What is the origin of the mosquito Aedes aegypti?
the mosquito A. aegypti It originates from Africa and spread throughout the world: first from the west coast of the continent to the Americas, then probably from the east coast to Asia.

why the name A. aegypti?
The vector was first described scientifically in 1762, when it was called Culex aegypti. Culex means "mosquito" and aegypti, Egyptian, therefore: Egyptian mosquito. the gender Aedes it was only described in 1818. Soon it was verified that the species aegypti, described years before, presents morphological and biological characteristics similar to those of species of the genus Aedes � and you are not of the already known genre Culex. So, the name was established Aedes aegypti.

How many people can a mosquito infect?
Female mosquitoes suck blood to produce eggs. If the dengue mosquito is infective, it can transmit the dengue virus in this process. In general, mosquitoes suck only one person for every batch of eggs they produce. The dengue mosquito has a peculiarity called “gonotrophic discordance”, which means that it is capable of biting more than one person for the same batch of eggs it produces. There is a report that a single infective dengue mosquito transmitted dengue to five people from the same family on the same day.

Genilton Vieira/IOC

Aedes aegypti female needs blood for egg production

Why only female pica?
The female needs blood for egg production. Both the male and the female feed on substances that contain sugar (nectar, sap, among others), but since the male does not produce eggs, he does not need blood. Although they may occasionally feed on blood before mating, females intensify their voracity through hematophagy after fertilization, when they need to ingest blood to carry out complete egg development and maturation in the ovaries. . Normally, three days after the ingestion of blood, the females are ready to lay eggs, and then start looking for a place to spawn.

Is it true that the mosquito A. aegypti has it been eradicated and then reintroduced in Brazil?
At the beginning of the 20th century, the identification of A. aegypti as a transmitter of urban yellow fever, it spurred the implementation of strict control measures that led, in 1955, to the eradication of the mosquito in the country. In 1958, the country was considered vector-free by the World Health Organization (WHO). However, eradication did not cover the entire American continent and the vector remained in areas such as Venezuela, the south of the United States, Guyanas and Suriname, in addition to the entire island extension that includes the Caribbean and Cuba .

The most likely hypothesis to explain the re-introduction of the mosquito in Brazil is the so-called passive dispersal of the vectors, through human displacements at sea or on land - the dynamics facilitated by the great resistance Vector egg resistance to drying. In Brazil, the relaxation of control measures after the eradication of A. aegypti allowed its reintroduction in the country at the end of the 1960s. Today the mosquito is found in all Brazilian states.

Like A. aegypti arrived in Brazil? Is there a historical record of dengue in the past?
The most accepted theories indicate that the A. aegypti has spread from Africa to the American continent by vessels that docked in Brazil to traffic in slaves. There is a record of the disease occurring in Curitiba (PR) at the end of the 19th century and in Niter�i (RJ) at the beginning of the 20th century.

Does dengue only occur in Brazil?
No. There are records of the disease in several countries in the Americas, as well as in Africa, Asia, Australia and Pacific Polynesia.

*All contents were reviewed by researchers at Instituto Oswaldo Cruz (IOC/Fiocroz)