Written and maintained by CASRAI Editorial Board
Last updated
Short answer: a public health emergency is a situation serious enough that a public authority formally recognises it as one. In the United States, the Secretary of Health and Human Services (HHS) can determine one exists under section 319 of the Public Health Service Act. Internationally, the World Health Organization (WHO) can declare a public health emergency of international concern (PHEIC) under the International Health Regulations. The two are separate declarations made by different bodies.
This page is written for researchers, laboratory and clinic staff, and supply and compliance teams who need to tell the declarations apart and see how they relate to preparedness work. It is general information, not medical advice.
Definition and scope
There is no single worldwide definition. The phrase is used for at least two formal mechanisms, and a reader should know which one a news report or notice means.
Under the US mechanism, HHS states that the Secretary “may, under section 319 of the Public Health Service (PHS) Act determine that” a disease or disorder presents a public health emergency, or that one otherwise exists. HHS lists significant outbreaks of infectious disease and bioterrorist attacks among the situations covered (HHS ASPR, Public Health Emergency legal page, read 2026-11-07).
Under the international mechanism, the International Health Regulations (2005) describe a PHEIC as “an extraordinary event which is determined to constitute a public health risk to other States” and one that may “potentially require a coordinated international response” (WHO questions and answers on emergencies, IHR and Emergency Committees, read 2026-11-07).
How a declaration works in practice
United States: section 319 determinations
HHS says a declaration “lasts for the duration of the emergency or 90 days, but may be extended by the Secretary.” Each extension is published as its own determination, titled “Renewal of Determination that a Public Health Emergency Exists”; HHS lists the nationwide opioid crisis determination, renewed repeatedly since 2017, as an example (HHS ASPR, read 2026-11-07). A declaration alone does not waive anything: for Medicare, Medicaid and CHIP flexibilities, see our guide to section 1135 waivers in a declared emergency, which covers the additional preconditions.
International: the WHO process
WHO states that an Emergency Committee of international experts gives technical advice to the WHO Director-General on whether an event is a PHEIC, on temporary recommendations, and on when the emergency ends; the Director-General makes the determination. Temporary recommendations aim to limit international spread while avoiding unnecessary interference with trade and travel, and they “automatically expire three months after their issuance” (WHO, read 2026-11-07). Countries report events through National IHR Focal Points. WHO reports that the amended IHR, including the 2024 amendments adopted in resolution WHA77.17, have been in force since 19 September 2025 (WHO, International Health Regulations page, read 2026-11-07).
The two meanings compared
| Feature | US section 319 public health emergency | WHO PHEIC |
|---|---|---|
| Who determines it | HHS Secretary | WHO Director-General, advised by an Emergency Committee |
| Legal basis | Section 319, Public Health Service Act | International Health Regulations (2005) |
| Duration | Duration of the emergency or 90 days, unless extended | Temporary recommendations expire after three months |
| Continuation | Separate published renewal determination | Committee advises on temporary recommendations and on when it ends |
| Scope | Disease, disorder, outbreak or bioterrorist attack | Event posing a risk to other States that may need coordinated international response |
The role of public health in emergency preparedness
Declaration, response and preparedness are different activities. A declaration is a formal determination; preparedness is the planning done before one. CDC says it established 15 capabilities in 2011 as national standards for public health preparedness planning, used by state, local, tribal and territorial programs to plan, operate and evaluate their work; they were updated in 2019 (CDC, Public Health Preparedness Capabilities, read 2026-11-07). The capabilities also address topics such as pandemic influenza, environmental health and at-risk populations.
Related CASRAI pages cover the supporting pieces: emergency operations plans, tabletop exercises, the Hospital Preparedness Program, the Strategic National Stockpile and sentinel surveillance.
Where it matters for labs, clinics and supply decisions
- A notice naming a “public health emergency” should be read for who issued it. A federal section 319 determination and a WHO PHEIC are different instruments with different issuers.
- Dates matter. Because a US declaration runs for the emergency or 90 days unless extended, the current renewal determination is the record of whether it is still in effect.
- Programs that depend on a declaration, such as Medicare flexibilities, state their own conditions; confirm those in the program’s own guidance rather than assuming a declaration is sufficient.
Common misunderstandings
- “PHE” and “PHEIC” are the same. They are not. One is a US determination by HHS; the other is a WHO determination under the IHR.
- A declaration lasts until cancelled. For the US mechanism, HHS describes a 90-day period unless extended, and renewals are separate determinations.
- A declaration automatically triggers waivers. See the section 1135 guide linked above for the additional conditions.
FAQ
What is the role of public health in emergency preparedness?
Public health agencies plan, operate and evaluate preparedness programs. In the US, CDC’s preparedness capabilities are the national standards for state, local, tribal and territorial programs (CDC, established 2011, updated 2019).
What is the definition of a medical crisis?
A public health emergency is a population-level determination by an authority, which differs from an individual medical emergency. For an urgent personal medical situation, contact local emergency services.
What are the most common medical emergencies?
This page covers population-level declarations rather than individual conditions. For personal medical concerns, consult a clinician or emergency services.
How can people deal with stress in emergency situations?
CDC’s guidance on healthy ways to deal with stress after a natural disaster lists: eat well-balanced meals, exercise regularly, get plenty of sleep, talk with a trusted person, avoid drugs and alcohol, and take a break from news coverage if it adds to stress. CDC says feeling emotional, nervous, or having trouble sleeping and eating can be normal reactions. If problems continue, or if you are thinking about suicide, CDC advises talking to a psychologist, social worker or professional counselor, and notes that SAMHSA’s Disaster Distress Hotline can be called or texted at 1-800-985-5990 (CDC, read 2026-11-07).
Sources
- HHS ASPR, Public Health Emergency declarations, read 2026-11-07.
- WHO, Emergencies, IHR and Emergency Committees, read 2026-11-07.
- WHO, International Health Regulations, read 2026-11-07.
- CDC, Public Health Preparedness Capabilities, read 2026-11-07.
- CDC, Healthy Ways to Deal with Stress after a Natural Disaster, read 2026-11-07.
