Prevention of invasive aspergillosis in high-risk patients: Universal versus preemptive, targeted treatment

Invasive aspergillosis (IA) is associated with increased morbidity and mortality, and there is a need for better preventative and therapeutic approaches. Successful treatment of documented IA remains difficult, often because of the inability to detect disease at an early stage. An important, recent advance in the management of aspergillosis is the availability of the newer broad-spectrum azoles, voriconazole and posaconazole, which have good activity against Aspergillus spp. In addition, newer diagnostic modalities including Aspergillus galactomannan, β-glucan, and polymerase chain reaction are more readily available. These diagnostic and treatment options have made new strategies possible for the management of IA. Prophylaxis and empirical therapy for high-risk patients have been popular for decades, and now a preemptive, targeted approach to IA management has become more attractive. This article reviews strategies for the prevention and management of IA and compares and contrasts universal prophylaxis to the preemptive, targeted approach for IA in high-risk patients.     

Advances in the serodiagnosis of blastomycosis

Blastomyces dermatitidis, the etiologic agent of blastomycosis, is endemic to certain areas of North America and other continents and can cause a variety of clinical manifestations that range from subclinical to life-threatening infections. Delineation of its ecology and epidemiology has been difficult because of the lack of rapid, sensitive, and specific noninvasive diagnostic tests. Despite efforts to develop such tests for clinical use, diagnosis of infection is still based on direct visualization of the organism in histopathologic or cytologic specimens and growth in the microbiologic laboratory. Serologic tests and skin testing have been hampered by low sensitivity and specificity caused by cross-reactivity with other endemic mycoses and are not commercially available. An antigen assay is now commercially available, but it also has significant cross-reactivity with other mycoses, especially histoplasmosis. The keys to diagnosis remain a high index of suspicion and knowledge of the disease’s varied clinical manifestations.     

Histoplasmosis as cause of penile ulcer in acquired immune deficiency syndrome (AIDS): three case reports

Background Histoplasma capsulatum is the causative agent of American histoplasmosis. The relationship between disseminated histoplasmosis and AIDS has been well established. Widespread hematogenous dissemination of Histoplasma capsulatum in HIV positive patients can cause a plethora of clinical manifestations; virtually any organic system can be affected. However, genital ulceration by H. capsulatum in patients with AIDS is a real challenge during investigation of the infection due to the great variety of differential diagnoses that are involved. Method The diagnosis was performed by histopathologic study; H. capsulatum was detected by silver staining (Grocott staining) and confirmed by immunocytochemistry. Results We report three cases of histoplasmosis in patients with AIDS, in which we observed genital ulcers, an unusual form of presentation of this disease. In one of these cases, the treatment resulted in total cure. Conclusion The cases reported herein are to illustrate the plurality of pathologies and clinical manifestations, which may affect immunocompromised patients. The correct diagnosis of fungal diseases in these patients following well established treatment will improve the prognosis.     

Histoplasmosis in Africa: Current perspectives,knowledge gaps,and research priorities

