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A Global Look at the COVID-19 Pandemic with Infectious Disease Expert Davidson Hamer, MD

Changing worldwide conditions may merit comprehensive re-evaluation of our public health preparedness and response to viral spread, he suggests.
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HealthCity sat down with Davidson Hamer, MD, an infectious disease specialist and expert in travel and tropical medicine at Boston Medical Center and Boston University School of Medicine, to talk about the coronavirus (COVID-19). As COVID-19 has quickly evolved into a global pandemic, and has particularly impacted the United States, Hamer has become an authoritative voice on the virus and its implications for communities locally and abroad.

He offers his insights into the global impact of the virus and how we need to think more comprehensively to prevent future pandemics in conditions that are increasingly conducive to viral spread.

HealthCity: How would you compare this pandemic to others we’ve seen in the past?

Davidson Hamer, MD: The most recent real pandemic was H1N1 in 2009. Experts estimated about 200 million people were infected. The difference with H1N1 is it was influenza — we already had some effective antiviral drugs we could use, and we had vaccines we could use, scale up quickly, and tailor to that stream of the virus. So we were better off, so to speak, because we already had tools in place both for treatment and prevention. With COVID-19, we are starting almost at ground zero.

"With COVID-19, we are starting almost at ground zero."

Going back in time, we've had other bad flu pandemics. In particular, 1918 was a pandemic with many important lessons learned. A lot of people died of bacterial pneumonia, so not having antibiotics at the time was part of the problem, but some of the lessons we learned were that intensive social isolation measures (or what are sometimes called non-pharmacologic interventions) controlled the spread of the influenza virus. There have been some really interesting retrospective analyses of this concept showing that if you start out with non-pharmacologic interventions early enough in an outbreak, you can truly flatten the curve.

HC: What are the worldwide implications of a pandemic like COVID-19?

DH: At this point, we don’t know if every single country in the world has been impacted by COVID-19, but a good majority of them have been. What really worries me as a global health researcher is what's happening in low- and middle-income countries. If we're running out of personal protective equipment (PPE) here, imagine what's going to happen in countries like Bangladesh as this takes off.

HC: How has limited testing influenced our understanding of the virus’s impact?

DH: Certainly the countries that have done best are those that test everybody and then try their best to isolate anyone who's infected to prevent continued transmission. We have not done this very well in the U.S. I'm worried about the approach we've taken — telling people with mild symptoms that they don’t really need to be tested and to just stay at home and tough it out. There's a risk for that person to infect their family members and anybody who they have contact with.

Another strategy that the U.S. has not really started, at least not on a widespread basis, is contact tracing — when you identify and test people who had contact with the infected person over the last 14 days. The problem is, people who have mild symptoms or no symptoms yet would probably be advised to not have the test because they’re in limited supply. Massachusetts Department of Public Health has mentioned they're going to start doing contact tracing, but there are so many other issues they're trying to address concurrently.

HC: What do we need to consider when trying to prevent this from happening again? What risk factors are we up against?

DH: It’s going to require a lot of investigation, but basically, humans having unusual dietary habits can lead to exposure to unknown viruses. And because COVID-19 is capable of human-to-human transmission, it led to a very rapid spread. The risk becomes greater for many other reasons, too. One being that the population of the planet is increasing and therefore, more urban areas are developing, especially urban slums. The demographics of our planet are changing, with a greater number of people living longer, so there are more people who have weaker immune systems and are more susceptible. We also have to consider deforestation and climate change — both can lead to increased interaction between humans and unknown environments.

HC: As these factors continue to change and increase risk, what are you most concerned about?

DH: The two biggest areas that concern me are respiratory viruses like COVID-19 — which can easily spread person-to-person and lead to widespread outbreak — and vector-borne diseases — those carried by mosquitoes and other insects. With global climate change, we're going to be seeing larger-scale outbreaks. Look at the West Nile virus or Zika virus. West Nile was only introduced in the United States in 1999 and then spread rapidly across the country, and Zika appeared in a big way just a couple of years ago. Before then, they were unheard of. We may be facing more of these and other novel emerging pathogens in the future.

"With global climate change, we're going to be seeing larger-scale outbreaks. We may be facing more of these and other novel emerging pathogens in the future." Click To Tweet

HC: What do you hope people take away when we’re past the worst of this?

DH: I hope people begin to better understand how readily transmissible respiratory viruses can be and ultimately implement strategies to reduce individual risk as well as the risk to our overall public health. As a country, we need to better prepare, making sure we can meet the demand on personal protective equipment and have adequate testing. We really fell short on the testing side, which has led to delays in being able to identify infected patients and isolate and quarantine them. We're catching up now, but we're catching up late. And that has an impact on everyone.

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