Serological testing is typically used to obtain a definitive diagnosis. Most serological tests would succeed only after a certain period of time past the symptom onset (usually a week). The differential diagnosis list includes typhus, ehrlichiosis, leptospirosis, Lyme disease, and virus-caused exanthema (measles or rubella).
Trench fever
Chikungunya
Cuban fever
Yellow fever
Cotton fever
Tomato fever
Barcoo fever
Ross River fever