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  • December 2016

Bugs, Behavior, and Beyond! Lessons from Recent and Historical Epidemics

By
  • Dr. Dave Rengachary
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In Brief
On October 13, 1976, an unassuming package arrived at the U.S. Centers for Disease Control and Prevention from Zaire (Congo). The specimen inside soon revealed a terrifying secret: the slender looping tail of the Zaire Ebola virus, the cause of one of the most lethal hemorrhagic fevers on earth. It would take nearly 40 years before Ebola would again capture the world’s attention, and only after graduating from a disease affecting isolated African villages into a global threat.

The specimen inside soon revealed a terrifying secret: the slender looping tail of the Zaire Ebola virus, the cause of one of the most lethal hemorrhagic fevers on earth. It would take nearly 40 years before Ebola would again capture the world’s attention, and only after graduating from a disease affecting isolated African villages into a global threat.

What distinguishes diseases such as Ebola, which seem to suddenly emerge and spread across nations, from “endemic” or predictable and geographically contained conditions such as hepatitis B? What lessons can insurers take from the past to more accurately manage infectious disease risk in a globalized world?

Know Your Bugs

In the strictest sense, an “epidemic” is any greater-than-expected occurrence of a particular disease in a given area or among a specific group of people. Generally, this term implies the relatively rapid spread of illness; also, epidemics are not limited to infectious diseases. A “pandemic,” on the other hand, occurs when an infectious disease crosses international boundaries and affects large populations. Pandemics may be characterized by explosive growth over wide geographies.  Minimal population immunity, high infectivity, and possible high severity can all drive the pandemic forward.  

To prevent both epidemics and pandemics, public health organizations traditionally focus on two goals:

  • Elimination, or the reduction of new cases to near zero in a defined geographical area. One area of intermittent success has been the fight against polio, where aggressive vaccination and prevention programs have eliminated the disease from many areas of the world.
  • Eradication or the complete and permanent worldwide reduction to zero of new cases of a disease. Beyond a few petri dishes in U.S. and Russian labs, smallpox no longer exists.

Several factors complicate this story, however. Pandemics are often viral in nature, and viral diseases are inherently difficult targets for modern medicine. Unlike living bacteria, viruses outside the human body are no more alive than a stone. They are instead pieces of cellular machinery that have evolved over time with one purpose: to replicate. A typical virus is about one-hundredth the size of a bacterium, with far fewer genes or proteins to target with treatments. Viruses also mutate much more quickly than bacteria, so therapies frequently fail.

With the rise of anti-microbial resistance, it is now harder to fight bacteria as well. When the first antimicrobials, including antibiotics, were developed in the 1940s, they were considered miracle cures – compounds with the ability to inhibit or kill the bacteria responsible for infections. Yet overuse has enabled bugs to adapt and resist these antimicrobials. We have entered the era of superbugs with the emergence of MCR-1, a bacteria that can fight the last group of antibiotics, polymyxins, by plasmid-mediated resistance.

Know Your Behavior

How do endemic diseases like Ebola suddenly become pandemics? Human behavior plays a critical role. In the case of Ebola, the same demographic and economic changes transforming much of the world were largely responsible.

People in Africa, Asia, and elsewhere are leaving rural communities and packing into dense urban centers, where disease can more rapidly spread. Activities such as road building, hunting, deforestation, and agricultural expansion are bringing more people into contact with wildlife, providing another avenue for disease transfer. (About 75% of emerging diseases in people come from animals, according to EcoHealth Alliance.) Additional factors such as global population migration, climate change-driven conflict, and changing sexual mores can all fuel the spread of disease.

Look Back

We can draw lessons from the pandemics of the past:

  • In 1334 the Silk Road trade route from China to Europe spread great wealth, as well as Yersinia pestis, or the “Black Death.” Generally considered to be deadliest pandemic by proportion of population killed, the Black Death wiped out an estimated 60% of Europe’s population, or 75-200 million people. The primary drivers were climate change and the medieval equivalent of globalization, and the most effective solution was quarantine.
  • The “mother of all pandemics,” Spanish influenza emerged in 1918 in the wake of the chaos of the First World War. Mortality estimates vary widely, but this member of the H1N1 family produced especially high relative virulence among those aged 15-34. Spanish flu proved that war and movement of armies can keep killing even after peace is declared.
  • In the modern era, the respiratory disease SARS took over 750 lives, but is most notable for the speed of its spread. SARS reached five countries within 24 hours and six continents and 30 countries within six months. A coronavirus similar to SARS, Middle East Respiratory Syndrome (MERS-CoV) emerged in the Arabian Peninsula in 2012 with a mortality rate greater than 35% and then appeared in Korea in 2015. In a hyper-connected world, SARS and MERS reveal our increased vulnerability to fast-moving pandemics and the critical need for a rapid-response health intelligence network to share information and treatments across borders.
  • A flavivirus first identified in Africa in 1947, Zika virus appeared sporadically over half a century, transmitted by Aedes mosquitoes. After epidemics in 2007 in Micronesia and in 2013 in French Polynesia, Zika arrived in Brazil in 2014. While non-fatal in most adults, Zika can trigger paralysis (Guillain-Barré Syndrome) and birth defects; the only known defense at this time is mosquito control measures.
  • Ebola experienced 20 significant outbreaks since 1976, but the emergence of the Zaire Ebola virus in Guinea in 2013 was the largest. Natural reservoirs for the disease remain unknown, but scientists believe Ebola spread so rapidly due to traditional cultural beliefs, including burial practices, intersecting with profound environmental and societal changes in West Africa. The disease is spread by direct contact with blood or body fluids, and the outbreak was ultimately controlled through quarantine. A vaccine is under development.
  • The flavivirus dengue fever produces more than 390 million cases a year globally, sending thousands of people to the hospital with hemorrhagic fever and shock. From 2003 to 2013, cases increased by a factor of five according to the Pan American Health Organization. A warming world has fueled the spread of dengue-carriers, Aedes mosquitoes. The good news: a phase 3 trial of a vaccine in five Latin American countries has yielded overall efficacy of 64.7%.

Look Beyond

What does this past tell us about the future? First, globalization, population migration, and climate change make us more vulnerable to pandemics than at any time in human history. Common-sense measures like mosquito control and quarantine are as effective now as they were centuries ago, and the traditional process of creating a vaccine may not be able to keep pace with the speed of transmission in the modern world.

Governments and researchers will have to work harder – and smarter – to stay ahead of the next great outbreak. Many see promise in the power of international cooperation and information sharing. Emerging discoveries in genetics and genomics, as well as advances in predictive analytics and “big data,” may help better identify patterns of transmission and stop pandemics before they start. And public health organizations can track anti-microbial resistance trends to speed diagnosis, ensure appropriate use of anti-microbials by doctors and patients, increase and streamline the development of new anti-microbials, and leverage technology to arrive at faster diagnosis and treatment alternatives.

The insurance industry response also is critical. RGA has a multi-part approach to pandemics.

  • Our Pandemic Risk Governance Team is organized to manage a coordinated response to rapidly evolving developments in disease. RGA’s Ebola Update and Insurance Implications paper is one example.
  • RGA partners with BlueDot, an organization that studies how infectious diseases disperse worldwide through analysis of big data.
  • We also conduct internal medical and actuarial assessment of pandemic tail risk events as mandated by regulators.

Pandemics pose a challenge that extends beyond borders, but continuing attention, constant innovation and global intelligence sharing together may be the best solutions in a rapidly changing world.

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Dr. Dave Rengachary
Author
Dr. Dave Rengachary
Senior Vice President, Head of Underwriting, U.S. Individual Life