#18,723
In 2017 (and again in 2018) the WHO released a short list (n=8) of priority diseases (see WHO List Of Blueprint Priority Diseases) - that in their estimation had the potential to spark a public health emergency and were in dire need of accelerated research:
- Crimean-Congo haemorrhagic fever (CCHF)
- Ebola virus disease and Marburg virus disease
- Lassa fever
- Middle East respiratory syndrome coronavirus (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS)
- Nipah and henipaviral diseases
- Rift Valley fever (RVF)
- Zika
- Disease X
As it turned out, a variant of #4 on their list (SARS-MERS) sparked the worst pandemic in a century less than 3 years later, while we've seen repeated outbreaks from the others.
Last summer the WHO unveiled an expanded 38-page Pathogens Prioritization report, increasing the number of priority pathogens to more than 30. Additions included 7 different influenza A subtypes (H1, H3, H3, H5, H6, H7, and H10), and 5 bacterial strains that cause cholera, plague, dysentery, diarrhea and pneumonia.
Today we've a retrospective analysis of disease outbreaks reported to the WHO from around the globe since 1996, which find > 3,000 significant events. Central Africa (DRC) and China (see Viral Reassortants: Rocking The Cradle Of Influenza) lead the pack, followed by the Middle East and parts of Southeast Asia.
They report:Influenza was the most frequently reported disease, with a total of 771 outbreak events, followed by Ebola virus and MERS-CoV. Other frequently reported diseases included yellow fever, cholera, and meningitis.
But of course, not every outbreak is reported, and the details on those that are can sometimes be sparse.
This is a lengthy and fairly detailed retrospective, so I've only reproduced the link and abstract below. Follow the link to read it in its entirety. I'll have a postscript after the break.
May 16, 2025
Global distribution and health impact of infectious disease outbreaks, 1996–2023: a worldwide retrospective analysis of World Health Organization emergency event reports
Qiao Liu1, Min Liu1,2,3, Wannian Liang4,5, Xuanjun Li1, Wenzhan Jing5,6, Zhongdan Chen7, Jue Liu1,2,3,8,9
Abstract
Background
Over 30 priority pathogens with pandemic potential were identified, underscoring the need for targeted surveillance and prevention. As infectious disease outbreaks increase globally, particularly from zoonotic and vector-borne pathogens, understanding their distribution is crucial for effective public health responses. We aimed to provide a comprehensive analysis of global infectious disease outbreaks from 1996–2023, addressing gaps in previous research.
Methods
We sourced data from the World Health Organization emergency events webpage, focusing on key details like disease name, location, date, and fatalities. We calculated case fatality rates (CFR) to assess outbreak severity. We categorised outbreaks into six types – respiratory, vector-borne, foodborne/waterborne, direct contact infections, non-infectious conditions, and others. Data extraction was independently performed and cross-verified for accuracy.
Results
Between 1996–2023, a total of 3013 global outbreak events were reported. The Democratic Republic of the Congo had the highest frequency of outbreaks, with 272 events, followed by China with 254, and Saudi Arabia with 202. Influenza was the most frequently reported disease, with 771 outbreaks, followed by Ebola (n = 342) and Middle East respiratory syndrome-related coronavirus (MERS-CoV) (n = 305). Significant outbreaks included the 2023 global dengue outbreak, which accounted for five million cases and 5000 deaths. The CFR was highest for the Marburg virus at 76.86%, followed by haemorrhagic fever at 63.63%, and Ebola at 63.00%. The data underscore the varying severity and distribution of outbreaks, highlighting the critical need for robust global health surveillance and targeted interventions.
Conclusions
In this study, we highlighted the significant impact of influenza, Ebola, and MERS-CoV. The high case fatality rates of viruses like Marburg and Ebola emphasised the need for early detection and rapid response systems. Strengthening global cooperation, investing in health care infrastructure, and integrating digital surveillance technologies are crucial to enhancing preparedness and reducing future outbreak impacts.
In the 1990s researcher George Armelagos of Emory University posited that since the mid-1970s the world had entered into an age of newly emerging infectious diseases, re-emerging diseases and a rise in antimicrobial resistant pathogens (see The Third Epidemiological Transition (Revisited).
And the following timeline, from the UK HAIRS group would seem to bear that out.
Recent studies suggest that the frequency, and impact, of pandemics are only expected to increase over the next few decades.
BMJ Global: Historical Trends Demonstrate a Pattern of Increasingly Frequent & Severe Zoonotic Spillover Events
PNAS Research: Intensity and Frequency of Extreme Novel Epidemics
And yet, at this critical juncture in history, we are dismantling our disease surveillance, investigative, and reporting systems at a furious rate (see Flying Blind In The Viral Storm). Many nations - including our own - have chosen to ignore the IHR 2005 regulations and stop (or severely limit) reporting to the WHO and WOAH on outbreaks (see From Here To Impunity).
While I can't tell you if H5Nx, MERS-CoV, or Nipah will spark the next pandemic, one thing is all but certain; Something will.
And when that happens, we'll regret every day we squandered not aggressively preparing for its arrival.
