Bluerhino

yellow fever

The first thing you will hear from physicians

Which countries are you visiting? And then “you do not need to be vaccinated”.

Technically this could be correct, but if you have this page as part of your preparation, it means I have experienced that it is required for this tour.

Generally it is at the border that the issue arrises. The medical officer at the border will ask to see your yellow fever card because he has instructions from his government to check it. So what your doctor in South Africa says is irrelevant when you get to the border official that will decide wether to allow you access or not.

Please do not confuse the requirement according to the WHO or your travel clinic and the official at the small dark border crossing in the middle of nowhere that has an instruction from his superiors. You will get nowhere with an argument.

It is also beneficial to get the vaccinations as you also get Hepatitis and other helpful boosters with yellow fever vaccination.

If you are medically unfit to receive this vaccination, you need a letter to confirm that you are medically not fit to receive the vaccination. This is perfectly fine and we will manage it as we go.

Please do not bring a letter from a doctor that says you do not need the injection in whatever country, it will get you nowhere!!!

Key facts about yellow fever

 

  • Yellow fever is an acute viral haemorrhagic disease transmitted by infected mosquitoes. The “yellow” in the name refers to the jaundice that affects some patients.
  • Symptoms of yellow fever include fever, headache, jaundice, muscle pain, nausea, vomiting and fatigue.
  • A small proportion of patients who contract the virus develop severe symptoms and approximately half of those die within 7 to 10 days.
  • The virus is endemic in tropical areas of Africa and Central and South America.
  • Large epidemics of yellow fever occur when infected people introduce the virus into heavily populated areas with high mosquito density and where most people have little or no immunity, due to lack of vaccination. In these conditions, infected mosquitoes of the Aedes aegypti specie transmit the virus from person to person.
  • Yellow fever is prevented by an extremely effective vaccine, which is safe and affordable. A single dose of yellow fever vaccine is sufficient to confer sustained immunity and life-long protection against yellow fever disease. A booster dose of the vaccine is not needed. The vaccine provides effective immunity within 10 days for 80-100% of people vaccinated, and within 30 days for more than 99% of people vaccinated.

What does it look like?

Signs and symptoms

Once contracted, the yellow fever virus incubates in the body for 3 to 6 days. Many people do not experience symptoms, but when these do occur, the most common are fever, muscle pain with prominent backache, headache, loss of appetite, and nausea or vomiting. In most cases, symptoms disappear after 3 to 4 days.

A small percentage of patients, however, enter a second, more toxic phase within 24 hours of recovering from initial symptoms. High fever returns and several body systems are affected, usually the liver and the kidneys. In this phase people are likely to develop jaundice (yellowing of the skin and eyes, hence the name ‘yellow fever’), dark urine and abdominal pain with vomiting. Bleeding can occur from the mouth, nose, eyes or stomach. Half of the patients who enter the toxic phase die within 7 – 10 days.

Diagnosis

Yellow fever is difficult to diagnose, especially during the early stages. A more severe case can be confused with severe malaria, leptospirosis, viral hepatitis (especially fulminant forms), other haemorrhagic fevers, infection with other flaviviruses (such as dengue haemorrhagic fever), and poisoning.

Your yellow fever card

Vaccination is the most important means of preventing yellow fever.

The yellow fever vaccine is safe, affordable and a single dose provides life-long protection against yellow fever disease. A booster dose of yellow fever vaccine is not needed.

There have been rare reports of serious side-effects from the yellow fever vaccine. The rates for these severe ‘adverse events following immunization’ (AEFI), when the vaccine provokes an attack on the liver, the kidneys or on the nervous system are between 0 and 0.21 cases per 10 000 doses in regions where yellow fever is endemic, and from 0.09 to 0.4 cases per 10 000 doses in populations not exposed to the virus (1).

The risk of AEFI is higher for people over 60 years of age and anyone with severe immunodeficiency due to symptomatic HIV/AIDS or other causes, or who have a thymus disorder. People over 60 years of age should be given the vaccine after a careful risk-benefit assessment.

People who are usually excluded from vaccination include:

  • infants aged less than 9 months;
  • pregnant women – except during a yellow fever outbreak when the risk of infection is high;
  • people with severe allergies to egg protein; and
  • people with severe immunodeficiency due to symptomatic HIV/AIDS or other causes, or who have a thymus disorder.

In accordance with the International Health Regulations (IHR), countries have the right to require travellers to provide a certificate of yellow fever vaccination. If there are medical grounds for not getting vaccinated, this must be certified by the appropriate authorities. The IHR are a legally binding framework to stop the spread of infectious diseases and other health threats. Requiring the certificate of vaccination from travellers is at the discretion of each State Party, and it is not currently required by all countries.