Gerberding discusses emergence of infectious diseases

We must focus on anticipating zoonotic infection emergence, increasing protection and prevention capabilities and committing to sustained engagement, former director of the U.S. Centers for Disease Control and Prevention Julie Gerberding said in a lecture on Monday.

Gerberding explained that personal encounters with infectious diseases were what first opened her eyes to the complex ecosystem of people, animals and health in our current world. She explained that, as of now, her primary focus for the future of medicine is the One Health Initiative founded by Laura Kahn, University physician and Wilson school scholar, which emphasizes collaboration between scientific, health and environmental disciplines.

Gerberding, who currently serves as the executive vice president for strategic communications, global public policy and population health at Merck and Co., has worked on vaccinations for multiple infectious diseases throughout her career. She discussed her experiences studying three types of infectious disease carriers: mosquitoes, bats and ticks.

Although the anopheles merus species is most widely known for its association with the transfer of malaria, Gerberding has focused particularly on the aedes aegypti and aedes albopictus species, as they have been associated with the recent spread of the Zika virus in the Americas.

There are currently 147 Zika cases in the U.S. as of Feb. 24, 2016. Gerberding explained that these species are especially tricky to deal with because they are particularly adaptable to urban environments and are even able to lay eggs in bottle caps.

Additionally, the Zika virus has many unexpected complications, as it has been associated with birth defects, still-birth, miscarriages and Guillain-Barré syndrome, which affects nerves in the brain and spinal cord. This issue is particularly prominent in communities with low diagnostic capabilities due to lack of experienced or qualified personnel.

“The question with this menacing mosquito and this particular virus, which is just getting started in this part of the world, is why is it here now, why is it so large-scale, why is it happening so fast?” Gerberding said, noting that none of these questions have been successfully answered yet.

Gerberding then expanded on bats, which she personally finds fascinating. She explained that bats have many ecological values, as they control insects, pollinate plants and provide models for signal processing.

They are also carriers of many diseases. Fruit bats were linked to the Ebola virus which broke out quickly in 2014 in West Africa. However, these diseases do not affect the bats themselves, and appear to only make humans sick.

“When [bats] fly, their temperature goes up, so by definition, any virus in a bat must be temperature tolerant. It must be able to tolerate fever,” Gerberding said. “So maybe that’s one of the reasons why they’re such successful hosts for viruses — that when transferred to human beings, we can’t ward off these viruses because they’re indifferent to our first line of defense.”

Another disease carrier, the tick, is particularly problematic in the New Jersey area, according to Gerberding. Lyme disease, which is spread by the Blacklegged (deer) tick, has only gotten worse and worse on the east coast of the U.S. The primary issue that Gerberding noted is that the question of why these diseases emerge at the exact time that they do has gone unanswered.

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“The concept of emergence is easy to get - we can all see that something is emerging - but it’s very difficult to understand. We really are just beginning to have theories about what is causing emergence,” Gerberding said.

Gerberding mentioned some popular theories about what is causing emergence, including global demographic changes, global urbanization, social disruption and displacement and increased traveling.

Traveling is an obvious multiplier, since there are currently tens of thousands of commercial air flights each day, excluding cargo or other flights. Gerberding admitted that in a world of increasing globalization, we are not able to keep viruses contained in one place.

She said that the biggest unknown is climate change, since scientists can only hypothesize how changes in vector ecology may be a result of more extreme weather.

Gerberding concluded her speech by stressing her three policy priorities again. She emphasized that the third policy is essential, as it is important for society to stop being reactive rather than proactive when it comes to disease control.

“What I have seen is, a problem emerges, money comes. The problem is managed, the money goes away. So all the things we know we should do, are not done on a sustained basis.”

The lecture, titled "Menacing Mosquitoes, Biting Bats, and Tormenting Ticks: Health Protection Priorities," took place in Robertson Hall at 4:30 p.m. on Monday as part of the Gilbert S. Omenn '61 Lectures in Science Policy. Gerberding’s three-day visit was also supported by the Christian A. Johnson Endeavor Foundation Leadership through Mentorship Program.