The next pandemic is already happening – targeted disease surveillance can help prevent it

Sustained surveillance for disease outbreaks at global hot spots may be the key to preventing the next pandemic. MR.Cole_Photographer/Getty Images

by Maureen Miller (Columbia University)

As more and more people around the world are getting vaccinated, one can almost hear the collective sigh of relief. But the next pandemic threat is likely already making its way through the population right now.

My research as an infectious disease epidemiologist has found that there is a simple strategy to mitigate emerging outbreaks: proactive, real-time surveillance in settings where animal-to-human disease spillover is most likely to occur.

In other words, don’t wait for sick people to show up at a hospital. Instead, monitor populations where disease spillover actually happens.

The current pandemic prevention strategy

Global health professionals have long known that pandemics fueled by zoonotic disease spillover, or animal-to-human disease transmission, were a problem. In 1947, the World Health Organization established a global network of hospitals to detect pandemic threats through a process called syndromic surveillance. The process relies on standardized symptom checklists to look for signals of emerging or reemerging diseases of pandemic potential among patient populations with symptoms that can’t be easily diagnosed.

This clinical strategy relies both on infected individuals coming to sentinel hospitals and medical authorities who are influential and persistent enough to raise the alarm.

Sentinel surveillance recruits select health institutions and groups to monitor potential disease outbreaks.

There’s only one hitch: By the time someone sick shows up at a hospital, an outbreak has already occurred. In the case of SARS-CoV-2, the virus that causes COVID-19, it was likely widespread long before it was detected. This time, the clinical strategy alone failed us.

Zoonotic disease spillover is not one and done

A more proactive approach is currently gaining prominence in the world of pandemic prevention: viral evolutionary theory. This theory suggests that animal viruses become dangerous human viruses incrementally over time through frequent zoonotic spillover.

It’s not a one-time deal: An “intermediary” animal such as a civet cat, pangolin or pig may be required to mutate the virus so it can make initial jumps to people. But the final host that allows a variant to become fully adapted to humans may be humans themselves.

Viral evolutionary theory is playing out in real time with the rapid development of COVID-19 variants. In fact, an international team of scientists have proposed that undetected human-to-human transmission after an animal-to-human jump is the likely origin of SARS-CoV-2.

Viruses jump species through a process of random mutations that allow them to successfully infect their hosts.

When novel zoonotic viral disease outbreaks like Ebola first came to the world’s attention in the 1970s, research on the extent of disease transmission relied on antibody assays, blood tests to identify people who have already been infected. Antibody surveillance, also called serosurveys, test blood samples from target populations to identify how many people have been infected. Serosurveys help determine whether diseases like Ebola are circulating undetected.

Turns out they were: Ebola antibodies were found in more than 5% of people tested in Liberia in 1982, decades before the West African epidemic in 2014. These results support viral evolutionary theory: It takes time – sometimes a lot of time – to make an animal virus dangerous and transmissible between humans.

What this also means is that scientists have a chance to intervene.

Measuring zoonotic disease spillover

One way to take advantage of the lead time for animal viruses to fully adapt to humans is long-term, repeated surveillance. Setting up a pandemic threats warning system with this strategy in mind could help detect pre-pandemic viruses before they become harmful to humans. And the best place to start is directly at the source.

My team worked with virologist Shi Zhengli of the Wuhan Institute of Virology to develop a human antibody assay to test for a very distant cousin of SARS-CoV-2 found in bats. We established proof of zoonotic spillover in a small 2015 serosurvey in Yunnan, China: 3% of study participants living near bats carrying this SARS-like coronavirus tested antibody positive. But there was one unexpected result: None of the previously infected study participants reported any harmful health effects. Earlier spillovers of SARS coronaviruses – like the first SARS epidemic in 2003 and Middle Eastern Respiratory Syndrome (MERS) in 2012 – had caused high levels of illness and death. This one did no such thing.

Researchers conducted a larger study in Southern China between 2015 and 2017. It’s a region home to bats known to carry SARS-like coronaviruses, including the one that caused the original 2003 SARS pandemic and the one most closely related to SARS-CoV-2.

Fewer than 1% of participants in this study tested antibody positive, meaning they had been previously infected with the SARS-like coronavirus. Again, none of them reported negative health effects. But syndromic surveillance – the same strategy used by sentinel hospitals – revealed something even more unexpected: An additional 5% of community participants reported symptoms consistent with SARS in the past year.

This study did more than just provide the biological evidence needed to establish proof of concept to measure zoonotic spillover. The pandemic threats warning system also picked up a signal for a SARS-like infection that couldn’t yet be detected through blood tests. It may even have detected early variants of SARS-CoV-2.

