Final answer:
Public health interventions have successfully decreased the number of new cases of infectious diseases. Vaccination programs and antiretroviral treatments have been particularly effective in reducing the impact of measles and HIV, respectively.
Step-by-step explanation:
Public health interventions aimed at decreasing the number of new cases of infectious diseases have been successful in many areas. Vaccination programs, improved nutrition, sanitation, and the use of antibiotics and vaccines have significantly reduced the impact of infectious diseases on human populations. For example, reported cases of measles in the United States dropped dramatically from around 700,000 a year in the 1950s to practically zero by the late 1990s. Additionally, antiretroviral treatments have been effective at reducing the number of infectious virions in people living with HIV.