Formalization of knowledge has become popular in Dengue domain and independent ontologies are developed and exist in isolation in the dengue domain. These knowledge-bases formalized not only the disease definition considering virus aspects, epidemic aspects but also physical and clinical diagnostic symptoms, kind of clinical test along with the pharmacological treatment applied. However, due to the lack of serious attempts towards combining these isolated knowledge-bases their usage to the fullest is limited. A Resource Description Framework (RDF)-based approach of combining three knowledge-bases formalizing dengue information covering different aspects of dengue disease is proposed in this paper that facilitates interoperable shareable comprehensive knowledge base in the Dengue domain. IDODEN, Ontology of Dengue Fever, is combined with a dengue patients’ ontology formalizing disease definition along with operational semantics supporting clinical and diagnostic reasoning which is subsequently merged with another ontology formalizing Dengue Drug information. SPARQL query is also executed successfully on the combined ontology.