Surgery General 276cf6a3 What should be the density of microfilaria in blood to make it infective to the vector A 5 microfilaria / drop of blood B 10 microfilaria / drop of blood C 15 microfilaria / drop of blood D 20 microfilaria / drop of blood High-Yield Explanation A density of 15 microfilaria / drop of blood are needed to make it infective.