Endemic mycoses: epidemiology and diagnostic strategies

ABSTRACT

Introduction

The global frequency of endemic mycoses has considerably increased, mainly due to environmental changes, population growth in endemic areas, and the increase in HIV-related immunosuppressed status. Among the most frequent endemic mycoses are coccidioidomycosis in semi-desert climates, and paracoccidioidomycosis, and histoplasmosis in tropical climates. The inoculum can enter the host through the airway or directly through the skin. Lymphatic and hematogenous spread may involve the skin.

Areas covered

In this article, we provide up-to-date epidemiological and diagnostic data on major (histoplasmosis, paracoccidioidomycosis, coccidioidomycosis, blastomycosis) and minor (talaromycosis, adiaspiromycosis, emergomycosis) endemic mycoses.

Expert opinion

Endemic mycoses include diseases with a localized endemic area, and a few of them converge. These mycoses all have in common the airway involvement and can cause pulmonary symptoms following initial asymptomatic infection. Among the risk groups to acquire these mycoses are travelers from endemic areas, archeologists, speleologists, and immigrants. Promising and useful diagnostic tools have been developed in endemic mycoses; however, most of them are not standardized or available in low-income countries.

KEYWORDS:

• Endemic mycosis
• histoplasmosis
• coccidioidomycosis
• paracoccidioidomycosis
• blastomycosis

Article highlights

• Endemic mycoses are caused by dimorphic fungi distributed worldwide, often provoking outbreaks.

• The most common endemic mycoses include coccidioidomycosis, histoplasmosis, paracoccidioidomycosis, and blastomycosis.

• All endemic mycosis fungi are included within the Onygenales order.

• The prevalence of endemic mycoses has increased in recent decades; the associated factors for this increasing need to be further assessed.

• The impact of these diseases due to the migratory and tourist activity is important, mainly in immunosuppressed subjects.

• Determinants of the disease include inoculum quantity, agent virulence, and host immune response.

• The clinical variability of endemic mycoses difficult the diagnosis, mainly in non-endemic countries.

• Culture is the gold standard in most endemic mycoses.

• 2Novel diagnostic methods, while promising, are not widely available, and there is a lack of standardization from many of these tests.

• The samples obtained of endemic mycoses cases, e.g., histoplasmosis and coccidioidomycosis, must be handled in level-III laboratories according to the biosafety-level classification with adequate facilities for the management of pathogens.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.