Rhinosporidiosis in the Americas: A Systematic Review of Native Cases

Rhinosporidiosis is a chronic mucosal infection caused by Rhinosporidium seeberi, an aquatic protistan parasite. It presents as nasal or ocular polypoidal or vascularized masses. It is endemic in tropical and subtropical areas, especially in South Asia; R. seeberi´s endemicity in the Americas is often overlooked. The objective of this study was to describe the demographic and clinical characteristics of patients with rhinosporidiosis in the Americas, its management, and patient outcomes. This study is a systematic review of cases of human rhinosporidiosis in the Americas reported in the literature from 1896 to February 28, 2019. This review screened 1,994 reports, of which 115 were eligible for further analysis. The selected reports described 286 cases of human rhinosporidiosis between 1896 and 2019. Cases were diagnosed in Brazil (32.2%), Colombia (24.4%), Paraguay (12.6%), and the United States (11.9%). The majority of the cases (91%) occurred in geographic areas with altitudes < 1,000 m above sea level and in areas with median temperatures ≥ 25°C (67.3%). Most of the patients presented nasal (65%) and ocular involvement (35%). Surgical treatment was provided for 99.6% of patients, but 19.8% of them recurred. This review describes the under-recognized geographic distribution and clinical presentation of rhinosporidiosis in the Americas and highlights clinical differences to cases in Asia, specifically in reference to a higher prevalence of ocular disease and higher relapse rates.