Fiocruz research in Antarctica detects Histoplasma capsulatum fungus for the first time in the continent

The fungus that causes histoplasmosis, a disease that can affect the lungs and lead to death, was detected in Antarctica for the first time, as revealed by the study Molecular Detection of Histoplasma capsulatum in Antarctica. Written by Fioantar researchers, the paper is part of the October issue of the Emerging Infectious Diseases Journal, published by the Centers for Disease Control and Prevention (CDC) of the United States, and is one of the first scientific publications of the Fiocruz project in the continent. “This discovery highlights the need for surveillance of emerging agents of systemic fungal diseases and their transmission between regions, animals and humans in Antarctica”, says the paper.

Researcher Luciana Trilles works at Antarctic collecting samples (image: Peter Ilicciev)

The discovery surprised the researchers, who were not expecting to find genetic evidence of this fungus in a region with such low temperatures. Although histoplasmosis is a cosmopolitan disease with global impact, it is more prevalent in the Americas and is not commonly observed in cold climate areas. The presence of Histoplasma sp. in the Antarctic continent raises questions such as when it got there and whether its detection is related to climate change.

“There are many possible explanations. It may have been carried by birds or other animals more recently. Or it may already have been there before the continents got separated, and then adapted to the different climate changes the continent has been through. Antarctica was once a tropical region. It only cooled down in a recent geological past”, observes Luciana Trilles, researcher of Fioantar and of the Mycology Laboratory of the Evandro Chagas National Infectiology Institute (INI/Fiocruz), correspondent author of the paper.

Lucas Machado Moreira, the first author of the paper and researcher of Fioantar and of the INI Mycology Laboratory, does not rule out the role of global warming. “The presence of this fungus in Antarctica may date from thousands of years back, but the impact of climate change collaborates with the increase of areas without an ice layer, exposing soils that had been frozen, and also influences the shift of masses of air, the level of seasonal snowfall, and animal migration, all facts that influence the dispersion of micro-organisms in the world”, said Moreira.

Latin America is the leader in number of cases

With molecular evidence detected in the soil and in penguin feces in the Potter Peninsula, located in the South Shetland Islands, in the Antarctic Peninsula, Histoplasma capsulatum had its DNA sequenced at Fiocruz laboratories, revealing evidence of the identification of lineages similar to those that exist in Latin America, the region with the highest number of histoplasmosis cases. Brazil is one of the most affected countries, being considered endemic for the disease, with a relevant incidence of cases in all regions. As in Antarctica, the agent that causes this disease, which affects both humans and animals, can be found in the soil and in environments rich with bird feces. Humans are infected with histoplasmosis as they inhale fungal propagules, which may reach the alveoli and cause pneumonia. The infection may remain restricted to the lungs or enter the bloodstream and affect other organs. Trilles explains that depending on the region or on the group of patients, the lethality rate of the disease can exceed 40%.

Fioantar researchers work in Antarctic looking for viruses, bacteria and fungi (image: Peter Ilicciev)

The study begins with samples collected in the summer of 2020 at the Potter Peninsula, an Antarctic Specially Protected Area (ASPA). The fungus there has found an ideal environment, rich in nitrogen thanks to the presence of bird feces, facilitating its proliferation. “Considering the ability this species has of causing epidemics with risk to life, and the intensification of human presence in the continent, identifying and monitoring fungi in various Antarctic habitats and animals has become a fundamental strategy for the monitoring of emerging systemic mycosis and of the flow of these agents between regions, animals and humans”, says the article.

DNA samples of various Antarctic substrates were collected and submitted to PCR Nested, a variation of conventional PCR but with higher sensitivity and specificity for the detection of pathogens. “Our idea now is to monitor the presence of this fungus and expand into other Antarctic islands, areas and regions. And to look for other agents that may cause disease”, Trilles said. At a later moment, Fioantar researchers will attempt to isolate the fungus itself.

Isolated, but not that much

Antarctica may seem distant and isolated, but it receives migratory animals and a considerable number of tourists every year. Together with air shifts and seasonal snow, these events favor the dispersion of fungi and other micro-organisms. Just like fungi, bacteria and viruses can be taken to the continent by humans and other animals, and they can also be brought to South America and to other continents.

“This discovery highlights the importance of our presence in Antarctica. The idea of the project since its very beginning was to implement surveillance of etiological agents in the continent, being able to identify new or known pathogenic organisms and to monitor the dispersion of these pathogens in the world”, added Moreira. “As for fungal diseases, the idea of the project is to investigate all etiological agents of systemic mycosis. Because they cause diseases that have a great impact on public health, especially in Brazil. Another goal of our project is to understand how Antarctica influences public health in Brazil. Finding this fungus that exists both here and there is a strong indication that monitoring studies must be made constantly.”

In addition to Moreira and Trilles, other participants of the study were Márcia Chame, Martha Lima Brandão, Adriana Marcos Vivoni, Juana Portugal and Bodo Wanke, of Fioantar, in addition to Wieland Meyer, of Sydney University, Australia. Specialized in infectious and parasitic diseases, with main focus on systemic mycosis, Bodo Wanke passed away on July 22nd, 2021.

Fioantar

Fioantar is part of the Brazilian Antarctic Program (Proantar), conducted by the Interministerial Commission for Sea Resources (Cirm), of the Brazilian Navy. The project was approved in a call notice of the National Council for Scientific and Technological Development (CNPq), of the Ministry of Science, Technology, Innovation and Communications (MCTIC), in December 2018, with an expected duration of four years, from 2019 to 2023.

With a multidisciplinary nature, it works along two main lines. The first one includes the investigation of new pathogens, such as viruses, fungi and bacteria, present in the Antarctic environment, and therefore strengthening epidemiological surveillance and prevention. For this purpose, Fiocruz has brought together researchers from eight different laboratories, professionals from the fields of production and innovation in health, international relations in health, and communication, so the population may follow the results and challenges of the project.

Another important line of research is bioprospecting: researchers aim to identify which of these organisms have the potential to be used to develop new health technologies and products, such as medicines and consumables.

In 2020, scientific expeditions were interrupted by the COVID-19 pandemic. They were resumed last year, under strict safety measures.