BackgroundHistoplasmosis is a chronic granulomatous disease caused by the thermally dimorphic fungus Histoplasma capsulatum. The 2 variants Histoplasma capsulatum var. capsulatum (Hcc) and Histoplasma capsulatum var. duboisii (Hcd) causes infection in humans and commonly termed classical or American histoplasmosis and African histoplasmosis, respectively. Histoplasma capsulatum var. farciminosum (Hcf) affects equines. In recent times, there have been heightened sensitization on fungal infections such as histoplasmosis in Africa, aimed at improving awareness among relevant stakeholders, particularly healthcare workers. This effort is expected to be paralleled with increased detection of both classical and African histoplasmosis, which has remained underdiagnosed over the years. In this narrative review, we describe the current perspectives of histoplasmosis in Africa, identify knowledge gaps, and suggest research priorities.MethodsA PubMed, Google Scholar, and Africa Journal Online (AJOL) literature search was conducted for studies on histoplasmosis in Africa between 2000 and 2020. Histoplasmosis essays in medical mycology textbooks were also consulted. This narrative review was prepared from the data gathered.FindingsIn the past 2 decades, histoplasmosis in general has seen a relative increase in case detection in some Africa countries, probably attributable to the gradually increasing medical mycology advocacy efforts in Africa. Histoplasmosis cases are dominated by African histoplasmosis mostly in Western and Central Africa, while classical histoplasmosis is more common in Southern and Northern Africa. Although both classical and African histoplasmosis are common in Africa, the latter is more restricted to Africa, and cases outside the continent usually have a travel history to the continent. Despite the clinical and laboratory difference between African histoplasmosis and classical histoplasmosis, it is not straightforward to distinguish them. The typical manifestation of African histoplasmosis is the appearance of lesions affecting the skin, bones, and lymph nodes and unusually linked to human immunodeficiency virus (HIV)/AIDS. By contrast, classical histoplasmosis mostly affects the lungs and is often associated with immunosuppression, mainly HIV/AIDS. The present perspectives of histoplasmosis in Africa highlight unclear details on the true burden, strain diversity, infection route and genetic basis of African histoplasmosis, availability of specie-specific diagnostic tools, and compliance with recommended antifungal therapy. These knowledge gaps represent research questions that require scientific exploration.ConclusionsDespite a subtle increase in identifying histoplasmosis cases in Africa, it remains underdiagnosed and neglected in some parts of the continent. Increasing awareness and training among healthcare workers, bridging diagnostic and therapeutic gaps, and encouraging more research in Africa are crucial to improve the current perspectives of histoplasmosis in Africa.     

Is Histoplasma capsulatum a native inhabitant of Japan?

Histoplasmosis is an infectious disease caused by inhaling spores of the fungal pathogen H. capsulatum and in Japan is considered an imported mycosis. However, some patients in Japan with histoplasmosis have no history of traveling overseas nor of risk of occupational exposure to Histoplasma. To investigate the possibility of native distribution of Histoplasma in Japan, 187 bat guano samples from 67 bat‐inhabited caves in 17 prefectures were collected. These were examined for H. capsulatum by culture and Histoplasma‐specific PCR in three independent laboratories. No H. capsulatum was detected by either method, therefore H. capsulatum is unlikely to be present in bat guano in Japanese caves.     

宏基因组学诊断播散型组织胞浆菌病1例

播散型组织胞浆菌病是一种进行性肺外疾病好发于免疫缺陷者。该病诊断的应结合组织胞浆菌病的高危因素(免疫抑制剂、高龄、高风险的暴露等)与临床表现。本文报道一例播散型组织胞浆菌病但免疫功能健全的病例,其表现为亚急性起病,后期病程进展迅速,骨髓涂片及宏基因测序诊断为播散型组织胞浆菌病。予以两性霉素B去氧胆酸盐及伊曲康唑治疗后病情明显好转。     

Treatment of the Midwestern Endemic Mycoses,Blastomycosis and Histoplasmosis

Purpose of Review

The purpose of this review is to assess the recommended treatment regimens for the major endemic mycoses, histoplasmosis and blastomycosis, which occur in the Midwestern USA and to provide information about the use of newer antifungal agents for these diseases.

Recent Findings

The basic approach to treatment of histoplasmosis and blastomycosis outlined in the IDSA Guidelines is helpful in managing these diseases. However, changes since these guidelines were published provide safer and better tolerated treatment regimens. Prolonged treatment with amphotericin B is rarely required, and lipid formulations of this drug have largely replaced the amphotericin B deoxycholate formulation. Although no clinical trials have been performed and the data are anecdotal, voriconazole and posaconazole are increasingly used in patients who cannot tolerate itraconazole. Voriconazole is especially useful when central nervous system infection is present. Posaconazole tablets provide consistently appropriate serum levels and the drug is well tolerated.

Summary

New azole agents provide alternative therapeutic options for histoplasmosis and blastomycosis.

