Yellow Fever Symptoms
Patients with yellow fever may be viremic (have virus in their blood) for 3 to 6 days before demonstrating symptoms. Initial symptoms include fever and chills, severe headache, back pain, general muscle aches, nausea, fatigue, and weakness. This phase may be followed by a short period of symptom remission.
The toxic phase develops as the fever returns, with clinical symptoms including high fever, headache, back pain, nausea, vomiting, abdominal pain, and fatigue. Hepatic coagulopathy produces hemorrhagic symptoms, including hematemesis (black vomit), epistaxis (nose bleed), gum bleeding, and petechial and purpuric hemorrhages (bruising). Deepening jaundice and proteinuria frequently occur in severe cases.
In the late stages of disease, patients can develop hypotension, shock, metabolic acidosis, acute tubular necrosis, myocardial dysfunction, and cardiac arrhythmia. Confusion, seizures, and coma can also occur. When epidemics occur in unvaccinated populations, case-fatality rates range from 15% to more than 50%. Secondary bacterial infections and kidney failure are complications. Symptoms of weakness and fatigue may last several months in people who recover.
Those who recover from yellow fever generally have lasting immunity against subsequent infection.
Content Source:
Division of Vector Borne Infectious Diseases
National Center for Zoonotic, Vector-Borne, and Enteric Diseases