Which of the following is considered a parasitic infection?

Malaria is classified as a parasitic infection because it is caused by protozoan parasites of the genus Plasmodium, which reside and reproduce within red blood cells in humans. The transmission of malaria occurs through the bite of infected female Anopheles mosquitoes, which introduces the parasites into the bloodstream. This infection is characterized by symptoms such as fever, chills, and flu-like illness, and it can lead to severe complications if not treated properly.

Understanding the nature of parasitic infections involves recognizing that they not only rely on a host for survival but can also cause significant disease. Each of the other options represents a different type of infection: influenza is a viral infection, strep throat is caused by bacterial infection (specifically by Streptococcus bacteria), and hepatitis refers to inflammation of the liver, which can be caused by various viruses. This distinction helps clarify why malaria is specifically categorized as a parasitic infection while the others fall under different infection types.