Retroviruses have an envelope; Polyomaviruses (which also cause cancer) do not. Which are harder to kill? Why? What level of disinfectants are needed to kill them? List two such disinfectants, and state their mechanism of action.

Answer and Explanation: Retroviruses are harder to kill because they have a proteic capsule responsible for protecting their RNA. So, although the consequences of polyomaviruses can be more lethal, retroviruses are more difficult to kill.

To kill it, an intermediate level desinfectant is needed because it is an agent which can destroy lipid and some non lipid encapsulated viruses. Examples of those are Surfactants, which acts in the membrane lipids by binding, penetrating and losing the permeability, resulting in leakage of the internal contents of the cell or desinfectants containing Chlorine compounds, because chlorine can kill pathogens by breaking the chemical bonds in their molecules.