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Ship operators with vessels visiting Brazil are advised to ensure seafarers are vaccinated against yellow fever and to implement measures to avoid mosquito bites.

Further to our alert of 31 Jan 2018, we have been advised by our correspondents in Brazil, Representacoes Proinde Ltda, that the country is facing a severe outbreak of yellow fever, having experienced a significant upsurge 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.

Typical symptoms of yellow fever tend to appear after an incubation period of three to six days and include moderate fever, muscle pain with prominent 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 is 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 and a WHO Q&A provides useful information about the certificate of vaccination.


Recommended precautions for vessels trading to South America/Brazil

According to Proinde’s Circular of 14 March 2018, vessels visiting Brazilian ports should take proactive 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 DR Congo, and no travel or trade restriction has been applied on the country to date, we recommend that all seafarers on board vessels calling at any Brazilian port be vaccinated and issued with the corresponding international certificate in conformity with the WHO standards. A map of areas at risk and yellow fever vaccination recommendations is also available on the WHO ITH website Yellow fever vaccination recommendations in the Americas, 2018.

Although vaccination is the only complete defence against the yellow fever virus, avoiding mosquito bites altogether is an effective way to prevent crew from being exposed to a mosquito borne disease. During a visit to a Brazilian port, it is therefore important to ensure that all crew members:

  • are 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;
  • stay indoors in screened or air‐conditioned rooms as much as possible;
  • wear protective clothing covering as much of the body as possible, also during daytime;
  • use effective insect repellents on exposed skin and/or clothing as directed on the product label; and
  • are familiar with yellow fever symptoms and seek immediate medical care should signs of the infection develop.

See also our Insight article Mosquitoes - one of the deadliest animals in the world for an overview of recommended precautions to be considered prior to, during and after a visit to areas where there is a risk of exposure to a mosquito-borne disease.

We thank our correspondents, Representacoes Proinde Ltda, Santos for the above information.