Pandemics, Epidemics, and Outbreaks

Becca Barrus

Becca Barrus


Before COVID-19 there was the H1N1 influenza virus—more commonly known as the swine flu—which is estimated to have infected 60.8 million people (including 12,469 deaths) from April 2009 to April 2010 in the United States alone.1 Like COVID-19, symptoms were described as flu-like, including fever, cough, and body aches. Unlike COVID-19, however, H1N1 was not likely to cause patients 65 and older to get significantly sick, although they were at a high risk of developing serious complications if they did contract it. Before H1N1, the last worldwide pandemic was an H3N2 influenza virus that resulted in 1 million deaths worldwide.2 H3N2 emerged in 1968, 10 years before Dr. Jeff Clawson released the Medical Priority Dispatch System (MPDS®).

Because it was the first global pandemic in 40 years, H1N1 gave the International Academies of Emergency Dispatch® (IAED) the impetus to create a protocol specifically for managing disease outbreaks. Protocol 36: Pandemic/Epidemic/Outbreak (Surveillance or Triage) was released in April 2009 and underwent some updates in April 2020 to more accurately serve emergency dispatchers and the community during the COVID-19 pandemic.

Photo by Ibrahim Boran on Unsplash

Protocol 36 is only to be used “during an officially declared outbreak, epidemic, or pandemic,” and thus doesn’t apply to regular seasonal flu.3

When does an outbreak turn into an epidemic and then become a pandemic? The definitions on Protocol 36 outline the differences between the related but distinct phenomena:

  • Outbreak: A sudden increase in the number of disease cases, or occurrence of a larger than expected number of cases, within a short period of time.
  • Epidemic: A sudden outbreak of a disease or an unusually large number of disease cases in a single community or relatively small area. Disease may spread from person to person and/or through the exposure of many persons to a single source, such as a water supply.
  • Pandemic: An epidemic that becomes widespread, affecting an entire region, continent, or the world.

Since a pandemic is usually made up of many regional and local outbreaks, the same disease may impact your agency and your service area much differently than other nearby regions, and those further away from your area. If Milan (Italy) has 22,000 active cases and your center has fewer than 500, you can both be using Protocol 36—just in different capacities.

What does Protocol 36 do? Simply put, Protocol 36 helps your EMS response system and your local hospitals do more with less. Like other protocols, Protocol 36 allows EMDs to quickly and accurately determine which cases need a rapid EMS response; however, unlike other protocols, Protocol 36 identifies patients with outbreak-specific symptoms to allow for a reduced or modified response—or perhaps no EMS response at all. During a severe outbreak in your region, conserving system resources and not overwhelming your local hospitals with outbreak patients is one of the most important public health goals.

Another way to use Protocol 36 is to surveil the situation in your area, watching carefully for signs of escalation. In the case of our current pandemic, many places in North America still have not seen their system severely stressed. Those regions can anticipate future activity and may want to watch for spikes in call load so they are able to implement response changes quickly. In situations where call load has already escalated, such as in New York City (USA) or Milan, there’s no need for that. It’s time for action—or rather, reduced action.

On the level

There are four levels of patient triage on this protocol: Level 0, Level 1, Level 2, and Level 3. In the original version of the protocol there were only Levels 1, 2, and 3. Level 0 was added in 2020 and is used to keep an eye on the number of disease cases in your specific jurisdiction. There is no change in response when your center is using Level 0 on Protocol 36. Levels 1–3 “allow for locally designated, potentially different levels of patient triage and reduced response.” Your local medical director or medical control authority will decide which specific Determinant Codes will get a reduced response. In Level 1, there should be a consideration of referring ALPHA cases only. In Level 2, there should be a consideration of reduced response for CHARLIE cases. In Level 3, there should be a consideration of referral for some CHARLIE cases and reduced response for DELTA cases. Obviously, Level 3 would be implemented during a time when your area has been hard hit by the disease and resources are truly decreased.

It’s important to note that if your agency moves to Level 1 or even Level 2, it isn’t locked in at that response level for the rest of the pandemic. It’s designed to be an adjustable protocol. If more of your resources are freed up, it might be time to return to more typical response assignments. You can revert back to Level 0 (surveillance mode) or discontinue the use of Protocol 36 altogether when infection levels in your area become more manageable.

The PDIs for Protocol 36 are adjustable as well. There are options for circumstances when regular dispatch is available, when dispatch is limited/reduced, when there is no EMS response at all or the patient should remain quarantined at home, and when there is no EMS response and an alternative treatment site is available. In the case of this last example, instructions decided on by local authorities will tell you where to send patients and how to get them alternative transportation if needed.

Too many questions?

Depending on the patient’s condition, there may be more Key Questions than most protocols have on average. However, you may or may not ask all questions for every single caller suspected of having the specified disease.

Rule 2 states that “Once two flu-like symptoms in Key Questions 4–13 have been identified, skip the rest of the questions to Key Question 14 and then choose the appropriate Determinant Code. If positive flu-like symptoms were mentioned in Case Entry, these Key Questions do not have to be asked again. More than one flu-like symptom creates a higher likelihood that the Chief Complaint is actually the current outbreak illness.” As with other protocols, priority symptoms are still relevant and will trigger a higher response level when they are present. Someone calling about a patient displaying INEFFECTIVE BREATHING with flu-like symptoms will receive a different response level than someone calling about a patient with multiple flu-like symptoms only.

Priority symptoms to watch out for include INEFFECTIVE BREATHING, DIFFICULTY SPEAKING BETWEEN BREATHS (DSBB), Abnormal breathing, level of consciousness, CHANGING COLOR, and Chest pain/discomfort (a higher Determinant Code will be assigned to patients aged 35 and up ). Key Question 14 also asks if the patient has any HIGH RISK conditions. Your Local Medical Control will have defined and authorized conditions that qualify a patient as HIGH RISK and they will likely include: patients aged 65 and older, blood disorders, diabetes, kidney and liver diseases/disorders, neurological diseases, pregnancy, sickle cell disease, and weakened immune system.

People aren’t going to stop having other medical emergencies just because there’s a pandemic. There will still be cardiac arrests, strokes, and falls that will require a quick response. Protocol 36 will help your center determine how best to respond to emergent medical situations when everything feels emergent.


1 “2009 H1N1 Pandemic (H1N1pdm09 virus).” Centers for Disease Control and Prevention. 2019; June 11. https://www.cdc.gov/flu/pandemic-resources/2009-h1n1-pandemic.html (accessed May 22, 2020).

2 “Influenza Historic Timeline.” Centers for Disease Control and Prevention. 2019; Jan. 30. https://www.cdc.gov/flu/pandemic-resources/pandemic-timeline-1930-and-beyond.htm (accessed May 22, 2020).

3 “Special Procedures Briefing: Protocol 36 and Emerging Infectious Disease Surveillance.” The International Academies of Emergency Dispatch. 2020; May 5. https://cdn.emergencydispatch.org/iaed/pdf/NAE_Pandemic_v13-3.pdf (accessed May 22, 2020).