Brazil is facing a severe outbreak of yellow fever, having experienced a significant increase in the number of fatal cases and the geographic spread of the disease in the last few months.
The yellow fever virus is transmitted by infected mosquitoes. The disease is endemic in tropical areas of Africa, Central America and South America, including some areas of Brazil, notably in the North and Centre‐West Regions.
Symptoms of yellow fever appear after an incubation period of three to six days and include moderate fever, muscle pain with backaches, intense headaches, shivers, loss of appetite, nausea or vomiting. About 15% of patients progress into a more toxic phase of the infection, which has symptoms such as high fever, jaundice and abdominal pain with vomiting. Half of the infected people who enter the severer form of the infection die within a couple of weeks. Those who survive generally acquire long‐lasting immunity to the disease.
Yellow fever can be prevented by an extremely effective vaccine, which is safe and affordable. Yellow fever is also listed in the International Health Regulations (IHR) as a disease for which countries may require proof of vaccination from travellers, including seafarers, as a condition of entry. The vaccination against yellow fever is valid for the life of the person vaccinated.
Operators travelling to Brazil are recommended to do the following:
- Vessels visiting Brazilian ports should take measures to avoid mosquito‐borne diseases through an efficient and well‐documented integrated vector management plan (IVM), including disinsection (mosquito eradication) of the vessel and removal of any stagnant water where mosquitoes may lay their eggs.
- While no proof of vaccination is currently required to enter Brazil, except for travellers arriving from Angola or the Congo, and no travel or trade restriction has been applied on the country, all seafarers on board vessels calling at any Brazilian port must be vaccinated and issued with the corresponding international certificate in conformity with the WHO standards.
- Crewmembers must be aware of peak mosquito hours. While the peak biting times for many mosquito species is dusk to dawn, the Aedes aegypti, one of the mosquitoes that transmits yellow fever virus, feeds during the daytime.
- Crewmembers are adised to stay indoors in screened or air‐conditioned rooms as much as possible;
- Protective clothing covering as much of the body as possible, also during daytime, is vital;
- Use effective insect repellents on exposed skin and/or clothing as directed on the product label;
- Be familiar with yellow fever symptoms and seek immediate medical care if signs of the infection develop.
The Brazilian government is now trying to prevent the spread of yellow fever to states which have not yet reported cases. For this reason it announced that it will start a nationwide vaccination campaign to immunize over 77.5 million that have not yet been vaccinated by April of 2019.
Rio de Janeiro, São Paulo and Bahia will be the first to extend vaccination to all municipalities. Brazil says that almost 40.9 million people have yet to be vaccinated in these states.
The new states included in the vaccination agenda will receive the standard vaccine, and are the following:
- Santa Catarina;
- Rio Grande do Sul in the South;
- Rio Grande do Norte in the Northeastern region of Brazil.
The remaining fourteen states have the yellow fever vaccine in their regular vaccination calendar.