Invasive fungal pathogens from the tropical and temperate areas – a challenge in pathology and diagnosis

Abstract

Fungi play a vital role in ensuring a physiological balance in the surrounding environments, interacting closely with humans, plants, and animals. While most of the time their contribution is beneficial, occasionally, they can become harmful, especially in patients with weakened immune systems. The work at hand aims to present the most common fungal pathogens involved in invasive infections, focusing on fungi that are present in the tropical and temperate areas of the world. While in the former, due to the humid climate, most fungal infections are caused by dimorphic fungi such as Coccidioides spp., Blastomyces spp., Histoplasma spp., Emergomyces spp. and Paracoccidioides spp., in the latter, after Candida spp., the most frequent fungi that are involved in disseminated mycosis are Aspergillus spp., Fusarium spp. and species from the order Mucorales. Nowadays, the etiology, severity, and number of cases of fungal diseases are starting to rise significantly. There are no exact reasons reported for this increase, but several factors are thought to be incriminated: the expansion of the range of medical conditions that constitute risk factors for developing the disease, an improvement in the available diagnostic methods, the commodity offered by modern traveling services associated with the lack of an available vaccine against fungal infections, as well as climatic influences. All the above-mentioned aspects consequently caused infections that used to be endemic to be spread worldwide. Therefore, it is of critical importance to understand the epidemiology, clinical manifestations of fungi induced diseases, virulence factors, and diagnosis for each of those pathogens.