Implementation of rapid diagnostics assays for detection of histoplasmosis and cryptococcosis in central american people living with HIV

Improving disseminated histoplasmosis diagnosis in HIV/AIDS patients in Suriname: The role of a urine lateral flow assay

Histoplasmosis is a frequent cause of infections in people living with HIV/AIDS (PLWHA). This study introduces the application of a Histoplasma capsulatum urine antigen lateral flow assay (LFA) for diagnosing disseminated histoplasmosis in PLWHA in Suriname. The LFA's diagnostic accuracy was compared with the current diagnostic approach, aiming to assess whether this test resulted in improved early detection and management. Additionally, the prevalence of histoplasmosis among advanced stage HIV patients without clinical suspicion of infection was evaluated using the same LFA. In total, 98 patients were included in the study, of which 58 were classified as "possible disseminated histoplasmosis (DH)" based on clinical criteria and 40 as 'controls". Of these possible DH cases, only 19 (32.7%) had a positive LFA. During the study, decisions for treatment were made without the treating physician being aware of the LFA result. Only 55% of the patients who started treatment for histoplasmosis based on clinical criteria had a positive LFA, and 21% of untreated patients had a positive LFA. This study shows that combining clinical signs with LFA results enhances diagnostic accuracy and is cost effective, resulting in better treatment decisions.

Estimated burden of fungal infections in Panama

Data published on Panamanian fungal disease are scarce, mostly case reports. To date, there is no paper that compiles the burden of fungal disease Here we estimate for the first time the incidence and prevalence of fungal diseases in Panama. Data on fungal disease were obtained from different search engines: PubMed, Google Scholar, Scielo and Lilacs. For population and at risk diseases, we used statistics from worldometer, UNAIDS, and WHO. Incidence, prevalence, and absolute numbers were calculated based on the population at risk. Panamanian population in 2022 was 4,429,739. We estimated that 85,530 (1.93 %) people suffer from fungal diseases. The most frequent fungal infection was recurrent Candida vaginitis (3285/100,000). There are 31,000 HIV-infected people in Panama and based on the number of cases not receiving anti-retroviral therapy (14,570), and previous reports of prevalence of opportunistic infections, we estimated annual incidences of 4.0/100,000 for cryptococcal meningitis, 29.5/100,000 for oral candidiasis, 23.1/100,000 for esophageal candidiasis, 29.5/100,000 for Pneumocystis pneumonia, 15.1/100,000, and for histoplasmosis. For chronic pulmonary aspergillosis (CPA) and fungal asthma we used data from Guatemala and Colombia to estimate COPD and asthma prevalence and WHO report for tuberculosis. We estimated annual incidences of 6.1/100,000 for invasive aspergillosis and prevalence of 31.5/100,000 for CPA, 60.2/100,000 for allergic bronchopulmonary aspergillosis, and 79.5/100,000 for severe asthma with fungal sensitisation. Other incidence estimates were 5.0/100,000 for candidaemia, 0.20/100,000 for mucormycosis, and 4.97/100,000 for fungal keratitis. Even though this report on burden of fungal disease is a forward step, more epidemiological studies to validate these estimates are needed.

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.

Current situation of endemic mycosis in the Americas and the Caribbean: Proceedings of the first international meeting on endemic mycoses of the Americas (IMEMA)

BACKGROUND

The Americas are home to biologically and clinically diverse endemic fungi, including Blastomyces, Coccidioides, Emergomyces, Histoplasma, Paracoccidioides and Sporothrix. In endemic areas with high risk of infection, these fungal pathogens represent an important public health problem.

OBJECTIVES

This report aims to summarise the main findings of the regional analysis carried out on the status of the endemic mycoses of the Americas, done at the first International Meeting on Endemic Mycoses of the Americas (IMEMA).

METHODS

A regional analysis for the Americas was done, the 27 territories were grouped into nine regions. A SWOT analysis was done.

RESULTS

All territories reported availability of microscopy. Seventy percent of territories reported antibody testing, 67% of territories reported availability of Histoplasma antigen testing. None of the territories reported the use of (1-3)-β-d-glucan. Fifty two percent of territories reported the availability of PCR testing in reference centres (mostly for histoplasmosis). Most of the territories reported access to medications such as trimethoprim-sulfamethoxazole, itraconazole, voriconazole and amphotericin B (AMB) deoxycholate. Many countries had limited access to liposomal formulation of AMB and newer azoles, such as posaconazole and isavuconazole. Surveillance of these fungal diseases was minimal.

CONCLUSIONS

A consensus emerged among meeting participants, this group concluded that endemic mycoses are neglected diseases, and due to their severity and lack of resources, the improvement of diagnosis, treatment and surveillance is needed.