     

Gastrointestinal Histoplasmosis in a Hepatitis C-Infected Individual

Gastrointestinal histoplasmosis is a rare manifestation of this fungal infection, typically identified in immunocompromised patients, such as those with HIV/AIDS. Here, we report a case of disseminated histoplasmosis with gastrointestinal involvement in a Hepatitis C-infected patient. The fungal agent was confirmed to be Histoplasma capsulatum by a DNA probe assay performed on a bone marrow sample. We propose that this fungal disease should be kept on the differential of patients infected with the Hepatitis C virus, as it has been reported to have numerous damaging effects on the adaptive immune system.     

Occurrence of histoplasmosis in Asia

The occurrence of histoplasmosis in Asia has been reviewed. Authentic cases of histoplasmosis in man are known from India, Malaysia, Singapore, Indonesia, Thailand, South Vietnam and Japan, but the autochthonous nature of the cases reported has not been established unequivocally. Of the 30 cases of human histoplasmosis recorded from Asia, 15 were confirmed by positive cultures, and their country-wise distribution is as follows: Malaysia — 4, Indonesia — 3, Singapore — 2, Thailand — 2, South Vietnam — 2 and one each from India and Japan. Authentic cases of histoplasmosis in animals are currently unknown from Asia, and likewise there is no information on the natural habitats of the etiologic agentH. capsulatum in this part of the world except for a solitary isolation from soil in bat-infested cave in Malaysia.The available data on the prevalence of cutaneous hypersensitivity to histoplasmin indicates that histoplasmin sensitivity is absent in Israel, Syria, Saudi Arabia, Lebanon and Qatar; sensitivity is negligible or of a very low order in Iran, Iraq, Pakistan and India, and for these countries it has been even suggested that the positive reactors observed may represent cross-sections with some unknown fungus/fungi which may be antigenically related toH. capsulatum. In Japan the frequency of histoplasmin positive reactors has been negligible except in groups of persons working near a U.S. Army base and in factories which used soil and sand imported from overseas including the U.S.A. In Burma and Taiwan the bulk of positive reactions in which the induration did not exceed 8 mm in diameter has been considered probably non-specific. In Indonesia and South Vietnam, on the other hand, where less than 10 per cent of the reactions tended to concentrate around an induration of 16 mm sensitivity to histoplasmin may represent specificH. capsulatum infection in certain cases. Likewisef the requently large reactions reported from the Philippines have also been interpreted to represent specific histoplasmosis infection.The recovery ofH. capsulatum from soil coupled with the finding of well-documented cases of histoplasmosis in Malaysia suggests that the disease is endemic in that country. It is not unlikely that histoplasmosis is endemic in other parts of Asia although this has not been demonstrated so far. Comprehensive mycological, serological and soil studies are indicated in order to investigate the prevalence and incidence of histoplasmosis and to map out the endemic areas of the disease in Asia.Paper read at the Eighth International Congresses for Tropical Medicine and Malaria, September 1968, Teheran (Iran).     

Histoplasmosis in a Brazilian center: clinical forms and laboratory tests

Histoplasmosis, caused by the dimorphic fungus Histoplasma capsulatum, is endemic in many regions of the Americas, Asia and Africa. It has a wide spectrum of clinical manifestations, from asymptomatic infection to severe disseminated disease. A retrospective study was carried out to describe the clinical forms and assess the clinical significance of the laboratory diagnostic tests of patients with histoplasmosis during the period of July 1987 to December 2003 at Instituto de Pesquisa Clínica Evandro Chagas/ FIOCRUZ, RJ, Brazil. Seventy-four patients were included. Forty-nine percent of the cases (n = 36) occurred in HIV positive patients who presented with disseminated disease. The remaining 38 cases were classified in different clinical forms. Histoplasma capsulatum was isolated from 69.5% of the clinical specimens sent to culture. Immunodiffusion and immunoblot were positive in 72.6% and 100% of the performed tests, respectively. Histopathologic findings suggestive of H. capsulatum were found in 63.2% of the performed exams. Serology had a lower proportion of positivity amongst AIDS patients, when compared with HIV negative patients (X2 = 6.65; p lower than 0.008). Statistical differences between AIDS and non-AIDS patients were not observed with culture and histopathology. The specific role of each test varies according to the clinical form. Physicians need to know the value and limitations of the available diagnostic tests, but before that, they have to think about histoplasmosis and consider this clinical entity in their differential diagnosis.     

