HIV crossed from chimps to humans in the 1920's in what is now the Democratic Republic of Congo. This was probably as a result of chimps carrying the Simian Immunodeficiency Virus (SIV), a virus closely related to HIV, being hunted and eaten by people living in the area.
You can't see them without a microscope, nor can you smell or taste them individually.
Answer: They should be used when handling ready- to-eat food.
Explanation: For example, washing produce, or when handling ready-to-eat ingredients for a dish that will be cooked to the correct internal temperature.