Validation of a Lateral Flow Assay for Rapid Diagnosis of Histoplasmosis in Advanced HIV Disease, Buenos Aires, Argentina

Histoplasmosis is a major cause of mortality in individuals with advanced human immunodeficiency virus (HIV) disease (AHD). We evaluated in patients with AHD a lateral flow assay (LFA) developed by MiraVista® Diagnostics (MVD LFA). Histoplasmosis was defined based on the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) case definitions. We also compared the results of this LFA with those obtained using a commercial enzyme immunoassay (EIA) developed by IMMY, Clarus Histoplasma GM EIA, IMMY (HGM EIA). A retrospective observational study was conducted at Hospital Juan A. Fernández, located in Buenos Aires, Argentina. The study included 48 urine specimens from patients aged >18 years with AHD. Urine specimens included 17 patients with disseminated histoplasmosis and 31 specimens from patients without evidence of histoplasmosis. Specimens were tested using the MVD LFA and the HGM EIA. The MVD LFA and the HGM EIA had similar analytical performance, with a sensitivity of 94%, specificity of 100%, positive predictive value of 100%, negative predictive value of 97%, and an accuracy of 98%. Comparison of the MVD LFA with the HGM EIA demonstrated a Kappa agreement index of 0.906. The LFA evaluated in this study had high analytical performance; it provided rapid diagnosis of histoplasmosis with minimal requirements for laboratory training, equipment, and laboratory infrastructure.

Cryptococcal and Histoplasma Antigen Screening among People With HIV in Ghana and Comparative Analysis of OIDx Histoplasma Lateral Flow Assay and IMMY Histoplasma Enzyme Immunoassay

Background

Cryptococcal meningitis (CM) and disseminated histoplasmosis (DH) are common in people with HIV (PWH) and diagnosed by detecting cryptococcal antigen (CrAg) and Histoplasma antigen (Histo Ag) respectively. In Ghana, CM and DH are rarely suspected by clinicians due to limited epidemiological data.

Methods

This study was conducted among PWH in Ghana who are unwell. Sociodemographic and clinical data were collected by questionnaire. Serum and/or urine were screened for CrAg and Histo Ag, using IMMY CrAg lateral flow assay (LFA) and IMMY Histoplasma enzyme immunoassay (EIA) kits, respectively, regardless of symptoms. Samples run with IMMY Histoplasma EIA were simultaneously run with OIDx Histoplasma LFA. Laboratory investigations were conducted by the research team while diagnosis incorporating clinical assessment, screening and confirmatory testing results and treatment decisions were made by the clinical team. Treatment and outcome information on CM and DH patients were evaluated.

Results

Overall, 150 participants were recruited. There were 73% (n = 109) females, and the age range was 18–62 years. The prevalence rates of CrAg and Histo Ag were 2.7% (4/150) and 4.7% (5/107), respectively. The OIDx Histoplasma LFA showed a high concordance (98.4%) with the IMMY Histoplasma EIA. All antigen-positive cases by standard tests were diagnosed with CM and DH. Antifungal treatment was given in five patients and follow-up revealed two deaths and three recoveries.

Conclusion

Histoplasmosis among PWH may be more common than previously anticipated and may be more frequent than cryptococcosis in Ghana. The performance of the OIDx Histoplasma LFA should be further explored.

Burden of serious fungal infections in Honduras

BACKGROUND

The burden of serious fungal infections in Honduras is unknown. The diagnosis of fungal diseases relies on almost exclusively on microscopy and culture limiting an accurate estimate of the burden of disease.

OBJECTIVES

The primary objective of the study was to estimate the burden of serious fungal infections in Honduras using previously described methods.

METHODS

National and international demographic data on population, HIV, tuberculosis, asthma, COPD and cancer were obtained. A thorough literature search was done for all epidemiological studies and case series of serious fungal diseases. Using these risk populations and whatever incidence and prevalence could be found that was most pertinent to Honduras, a burden estimate was derived.

RESULTS

The estimated number of serious fungal infection was estimated to be between 178,772 and 179,624 with nearly 2300 cases of these representing opportunistic infections in people living with HIV. The incidence of histoplasmosis and cryptococcosis in people living with HIV is high and estimated to be 4.3 and 4.6 cases per 100,000 population respectively. Approximately 12,247-13,099 cases of aspergillosis and 164,227 of other serious fungal infections were estimated to occur each year.

CONCLUSION

An accurate estimate of the burden of serious fungal infections in Honduras is unknown but based on our results, likely significant. Serious fungal infections represent an important public health problem in Honduras affecting approximately 1.8% of the population. There is a clear need for better access to diagnostic tools and antifungals to conduct research to better understand the impact of fungal diseases in Honduras.

