13.3: Infectious Disease Prevention and Control
By the end of this section, you should be able to:
- Define public health surveillance.
- Explain the steps in public health surveillance for infectious diseases.
- Describe how an outbreak is established.
- Discuss the steps in an outbreak investigation.
- Describe efforts to prevent foodborne and waterborne diseases.
- Explain the nurse’s role in emergency preparedness and disaster response during an infectious disease outbreak.
In the 20th century, improvements in sanitation and hygiene, the discovery of antibiotics , and the implementation of immunization programs resulted in disease control and a major shift in life expectancy and the diseases causing death (CDC, 1999). By 1900, 40 states had established health departments, and from the 1930s to the 1950s, they oversaw progress in sewage disposal, water treatment, food safety, and handwashing and food-handling education. Improvements in housing and TB-control programs decreased the incidence of TB deaths (CDC, 1999). In addition to these public health achievements, 1946 saw the creation of the Communicable Disease Center (CDC) with a primary mission of preventing the spread of malaria (CDC, 2018c). Over the next 40 years, the CDC provided disease surveillance and immunization programs. In 1992, it was officially renamed the Centers for Disease Control and Prevention to reflect its leadership in public health initiatives (CDC, 2023b). Communicable disease control and prevention is one of the greatest public health achievements of the 20th century (CDC, 1999). The development of new vaccines has continued into the 21st century, resulting in fewer serious illnesses and deaths due to VPDs. Eight of the 10 leading causes of death for 2021 were related to chronic diseases, a significant shift from the last century (CDC, 2023h). Chronic diseases such as heart disease and cancer are leading causes of death and disability and the primary drivers of annual health care costs (CDC, 2021b). This evolution in infectious disease prevention and control would not have occurred without the efforts of public health professionals who recognized the importance of sanitation, education, vaccine development, and public health surveillance.
Public Health Surveillance
Public health surveillance is the “ongoing, systematic collection, analysis, and interpretation of health-related data essential to planning, implementation, and evaluation of public health practice” (CDC, 2018b, para 1) and more specifically refers to the monitoring of communicable diseases, noncommunicable diseases, injuries, and risk factors for these health outcomes in a population. Using data to monitor health problems is a key function of public health surveillance as it assists in prevention or control. Public health officials can use data to prioritize planning prevention and control programs (CDC, 2012).
Although numerous health issues affect global populations, many are neither urgent nor directly threaten health. Some health issues, such as breast cancer, are persistent and chronic, with a stable incidence and prevalence in the community. Therefore, the first step in public health surveillance is to identify which health problems to monitor. Selecting and prioritizing health problems for surveillance involves identifying issues that impact public health. The second step relates to the incidence, prevalence, severity, mortality, socioeconomic impact, and communicability of the disease or problem and the ability to prevent or control it. In general, communicable diseases are more commonly under surveillance, given their possibility of causing an increased threat to public health. Within the United States, surveillance begins at local and state-level public health departments as each state sets local laws for diseases and conditions that must be reported. Local health departments work with laboratories, hospitals, and health care providers to obtain information on reportable diseases and then convey it to the state health department. The state health department uses the data to locate the source of a potential outbreak to prevent its spread and sometimes will involve the CDC, depending on the scope of the issue (CDC, 2022aj).
Local and state health departments are also responsible for notifying the CDC about agreed-upon notifiable diseases and health conditions. The Council of State and Territorial Epidemiologists and the CDC identify this list together, and states voluntarily inform the CDC when an individual meets the criteria to become a case. The CDC then uses this data to monitor and alert communities about potential health threats (CDC, 2022aj). The CDC also partners with the WHO through the Global Outbreak Alert and Response Network (Christensen et al., 2021).
The CDC conducts public health surveillance through the National Notifiable Diseases Surveillance System (NNDSS) to track reportable and notifiable diseases and conditions with the assistance of local health departments. Currently, approximately 120 diseases are under NNDSS surveillance, including communicable and noncommunicable diseases and bioterrorism agents, with almost 2.7 million disease cases reported each year (CDC, 2022aj).
