Define what is meant by infectious disease.
Describe the route by which malaria is transmitted from an infected person to someone who is not infected.
In contrast to malaria, TB occurs in every part of the world. Explain why malaria has the distribution pattern shown in Fig. 4.1, whereas TB is present everywhere.
Vaccinations are used to keep infectious diseases under control. They were part of the drive to eradicate smallpox and are still used in programmes against diseases such as polio and measles. Smallpox was eradicated worldwide in the 1970s. Polio is likely to be the next infectious disease to be eradicated. TB and malaria remain major diseases. Explain how vaccination confers immunity as an important element of programmes to control and eradicate infectious diseases.