There are around 40 million people around the world living with HIV/AIDS today; more than half of which are in Sub-Saharan Africa. Everyday around 7,000 more people become infected with AIDS and everyday around 6,000 people are claimed by the disease; killing more than 3 million people every year. (statistics gathered from Steps of Justice)
The red ribbon is the recognized, worldwide symbol for AIDS awareness. The snail represents the slow pace that we as a humaninity have been walking at in finding a cure; it also represents the slow and painful death that comes with AIDS, leaving a blurry trail of blood that has claimed billions of lives.
One of the major reasons that AIDS continues to spread, especially through Africa, is lack of education. Most people groups lack a basic understanding of sanitation and hygene which leaves them even less aware as to how to protect themselves against the disease. Most people group's understanding of the disease is still widely dominated by their superstitions. All of these things play a key role in the spreading of the disease. Here's a video that will hopefully give you a bit more insight into the situation (this is just a clip, there is a longer 2 part version on YouTube) but it's certainly not it. The best thing that you can do is to be educated about the situation and act (a good place to start is by sharing this post).