Lesson: Notable Emerging Diseases – Causes and Global Impact

1. Background Context and Historical Significance

Throughout history, humans have faced new and emerging diseases that have significantly impacted societies. From the plague to recent pandemics, the introduction and spread of novel pathogens have often resulted in considerable morbidity, mortality, and socio-economic disruption.

2. Detailed Content and its Relevance in the Broader Framework

a) Notable Emerging Diseases:

  • HIV/AIDS: Identified in the early 1980s, it’s believed to have transferred to humans from primates. This disease attacks the immune system, making the body more vulnerable to other infections.
  • Ebola Virus Disease: First recognized in 1976, outbreaks have occurred in Africa, affecting humans and primates. Its severe and often fatal illness in humans has garnered global attention.
  • Zika Virus: While first identified in 1947, a significant outbreak occurred in 2015-2016, primarily in the Americas. It’s linked with birth defects when pregnant women are infected.
  • COVID-19: Caused by the SARS-CoV-2 virus, it emerged in late 2019 and led to a global pandemic. This respiratory disease has affected millions worldwide.

b) Causes of Emerging Diseases:

  • Zoonotic Transfer: Many emerging diseases, like HIV and Ebola, are believed to have originated in animals before transferring to humans.
  • Globalization: Increased global travel and trade mean that diseases can spread more rapidly than before.
  • Environmental Changes: Deforestation, urbanization, and climate change can alter habitats and bring humans closer to disease reservoirs.
  • Antimicrobial Resistance: Overuse of antibiotics in humans and livestock can lead to resistant strains of bacteria, leading to diseases that are harder to treat.

c) Global Impact of Emerging Diseases:

  • Healthcare Systems: Outbreaks can overwhelm health facilities and staff, especially in countries with weaker healthcare systems.
  • Economy: Global economies can take severe hits due to reduced productivity, job losses, and disruption of trade.
  • Societal Impact: Fear of contagion can lead to stigmatization of patients or entire communities. It can also lead to significant lifestyle changes, as seen with lockdowns and travel restrictions during the COVID-19 pandemic.
  • Policy and Infrastructure: Governments worldwide have had to invest in surveillance, research, and healthcare infrastructure to detect and manage outbreaks.

3. Patterns and Trends Associated with the Topic

  • Increased Surveillance: Global health organizations have established more robust surveillance systems to detect and manage outbreaks.
  • Global Cooperation: Diseases know no borders. Thus, international cooperation, as seen during the COVID-19 pandemic, becomes crucial in managing global health crises.

4. Influential Figures or Works Pertinent to the Lesson

  • Dr. Anthony Fauci: Director of the U.S. National Institute of Allergy and Infectious Diseases, he’s been a prominent figure in the research and management of HIV/AIDS and more recently, COVID-19.
  • Books: “The Coming Plague” by Laurie Garrett provides an in-depth look at various emerging diseases and the challenges of controlling them.


Emerging diseases have, and will continue to have, a profound impact on global health, economies, and societies. Understanding their origins, effects, and mechanisms of spread is crucial to mitigate their effects and protect public health.