Had surveillance protocols been in place, these results would have triggered a search for community members who may have been part of an undetected outbreak. But without an established plan, the signal was missed.

From prediction to surveillance to genetic sequencing

The lion’s share of pandemic prevention funding and effort over the past two decades has focused on discovering wildlife pathogens, and predicting pandemics before animal viruses can infect humans. But this approach has not predicted any major zoonotic disease outbreaks – including H1N1 influenza in 2009, MERS in 2012, the West African Ebola epidemic in 2014 or the current COVID-19 pandemic.

Gregory Gray and his team at Duke University recently discovered a novel canine coronavirus at a global “hot spot” through surveillance and genetic sequencing

Predictive modeling has, however, provided robust heat maps of the global “hot spots” where zoonotic spillover is most likely to occur.

Long-term, regular surveillance at these “hot spots” could detect spillover signals, as well as any changes that occur over time. These could include an uptick in antibody-positive individuals, increased levels of illness and demographic changes among infected people. As with any proactive disease surveillance, if a signal is detected, an outbreak investigation would follow. People identified with symptoms that can’t be easily diagnosed can then be screened using genetic sequencing to characterize and identify new viruses.

This is exactly what Greg Gray and his team from Duke University did in their search for undiscovered coronaviruses in rural Sarawak, Malaysia, a known “hot spot” for zoonotic spillover. Eight of 301 specimens collected from pneumonia patients hospitalized in 2017-2018 were found to have a canine coronavirus never before seen in humans. Complete viral genome sequencing not only suggested that it had recently jumped from an animal host – it also harbored the same mutation that made both SARS and SARS-CoV-2 so deadly.

Let’s not miss the next pandemic warning signal

The good news is that surveillance infrastructure in global “hot spots” already exists. The Connecting Organisations for Regional Disease Surveillance program links six regional disease surveillance networks in 28 countries. They pioneered “participant surveillance,” partnering with communities at high risk for both initial zoonotic spillover and the gravest health outcomes to contribute to prevention efforts.

For example, Cambodia, a country at risk of pandemic avian influenza spillover, established a free national hotline for community members to report animal illnesses directly to the Ministry of Health in real time. Boots-on-the-ground approaches like these are key to a timely and coordinated public health response to stop outbreaks before they become pandemics.

It is easy to miss warning signals when global and local priorities are tentative. The same mistake need not happen again.

Maureen Miller, Adjunct Associate Professor of Epidemiology, Columbia University

This article is republished from The Conversation under a Creative Commons license. Read the original article.


I-Pollinate is a research initiative designed to collect state-wide pollinator data for studies at the University of Illinois Urbana-Champaign. Citizen scientists participate by collecting data on monarch egg and caterpillar abundance, pollinator visitation to ornamental flowers, and state bee demographics.

Tackling the impacts of pesticides on human, animal and environmental health

Read the full story at Open Access Government.

Jane Mills, University of Gloucestershire, tells us about the SPRINT project’s aim to tackle the impacts of pesticides on human, animal and environmental health.

When conservation work pays off: After 20 years, the Saker Falcon breeds again in Bulgaria

Read the full story from Pensoft Publishers.

Considered extinct as a breeding species in the early 2000s, the Saker Falcon was recovered when the first active nest from the new history of the species in Bulgaria was discovered in 2018, built by two birds that were reintroduced back in 2015.

CO2 and temperature challenge photosynthesis

Read the full story at Western Producer.

Heat may impair the enzymes that drive photosynthesis, hindering plants’ abilities to regulate carbon uptake and water loss

Enough solar and wind to clean the U.S. power grid… available yesterday

Read the full story at pv magazine.

Data show that the U.S. has more than 750 GWac of electricity generation capacity in interconnection queues, with 90% of that clean energy-related. But how much actually will be built?

USGS releases nationwide marsh vulnerability maps

Prime Hook National Wildlife Refuge (Delaware) UVVR
Prime Hook National Wildlife Refuge (Delaware) UVVR

U.S. Geological Survey scientists have developed and made available a new mapping resource that can identify the most vulnerable marshes across the contiguous U.S. through a combination of remote-sensing and satellite technologies. These maps provide critical information to land managers and help inform marsh conservation and restoration strategies without costly site-specific or labor-intensive assessments.

