Sao Paulo, Brazil Designated a Yellow Fever Hot-Spot

The World Health Organization (WHO) Secretariat has determined that the entire state of São Paulo, Brazil should also be considered at risk for yellow fever transmission.

The WHO is recommending that all international visitors headed to Sao Paulo state get vaccinated for the yellow fever virus.

This news comes as Brazil prepares for Carnival, the annual festival that draws tourists from around the world.

Brazil’s requirements for the International Certificate of Vaccination or Prophylaxis, with proof of vaccination against yellow fever, are available on the WHO International Travel and Health website: Annex 1 and country list.

Yellow Fever may be transmitted by Ae. aegypti mosquitoes during both the rainy and dry seasons, according to the Centers for Disease Control and Prevention (CDC).

But, there is still no evidence that the Aedes aegypti mosquito is involved in the current transmission cycle, the PAHO report said.

"The number of human cases and epizootics collectively reported in this period in the Region of the Americas is the highest observed in decades. The observed increase is as much related to an ecosystem favorable to the dissemination of the virus as to the unimmunized populations," PAHO said.

In related news, a Dutchman who traveled to Brazil contracted yellow fever. He traveled to Sau Paulo, Brazil between Dec 18 and Jan 8, 2018. He has recovered fully.

His case shows the need for travelers to be vaccinated against yellow fever and for clinicians to include yellow fever in the differential diagnosis when patients return from areas, where the yellow fever disease is endemic.

The current advice by the WHO Secretariat for international travelers going to areas in Brazil deemed to be at risk for yellow fever are the following:

• Vaccination against yellow fever at least 10 days prior to the travel.
• As per Annex 7 of the International Health Regulations (2005), a single dose of a yellow fever vaccine approved by WHO is sufficient to confer sustained immunity and life-long protection against yellow fever disease.
• Travellers with contraindications for yellow fever vaccine (children below 9 months, pregnant or breastfeeding women, people with severe hypersensitivity to egg antigens, and severe immunodeficiency) or, over 60 years of age should consult their health professional for advice;
• Adoption of measures to avoid mosquito bites;
• Awareness of symptoms and signs of yellow fever;
• Seeking care in case of symptoms and signs of yellow fever, while traveling and upon return from areas at risk for yellow fever transmission.

Yellow fever is an acute viral haemorrhagic disease that is endemic in tropical areas of Africa and Latin America. Cases can be difficult to distinguish from other viral hemorrhagic fevers such as arenavirus, hantavirus or dengue, according to the WHO.

Symptoms of yellow fever usually appear 3 to 6 days after the bite of an infected mosquito.

In the initial phase, they include fever, muscle pain, headache, shivers, loss of appetite, and nausea or vomiting. For most patients, these symptoms disappear after 3 to 4 days.

However, 15% of patients enter a second, more toxic phase within 24 hours of the initial remission when high fever returns, and several body systems are affected, including the kidneys.

Vaccination is the most important preventive measure against yellow fever, providing effective immunity within 30 days for 99% of those vaccinated, says the WHO.

A single dose is sufficient to confer sustained immunity and life-long protection, with no need for a booster.

Because of a depletion of the FDA approved YF-Vax vaccine, the manufacturer Sanofi Pasteur has worked with the CDC to make an alternative yellow fever vaccine available in the USA.

The Stamaril vaccine, which is currently available in 70 countries worldwide, has a clinical efficacy profile similar to YF-VAX.

Stamaril is only available at select locations in the United States.

The CDC is suggesting people who are contemplating traveling to Yellow Fever endemic areas should schedule a vaccination appointment at least 2 months before departure.

Once vaccinated, travelers should receive a yellow card called the International Certificate of Vaccination or Prophylaxis (ICVP) to prove that you have had yellow fever vaccine.

The CDC Vaccine Price List provides the private sector vaccine prices for general information.  

Vaccine discounts can be found here.

Vaccines, like any medicine, can have side effects, says the CDC. You are encouraged to report negative side effects of vaccines to the FDA or CDC.