moderately severe disease, followed by a maintenance therapy with itraconazole for 12 months; a shorter maintenance therapy could be considered if the patient is clinically stable and if immune status has improved; (3) antiretroviral therapy initiation as soon as possible among patients with histoplasmosis without involvement of central nervous system; and (4) that for the treatment of co-infection with histoplasmosis and tuberculosis (TB), treatment of TB should be initiated according to the World Health Organization treatment guidelines. Appropriate health education of providers, supportive supervision, and policy guidance for the care of PLHIV are required.