The concern with yellow fever only increases and the doubts remain. SEE helps to understand what causes the disease, what symptoms and how to prevent it
Below, questions and answers about the outbreak of yellow fever.
There are two types of yellow fever, wild and urban. What is the difference between them?
The wild is disseminated by the Haemagogus and Sabethes mosquitoes ,circulating in forests, not in cities. The urban version is transmitted by Aedes aegypti , the same as dengue, zika and chikungunya. There has been no record of urban yellow fever in Brazil since 1942. The deaths of now were caused by the wild version alone.
Is it possible that the Haemagogus and Sabethes mosquitoes go to the urban area?
No. The Haemagogus and Sabethes mosquitoes are of different genres but have similar behaviors. They live in dense forest areas with abundant vegetation. They fly high and usually stand in the treetops. Their main source of food is the blood of the monkeys that are up there. That is, they are totally adapted to wild habits that they will not find in the city.
Why is the urban version a problem?
Because its potential for dissemination is great, as it would circulate in cities, among a much larger number of people.
Can the monkey transmit yellow fever?
No. Yellow fever is not a contagious disease, so its transmission is not made from animal to animal, neither from animal to human nor from human. The only form of transmission is by the bite of infected mosquitoes.
What is the role of primates in the transmission?
Primates can become contaminated with the virus, also acting as hosts. If stung, animals transmit the virus to the mosquito, thereby increasing the risk of spreading the disease.
If a person who was infected with yellow fever in a wilderness is in the center of São Paulo and is bitten by an urban mosquito, Aedes aegypti , does that mosquito contract the virus and spread the disease?
Yes, and that would be the beginning of the urban cycle of the disease. Urban yellow fever happens just when the Aedes aegypti stings a sick person and then itches another susceptible person, transmitting the disease. Just like dengue, zika and chikungunya. That is why it is important that all people who live or frequent at-risk areas get vaccinated.
Who needs to take the vaccine?
The Ministry of Health recommends vaccination in children from 9 months of age (6 months in endemic areas) and people living near areas at risk.
Where is it available?
The vaccine is available free of charge at basic public health units. It is also possible to find it in private clinics, at the cost of about 250 reais.
Who should not take the vaccine?
Children under 6 months should not take the vaccine under any circumstances. Mothers who are breastfeeding children at this age should also avoid getting immunized. If vaccination is required, the ideal is to stay ten days without breast-feeding. In children between 6 and 9 months of age, vaccination should only be performed with a medical indication. The same recommendation applies to pregnant women. Immunocompromised patients, such as people on chemotherapy, radiation therapy, AIDS, or taking corticosteroids at high doses, and people with severe egg allergy, should also not be vaccinated.