Which of the following is a bloodborne pathogen?

HIV is classified as a bloodborne pathogen because it is transmitted through direct contact with infected blood fluids. Bloodborne pathogens are microorganisms that are present in human blood and can cause disease in humans, with HIV being a notable example due to its association with immunodeficiency and the potential for transmission through blood transfusions, sharing needles, or other exposure to infected blood.

In contrast, Salmonella is a bacteria primarily associated with foodborne illness, as it is commonly transmitted through contaminated food or water. Roundworms are parasites that spread through ingestion of their eggs, often through contaminated soil or food, but do not exist in the bloodstream in a way that would qualify them as bloodborne pathogens. Chickenpox, caused by the varicella-zoster virus, is primarily spread through respiratory droplets and direct contact with the skin lesions of an infected person, rather than through blood. Understanding these nuances helps in identifying the specific characteristics and transmission methods of different pathogens.