<s>[INST] How are dengue infections diagnosed? [/INST] Dengue is diagnosed by a blood test. The physician will have to rule out a variety of illness with similar course, including early stages of malaria, mild yellow fever, influenza, viral hepatitis, typhoid, Rift Valley fever, and leptospirosis. Source: TEXAS HEALTH AND HUMAN SERVICES. Link: https://www.dshs.texas.gov/mosquito-borne-diseases/dengue/dengue-faqs. Field: Infectious Disease. Disease: Dengue </s>