Monkeypox. Polio. Covid. A quick glance at the news on any given day seems to indicate that outbreaks, epidemics, and perhaps even pandemics are increasing in frequency.
Granted, these types of events are hardly new; from the plagues of the 5th and 13th centuries to the Spanish flu in the 20th century and SARS-CoV-2 today, they’ve been with us from time immemorial.
What appears to be different, however, is not their frequency, but their intensity, with research reinforcing that we may be facing unique challenges and smaller windows to intervene as we move forward.
Findings from a modeling study published in 2021 in Proceedings of the National Academy of Sciences underscore that without effective intervention the probability of extreme events like COVID-19 will likely increase threefold in the coming decades.
Dr Amesh Adalja
“The fact is, pandemic preparedness is not something that people have valued or thought of as important, or paid much attention to,” Amesh Adalja MD, senior scholar, Johns Hopkins Center for Health Security, Baltimore, Maryland, told Medscape Medical News.
“It’s all been based on some unusual cluster of cases that were causing severe disease and overwhelming local authorities. So often, like Indiana Jones, somebody got dispatched to deal with an outbreak,” Adalja said.
In a perfect post-COVID world, government bodies, scientists, clinicians, and others would cross silos to coordinate pandemic prevention, not just preparedness. The public would trust those who carry the title “public health” in their daily responsibilities, and in turn, public health experts would get back to their core responsibility — infectious disease preparedness — the role they were initially assigned following Europe’s Black Death during the 14th century. Instead, the world finds itself at a crossroads, with emerging and reemerging infectious disease outbreaks that on the surface appear to arise haphazardly but in reality are the result of decades of reaction and containment policies aimed at putting out fires, not addressing their cause.
Adalja noted that only when the threat of biological weapons became a reality in the mid-2000s was there a realization that economies of scale could be exploited by merging interests and efforts to develop health security medical countermeasures. For example, it encouraged governments to more closely integrate agencies like the Biomedical Advanced Research and Development Authority and infectious disease research organizations and individuals.
Still, while significant strides have been made in certain areas, the ongoing COVID-19 pandemic has revealed substantial weaknesses remaining in public and private health systems, as well as major gaps in infectious disease preparedness.
The Role of Spillover Events
No matter whom you ask, scientists, public health and conservation experts, and infectious disease clinicians all point to one of the most important threats to human health. As Walt Kelly’s Pogo famously put it, “We have met the enemy and he is us.”
Dr Neil M. Vora
“The reason why these outbreaks of novel infectious diseases are increasingly occurring is because of human-driven environmental change, particularly land use, unsafe practices when raising farmed animals, and commercial wildlife markets,” Neil M. Vora, MD, a physician specializing in pandemic prevention at Conservation International and a former Centers for Disease Control and Prevention epidemic intelligence officer, told Medscape Medical News.
In fact, more than 60% of emerging infections and diseases are due to these “spillover events” (zoonotic spillover) that occur when pathogens that commonly circulate in wildlife jump over to new, human hosts.
Several examples come to mind.
COVID-19 may have begun as an enzootic virus from two undetermined animals, using the Huanan Seafood Market as a possible intermediate reservoir, according to a July 16 preprint in the journal Science.
Likewise, while the Ebola virus was originally attributed to deforestation efforts to create palm oil (which allowed fruit bat carriers to transfer the virus to humans), recent research suggests that bats dwelling in the walls of human dwellings and hospitals are responsible for the 2018 outbreak in the Democratic Republic of Congo.
(Incidentally, just this week, a new Ebola case was confirmed in Eastern Congo, and it has been genetically linked to the previous outbreak, despite that outbreak having been declared over in early July.)
“When we clear forests, we create opportunities for humans to live alongside the forest edge and displace wildlife. There’s evidence that shows when [these] biodiverse areas are cleared, specialist species that evolved to live in the forests first start to disappear, whereas generalist species — rodents and bats — continue to survive and are able to carry pathogens that can be passed on to humans,” Vora explained.
So far, China’s outbreak of the novel Langya henipavirus is believed to have spread (either directly or indirectly) by rodents and shrews, according to reports from public health authorities like the European Centre for Disease Prevention and Control, which is currently monitoring the situation.
Yet, an overreliance on surveillance and containment only perpetuates what Vora says are cycles of panic and neglect.
