Welcome to the summer edition of
The Lowdown. This latest issue focuses on outbreaks and some of their associated diseases. Long-term care facilities present unique challenges during an infectious disease outbreak. Resident risk factors, such as comorbidities, shared common spaces and equipment, and facility factors (e.g., staffing shortages or poor infection prevention practices) provide the opportunity for diseases to spread rapidly and cause an outbreak. This issue provides resources to assist you in preparing for an outbreak situation. Happy reading!
What Is an Outbreak?
An outbreak is an increase in the number of cases of a disease above what is expected for a specific location, in a given time period, for a targeted group, such as long-term care residents.1 In the case of a rare disease, such as anthrax or measles, one case is considered an outbreak.1
The Centers for Medicare & Medicaid Services (CMS) defines an outbreak in healthcare facilities as “the occurrence of more cases of a particular infection than is normally expected, the occurrence of an unusual organism, or the occurrence of unusual antibiotic resistance patterns.”2
When an outbreak occurs, it is important to respond quickly and efficiently to protect the health of residents and staff and to minimize the spread of the disease.3,4 The Centers for Disease Control and Prevention (CDC) defines the following steps of an outbreak investigation that may occur concurrently:3
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Identify an increase in cases or unusual patterns of a disease.
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Establish a case definition and identify the affected people.
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Describe the outbreak by time, location, and affected people.
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Develop a hypothesis based on the data collected.
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Evaluate or test the hypothesis.
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Implement infection prevention measures to prevent transmission.
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Communicate investigation results.
Notify your local health department of a suspected outbreak. They can provide support such as information on laboratory testing, recommendations to help stop transmission of the disease, and assistance in identifying possible sources of the disease.5
Outbreak Resources
Measles
The United States is currently experiencing ongoing out-breaks of measles: a highly contagious, respiratory virus that is spread through the air; by direct contact; or by droplets when the infected person talks, coughs, or sneezes. The virus can circulate in the air for hours, even if the infected person is no longer in the area.
Symptoms of measles begin seven to 21 days after exposure. Common symptoms include a fever (up to 104 degrees), cough, conjunctivitis (red, watery eyes), and rhinorrhea (runny nose); about three to five days later, the infected person develops a red rash. An infected person can spread measles prior to developing symptoms and for four days after the rash appears. Immunocompromised people will be contagious throughout the entire illness.
There is no specific treatment for measles, and it is best prevented by vaccination. It is important to verify staff and resident immunity. CDC recommends adults born during or after 1957 that do not have evidence of measles immunity should be vaccinated with two doses of MMR. Learn more at cdc.gov/measles/ and apic.org/measles/.
Influenza (Flu)
The flu is a very contagious respiratory illness caused by a virus. It is one of the 10 leading causes of death in the United States when combined with pneumonia. Flu seasons are unpredictable and can be severe depending on the characteristics of the circulating virus strains. Influenza viruses are unique as they cause both recurrent annual epidemics and more serious pandemics. Elderly people, pregnant women, young children, and people with chronic medical conditions, such as diabetes and heart disease, are at higher risk of developing complications from the flu.
Vaccination is the most effective way to prevent influenza!
Influenza spreads from person to person by droplets released when an infected person coughs, talks, or sneezes. Touching objects that are contaminated with the flu virus and then touching your mouth, nose, or eyes may also cause infection. Vaccination can reduce the risks of getting the flu, hospitalization, and death. It is critical to vaccinate everyone who is able to get vaccinated. For more information, visit cdc.gov/flu/index.html.
Norovirus
Norovirus is the principal cause of acute gastroenteritis (AGE) epidemics and healthcare facility outbreaks. It can be fatal among vulnerable populations such as infants, the elderly, and immunocompromised people. The incidence of norovirus outbreaks tends to peak in cold weather. A norovirus outbreak affects resident and staff safety, disrupts facility operations, and may cause financial and operational challenges. Developing norovirus preparation measures and having a rapid response plan is one of the best ways to reduce the risk of or mitigate an outbreak.6
Additional information and tools on norovirus: patientsafety.pa.gov/pst/Pages/Infection%20Prevention%20%E2%80%94%20Norovirus/hm.aspx
Prepare for norovirus season:6
Education
Provide education on transmission, symptoms, and prevention. Reinforce infection prevention measures and hand hygiene with staff, residents, and visitors.
Review, monitor, and reinforce adherence to facility protocols on infection prevention and control measures.
Surveillance System
Develop and institute facility policies for rapid confirmation of potential cases. These policies should include:
- A clear case definition
- Unit-based systems to find, monitor, and record case information
- Line listing logs to record daily symptoms and case information for residents and staff
- Facility-specific norovirus baseline
- Facility-specific norovirus attack rate by unit
References
- Centers for Disease Control and Prevention. Outbreak and Case Definitions. CDC. https://www.cdc.gov/urdo/php/surveillance/outbreak-case- definitions.html. Published May 28, 2024. Accessed June 2025.
- Centers for Medicare & Medicaid Services. CMS Manual System Pub. 100-07 State Operations, Provider Certification Transmittal 51. https://www. cms.gov/regulations-and-guidance/guidance/transmittals/downloads/r51soma.pdf. Department of Health & Human Services (DHHS). Published July 20, 2009. Accessed June 2025.
- Centers for Disease Control and Prevention. Lesson 6: Investigating an Outbreak. CDC Archive. https://archive.cdc.gov/www_cdc_gov/csels/dsepd/ ss1978/lesson6/section2.html. Last Reviewed September 15, 2016. Accessed June 2025.
- World Health Organization. Outbreak Toolkit. WHO. https://www.who.int/emergencies/outbreak-toolkit/investigating-outbreak-of-unknown-disease. Accessed June 2025.5. Center for Disease Control and Prevention. Long-Term Care Facilities - Viral Respiratory Pathogens Toolkit for Nursing Homes. CDC. https://www. cdc.gov/long-term-care-facilities/hcp/respiratory-virus-toolkit/index.html. Published January 8, 2025. Accessed June 2025.
- Patient Safety Authority. Controlling the Annual Threat of Norovirus Gastroenteritis Outbreaks. Pa Patient Saf Advis. 2010;7(4):141-8.