Acute febrile illness was defined as a patient with fever of 38°C or higher at presentation to ED or history of fever that persisted for 2–7 days with no localizing. This might be more likely if your fever has lasted for more than a week or 2. In most cases, the higher temperature itself isn't harmful. It actually helps the body fight infections. A fever doesn't need to be treated unless you feel very uncomfortable. Among these acute febrile illnesses, rickettsial related diseases, such as scrub typhus, murine typhus, spotted fever group rickettsia, Q fever and leptospirosis, have emerged or re-emerged in different area around the globe.