Fungal endocarditis

Recent advances in medicine have caused fungal endocarditis (FE) to be a more common disease entity. A list of fungi is expanding as potential pathogens in FE, with Candida species and Aspergillus species being the most common. The combination of valvular heart disease along with indwelling devices and antibiotic use are the major predisposing factors for yeast endocarditis, whereas the presence of immunosuppression along with valvulopathy predisposes for mold endocarditis. The expanding population of immunosuppresed patients and individuals with intravascular devices has led to increased incidence of FE. Better outcome of FE depends on fast and accurate diagnosis and subsequent treatment. Echocardiography the most valuable recent technique allowed for early diagnosis of FE and is probably responsible for the improved prognosis of patients with FE. Nonculture-based diagnostic tests may further improve the sensitivity, specificity, and rapidity of microbiologic diagnosis of FE. The availability of the newer triazoles and echinocandins, providing broad spectrum antifungal activities with favorable safety profile may assist in achieving cure and further improving the prognosis of this disease entity.     

The kSORT Assay to Detect Renal Transplant Patients at High Risk for Acute Rejection: Results of the Multicenter AART Study

BackgroundDevelopment of noninvasive molecular assays to improve disease diagnosis and patient monitoring is a critical need. In renal transplantation, acute rejection (AR) increases the risk for chronic graft injury and failure. Noninvasive diagnostic assays to improve current late and nonspecific diagnosis of rejection are needed. We sought to develop a test using a simple blood gene expression assay to detect patients at high risk for AR.ConclusionsThe kSORT blood QPCR assay is a noninvasive tool to detect high risk of AR of renal transplants.Please see later in the article for the Editors'' Summary     

Improved carrier testing for multiple endocrine neoplasia,type 1, using new microsatellite-type DNA markers

Familial multiple endocrine neoplasia, type 1 (FMEN1), is an autosomal dominant trait generated by hyperfunction of various endocrine glands. The gene for MEN1 has been mapped to chromosome 11q13 by genetic linkage and deletion mapping in tumors. Eight Finnish families, including 46 individuals carrying the risk haplotype, have been typed for four polymorphic microsatellite DNA markers spanning the MEN1 chromosomal region. Three of the loci concerned, D11S913, D11S987, and D11S1337, displayed maximum lod scores (Z _max ) 6.70, 9.88, and 2.54, respectively, with no recombinations with the disease gene, whereas a Z _max of 8.43 was obtained for D11S971 at a recombination fraction of 0.03. Our results indicate that the use of this set of markers considerably improves the diagnostic value of genotyping patients at risk of developing MEN1.     

Epidemiology of Histoplasmosis

Purpose of Review

Histoplasma capsulatum is an environmental fungus that contributes significant morbidity and mortality throughout the globe, especially in immunocompromised hosts. This review presents current data on the understanding of histoplasmosis epidemiology, including changing incidence among geographic regions and patient populations with increased risk.

Recent Findings

Global cases are more frequently identified due to the HIV epidemic, an increasing number of immunocompromised patients, and improved diagnostic capabilities. The global distribution of histoplasmosis extends to several countries in Central and South America and the Caribbean, as well as southern and sub-Saharan Africa, India, China, and Southeast Asia. Cases are also seen throughout Europe and non-endemic regions of the USA often due to migration and travelers.

Summary

The changing epidemiology of histoplasmosis underlines the importance of continued surveillance and reporting to better understand the regions which place patients at a higher risk for infection.

