Module Components

• Overview

Topics

• Definitions
• Epidemiologic Frameworks
• Communicable and Emerging Infectious Diseases
• Role of the Public Health Nurse

Nurs 467 - Public Health Nursing

Module 4: Epidemiology, Communicable Disease and Emerging Infectious Diseases

Communicable Disease

More people die globally from chronic, non-communicable diseases such as heart disease, diabetes and cancer than communicable diseases. However, public health officials are always diligent about communicable diseases, whether it is resurgence such as pertussis, the emergence of drug-resistant bacteria such as carbapenem-resistant enterobacteriaceae (CRE) or spread of a new infection such as Zika. In addition, concern about bioterrorism occurring on US soil remains high.

There are numerous communicable diseases and the focus of the public, the media, healthcare providers and government officials change often. Our attention was recently on the Zika virus and the devastating effects it can have on the fetus, but not that long ago fears about the spread of Ebola were evident around the country. The community/public health nurse plays an important role in communicable disease education and control. Actions may range from recognizing signs of an outbreak (read the story of a school nurse who alerted officials to a swine flu outbreak) to obtaining specimens from community members during an epidemiologic investigation to treatment adherence (for example, directly observed therapy (DOT) for tuberculosis clients).

Review the differences between endemic, epidemic and pandemic (focus just on these three terms). Here is another explanation with some examples you may remember.

Immunizations have been a major success story in public health. Morbidity and mortality from many communicable diseases are a fraction of what they were 100 years ago due to immunizations. However, not all people are medically able to be vaccinated – severe allergies or poor immune function can be contraindications. Therefore, it is important that healthy individuals receive vaccinations to help provide “herd immunity” to others. Unfortunately, barriers such as inadequate health care systems, culture, politics, erroneous information and religious beliefs affect immunization levels here in the United States and abroad. For example, immunization workers in Pakistan have been executed because of a belief that the polio vaccine is a plot to sterilize Muslim children. In the United States, there is still the belief that vaccines cause autism although overwhelming evidence finds no link. For these reasons, outbreaks of preventable communicable diseases still occur and efforts to eradicate them have not been successful. To date, smallpox is the only infectious disease to have been successfully eradicated (last case in the United States was in the 1940’s and the last case in the world was in 1977 in Somalia) thanks to an effective vaccine and the commitment of the World Health Organization, CDC and other agencies.

You may have heard about the recent measles outbreak in the Pacific Northwest. Skim this NPR article for the story. This map tracks outbreaks of all kinds around the world. Do a little exploring to see what’s trending.

One threat that has been around for centuries (first documented in 1346) but that the world takes more seriously these days is bioterrorism. Watch this 10-minute video about the role of nursing in preparing for bioterrorism.

Emerging Diseases

Emerging infectious disease is an infection that has newly appeared in a population or one that has existed but is now rapidly increasing in incidence or geographic range.

• Emerging: unknown in that location before
• Reemerging: present in that location in the past as was eradicated or well-controlled, now present again and increasing

Let’s use the epidemiologic triangle to explore factors that may contribute to emergence.

• Agent
• Evolution of pathogenic infectious agents (microbial adaptation and change)
• Drug or pesticide resistance
• Host
• Changes in human demographics, behavior
• Increased susceptibility to infection
• Poverty and social inequality
• Environment
• Changing climate and ecosystems
• Economic development and land use (urbanization, deforestation)
• Technology and industry (food processing and handling)

Other factors that may also contribute to infectious disease emergence include increased international travel and commerce, breakdown in public health measures in some regions due to war/unrest, and decreased surveillance activities in some regions due to lack of political will.

Check out the recent work of the National Center for Emerging and Zoonotic Infectious Diseases, an organization dedicated to protecting people from infectious and emerging diseases.