THE ZIKA VIRUS# MICROCEPHALY.

The Zika virus is "spreading explosively" in the Americas and the region may see up to four million cases of the disease strongly suspected of causing birth defects, the World Health Organization . The Zika virus, unlike other mosquito-borne viruses such as dengue, is relatively unknown and unstudied. That is set to change since Zika, now spreading through Latin America and the Caribbean, has been associated with an alarming rise in babies born in Brazil with abnormally small heads and brain defects -- a condition called microcephaly. Since the Zika outbreak began in northeastern Brazil last spring, an estimated 500,000 to 1.5 million people have been infected. The resulting illness only lasts a few days. The symptoms, including a rash, joint pains, inflammation of the eyes and fever, tend to be less debilitating than those of dengue. As many as 80 percent of infected people may be asymptomatic. It was not until months after Zika cases showed up in Brazil that a spike in microcephaly births was tied to women infected during pregnancy. More than 3,500 microcephaly cases have been reported since October in Brazil, compared to around 150 cases in 2014. While Zika's connection to microcephaly has yet to be definitively proven, the presence of the virus has been found in the bodies of five of the newborns that died with the condition and in the placentas of two women who miscarried babies with microcephaly.