     

How I Treat Histoplasmosis

Histoplasmosis is an endemic mycosis caused by the dimorphic fungus Histoplasma capsulatum. Some important manifestations of infection include acute or chronic pulmonary disease, histoplasmomas, progressive disseminated histoplasmosis, and central nervous system infection. Depending on the clinical presentation, site of infection and severity of disease, either amphotericin B preparations followed by itraconazole, or itraconazole alone have become the preferred treatments. Because prolonged therapy (6 weeks to 24 months) may be required, careful monitoring for nephrotoxicity in patients on amphotericin B preparations is necessary. In addition, in patients receiving itraconazole, vigilance for drug interactions and pharmacokinetic properties is warranted. Histoplasma antigen testing has improved rapidity of diagnosis and the ability of long-term monitoring for clinical response in patients with histoplasmosis.     

Gingival histoplasmosis: An atypical presentation of African histoplasmosis in three baboons (Papio spp)

Gingival lesions as the sole manifestation of African histoplasmosis (Histoplasma capsulatum var. duboisii) have never been reported in baboons. Grossly, lesions can be indistinguishable from bacterial ulcerative gingivitis or gingival hyperplasia. Clinical outcomes of primary gingival histoplasmosis in baboons are unknown and may complicate colony management decisions.     

Antiviral drug treatment for nonsevere COVID-19: a systematic review and network meta-analysis

Background:Randomized trial evidence suggests that some antiviral drugs are effective in patients with COVID-19. However, the comparative effectiveness of antiviral drugs in nonsevere COVID-19 is unclear.Methods:We searched the Epistemonikos COVID-19 L·OVE (Living Overview of Evidence) database for randomized trials comparing antiviral treatments, standard care or placebo in adult patients with nonsevere COVID-19 up to Apr. 25, 2022. Reviewers extracted data and assessed risk of bias. We performed a frequentist network meta-analysis and assessed the certainty of evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.Results:We identified 41 trials, which included 18 568 patients. Compared with standard care or placebo, molnupiravir and nirmatrelvir–ritonavir each reduced risk of death with moderate certainty (10.9 fewer deaths per 1000, 95% confidence interval [CI] 12.6 to 4.5 fewer for molnupiravir; 11.7 fewer deaths per 1000, 95% CI 13.1 fewer to 2.6 more). Compared with molnupiravir, nirmatrelvir–ritonavir probably reduced risk of hospital admission (27.8 fewer admissions per 1000, 95% CI 32.8 to 18.3 fewer; moderate certainty). Remdesivir probably has no effect on risk of death, but may reduce hospital admissions (39.1 fewer admissions per 1000, 95% CI 48.7 to 13.7 fewer; low certainty).Interpretation:Molnupiravir and nirmatrelvir–ritonavir probably reduce risk of hospital admissions and death among patients with nonsevere COVID-19. Nirmatrelvir–ritonavir is probably more effective than molnupiravir for reducing risk of hospital admissions. Most trials were conducted with unvaccinated patients, before the emergence of the Omicron variant; the effectiveness of these drugs must thus be tested among vaccinated patients and against newer variants.

Most trials addressing the treatment of patients with COVID-19 have targeted patients admitted to hospital with severe or critical disease.¹ However, more recently, several treatments, including antiviral drugs, antidepressants, monoclonal antibodies and inhaled corticosteroids, have been studied for patients with nonsevere COVID-19.² Preliminary evidence from ongoing or recently completed trials suggests that 2 novel antiviral drugs — molnupiravir and nirmatrelvir–ritonavir (Paxlovid) — may be effective at reducing risk of hospital admission.^3–5 To date, evidence on antiviral drugs for nonsevere COVID-19 has not been systematically synthesized or appraised. Furthermore, although efficacy data from trials of molnupiravir, nirmatrelvir–ritonavir and remdesivir are promising, no head-to-head trials have compared these drugs.A network meta-analysis allows for comparison of treatments that have not been compared in randomized controlled trials (RCTs), using pooled estimates from direct and indirect evidence. They can provide guidance to clinicians and evidence users in determining which treatments are superior. This is particularly important as health care systems attempt to prioritize access to effective COVID-19 treatments in the early stages of the disease.We sought to compare the effectiveness of antiviral drugs for patients with nonsevere COVID-19.     

