No. The venom of Apis mellifera scutellata, the so-called Africanized honey bee, is no more toxic than any other Apis mellifera subspecies. The problem with Africanized honey bees lies in their behavior:

• they respond more quickly to disturbances of the hive
• they defend a larger area around a hive
• they send out more defensive bees in response to a disturbance
• they will pursue an intruder for longer distances

In short, it is the number of stings, not the toxicity of the stings, that causes a problem.