Each time a public health agency collects information about an individual diagnosed with a health condition that could threaten others, it is called case surveillance . This case surveillance is at the foundation of public health practice (CDC, 2022an). Recall John Snow’s cholera outbreak investigation in London in Epidemiology for Informing Population/Community Health Decisions. Case surveillance usually includes infectious diseases, such as COVID-19, or foodborne outbreaks, like E. coli . However, some noninfectious conditions are also surveilled, such as lead poisoning (CDC, 2022aj). Health departments notify the CDC to report instances of an estimated 120 diseases and conditions monitored under NNDSS surveillance. Case surveillance captures information about the population affected, the geographical area involved, and the course of illness and treatment that public health professionals can use to inform prevention and control efforts (CDC, 2022aj).
A surveillance case definition is a set of criteria used to define a disease for public health surveillance. Case definitions include clinical criteria such as expected signs or symptoms and often have restrictions by time, place, and person, especially in the setting of potential health threats to others. This enables public health officials to be consistent in case classifications and counting across states. Surveillance case definitions are not the criteria that health care providers use to diagnose, manage, and treat conditions in the clinical setting; they are used for data reporting and tracking purposes only (CDC, 2022ah). Surveillance data are also included in the CDC’s Morbidity and Mortality Weekly Report (MMWR) series. This publication is the agency’s main dissemination of authoritative, useful public health information and recommendations. MMWR is targeted toward scientists, health professionals, epidemiologists, and public health professionals, including public health and community health nurses (CDC, 2023k).
In this informational video by the CDC National Notifiable Diseases Surveillance System, Dr. Paula Yoon discusses current public health threats and efforts to control and prevent these threats.
Watch the video, and then respond to the following questions.
- What is the role of the public health nurse in disease surveillance and reporting?
- What contemporary examples of applying the National Notifiable Disease Surveillance System can you think of?
- How does the National Notifiable Disease Surveillance System contribute to public health safety?
Outbreak Investigation
A disease outbreak refers to more cases of a certain disease or health condition than expected. Gathering surveillance data is one method of establishing the existence of an outbreak. This process can occur at the local or state health department and in hospital facilities looking to identify any hospital-acquired infections. Similarly, the CDC regularly reviews surveillance data and laboratory patterns of disease-causing organisms to detect clusters of illness. Another way to detect an outbreak is when a health care provider alerts the local health department about unusual cases—unusual due to the frequency or type of condition. An example is the 1999 WNV infection, which was discovered after a New York City health department received a call from a physician who had recently evaluated two clients with encephalitis (CDC, 2012, pp. 6–2). Community members may also call local health departments to report abnormal clusters of illness. An example is foodborne-related illness where an individual calls the health department and reports that seven of their friends are ill with similar symptoms after eating at the same restaurant. Another example would be a concerned community member reporting a cancer cluster in their neighborhood. A health department’s decision to investigate a potential outbreak depends on many factors, such as illness severity, number of cases, mode of transmission, and availability of prevention and control measures (Figure 13.6). Typically, the more individuals affected or the more serious the illness, the greater the likelihood of an outbreak investigation with the ultimate goal to assist in disease prevention and control (CDC, 2012).
This video breaks down the eight steps of an outbreak investigation.
Watch the video, and then respond to the following questions.
- What are the steps in an outbreak investigation?
- What are some reasons a nurse may see an increased number of cases of a certain disease compared with the baseline level normally seen?
- What necessary information does the nurse need to describe an outbreak?
- How are control measures utilized in an outbreak? Give some examples of control measures.