Aspects of early arthritis. Biological therapy in early arthritis – overtreatment or the way to go?

The availability of newer, and more expensive, therapies for patients with rheumatoid arthritis has changed treatment beyond recognition. Disease remission is the goal for all new patients. Studies have shown that a combination of tumour necrosis factor (TNF)-blocking drugs and methotrexate produces superior outcomes over monotherapy alone; however, use is limited by cost and potential side-effects. Currently, anti-TNF therapy is normally reserved for patients who have failed traditional disease-modifying anti-rheumatic drugs. The question that remains is whether TNF-blocking drugs are better used if given early; the high direct costs are countered by both direct and indirect savings in healthcare costs from optimal control of disease, and the benefits of early control outweigh the increased risk of infection and malignancy.     

Aspects of early arthritis. Biological therapy in early arthritis--overtreatment or the way to go?

The availability of newer, and more expensive, therapies for patients with rheumatoid arthritis has changed treatment beyond recognition. Disease remission is the goal for all new patients. Studies have shown that a combination of tumour necrosis factor (TNF)-blocking drugs and methotrexate produces superior outcomes over monotherapy alone; however, use is limited by cost and potential side-effects. Currently, anti-TNF therapy is normally reserved for patients who have failed traditional disease-modifying anti-rheumatic drugs. The question that remains is whether TNF-blocking drugs are better used if given early; the high direct costs are countered by both direct and indirect savings in healthcare costs from optimal control of disease, and the benefits of early control outweigh the increased risk of infection and malignancy.     

Two Specific Strains of <Emphasis Type="Italic">Histoplasma capsulatum</Emphasis> causing Mucocutaneous Manifestations of Histoplasmosis: Preliminary Analysis of a Frequent Manifestation of Histoplasmosis in Southern Brazil

Objectives  Skin lesions, uncommon in US cases (<10%), occur in 38–85% of cases reported from Latin America. Although these differences may reflect reporting bias, delayed diagnosis, or differences in host immune response among different ethnic groups, they also could result from genetic differences changing the pathobiology of the organism. It is possible that genetic differences among strains of H. capsulatum may influence the pathogenesis and clinical manifestations of histoplasmosis. Methods  We examined the clinical features of patients with mucocutaneous manifestations of histoplasmosis and performed genetic analysis based on nucleotide sequence variations in the internal transcribed spacer regions of rRNA genes of H. capsulatum isolates of patients. Two pairs of PCR primers were designed to develop and amplify the ITS regions of H. capsulatum, 5′-TACCCGGCCACCCTTGTCTA-3′ and 5′-AGCGGGTGGCAAAGCCC-3′. These primers were based on the ITS sequence of Ajellomyces capsulatus, the ascomycetous teleomorph form of H. capsulatum, deposited in the GenBank (accession number U18363). Eight patients attending a tertiary-care hospital in southern Brazil were enrolled into the study. All case patients had skin cultures growing H. capsulatum at the mycology laboratory. Results  Six of eight (75%) patients were HIV-positive and presented involvement of multiples organs by H. capsulatum. Two HIV-negative patients did not present evidence of involvement of other organs besides mucosa and skin. ITS sequencing of a DNA H. capsulatum fragment of 485-bp from isolates of 8 patients revealed two distinct strains. The 2 distinct fragments (Hc1, Hc2) differed from each other at 7 positions in the ITS regions. They were identical to strains of H. capsulatum isolated in patients from Colombia and Argentina, but different from strains isolated in US. Hc1 and Hc2 were isolated in 5 patients and 3 patients, respectively, with mucocutaneous manifestations of histoplasmosis. Both Hc1 and Hc2 strains were isolated in HIV-infected and non-HIV-infected patients. Conclusions  Mucocutaneous manifestations of histoplasmosis, which are frequently seen in Brazilian patients were caused by 2 specific strains in our institution. Those strains have been isolated in patients with these particular clinical features of histoplasmosis in Latin America. Our study suggests that unique pathogenic characteristics among the Latin American species of H. capsulatum might explain its increased dermatotropism.