Department of Population Health and Pathobiology, College of Veterinary Medicine, Raleigh, North Carolina.
Programa de Pós-graduação em Medicina Veterinária, Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brasil.
Transbound Emerg Dis. 2018 Dec;65(6):1671-1679. doi: 10.1111/tbed.12925. Epub 2018 Jun 19.
Pythium insidiosum is a widespread pathogen that causes pythiosis, a disease with severe health consequences in horses and humans worldwide. Latin America hosts one of the largest, but scattered, horse herds, making it critical to identify areas at high risk of pythiosis transmission to help guide surveillance in areas with disease transmission risk. We utilized ecological niche modelling and epidemiological data to reconstruct the ecological conditions for pathogen circulation to identify areas with potential risk of pythiosis in Brazil and Uruguay. We surveyed 338 horse farm locations in southern Brazil and reconstructed the landscape conditions where the disease is endemic, based on the association between high-resolution satellite imagery and P. insidiosum serology. The final model was projected to the entire Brazil-Uruguay border region to predict areas at risk of disease transmission. We detected 66 seropositive farms and risk of infection in areas with low vegetation and low temperatures. There was a significant difference between seropositive and seronegative locations, mainly during the summer, suggesting that P. insidiosum circulates under specific landscape conditions. Areas that were unsuitable for P. insidiosum circulation were clustered in the central, north-eastern, and north-western regions of the study area. Our findings suggest that P. insidiosum is a generalist pathogen that has the potential to circulate across broad areas in Uruguay and Rio Grande do Sul in Brazil. The risk maps generated may help stakeholders with disease prevention, as well as highlight pythiosis as a potential transboundary disease with economic and public health importance.
腐霉是一种广泛存在的病原体，可引起腐霉病，这种疾病对全球的马和人类都有严重的健康影响。拉丁美洲拥有数量最多但分散的马群之一，因此确定高风险的腐霉病传播地区至关重要，这有助于指导有疾病传播风险地区的监测。我们利用生态位模型和流行病学数据来重建病原体循环的生态条件，以确定巴西和乌拉圭有腐霉病潜在风险的地区。我们调查了巴西南部的 338 个马场位置，并根据高分辨率卫星图像和腐霉病血清学之间的关联，重建了疾病流行的景观条件。最终模型被投影到整个巴西-乌拉圭边境地区，以预测疾病传播的风险地区。我们检测到 66 个血清阳性农场，在植被和温度较低的地区存在感染风险。血清阳性和阴性地区之间存在显著差异，主要发生在夏季，表明腐霉在特定的景观条件下循环。不适合腐霉循环的地区集中在研究区域的中心、东北部和西北部。我们的研究结果表明，腐霉是一种广适性病原体，有可能在乌拉圭和巴西南里奥格兰德州广泛传播。生成的风险图可能有助于利益相关者进行疾病预防，并强调腐霉病作为一种具有经济和公共卫生重要性的潜在跨境疾病。
