Potential distribution of Pythium insidiosum in Rio Grande do Sul, Brazil, and projections to neighbour countries.

The research investigates the potential distribution of Pythium insidiosum, the pathogen causing the harmful disease pythiosis, in Brazil and Uruguay, by using ecological niche modelling and epidemiological data. Findings suggest the pathogen has the potential to circulate in wide areas.

Research Methodology

• The study applied ecological niche modelling and epidemiological data to recreate the environmental conditions adequate for the P. insidiosum pathogen to thrive.
• A total of 338 horse farm locations within the southern part of Brazil were surveyed, and land conditions where the disease is prevalent were reconstructed.
• This was done through the correlation of high-resolution satellite images and P. insidiosum serology.

Survey Findings

• The survey discovered 66 seropositive farms and highlighted an increased risk of infection in areas with sparse vegetation and low temperatures.
• It was observed that there was a significant difference between seropositive and seronegative locations, particularly during the summer, suggesting that the P. insidiosum pathogen circulates under certain landscape conditions.

Model Projections and Implications

• Using the data from the survey, the model was projected onto the entire Brazil-Uruguay border to predict areas at risk of disease transmission.
• Locations that were not conducive for the circulation of P. insidiosum were distributed in the central, north-eastern, and north-western parts of the study area.
• Findings suggest that P. insidiosum is a generalist pathogen, capable of circulating across wide geographical regions in Uruguay and Rio Grande do Sul in Brazil.
• The risk maps generated can be a valuable tool for stakeholders to plan disease prevention strategies, raising the profile of pythiosis as a potential cross-border disease with economic and public health significance.