First up, the mayor of Dallas, Texas says his city is facing an emergency. The problem is West Nile Virus. There is an outbreak of it happening around the U.S. It’s the biggest jump in the number of reported cases of West Nile since 2004, and the outbreak is spreading. This map shows some of the states that have been hit the hardest. By far(到目前为止), Texas has had it the worst: More than 380 confirmed cases of West Nile there. Officials are trying to fight the outbreak by using a spray to kill infected mosquitoes. The insects spread the disease after they get it from birds. West Nile started in Africa. No one knows how it got to the U.S., but we do know when it arrived: 1999. Most people who get West Nile don’t get seriously sick. Dr. Sanjay Gupta runs through some of the symptoms of this disease.

 

 

 

The vast majority of people who get West Nile, well, won’t have hardly any symptoms at all, or so mild that they won’t realize that in fact they have West Nile. So when you look at the numbers of cases, keep that in mind, they are probably a lot higher. And people with the mild illness, you know, it’s a fever, and they can have swollen lymph glands, they sometimes get a characteristic rash that’s usually on the chest to the back or the stomach, sort of in a truncal(躯干的) area of the body. That can happen. There is a more severe form, one in 150 cases, they have something known as a neuroinvasive(神经侵入性的) form. That gets into the brain and spinal cord area, and that crosses the blood brain barrier, can cause someone to be lethargic(瞌睡的), can cause someone to have a neck stiffness, you know, people can also get joint pain and nausea. So, they can be sometimes vague(神志不清).

 

 

 

Yesterday, we reported on the U.S. Air Force flight test, a hypersonic aircraft was supposed to fly for 300 seconds, at 4600 miles per hour. This animation shows you how it would have worked. Except it didn’t. Officials say, a tail fin problem caused the aircraft to fly out of control, so they had to cut the test flight short and destroy the aircraft. They are not sure if they’ll try another one.