The Centers for Disease Control have issued a couple of updates on the Zika virus. The first concerns travel to Zika-infested areas, and a study finds that the mosquito that spreads the virus, Aedes egypti, is not active at higher elevations. Researchers mapped new cases and found that they occur at elevations below 2000 meters (about 6,500 feet). If your travel plans take you to higher elevations in Zika-affected countries in the tropics, your risk of Zika is low to non-existent. Extraordinary mosquito protections are not necessary because the cooler, drier climate of mountainous zones. In a second report, the CDC has approved a test to screen blood donations. This will be of great help in countries affected by the virus, because it will improve the safety of blood transfusion. The virus does linger a bit after the infection clears. In a related notice, the CDC recommends that pregnancy be delayed for about 2 months after travel to Zika-affected areas. However, the real connection of the virus to microcephaly (small infant head with mental defects) remains elusive.