Hemophagocytic Syndrome in a Patient with HIV and Histoplasmosis: A not so Rare Correlation

Hemophagocytic lymphohistiocytosis (HLH) is a disorder that occurs due to unsuitable monocyte activation in a variety of infections. In human immunodeficiency virus (HIV) infections, patients with advanced immunossupression associated with opportunistic infections are at increased risk of developing HLH. We describe a clinical case of a 33-year-old male student diagnosed with HIV who was hospitalized for investigation of asthenia and dyspnea, accompanied by adynamia, decreased motor force in the left leg, dysphagia, and dysfluency. His general condition was regular, he was pale, feverish, and had normal cardiac and pulmonary auscultation. Physical examination revealed ulcerated lesions in the perianal region and hepatosplenomegaly without palpable lymph node enlargement. Laboratory parameters showed pancytopenia, a slight increase in liver function accompanied by high lactate dehydrogenase, and hiperferritinemia. The initial diagnosis was disseminated histoplasmosis, thus amphotericin B deoxycholate was empirically prescribed while waiting on myeloculture and blood cultures for fungi and mycobacteria. Other clinical procedures were blood transfusion, resumption of antiretroviral therapy (ART) and secondary prophylaxis. Myeloculture blood cultures of fungi and mycobacteria were negative. Patient evolved well in relation to the initial complaints and showed partial clinical and laboratory improvement. However, 23 days after hospitalization, he developed a febrile episode accompanied by chills and a convulsive crisis. The patient was transferred to the intensive unit care and developed septic shock and respiratory failure. He died 25 days after the onset of the condition. After the postmortem examination, histopathology revealed countless rounded fungal structures compatible with Histoplasma sp., which were observed in the peripancreatic lymph node, liver, and spleen, in addition to hemophagocytosis in the splenic parenchyma. We thus conclude that when the patient met criteria for HLH, such as fever, hepatosplenomegaly, hiperferritinemia, and pancytopenia, the evolution was fast due to the aggressive and rapidly fatal nature of HLH, despite anti-fungal and corticoid treatment. Therefore, this case report reinforces the need to consider hemophagocytic syndrome in patients with HIV and disseminated histoplasmosis, especially where histoplasmosis is highly endemic, in order for the treatment be started early when there is high clinical suspicion.

Diagnosis of Histoplasmosis Using the MVista Histoplasma Galactomannan Antigen Qualitative Lateral Flow-Based Immunoassay: A Multicenter Study

Background

Accurate and timely methods for the diagnosis of histoplasmosis in resource-limited countries are lacking. Histoplasma antigen detection by enzyme immunoassay (EIA) is widely used in the United States (US) but not in resource-limited countries, leading to missed or delayed diagnoses and poor outcomes. Lateral flow assays (LFAs) can be used in this setting.

Methods

Frozen urine specimens were submitted to MiraVista diagnostics for antigen testing from 3 medical centers in endemic areas of the US. They were blinded and tested for the MVista Histoplasma LFA. Patients were classified as controls or cases of histoplasmosis. Cases were divided into proven or probable; pulmonary or disseminated; immunocompetent or immunosuppressed; and mild, moderate, or severe.

Results

Three hundred fifty-two subjects were enrolled, including 66 cases (44 proven, 22 probable) and 286 controls. Most of the cases were immunocompromised (71%), and 46 had disseminated and 20 had pulmonary histoplasmosis. Four cases were mild, 42 moderate, and 20 severe. LFA and EIA were highly concordant (κ = 0.84). Sensitivity and specificity of the LFA were 78.8% and 99.3%, respectively. LFA sensitivity was higher in proven cases (93.2%), patients with disseminated (91.3%), moderate (78.6%), and severe disease (80%), and those with galactomannan levels >1.8 ng/mL (97.8%). Specificity was 99.3% in proven cases, 99.3% in patients with moderate or severe disease, and 96.8% in those with galactomannan levels >1.8 ng/mL. Cross-reactivity was noted with other endemic mycoses.

Conclusions

The MVista Histoplasma LFA meets the need for accurate rapid diagnosis of histoplasmosis in resource-limited countries, especially in patients with high disease burden, potentially reducing morbidity and mortality.

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.

Diagnosis of fungal opportunistic infections in people living with HIV from Guatemala and El Salvador

Objectives

Histoplasmosis and cryptococcosis are important public health problems in people living with HIV (PLHIV) in Central America. Conventional laboratory tests, such as culture and microscopy, are not optimal; however, antigen (Ag) tests are rapid, highly sensitive, and specific for diagnosis of fungal opportunistic infections (OI). The aim of this study was to describe the results of a laboratory‐based surveillance system for histoplasmosis and cryptococcosis.

Methods

An observational cross‐sectional study based on laboratory surveillance, was carried out in two hospitals in Guatemala and one hospital in El Salvador, between July 2012 and December 2014. Diagnosis of histoplasmosis and cryptococcosis in PLHIV were performed by culture and Ag test.

Results

A total of 160 PLHIV were diagnosed with fungal OI, of which, 96 (60%) were diagnosed with histoplasmosis, 62 (39%) were with cryptococcosis, and two patients (1%) were diagnosed with both fungal diseases. Of the 160 patients analysed in this study, 94 (59%) were diagnosed using only an Ag assay. CD4 cell count data were available for 136 (85%) patients; 127 (93%) patients had a CD4 count <200; and 90 (66%) had counts <50 CD4 cells per µl. Antiretroviral therapy utilisation at diagnosis was low (33%). Seventy‐one out of 160 (44%) were co‐infected with tuberculosis or other OIs.

Conclusion

More than half of the patients in this study were diagnosed only by rapid laboratory Ag tests. A high per cent of the patients had advanced HIV disease.