If you are planning an overseas trip, it always makes sense to check what your health needs are and if any vaccinations are required. This can even apply in some European countries, although most pose few novel dangers not found in the UK.
However, there are some diseases you will certainly need to know about and take action against. Yellow fever is one of them. There are some diseases for which it is advisable to get vaccinated, but there are others where it is a mandatory requirement, which means you don’t just need a jab at least a few weeks before you go, but to carry certified proof of it.
Our travel health clinic can provide this, giving you protection that will last for life. But, you may ask, what exactly is yellow fever, and how many countries require you to have it before entry?
Yellow Fever Explained
Yellow fever is a tropical virus carried by mosquitoes. Symptoms typically include a headache, fever, aches and pains, feeling sick and a loss of appetite. These start to emerge between three and six days after an infectious bite.
Most people recover after a few days, although this will have spoiled the trip. However, for a minority, the infection will get worse and can lead to more severe disease. This includes jaundice, which is where the name of the virus comes from.
Dark urine, bleeding from the eyes and bleeding when you visit the toilet are all more severe symptoms. If it gets this bad, there is a genuine possibility of death.
As with any insect-borne virus, you can help yourself by using repellent, sleeping under mosquito nets and wearing long, light clothing at night to cover your arms and legs. This offers extra protection, not least against other viruses for which there is no vaccine, such as malaria.
Yellow Fever Vaccination
Nonetheless, vaccination is essential as it is an effective way to stop the virus. Fortunately, this is now increasingly happening to the resident populations of affected countries. For instance, the World Health Organization (WHO) recently revealed that 92 per cent of Ugandans have now been immunised.
Sub-Saharan countries like Uganda are among the highest-risk places for yellow fever, along with South America and some parts of the Caribbean. It is not present in Asia, Europe, Australasia, or the Pacific islands.
The latest WHO update is that yellow fever is currently a risk in part or all of 34 countries. In South America, cases have been reported in Brazil, Bolivia, Peru, Colombia and Ecuador, with 96 deaths so far this year, as of May 2025. These have mainly occurred in the Amazon areas of these countries, but urban areas in the tropics can be affected too.
Beware Yellow Fever Certification Rules
While it is worth being aware of these threats, it is also important to be aware that yellow fever certification to prove you have had the jab is also a requirement in some countries, without the virus being present at the moment.
For instance, while you are not going to be at risk of contracting the virus from a mosquito bite in a Middle Eastern country such as Saudi Arabia, there is still a certificate requirement.
This will not apply if you are arriving directly from the UK, but it will if you are arriving there from a country where yellow fever is present, including transiting through one of its airports. This is worth bearing in mind if you are on a trip taking in multiple countries.
A good reason for this rule is that there is a danger of an infected person who has just been bitten but not yet manifested symptoms becoming ill there, placing an extra burden on the country’s health system.
While Saudi Arabia is a wealthy country, it deals with a large number of visitors from around the globe, especially Muslims on the Hajj and Umrah pilgrimages. Many of these will come from countries where yellow fever is present.
However, this form of yellow fever certification is also a requirement in other Middle Eastern countries, such as Qatar.
Caribbean Considerations
These are not the only places where this applies. This is also true in some Caribbean countries, such as Antigua & Barbuda or Barbados. The latter has additional requirements for anyone coming from Guyana and the island of Trinidad (as opposed to the whole of Trinidad and Tobago), so those touring the Caribbean need to be prepared accordingly.
Because your vaccination is for life, you may be very glad you got the jab. Make sure you keep the certificate in a safe place, as there are many places where you may need it, not all of them where the disease is endemic.