The USGS has shown that marsh resilience can be evaluated by calculating the ratio of unvegetated area to vegetated area across an entire marsh system, covering marsh plains, channels, ponds and intertidal flats. The method, termed the UnVegetated-Vegetated marsh Ratio or UVVR. UVVR, uses data collected from 2014-2018 through remote sensing techniques, such as satellite imagery and aerial photography, to gauge how much of an individual marsh is open water and how much marsh plants cover it. By comparing the ratio of ponds, channels and tidal flats to marsh vegetation, land managers can determine which marshes stand the best chance of persisting in the face of changing conditions. 

“The UVVR is a great metric for quickly identifying marshes that may have crossed a stability threshold. When combined with on-the-ground knowledge of an area, it will help managers objectively prioritize restoration.”  

Neil GanjO, OCEANOGRAPHER, USGS Woods Hole Coastal and Marine Science Center

Salt marshes are among the most productive and valuable ecosystems in the world. The vegetation in these coastal systems acts as a natural buffer between land and sea, protecting coastline infrastructures under various conditions. Salt marshes also provide essential food, refuge and nursery habitat for commercially and recreationally important species, among other benefits. To continue providing these numerous services, salt marshes need to persist and expand to counteract the effects of sea-level rise and storms that physically erode them.  

In the future, the USGS plans to regularly update UVVR assessments using aerial imagery, Landsat and newer satellites to support marsh restoration efforts by the U.S. National Park Service, U.S. Fish and Wildlife Service and coastal state agencies.   

The new data products complement detailed mapping by the USFWS’s National Wetland Inventory program by enabling comparison of vulnerability between wetland types differentiated by the NWI. The national map of UVVR can also be combined with the Coastal National Elevation Database to generate national estimates of marsh lifespan under varying sea-level rise scenarios.  

The UVVR data can be accessed through the USGS Coastal Change Hazards Portal under the Sea Level Rise theme (salt marsh vulnerability) and includes regional and national assessments. The nationwide UVVR data is also available to download in Science Base.  


Boom in ships that fly ‘fake’ flags and trash the environment

Read the full story in Nature.

The number of ships using a ‘flag of convenience’ loophole that allows them to be scrapped in a place with lax environmental regulations is skyrocketing.

Net Zero by 2050: A Roadmap for the Global Energy Sector

Download the document.

The number of countries announcing pledges to achieve net-zero emissions over the coming decades continues to grow. But the pledges by governments to date – even if fully achieved – fall well short of what is required to bring global energy-related carbon dioxide emissions to net zero by 2050 and give the world an even chance of limiting the global temperature rise to 1.5 °C.

This special report is the world’s first comprehensive study of how to transition to a net zero energy system by 2050 while ensuring stable and affordable energy supplies, providing universal energy access, and enabling robust economic growth. It sets out a cost-effective and economically productive pathway, resulting in a clean, dynamic and resilient energy economy dominated by renewables like solar and wind instead of fossil fuels. The report also examines key uncertainties, such as the roles of bioenergy, carbon capture and behavioral changes in reaching net zero.

Overcrowded US national parks need a reservation system

Traffic at the south entrance to Yellowstone National Park on Aug. 20, 2015. Neal Herbert, NPS/Flickr

by Michael Childers (Colorado State University)

If you’re headed out into the wild this summer, you may need to jump online and book a reservation before you go. For the second consecutive year, reservations are required to visit Yosemite, Rocky Mountain and Glacier national parks. Other popular sites, including Maine’s Acadia National Park, encourage visitors to buy entrance passes in advance.

Limiting visitors has two purposes: reducing COVID-19 risks and allowing some parks to recover from recent wildfires. Rocky Mountain will allow 75% to 85% of capacity. Yosemite will again restrict the number of vehicles allowed in; last year, it hosted half of its average 4 million annual visitors.

Nationwide, some U.S. parks were emptier than normal during the pandemic, while Yellowstone and others were near capacity. But the pandemic likely was a temporary pause in a rising tide of visitors.

America’s national parks face a popularity crisis. From 2010 to 2019, the number of national park visitors spiked from 281 million to 327 million, largely driven by social media, advertising and increasing foreign tourism.

This exponential growth is generating pollution and putting wildlife at risk to a degree that threatens the future of the park system. And with Americans eager to get back out into the world, the summer of 2021 promises to be one of the busiest domestic travel seasons in recent history. Reservations and other policies to manage visitor numbers could become features at many of the most popular parks.

Crowding in the national parks has been rising for years and has spiked since 2010.

Protecting treasured lands

In my work, I’ve explored the history of national parks and the factors that drive people to seek experiences outdoors. I’ve also studied the impacts of national park visitation and ways to keep the public from loving national parks to death.

Much of that research has focused on California’s Yosemite National Park, which contains nearly 1,200 square miles of wilderness, including iconic granite rock formations, deep valleys, waterfalls and ancient giant sequoias.

