In epidemics, an unusually high incidence of disease occurs in a specific population. An infectious disease follows a predictable clinical pattern in the host. Distinguish between an endemic disease, an epidemic disease, and a pandemic disease. Distinguish between morbidity and mortality. To understand how diseases develop, the pathogen reservoir must be known.
Some pathogens exist in soil, water, or animals.
An understanding of disease carriers, and pathogen life cycles, is critical for controlling disease. Distinguish between acute and chronic carriers. Section 22.4 AIDS is one of the newest, and most studied pandemics. AIDS will continue to be a major public health problem, especially in developing countries. There is no effective cure or immunization to prevent AIDS, although we now know a great deal about its pathology and spread.