A man with Ebola spent four days out in the Dallas community, possibly infecting others. So why are health officials so sure they can stop Ebola from spreading?
Several dozen children in California and Colorado have suffered paralyzed limbs, which doctors speculate could be caused by the respiratory virus EV-68. But we're a long way from knowing for sure.
Health leaders now say the Ebola epidemic is growing exponentially. That means, if nothing changes in the next few weeks, we could see at least 60,000 Ebola cases by the end of 2014.
Diagnosing and treating Ebola isn't so hard, health workers say; hospitals across the U.S. should be ready. But initial symptoms, such as fever and headache, can look the same as other illnesses.
A man who flew to the U.S. from Liberia has tested positive for Ebola. He was not sick on the plane, but developed symptoms later. He is currently in isolation at a hospital in Dallas.
Scientists are deeply divided on whether lab-made flu viruses are legitimate medical research or national security threats. A new federal policy asks institutions to evaluate those risks early on.
You'd think that mosquitoes wouldn't like drought, but that's not what's happening in California, where stagnant water breeds more mosquitoes. Cases of West Nile virus have doubled since last year.
The Ebola epidemic is growing exponentially. And clinics don't have space for patients. So the U.S. government is giving families kits for treating people at home. Will this help slow the epidemic?
City Supervisor Scott Wiener said he is taking a pill that can dramatically reduce the risk of HIV infection. He appears to be the first elected official to have gone public with the decision.