A third of humanity lives in countries where Zika virus could still spread, reveals a study published Friday in the British medical journal The Lancet Infectious Diseases .
“Approximately 2.6 billion people live in areas of Africa and Asia-Pacific where local species of mosquitoes and suitable climatic conditions make transmission possible Zika virus in theory,” says the lead author of the study, Dr. Kamran Khan.
This figure is based on the screenplay “most prudent” used by scientists, knowing that the extension area of the Zika virus is the same as that of dengue.
Currently it is in Brazil that we find the greatest number of people with Zika. Nearly 1,600 babies are born with birth defects and neurological complications of the virus.
Angola, which is already struggling with an epidemic of yellow fever, would be one of the African countries most at risk because of its important economic ties with Brazil.
Other countries such as Vietnam or Thailand could see the birth of new disease outbreaks, as well as African countries such as Tanzania and Sudan.
The researchers are based on a model based on the number of travelers from countries affected America, climatic conditions, population density and efficiency of health care systems to achieve these numbers.
Dr. Kahn recognizes that many “uncertainties” remain, including the transmission of the virus, which is done primarily by Aedes mosquitoes, but can also be transmitted during sexual intercourse.
A virus identified in Africa
Zika virus was spotted for the first time in Uganda on a monkey in 1947 and has spread to humans in several African and Asian countries in the 1970s.
These are strains belonging to the Asian lineage of the virus that emerged in Brazil in 2015, before expanding in nearly 40 American countries.
“Although sporadic cases of Zika were reported on both continents, the extent of previous infections remains unknown,” the researchers noted.
According to them, African countries are more at risk than Asian countries to be affected “because the strain involved in the current outbreak is not Asian and African.”
The study concludes, however, that it is difficult to assess the number of people who have been in contact with the African or Asian strain of virus in the past.