Seems like a bigger problem than a bunch of migrants slowly walking towards the southern border.
This doesn't seem like a problem to the welfare of Americans at all, while the caravan is. I presume that's the reason it's not in the news. Also the Ebola scare was already sold back in the day and in the end nothing important happened, so it's going to be hard to sell this. (If you're going to downvote please provide an argument, thanks.)
Contrary to what has been reported in the Fox News / Trump Birds bubble, the people in the caravan have expressed their intention to follow a fully legal process of applying for asylum.
As to why people lawfully applying for asylum might be a problem, I don't think it is a one. You may agree... or if you disagree, I would point out the fact that such acts follow a long tradition of lawful immigration to the United States, one which has built our country from some of the most motivated people in the world. But you may be laboring under the false assumption that they are intending to enter the US illegally.
Based on the amount of false information being pushed by people with a lot of money and very loud voices, it seems likely that your opinion that the caravan is a problem may be based on this particular misunderstanding of what's going on... that you think they plan to enter illegally.
If not, we're in a different conversation entirely, about what America is at its core.