- Bacterial Infections 101 Pictures Slideshow
- Take the Tummy Trouble Quiz
- Hepatitis C Slideshow Pictures
- Find a local Doctor in your town
- Yellow fever facts
- What is yellow fever? What is the history of yellow fever?
- What causes yellow fever?
- How is yellow fever transmitted?
- What areas are high risk for contracting yellow fever?
- What is the incubation period for yellow fever?
- Is yellow fever contagious? How long is the contagious period for yellow fever?
- What types of specialists treat yellow fever?
- What are yellow fever symptoms and signs?
- How do health-care professionals diagnose yellow fever?
- What is the treatment for yellow fever?
- How long does yellow fever last?
- What is the prognosis for people with yellow fever?
- Is it possible to prevent yellow fever?
- What are the side effects of the yellow fever vaccine?
- Where can people get more information on yellow fever?
Quick Guide25 Ways to Stay Well Abroad in Pictures
How do health-care professionals diagnose yellow fever?
Because the symptoms during the initial phase of yellow fever are nonspecific and similar to a flu-like illness, diagnosis during this stage can be difficult. Therefore, the preliminary diagnosis is often made clinically based on the patient's signs and symptoms, the travel history (when and where), and the related travel activities.
Various blood test abnormalities may be present in individuals with yellow fever, particularly those who go on to develop the second toxic phase of the disease. Blood test abnormalities may include a low white blood cell count (leukopenia), a low platelet count (thrombocytopenia), elevations in liver function tests, abnormally prolonged blood clotting times, and abnormal electrolyte and kidney function tests. None of these test results are specific to yellow fever and alone allow the health-care provider to make a diagnosis. Urine tests may demonstrate elevated levels of urinary protein and urobilinogen. An electrocardiogram (ECG) may reveal heart conduction or rhythm disturbances if cardiac involvement has occurred.
The laboratory diagnosis of yellow fever requires specialized testing. Blood tests may demonstrate the presence of virus-specific antibodies (IgM and IgG) produced in response to the infection, though cross-reactivity with antibodies from other flaviviruses may occur. Therefore, specific antibody testing, such as a plaque reduction neutralization test, may be done for confirmation.