Yellow fever

Introduction

Yellow fever is caused by a virus transmitted to man by a species of mosquitoes (Aedes aegypti) from infected monkeys.
The disease is not spread from person to person. Classical yellow fever is usually fatal.
After the onset of symptoms, there is a brief remission of 2-24 hours, following which the symptoms may recur with the development of epigastric pain, jaundice, renal insufficiency, cardiovascular instability and bleeding from various sites (e.g. gums and needle-puncture sites).
Yellow fever vaccination is protective against the disease and needs to be repeated every ten years.

Causes of yellow fever

  • Yellow fever virus

Symptoms of yellow fever

  1. Fever
  2. Muscle pain, particularly backache
  3. Headache
  4. Shivering
  5. Loss of appetite
  6.  Nausea or vomiting
  7. Diarrhoea

Signs of yellow fever

  1. Congestion of the conjunctivae
  2. Jaundice
  3. Bleeding from various sites (petechiae, ecchymosis, etc.)
  4. Right upper abdominal quadrant tenderness
  5. Signs of renal failure

Investigations

  • Urinalysis – proteinuria and raised urobilinogen levels
  • Liver function test
  • Blood urea, electrolytes and creatinine
  • Blood sample for yellow fever virus serology

Treatment for yellow fever

Objectives

  • To provide supportive care for hepatic, renal and circulatory failure
  • To manage bleeding disorder

Non-pharmacological treatment

  • If yellow fever is suspected in a patient, admit immediately to an isolation ward
  • Full supportive treatment for hepatic failure and acute renal failure

Pharmacological treatment

A. Antiviral therapy

  • There is no specific treatment

For bleeding patients

  • Fresh frozen plasma

Referral Criteria

Refer to a hospital, preferably one with an isolation unit