There is an ongoing Oropouche Fever (OF) outbreak in Brazil since 2024. There are dengue and chikungunya prediction models available, but none to help discriminate dengue, chikungunya, and OF. Objective: This study aims to develop and validate clinical prediction models for dengue, chikungunya, OF. Methods: This study uses surveillance data from Espirito Santo state / Brazil, from 2023-2025. Epidemiological investigations and biological samples were used to conclude cases as either (a) clinical-epidemiologically confirmed, (b) laboratory confirmed, or (c) discarded. The predictors were all data related to signs, symptoms, and comorbidities available in the notification forms. The analysis was performed using random forest regression models, one for each outcome, in development and validation datasets. Results: A total of 465,280 observations were analyzed, 261,691 dengue cases (56.6%), 18,676 chikungunya cases (4.0%), 12,174 OF cases (2.6%), and 179,115 discarded cases (38.6%). All three models had good discrimination and moderate to good calibration after scaling prediction. The models retained from 26 to 16 predictors each. Leukopenia and vomiting were the most discriminatory predictors for dengue, arthritis, arthralgia, and rash were the most discriminatory for chikungunya, and epidemiological features were the most relevant for OF. The dengue, chikungunya, and OF models had ROC AUC of 0.726, 0.851, and 0.896 in the validation set, respectively. Conclusion: This research identified predictors most discriminative between dengue, chikungunya, and OF. We developed and validated predictive models, one for each condition, with moderate to very good performance available at https://pedrobrasil.shinyapps.io/INDWELL/. One may use them in diagnostic work-up and arbovirus surveillance.

Urban arboviral diseases represent a persistent epidemiological challenge for the Brazilian Unified Health System (SUS), requiring institutional resilience and health compliance from local governments. Objective: To analyze the resilience of municipal health systems in responding to urban arboviruses in a health region of Espírito Santo, Brazil, using secondary data from the Integrated Instrument for the Assessment of the Response to Arboviruses (IIARA 2026), while preserving the anonymity of the federated entities. Methods: Observational, descriptive and analytical ecological study based on aggregated secondary data from 23 municipalities. Forty-eight criteria distributed across six thematic axes were assessed. The Resilience Index (IR%) was calculated per axis and globally, applying the "Deal Breaker" (Critical Cut-off) rule to the risk classification criteria in primary and hospital care. Results: The mean regional global IR was 67.15% (range 40.3%–89.6%). The Epidemiological Surveillance axis showed the best performance (87.7%), whereas Management and Governance showed the greatest fragility (41.4%). Only six municipalities achieved the Silver Seal; four municipalities with global scores above 70% were withheld by the Deal Breaker due to failures in care risk classification, preventing certification. Conclusion: The IIARA proved to be an effective health compliance tool, revealing significant regional heterogeneity. The Deal Breaker rule fulfilled its role by preventing the certification of municipalities with critical care fragilities, pointing to the need for priority interventions in local governance and in risk-classified reception.