A little-known virus is gaining a major foothold in South and Central America.  The Zika virus, which has only recently moved beyond Africa and Southeast Asia, has already had debilitating effects in the Americas. It’s especially problematic in Brazil, where it’s appears to be connected to a serious birth defect.

The Zika virus was originally identified in 1947 in Uganda. It’s primarily transmitted by tropical mosquitoes — the same kind known for spreading dengue — that pick up the virus from infected people, according to the CDC. It was relatively unknown until 2007, when there was an outbreak of the virus in Micronesia.

Until 2014, the virus had only broken out in Africa, Southeast Asia, and the Pacific Islands. That year, it spread to Easter Island and Chile. By May 2015 Zika had made its way to Brazil. In the past year, Brazil has seen have been more than 84,000 cases of the virus. FULL REPORT