A presumptive diagnosis of yellow fever is often based on the patient's clinical features, places and dates of travel (if the patient is from a non-endemic country or area), activities, and epidemiologic history of the location where the presumed infection occurred.
Laboratory diagnosis of yellow fever is generally accomplished by testing of serum to detect virus-specific IgM and neutralizing antibodies. Sometimes the virus can be found in blood samples taken early in the illness.
In fatal cases, nucleic acid amplification, histopathology with immunohistochemistry, and virus culture of biopsy or autopsy tissues can also be positive. Only a few state laboratories or other specialized laboratories, including those at CDC, are capable of doing these specialized tests. Instructions for sending diagnostic specimens to CDC’s Arbovirus Diagnostic Laboratory can be found at CDC’s Division of Vector-Borne Diseases Arboviral Specimens submission page .
Test results are normally available 4 to 14 days after specimen receipt. Reporting times for test results may be longer during summer months when domestic arbovirus activity increases. Receipt of a hard copy of the results will take at least 2 weeks after testing is completed. Initial serological testing will be performed using IgM-capture ELISA, MIA (Microsphere-based Immunoassay) and IgG ELISA. If the initial results are positive, further confirmatory testing may delay the reporting of final results. ALL RESULTS WILL BE SENT TO THE APPROPRIATE STATE HEALTH DEPARTMENT. Notify your state health department of any direct submissions to CDC. Find more information about laboratory testing in suspected cases of yellow fever from the yellow fever clinical laboratory evaluation page.