“We saw it with Ebola in 2015, in 2016 to 2017 with Zika, you see it with tuberculosis, with sexually transmitted infections, and with COVID. You have policymakers working on solutions and once they think that they’ve fixed the problem, they’re going to move on to the next crisis.”
It’s also a question of equity.
Reports detailing the reemergence of monkeypox in Nigeria in 2017 were largely ignored, despite the fact that the United States assisted in diagnosing an early case in an 11-year-old boy. At the time, it was clear that the virus was spreading by human-to-human transmission vs animal-to-human transmission, something that had not been seen previously.
“The current model of waiting for pathogens to spill over and then continue to spread signals that rich countries are tolerant of these outbreaks so long as they don’t grow into epidemics or pandemics,” Vora said.
This model is clearly broken; roughly 5 years after Nigeria reported the resurgence of monkeypox, the United States has more than 14,000 confirmed cases, which represents more than a quarter of the total number of cases reported worldwide.
Public Health on the Brink
I’s difficult to imagine a future without outbreaks and more pandemics, and if experts are to be believed, we are ill-prepared.
“I think that we are in a situation where this is a major threat and people have become complacent about it,” said Adalja, who noted that we should be asking ourselves if the “government is actually in a position to be able to respond in a way that we need them to or is [that response] tied up in bureaucracy and inefficiency?”
COVID-19 should have been seen as a wake-up call, and many of those deaths were preventable. “With monkeypox, they’re faltering; it should have been a layup, not a disaster,” he emphasized.
Dr Ellen Eaton
Ellen Eaton MD, associate professor of infectious diseases at the University of Alabama at Birmingham, also pointed to the reality that by the time COVID-19 reached North America the United States had already moved away from the model of the public health department as the epicenter of knowledge, education, awareness, and, ironically, public health.
“Thinking about my community, very few people knew the face and name of our local and state health officers,” she told Medscape Medical News.
“There was just this inherent mistrust of these people. If you add in a lot of talking heads, a lot of politicians and messaging from non-experts that countered what was coming out of our public health agencies early, you had this huge disconnect; in the South, it was the perfect storm for vaccine hesitancy.”
At last count, this perfect storm has led to 1.46 million COVID cases and just over 20,000 deaths — many of which were preventable — in Alabama alone.
“In certain parts of America, we were starting with a broken system with limited resources and few providers,” Eaton explained.
Eaton said that a lot of fields, not just medicine and public health, have finite resources that have been stretched to capacity by COVID, and now monkeypox, and wondered what was next as we’re headed into autumn and influenza season. But she also mentioned the tremendous implications of climate change on infectious diseases and community health and wellness.
“There’s a tremendous need to have the ability to survey not just humans but also how the disease burden in our environment that is fluctuating with climate change is going to impact communities in really important ways,” Eaton said.
Upstream Prevention
Vora said he could not agree more and believes that upstream prevention holds the key.
“We have to make sure while there’s tension on this issue that the right solutions are implemented,” he said.
In coming years, postspillover containment strategies — vaccine research and development and strengthening healthcare surveillance, for example — are likely to become inadequate.
“We saw it with COVID and we are seeing it again with monkeypox,” Vora said. “We also have to invest further upstream to prevent spillovers in the first place, for example, by addressing deforestation, commercial wildlife markets and trade, [and] infection control when raising farm animals.”
“The thing is, when you invest in those upstream solutions, you are also mitigating climate change and loss of biodiversity. I’m not saying that we should not invest in post-spillover containment efforts; we’re never going to contain every spillover. But we also have to invest in prevention,” he added.
In a piece published this past May in Nature , Vora and his coauthors acknowledge that several international bodies such as the World Health Organization and G7 have invested in initiatives to facilitate coordinated, global responses to climate change, pandemic preparedness, and response. But they point out that these efforts fail to “explicitly address the negative feedback cycle between environmental degradation, wildlife exploitation, and the emergence of pathogens.”
“Environmental conservation is no longer a left-wing fringe issue, it’s moving into public consciousness, and…it is public health” Vora said.
“When we destroy nature, we’re destroying our own ability to survive,”
Adalja, Vora, and Eaton report no relevant financial relationships.
Liz Scherer is an independent journalist specializing in infectious and emerging diseases, cannabinoid therapeutics, and women’s health.
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