In the past half century or so, researchers have found cases of the virus sporadically across the region. But since Zika became the viral pandemic it is today, they have so far not found the widespread outbreaks that might be expected in a region seemingly so ripe for them. For instance Thailand has reported only about 200 cases since January, with no cases linked to microcephaly.
That means local populations might have been infected for decades and developed an immunity that could slow down, if not stop, the disease from spreading. Once you get Zika, you probably can’t get it again, Sam noted.
Of course the virus might have mutated a great deal over the years, taking on a more more dangerous form that causes birth defects. The World Health Organization, however, can’t yet confirm whether the current outbreak is the same as existing strains in the region.
from Stowe Boyd http://www.stoweboyd.com/post/150958737342
