On The Pump Handle, Liz Borkowski reports on a "public health nightmare" in Brazil that threatens to become more common around the world. The culprit is a virus called Zika, known to cause mild infections since 1947 but now "linked to nearly 4,000 cases of microcephaly – infants born with abnormally small brains and heads." On Aetiology, Tara C. Smith writes that the link between Zika and microcephaly is not conclusive, and explains how scientists will search for a definite relationship. In the meantime, officials in Brazil and other South American countries are telling women to postpone becoming pregnant. On Respectful Insolence, Orac writes "there’s enough evidence there to raise justified concerns, but there’s an incredible amount of uncertainty, and humans tend not to deal with uncertainty very well at all."
Zika, which is transmitted by the Aedes aegypti mosquito, is newly prevalent in South America, and threatens regions as far north as Florida and the southeastern United States. Barring eradication and/or manipulation of mosquito populations, Zika is set to spread, as climate change warms temperate latitudes. Orac notes that medical science is unprepared to protect humans from the virus itself; there has no historical incentive to develop a vaccine for Zika because the primary symptoms are so mild. But now Zika and associated cases of microcephaly will attract a lot of scientific resources, as well as a lot of conspiracy mongering—documented by Orac and Tara C. Smith on Aetiology—including Mike Adams' claim that the U.S. government is "testing a bioweapon delivery system against humanity." On Pharyngula, PZ Myers looks at the bright side: "this one, tragic as its consequences can be, isn’t the big pandemic that will kill us all."