One of the frequent calls I get at the Adventure Doc Clinic is from travelers that “need a yellow fever vaccine”. These patients are some times not interested in a consult, any other vaccines or discussing their travel plans. They simple want their vaccine and to move on with their planning. In fact, the other day I spoke with a potential patient that stated exactly this.
This potential patient called up and requested the Yellow Fever Vaccine. I asked her where she was going and informed her that a consult would be necessary for several reasons including a need to asses if she even needed the vaccine and if the vaccine would be safe for her personal case. I informed her that simply getting a vaccine without a consult is not our common practice and she would need to consult with us, before we gave the vaccine. She protested and eventually no appointment was made. I asked her why she thought she needed the YF vaccine and her response was “My travel agent told me that I might need one”.
Before getting into the details of Yellow Fever Vaccines a small refresher on YF might help:
Yellow Fever Basics:
An Arbovirus spread via arthropods (mosquitos) in the genus Flavivirus. Symptoms include fever, head and backaches, fatigue and nausea. May progress to hemorrhagic complications and/or liver failure. This is a vaccine preventable disease and proof of vaccination is often required at customs.
Location:
Only in Africa and South America. No reported cases in Asia, yet…
Transmission/Incubation:
Bites from infected Aedes species mosquitoes in cities or Haemagogus species in jungles. Main vector is Aedes Aegypti. Incubation of 3-6 days.
Prevention:
Vaccination lasts for 10 years and is a live virus. Contraindicated with egg allergy, immunocompromised, pregnancy or less that 9 months old individuals. Mosquito awareness/ bite prevention (see malaria section for more information on this).
Treatment:
This is a vaccine preventable disease, treatment once infected is supportive and centers on fluid replacement and fever reduction.
Do I need to be vaccinated?
The practice of Travel Medicine is not an exact science and centers on the reduction of disease risk for travelers. There is never a 100% method of protection and disease prevention, in any field of medicine. Travel medicine seeks to balance minimizing risk and harm to the patient by un-necessary vaccines and medical treatments with actual disease risk. The CDC and World Health Organization provide a detailed list of countries that require the YF vaccine prior to entry, provided the traveler is coming from an area of Yellow Fever activity or endemic area. However, upon closer inspection we see that some of these countries are quite large and cover vast geographical areas. To date, I am unaware of mosquitoes respecting political boundaries and not crossing borders simply because “there is no mosquito activity in that area”.
With this being said, we can apply basic knowledge of mosquito behaviors to help determine risk of the diseases they carry. Brazil is a wonderful example. A large country with legitimate risk for Yellow Fever transmission…in some areas of the country. Some coastal regions of Brazil do not have YF risk and a traveler headed exclusively to those areas would not require the YF vaccine. Giving a YF vaccine to this patient would only put them at risk for vaccine complications and take money from their pocket. A traveler headed to an altitude of 5,000 meters would also likely not benefit from a YF vaccine due to the lack of mosquitoes living at that altitude. The need for disease prevention is not worth the risk of receiving the vaccine. This type of information is only able to be determined by consulting a travel heath professional who does exactly this.
The value of expert consultation:
When I have a patient who might have a heart condition or complicated matter involving their lungs, they should be referred to speak with a specialist in that area of medicine. Cardiologists spend all day working with the heart and are experts in that field. Travel medicine consultants are they same in that they specialize in their field. Any physician can start a patient on a high blood pressure medicine but that medicine might cause more problems that good, could have harmful effects and might not always be the correct choice. Simply giving a vaccine or not giving a vaccine should be decided by an expert in that area.
Travel medicine is a specialization that seeks to help travelers enjoy their adventures then come home safe and healthy. This is a speciality that blends emergency medicine, primary care, occupational health, internal medicine, pediatrics, tropical medicine, infectious diseease, immunology, geography, meterology and entemology…just to name a few! A responsible traveler that is serious about their health while on their adventures should consider consulting with an expert prior to their voyage. There are many groups that will simply give a vaccine upon patient request without actually looking at the individual case and helping the patient make an informed decision on risk/benefit. To me, this is bad medicine and only hurts the patients in the long run.