Disseminated Histoplasmosis in an Immunocompetent Patient Diagnosed on Bone Marrow Aspirate - A Rare Presentation from a Non-Endemic Area

Histoplasma seropositivity and environmental risk factors for exposure in a general population in Upper River Region, The Gambia: A cross-sectional study

Robust surveillance of Histoplasma species is warranted in endemic regions, including investigation of community-level transmission dynamics. This cross-sectional study explored anti-Histoplasma antibody seroprevalence and risk factors for exposure in a general population in Upper River Region (URR), The Gambia. Study participants were recruited (December 2022-March 2023) by random household sampling across 12 Enumeration Areas (EAs) of URR. A questionnaire and clinical examination were performed; exploring demographic, clinical and environmental risk factors for Histoplasma exposure. One venous blood sample per participant was subject to IMMY Latex Agglutination Histoplasma test to determine presence of a recent IgM response to Histoplasma. Seropositivity risk factors were explored by multi-level, multivariable logistic regression analysis. The study population (n = 298) aged 5-83 years, demonstrated a positively skewed age distribution and comprised 55.4% females. An apparent seroprevalence of 18.8% (n = 56/298, 95% CI 14.5-23.7%) was measured using the LAT. A multivariable model demonstrated increased odds of Histoplasma seropositivity amongst female participants (OR = 2.41 95% CI 1.14-5.10); and participants reporting involvement in animal manure management (OR = 4.21 95% CI 1.38-12.90), and management of domestic animals inside the compound at night during the dry season (OR = 10.72 95% CI 2.02-56.83). Increasing age (OR = 0.96 95% CI 0.93-0.98) was associated with decreased odds of seropositivity. Clustering at EA level was responsible for 17.2% of seropositivity variance. The study indicates frequent recent Histoplasma exposure and presents plausible demographic and environmental risk factors for seropositivity. Histoplasma spp. characterisation at this human-animal-environment interface is warranted, to determine public health implications of environmental reservoirs in The Gambia. The study was supported by Wellcome Trust (206,638/Z/17/Z to CES) and a University of Liverpool-funded PhD studentship (to TRC).

Collective outbreak of severe acute histoplasmosis in immunocompetent Chinese in South America: the clinical characteristics and continuous monitoring of serum cytokines/chemokines

Background

Acute histoplasmosis is a rare fungal disease in China. This study is aimed to summarize the clinical characteristics of the first large-scale outbreak of imported acute histoplasmosis in Chinese, so as to provide suggestions for clinical diagnosis and treatment.

Methods

We collected the symptoms, signs, laboratory examination and imaging data of 10 patients in so far the biggest outbreak of imported acute histoplasmosis in immunocompetent Chinese. Their clinical characteristics and time-varying cytokine/chemokine levels were analyzed, and rank correlation analysis between these markers was utilized to show their condition.

Results

The 10 patients of imported acute histoplasmosis were working without any respiratory protection in an abandoned mine tunnel in Guyana. The most common symptoms were fever and cough. Their chest CT imaging showed multiple nodular shadows in lungs. Laboratory examination showed that at admission the CRP, PCT, LDH, CysC, G-test, β2-MG were all increased in at least 9 patients, and the CD4/CD8 was decreased to < 1 in all patients. Most cytokines/chemokines (other than IL-4, IL-12, INF-α, TNF-α) varied widely with patients and time, but their overall trend is higher at admission and decreasing gradually during hospitalization, especially for the IL-6, IL-8, IL-10 and IFN-γ. The LDH, CysC, G-test, β2-MG, N/L, IL-6, IL-8, IL-10, IFN-γ, IL-27 are in positive associations to both CRP and PCT.

Conclusions

The diagnosis of acute histoplasmosis needs a comprehensive analysis of epidemiological history, clinical symptoms and signs, and results of imaging, laboratory, microbiological and pathological examinations. Although none of the CRP, PCT, G-test, N/L, LDH, CysC, β2-MG, IL-6, IL-8, IL-10, IFN-γ shows specificity in the diagnosis of acute histoplasmosis, there is possibility that the above factors might help in the inflammation and prognosis estimation. However, more studies and further investigation are still required for the verification.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-022-01771-2.

Acute histoplasmosis in immunocompetent travelers: a systematic review of literature

Background

Histoplasmosis is a fungal infection highly endemic in the American continent. The disease can be severe in immunocompromised subjects. In immunocompetent subjects the clinical manifestations are variable. Aim of this work was to review the cases of acute histoplasmosis in immunocompetent travelers reported in literature.

Methods

A systematic review of literature was conducted. Electronic search was performed in Pubmed and LILACS. Two reviewers independently extracted data on demographic, clinical and radiological features, and treatment. Cases were classified according to Wheat’s definitions.

Results

Seventy-one studies were included in the analysis, comprising a total of 814 patients. Twenty-one patients diagnosed at the Centre of Tropical Diseases, Negrar (VR), Italy were also included. The most common travel destination was Central America (168 people, 29.8%); the most common way of exposure to histoplasma was the exploration of caves and/or contact with bat guano (349 people, 60.9%). The multivariate logistic regression model showed association between the development of disseminated histoplasmosis (DH) and activities that involved the exploration of caves and/or the contact with bats’ guano (adjusted OR: 34.20 95% CI: 5.29 to 220.93) or other outdoor activities (adjusted OR: 4.61 95% CI: 1.09 to 19.56). No significant difference in the attack rate between countries of destination was observed (p-value: 0.8906, Kruskal-Wallis test).

Conclusions

Histoplasmosis often causes no or mild symptoms in immunocompetent individuals, although a severe syndrome may occur. The infection can mimic other diseases, and the epidemiological risk of exposure is an important clue to raise the index of suspicion.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3476-z) contains supplementary material, which is available to authorized users.

A Twenty-First-Century Perspective of Disseminated Histoplasmosis in India: Literature Review and Retrospective Analysis of Published and Unpublished Cases at a Tertiary Care Hospital in North India

PURPOSE

Published literature lacks systematic studies on disseminated histoplasmosis in India, and previous reviews on its epidemiology in India were conducted two decades back. Thus, we review the Indian studies published in this century to understand the recent epidemiology of histoplasmosis in India and do a retrospective analysis of all cases diagnosed at our institute.

METHODS

A literature of review search was done in Pubmed/Medline and Scopus. Studies published during January 2001-December 2015 were considered along with retrospective analysis of cases presented to us. A distinction was made in the clinical presentation of immunocompetent and immunocompromised cases.

RESULTS

Ninety-five included studies described 204 cases, and 10 cases from our retrospective analysis were included. The mean age at presentation was 45.1 ± 15.4 years [range 3-83, median 45, interquartile range 37-55], and male-to-female ratio was 6:1. Most cases were reported from northern and northeastern states of India along the rivers Ganges, Yamuna and Brahmaputra and in people associated with agricultural activity. About 33% of cases were immunocompromised, out of which immunosuppression due to HIV was seen in 72% cases. The mean age of presentation was significantly lower in immunocompromised cases (37.9 vs. 49.2 years; p < 0.00001, Mann-Whitney test), and mortality was also higher (10 vs. 27.5%, p = 0.01, Fisher's exact test). Adrenal involvement was in significantly higher proportion of immunocompetent patients compared to immunocompromised population.

CONCLUSIONS

Disseminated histoplasmosis is being increasingly recognized in India. There is a need to undertake well-designed, analytical studies utilizing appropriate diagnostic modalities to understand the epidemiology of this neglected disease in proper perspective.