Zika outbreak 'to end in 2 to 3 years'
The Zika outbreak in Latin America will likely burn itself out in the next two to three years, given people develop immunity to the virus after an initial infection, British scientists say.
The researchers, whose work is published in the journal Science on Thursday, estimated that infections from the mosquito-borne virus will become so widespread in affected countries that populations will develop what is called "herd immunity".
That would prevent further transmission of the Zika virus for at least a decade, with only smaller, intermittent outbreaks, they said.
"Because the virus is unable to infect the same person twice - thanks to the immune system generating antibodies to kill it - the epidemic reaches a stage where there are too few people left to infect for transmission to be sustained," study author Neil Ferguson of the School of Public Health at Imperial College London said.
There is no vaccine or specific treatment for Zika.
The study was based on mathematical models of the virus, which has been shown to cause microcephaly, a birth defect marked by small head size that can lead to severe developmental problems in babies.
The connection between Zika and microcephaly first came to light last autumn in Brazil, which has now confirmed more than 1600 cases of microcephaly that it considers related to Zika infections in the mothers.
The researchers compared data from Zika's transmission across Latin America to data on similar viruses, such as dengue, to create a model of projected Zika transmission.
They forecast that large-scale transmission will end in two to three years and not resume for a decade.
Similar patterns have been seen in related viral infections, including chikungunya, Ferguson said.
Ferguson said it may be too late to try to control mosquito populations to prevent widespread Zika transmission, and mosquito abatement efforts might delay and prolong the outbreak, which will eventually die out naturally.