I just heard from my Senior Accountant that this kind of event is also happening in India Recently, because these are the acts of some HIV Positive people. They are taking some blood from their own by a Syringe and stick it to anyone whom they see as a target. 
So I think, all of us now should be careful!! Astagferullah!!! If this happens to you, make sure to wash the affected area with soap and water then go to the nearest hospital in order to be given post exposure prophylaxis within 72 hrs., HIV test is also part of the intervention
The post-exposure prophylaxis is a combination of anti-retroviral drugs given to patients for 6 weeks (depends on the protocol of the country). If 72 hrs had passed already there is a high chance that patient will get infected, especially if the degree of the injury is deep. 
This is a serious matter, since HIV is one of those diseases that doesn’t have cure yet. We have to be extra-careful