Yellow Fever: Disease Information for Travelers
Yellow fever is a serious viral disease found in Africa and South America. Learn about transmission, symptoms, vaccination, and certification requirements for international travel. Available at our Mississauga travel clinic.
What Is Yellow Fever?
Yellow fever is a serious viral hemorrhagic disease endemic in tropical regions of Africa and South America. It is transmitted by infected mosquitoes and can cause severe, potentially fatal illness. Vaccination is the single most effective prevention method and is required for entry into many countries.
How Yellow Fever Is Transmitted
Yellow fever is transmitted through the bite of infected Aedes and Haemagogus mosquitoes, which are found in tropical regions. These mosquitoes are daytime feeders, with peak activity in the early morning and late afternoon. The virus replicates in the mosquito and is transmitted through saliva during feeding. Human-to-human transmission does not occur except through maternal transmission during pregnancy.
Two Phases of Yellow Fever
Acute Phase (Initial Phase)
Occurs 3-6 days after infection. Symptoms include sudden fever, headache, backache, muscle pain, fatigue, weakness, and sometimes nausea and vomiting. Most people recover completely at this stage. However, approximately 15% of infected individuals progress to the toxic phase.
Toxic Phase (Severe Phase)
Occurs 3-6 days after the acute phase. Symptoms include jaundice (yellowing of skin and eyes), bleeding (from gums, nose, gastrointestinal tract), organ failure (liver, kidney), shock, and coma. This phase has a mortality rate of approximately 50%. Those who survive may experience chronic complications including post-yellow fever syndrome.
Why Yellow Fever Is Serious
- • No specific antiviral treatment exists; management is supportive only
- • Mortality rate is 15% overall, up to 50% in those with severe disease
- • Even asymptomatic infection can result in viremia and spread
- • Many countries require proof of vaccination for entry
Who Is at Risk?
Yellow fever risk is limited to specific geographic regions:
Endemic Regions
Africa (Highest Risk)
Sub-Saharan Africa, especially Nigeria, Cameroon, and DRC
South America
Brazil, Peru, Bolivia, Colombia, Ecuador, and Venezuela
Higher-Risk Travelers
- • Travelers to yellow fever-endemic areas
- • Those visiting rural and jungle regions
- • Outdoor enthusiasts and eco-tourists
- • Healthcare and humanitarian workers
- • Long-term residents (>3 months)
How to Prevent Yellow Fever
1. Yellow Fever Vaccination
Yellow fever vaccination is the most important prevention tool. It is highly effective and provides lifelong protection. Peel Travel Clinic is a PHAC-designated Yellow Fever Vaccination Centre and can provide the vaccine and issue the official International Certificate of Vaccination or Prophylaxis (ICVP). Book your yellow fever vaccine in Mississauga.
Dose: Single intramuscular injection
Protection: Begins 10 days after vaccination
Duration: Lifelong immunity (WHO current recommendation — no booster needed)
Certificate: ICVP valid for life, recognized internationally
2. Mosquito Avoidance Measures
While vaccination is primary protection, additional mosquito avoidance measures reduce risk:
- • Use DEET-based insect repellents (20-30%) on exposed skin
- • Wear long sleeves and pants, especially during daytime hours
- • Stay in screened or air-conditioned accommodations
- • Avoid outdoor activities during peak mosquito hours (early morning, late afternoon)
- • Use bed nets if screened accommodation is unavailable
3. International Certificate Requirements
Many countries require proof of yellow fever vaccination for entry. Some countries require the International Certificate of Vaccination or Prophylaxis (ICVP), while others accept digital certificates.
Our Yellow Fever Vaccination Service
Peel Travel Clinic is an officially designated Yellow Fever Vaccination Centre (PHAC-designated). We provide the yellow fever vaccine and issue the official International Certificate of Vaccination or Prophylaxis (ICVP) recognized globally.
Our Service Includes:
- • Risk assessment based on your itinerary
- • Yellow fever vaccination by our physician
- • Official International Certificate of Vaccination or Prophylaxis (ICVP) issued same-day
- • Review of contraindications and medical history
- • Guidance on post-vaccination care
Important: The ICVP becomes valid 10 days after vaccination. Plan your vaccination at least 10 days before travel to countries requiring proof of vaccination.
40+
Years of Clinical Experience
ISTM
Travel Medicine Society Member
CAME
Transport Canada Designated
YF Centre
Yellow Fever Designated Centre
550 Matheson Blvd W, Unit 107, Mississauga, Ontario L5R 4B8 · (905) 890-2757
Get Your Yellow Fever Vaccination Today
Disclaimer: Vaccine requirements and health recommendations vary by itinerary, medical history, and current health advisories. The information on this page is for general guidance only and does not replace a personalized travel health consultation. Please book an appointment with our physician for advice specific to your trip.