Overview: Pandemics

Author: Dr. Ronald St. John

Throughout history there have been outbreaks of infectious diseases. The well-known plague epidemic (Black Death) was a devastating global epidemic of bubonic plague that struck Europe and Asia in the mid-1300s, wiping out an estimated one-third of the population. Disease outbreaks, when large in scope, have been referred to as epidemics. More recently, epidemics that have involved or might involve the global population have been labelled as pandemics.

When does an epidemic become a pandemic? There is no single accepted definition of the term pandemic (ref: Journal of Infectious Diseases, Vol. 200:7, 1 October 2009). Some considerations for labelling an outbreak as a pandemic include outbreaks of diseases:

  • that extend over large geographic areas, e.g., influenza, HIV/AIDS
  • that have high attack rates and explosiveness, e.g., common-source acquisition and highly contagious diseases with short incubation periods
  • that affect populations with minimal population immunity
  • that involve a new or novel version of an infectious agent – the term pandemic has been used most commonly to describe diseases that are new, or at least associated with novel variants of existing organisms, e.g., influenza.
  • that are highly contagious. Many, if not most, infectious diseases considered to be pandemic by public health officials are contagious from person to person
  • that have severe health consequences. The term pandemic has been applied to severe or fatal diseases

For purposes of this paper, a pandemic is an epidemic occurring worldwide, or over a very wide area, crossing international boundaries and usually affecting a large number of people.1

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  1. www.ncbi.nlm.nih.gov/pmc/articles/PMC3127276/  (back)
  2. www.census.gov/main/www/popclock.html  (back)
  3. Source: UN’s Department of Economic and Social Affairs. May 17, 2018.  (back)
  4. www.iata.org/pressroom/pr/Pages/2016-10-18-02.aspx  (back)
  5. Lena Sun, “Bill Gates calls on U.S. to lead fight against a pandemic that could kill 33 millionThe Washington Post, April 27, 2018.  (back)
  6. David Mannheim, “Questioning Estimates of Natural Pandemic Risk”, Health Security, Vol. 16, No. 6 2018.  (back)

Author: Dr Ronald St. John

13 thoughts on “Overview: Pandemics

  1. Amy Kempainen LeBoeuf shared a post.about Leptospirosis, the most widespread zoonotic disease in the world. It is an infectious bacterial disease that occurs in rodents, dogs, and other mammals and can be transmitted to humans. Its presence in the Republic of Korea poses a potential threat to the people living there. This poster advises Us military personnel in particular.
    Armed Forces Health Surveillance Branch-AFHSB


  2. Andrés Cartín-Rojas shared a link.
    “Flies in Hospitals are Full of Anti-biotic-Resistant Bacteria,”
    A new study in Great Britain found that nine in ten insects caught in seven hospitals harbored dangerous bacteria, much of which was found to be resistant to antibiotics. The researchers found 86 bacterial strains on the exoskeletons and inside the insects, including many that can infect humans. Enterobacteriaceae, a group that includes E. coli, made up 41 percent of the strains while Bacillus bacteria, including some that cause food poisoning, made up 24 percent. Staphylococci, including the nasty bug S. aureus which causes skin, bone infections and pneumonia, made up 19 percent.
    Flies aren’t the only things that can transmit bugs around hospitals. Studies have found that neckties worn by doctors can be a source of infection. But the biggest bug transmitter is something most people have been taught since toddlerhood to keep clean: their hands.


  3. Andrés Cartín-Rojas shared a link.
    “First Getah virus infection confirmed in a horse in China – Horetalk.co.nz
    Samples taken when the horse suddenly developed a fever confirmed the presence of the mosquito-borne virus, which was first isolated in 1955 in Malaysia.
    There is no effective antiviral treatment for horses with the infection. Getah virus is capable of infecting humans and many other mammals.
    Cases in horses have been reported in Japan and India. The virus has been responsible for six major outbreaks among racehorses, causing huge economic losses. The virus has since been identified in mosquitoes, pigs, foxes, and cattle, with a wide geographical distribution across the country. However, it has not been detected in horses until now.

  4. Catriona Manby shared a link.
    “Honeybees infect wild bumblebees through shared flowers”
    A newly published paper shows that honeybees leave RNA viruses on the flowers they visit which can then be transmitted to wild bumblebees. This has a negative impact on the health of the wild bumblebee populations and may be contributing to the declines of those populations. Link to the study: https://journals.plos.org/plosone/article… – The Mad Virologist


  5. World Economic Forum presented:
    ““Antimicrobial Resistance: Tackling the Gap in R&D Resources with Pull Incentives – in collaboration with Wellcome Trust.”

    Not enough new antibiotics are in development to guarantee that we can continue to treat infections. Current market conditions will not incentivise the investment necessary to restock the antibiotic pipeline, and “push” funding that directly supports early-stage R&D is insufficient to create a functioning market for the future.

    This briefing outlines why pull incentives are necessary; some of the key principles they need to fulfill; and next steps towards implementing or piloting a pull incentive.


  6. World economic Forum presented this report, which was produced in collaboration with the Harvard Global Health Institute.

    ““Outbreak Readiness and Business Impact: Protecting Lives and Livelihoods across the Global Economy”

    In the coming decades, pandemics will cause average annual economic losses of 0.7% of global GDP – a threat similar in scale to that estimated for climate change.

  7. Michelle Kleinhans shared an invitation to disaster workers in South Africa for a training in Incident Management:
    Prepare your family and community on evacuation procedures and prepsredness plans during large scale incidents to ensure safety to all.
    Contact Dynamic Incident Management for your tailored training session and workshop.

  8. From Facebook Group Emergency Manager’s Weekly Report: June 19, 2019:

    ‘WHO flags critical funding gap, calls for political parties to join fight against Ebola” The Ebola outbreak in the Democratic Republic of the Congo will only end with bipartisan political cooperation and community ownership, according to the World Health Organization’s Director-General, Dr Tedros Adhanom Ghebreyesus. WHO’s funding needs for the response are US$98 million, of which US$44 million have been received, leaving a gap of US$54 million. The funding shortfall is immediate and critical: if the funds are not received, WHO will be unable to sustain the response at the current scale. Another clear need was better use of the Ebola vaccine, which is a very effective tool if provided to all people who have been in contact with a confirmed case.

    Vaccination is being stepped up and offered to more people, including pregnant and breastfeeding women, and children over six months old (rather than only 1 year and older). https://www.who.int/news-room/detail/19-06-2019-who-flags-critical-funding-gap-calls-for-political-parties-to-join-fight-against-ebola

  9. Emergency Manager’s Weekly Report (A Facebook Group @emweeklyreport) posts this announcement: of an e-learning event:

    “Social Media Monitoring in Public Health Emergencies Webinar” on July 24, 1 pm – 2:15 pm.
    For the second year in a row, NACCHO is pleased to host a multi-part webinar series to help local health departments build capacity to engage in public health communication. Hosted by the National Association of County and City Health Officials and presented by the New York City Department of Health and Mental Hygiene, “Social Media Monitoring in Public Health Emergencies“ webinar will help participants learn how to use social media to monitor and respond to the spread of (mis)information during public health emergencies.


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