Chapter Summary

The lessons of pandemics throughout history have shaped how public health addresses emerging infectious disease threats. These lessons illustrate the vital need for public health organizations at the federal, state, and local levels to guide disease control and prevention efforts.

Pathogenic microorganisms cause infectious diseases that spread by direct or indirect transmission. A disease is communicable if the infected host has a portal of exit, a means of transmission, and a portal of entry into another susceptible host. If an environment is favorable for the infectious agent’s survival and opportunity exists for the host’s exposure to it, infection and disease will ensue. Some infectious disease outbreaks result from direct contact with an infected individual’s respiratory secretions, while others are transmitted through blood or bodily fluids. Still others result from an intermediary, such as vectors, water, or food. Breaking the chain of transmission is key to control and prevention of these illnesses and outbreaks.

Local health care providers, state or local data surveillance, or the CDC’s review of surveillance data and laboratory patterns detect illness clusters to identify outbreaks. Public health surveillance uses data to monitor communicable and noncommunicable diseases, injuries, and risk factors for health outcomes in a population and prevent or control them. Steps in outbreak prevention include preparation; establishing an outbreak’s existence; forming a case definition; finding cases; conducting descriptive epidemiology; developing, evaluating, and refining the hypothesis about the cause; implementing control and prevention measures; maintaining surveillance; and communicating the findings. Nursing’s distinct role in pandemics and outbreaks includes assessment (epidemiological surveillance) and detection (contact tracing). Public health nurses assist with coordinating and implementing local and state disaster plans and participate in the multidisciplinary effort of understanding a health care system’s capacity before a public health emergency strikes.