Surveillance for and Prevention of Foodborne Diseases
Prevention of foodborne diseases requires careful oversight and monitoring along the food supply chain. The CDC works collaboratively with the U.S. Department of Agriculture (USDA), the Food and Drug Administration (FDA), and local and state public health departments to ensure food safety along the steps in the food chain. This work involves identifying foodborne illness, investigating multistate foodborne disease outbreaks, providing education to prevent outbreaks, and implementing systems to better address, detect, and stop outbreaks (CDC, 2022b). The CDC helps to track and investigate foodborne illnesses through the following surveillance systems:
- PulseNet
- Foodborne Diseases Active Surveillance Network ( FoodNet FAST )
- System for Enteric Disease Response, Investigation, and Coordination (SEDRIC)
- Foodborne Disease Outbreak Surveillance System (FDOSS)
Whole genome sequencing (WGS) is an advanced technology that assists epidemiologists in finding foodborne outbreaks. WGS data helps scientists determine DNA similarities in strains of pathogens, indicating they come from the same source and allowing the CDC and its partners to detect outbreaks more quickly and to solve outbreaks while they are still small. When PulseNet scientists determine the same strain causes a group of illnesses, disease detectives can investigate the illness to determine if they came from the same food or food source (Figure 13.7). This has improved the ability to link foodborne illnesses and detect outbreaks (CDC, 2022b).
The CDC investigates multistate foodborne outbreaks using a seven-step process (CDC, 2022ag):
- Detect a possible outbreak through data surveillance.
- Find individuals included in the outbreak and look for additional ill individuals.
- Generate hypotheses by interviewing ill individuals.
- Test hypotheses by comparing what ill individuals ate to what well people of a similar group ate.
- Solve by confirming the contaminated food using epidemiologic and lab information to identify the contamination point.
- Control and stop the outbreak by recalling the food, cleaning or closing facilities, and educating those involved.
- Decide the outbreak is over when illness ends and the contaminated foods are no longer available.
Surveillance for and Prevention of Waterborne Diseases
Preventing waterborne illnesses is multifaceted. Consumers need to know where their drinking water comes from and understand their water supply’s testing frequency and test results. Many community water systems use groundwater and are regulated by the EPA, but some municipal water supplies are unsafe, as was the case for years in Flint, Michigan (CDC, 2020d, 2022ac; Ruckart et al., 2019). Private wells must also be maintained and tested to ensure they are far enough away from septic tanks (CDC, 2022ac). The CDC provides guidance to consumers about ways to mitigate waterborne pathogens that can grow in pipes and devices that use water, such as humidifiers. Pathogens thrive in stagnant water or water that is not treated with enough disinfectant. Due to EPA requirements, public water utilities provide water that meets certain quality and safety standards, but tap water is not sterile. The small number of pathogens in the water can congregate in pipes and potentially multiply, especially if taps are unused for long periods and water sits in the pipes (CDC, 2022ac).
Read the scenario, and then respond to the questions that follow.
Janessa Jones is a 6-year-old client who presented to Dr. Liu’s office complaining of a fever, abdominal cramping, vomiting, and diarrhea for the past two days. She is a generally healthy child with no significant medical history and does not take any medications on a daily basis. Sally, a public health nurse, received notification from Dr. Liu about the unusually high number of children presenting with similar symptoms in the past day. Janessa was the first child Dr. Liu evaluated with these complaints, but by the end of the day, she had seen eight children with similar presentations. Dr. Liu mentioned that each of the children had a recent history of swimming in the town’s recreational pool.
- What is Nurse Sally’s role in this case?
- Identify Nurse Sally’s next steps in addressing Dr. Liu’s concerns.
- Discuss interventions the public health nurse can implement to reduce the risk of waterborne diseases.
