Why isn't it that there so many hiv aids victim get from blood transmissions?

does the doctors,hospitals or blood centers has risk for this?
and y isnt it until now there's no treatment for this disease?

Before you can donate blood you have to be at NO risk for having the disease (as well as several other diseases such as malaria). You are tested before you can give blood to make sure you do not have any blood born diseases.

As for doctors, nurses, etc... they are at risk for getting HIV anytime they treat a patient. There is a protocol if you think you have been infected where you take certain medications within 1 hour of the event, for up to 6 months. This MAY prevent the disease.

There is no cure since most people are not aware they got AIDS until a longer period of time into the illness. The virus is very tricky because it mutates all the time, thus we are unable to design a drug that will work with any mutant form of the virus. Furthermore, the virus "hides" inside your own white blood cells (cells that usually are designed to kill viruses).

I would add that while there is no vaccine and no cure, medicine has made significant strides in treating/managing HIV/AIDS. While it is still a very serious and often fatal disease, it is not the death sentence that it was 20 years ago. Things like protease inhibitors and strong antibiotics for some opportunistic infections have very much changed the way the disease is managed in a given patient.