# Histoplasma capsulatum in Bat Species in Portugal

## TL;DR

A study of 285 bat guano samples in Portugal found no evidence of the fungus Histoplasma capsulatum, suggesting bats there are unlikely to spread the disease.

## Contribution

This is the first study to investigate Histoplasma capsulatum in Portuguese bat populations using a sensitive PCR method.

## Key findings

- No Histoplasma capsulatum was detected in 285 bat guano samples from Portugal.
- The absence of the fungus aligns with low detection rates in Europe but contrasts with higher prevalence in regions like Brazil and Mexico.
- The findings suggest local environmental factors influence the distribution of the fungus in European bat populations.

## Abstract

Histoplasmosis, caused by the fungus Histoplasma capsulatum, can impact animals and humans, with bats as known carriers. We tested 285 bat guano samples from Portugal and found no positive cases, consistent with low detection rates in Europe. This suggests that bats in Portugal are unlikely to spread Histoplasma capsulatum and highlights the need for continued monitoring.

Histoplasmosis, caused by the fungus Histoplasma capsulatum, poses health risks to various mammals, including humans. Bats are primary wild carriers of Histoplasma capsulatum, playing a crucial role in its epidemiology. However, fecal shedding in Europe remains poorly studied, with no data available for Portugal. This study analyzed 285 guano samples from 22 bat species, collected across Portuguese regions between 2014 and 2018, using a nested PCR assay. Despite using a sensitive method, no positive samples were detected. These results align with other European studies, suggesting that Histoplasma capsulatum circulates at low levels in European bat populations. However, they contrast with findings from regions like Brazil and Mexico, where the fungus is more prevalent due to differing geographic, climatic, and ecological factors. The absence of Histoplasma capsulatum in Portuguese bat guano highlights the importance of local environmental conditions and raises questions about its distribution in Europe. Although bats can harbor zoonotic pathogens, our findings suggest they do not shed Histoplasma capsulatum in Portugal. Continuous monitoring and research are essential in understanding infectious disease dynamics. Targeted surveillance in caves could improve early detection and management strategies for potential histoplasmosis outbreaks, contributing to public health efforts in these ecosystems.