A waterborne disease outbreak is defined when two or more individuals contract the same illness from the same contaminated water source. Waterborne disease surveillance data informs policy in developing drinking water regulations and regulations for certain recreational water activities (CDC, 2019f). The CDC oversees waterborne disease and outbreak tracking to help guide efforts to decrease and prevent future outbreaks. The national Waterborne Disease and Outbreak Surveillance System ( WBDOSS ) collects data on waterborne illnesses related to recreational, drinking, and environmental water (CDC, 2019f). The WBDOSS also gathers information on hospitalizations, deaths, agents, types of water implicated, and water settings, which collectively inform next steps during an outbreak. Determining the etiology of waterborne illness is a complicated process as many pathogens spread by water can also be spread in other ways, making it difficult to link illness to water. Without an outbreak investigation, it is nearly impossible to link illness to water (CDC, 2019g). Therefore, anyone suspecting a possible outbreak is encouraged to contact their local health department, which will often enlist the assistance of the state health department (CDC, 2019h).
Waterborne disease outbreaks became nationally notifiable in 2009, and every state is responsible for identifying, investigating, and reporting them electronically through the CDC’s National Outbreak Reporting System ( NORS ). WBDOSS collects the data reported to NORS on waterborne disease and outbreaks associated with recreational water, drinking water, and non-recreational water exposures (CDC, 2019h) and publishes annual surveillance data reports in the MMWR (CDC, 2019k). These data have supported efforts to reduce waterborne disease outbreaks by assisting the EPA in developing drinking water regulations, guiding the CDC’s recreational water activities program, and highlighting the emergence of Legionella outbreaks through various exposures and settings, supporting prevention efforts (CDC, 2019k).
Nurse’s Role During an Infectious Disease Outbreak
Nursing plays a distinct role in pandemics and other infectious disease outbreaks. As part of the three core functions of public health nursing, nurses are involved with assessment in terms of epidemiological surveillance and detection, such as contact tracing. A school nurse working in New York City is credited with first observing and notifying the CDC about the 2009 H1N1 flu pandemic (National Academies of Sciences, Engineering, and Medicine [NASEM], 2021). During the COVID-19 pandemic, nurses conducted most contact tracing at the local board of health, at the state level, and in school districts. Public health nurses assist with coordinating and implementing disaster plans at the local and state levels, an aspect of policy development. Preparedness is a multidisciplinary effort to understand a health care system’s capacity in advance of a public health emergency, including workforce capacity, access to personal protective equipment, and medical supplies, an aspect of assurance (NASEM, 2021).
During an evolving infectious disease outbreak, the nursing role may shift as health care shifts from routine care to public health care, emergency preparedness, and disaster response. Nurses working in various practice settings serve on the front line of public health emergencies, assisting individuals and communities through a crisis. Promoting health and well-being is one of the essential roles of nursing. Nurses engage and connect with individuals and communities to ensure they have what they need to be healthy (NASEM, 2021).
As the COVID-19 pandemic revealed, this engagement, ability, and willingness to respond to public health crises takes a toll on nursing; during that pandemic, many nurses reported feeling unsafe, unsupported, and unprepared, resulting in a profound mental health burden (NASEM, 2021). The COVID-19 pandemic required nurses to take on multiple roles: for example, outpatient endoscopy nurses were asked to care for medical-surgical clients, and non–critical care nurses were asked to care for critically ill clients. Nurses also provided end-of-life care and served as a means of communication between dying or ill clients and their families. This most recent pandemic has illustrated the vital importance of protecting nurses’ well-being and mental health so that they can respond to disasters effectively and safely (NASEM, 2021).
Nurses also have a role within the health promotion and disease prevention framework along the three levels of prevention. Within an infectious disease outbreak, the public health nurse plays a vital role in primary, secondary, and tertiary prevention (Table 13.13).
| Primary Prevention |
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| Secondary Prevention |
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| Tertiary Prevention |
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Healthy People 2030 has a focused goal of improving emergency preparedness and response by building community resilience. The objectives are divided into the following categories of emergency preparedness: general, global health, health communication, and heart disease and stroke. Most of these objectives are in the developmental stage but recognize the value of individuals who are prepared for a disease outbreak.