One Health Index (OHI) applied to Curitiba, the ninth-largest metropolitan area of Brazil, with concomitant assessment of animal, environmental, and human health indicators.

One Health has been defined as a comprehensive approach to human, animal, and environmental health, but unsuccessful in providing a specific index for city, state, or country assessment. Accordingly, the present study aimed to calculate the One Health Index (OHI) in 29 cities of the Curitiba metropolitan area, the ninth largest in Brazil. Animal and Environmental health indicators were obtained from the city secretary of environment. The social vulnerability index (SVI) was used as the overall human health indicator. The indicators were parameterized following a binary logic Principal component analysis (PCA) was applied in association with city population, per capita income, and distance from the capital Curitiba. Permutational multivariate analysis of variance (PERMANOVA) was applied using the three first coefficients of the principal components obtained from Principal Component Analysis Plot (PCA) and exploring a pairwise comparison between the scenario ranges. A value of p less than 0.05 was considered significant. Overall, a higher OHI was associated with a higher city population and income, and shorter distance from the capital, and tendency of low-income cities to present lower OHI compared to higher-income cities. In conclusion, the OHI proposed herein portrays a holistic representation of a city's overall health. Moreover, animal issues should be considered part of local to global sustainability, considering OHI to calculate sustainability indexes.