Its creation dates to the Civil War. In 1864, with this landscape threatened by an influx of settlers and visitors, Abraham Lincoln signed the Yosemite Act, which ceded the region to California for “public use, resort, and recreation.” This step set a precedent that parks were for everyone’s benefit and enjoyment. Congress made Yosemite a national park in 1890.

Roosevelt on horseback looking elated.
President Theodore Roosevelt arriving at Yellowstone National Park in 1903. Library of Congress, CC BY-ND

Influenced by naturalist John Muir, President Theodore Roosevelt established five new parks in the early 1900s, along with 16 national monuments that included the Grand Canyon. Roosevelt wanted to protect these natural treasures from hunting, mining, logging and other exploitation.

To coordinate management, Congress established the National Park Service and the National Park System in 1916. The National Park Service Organic Act directs the agency to protect the parks’ wildlife and natural and cultural heritage “in such manner and by such means as will leave them unimpaired for the enjoyment of future generations” – a mission that is becoming increasingly difficult today.

Loving the parks to death

Americans fell in love with their parks – and several waves of overpopularity nearly destroyed the very experiences that drew people there.

The advent of automobile tourism in the 1920s opened national parks to hundreds of thousands of new visitors, who overwhelmed limited, aging roads, trails, restrooms, water treatment systems and visitor facilities. Ironically, relief came during the Great Depression. The New Deal funded massive construction projects in the parks, including campground comfort stations, museums and other structures. Hundreds of miles of roads and trails opened wild backcountry.

Crowds at a ceremony with mountains in the background.
Dedication of Going-to-the-Sun Road in Glacier National Park, Montana, on July 15, 1933. George A. Grant, NPS/Flickr

Between 1929 and 1941, the number of annual park visitors grew from 3 million to 20 million. This increasing torrent slowed only when the U.S. entered World War II.

In the postwar boom, people returned en masse. The National Park Service launched “Mission 66,” another flurry of construction that again expanded capacity.

Conservationists and others condemned the development, alarmed by its environmental impacts and the threat of overcrowding. By the mid-1960s, total yearly park visitation exceeded 100 million.

Riding the tourism wave

Today the national park system has grown to comprise 63 national parks, with ever more visitors, plus 360 sites with other designations, such as national seashores, monuments and battlefields. Some of these other sites, such as Cape Cod National Seashore in Massachusetts and Gettysburg National Military Park in Pennsylvania, also attract millions of visitors yearly.

In 2019, a record-setting 327 million people visited the national parks, with the heaviest impacts on parks located near cities, like Rocky Mountain National Park outside Denver. This crowding spotlighted problems that park officials had been raising concerns about for years: The parks are underfunded, overrun, overbuilt and threatened by air and water pollution in violation of the laws and executive orders that protected them.

Park horror stories have grown common in recent years. They include miles-long traffic jams in Yellowstone, three-hour waits to enter Yosemite, trails littered with trash and confrontations between tourists and wildlife.

In 2020, Congress passed the Great American Outdoors Act, which will provide up to US$1.9 billion a year for five years to address the park system’s nearly $12 billion maintenance backlog. This long list of postponed projects reflects Congress’ reluctance to adequately fund the national park system over many years.

But as the New Deal and Mission 66 demonstrated, increased infrastructure spending often boosts visitation. The Great American Outdoors Act doesn’t cover conservation efforts or significant personnel needs, which will require increased federal funding. Many repairs are needed throughout the parks, but the system’s future sustainability relies more on staffing than infrastructure.

Cruise ship, crowds lining the railings.
A cruise ship approaches Margerie Glacier in Alaska’s Glacier Bay National Park in 2018. NPS/Flickr

And neither more money nor additional park rangers will solve the overcrowding crisis. I believe the most popular national parks need a reservation system to save these protected lands from further damage.

This won’t be a popular solution, since it contradicts the founding premise that national parks were built for public benefit and enjoyment. Critics have already created a petition opposing Rocky Mountain National Park’s timed entry permits as unnecessary, unfair, undemocratic and discriminatory.

But the parks’ unrelenting popularity is making it impossible to preserve them “unimpaired.” In my view, crowd control has become essential in the most popular parks.

While there is only one Yosemite Valley, the national park system offers many less crowded destinations. Sites such as Hovenweep National Monument in Colorado and Utah and the Brown v. Board of Education National Historic Site in Kansas deserve attention for their natural beauty and the depth they add to Americans’ shared heritage.

Michael Childers, Assistant Professor of History, Colorado State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.