NEW YORK – While a certain part of the population may doubt the existence of climate change, some experts point to the emergence of new diseases, and the appearance of existing ones in places they have not been in before, as a warning about the health consequences of a warming planet.
For diagnostic developers, that has meant new priorities and preparations as they try to cope with a shifting infectious disease landscape.
According to a 2022 report from the United Nations' Intergovernmental Panel on Climate Change, the incidence of vector-borne diseases is on the rise, resulting from an expanding geographic range and an increased reproduction of disease vectors. Meanwhile, animal and human diseases are emerging in new areas due to climate change. Climate-sensitive disease risks are expected to increase under all levels of warming without additional adaptation, the report said, and higher temperatures — in combination with changes in land use — are making more areas vulnerable to the transmission of vector-borne diseases.
Vector-borne disease transmission is also expected to expand to higher latitudes and altitudes, and the length of seasonal transmission risk is expected to increase.
The effects of climate change are varied: As weather patterns evolve and temperatures rise, there are possibilities for new infectious diseases, particularly zoonotic diseases, to emerge.
But there are also differences in the distribution of existing diseases, with some diseases expanding in scope and others contracting, said Daniel Bausch, senior adviser on global health security for FIND, and there is a risk that tropical diseases could spread to new areas. For example, in some places where it formerly has been too cold for mosquitoes to survive, they are now able to thrive, changing the usual distribution of mosquito-borne diseases such as malaria or dengue fever.
Just last week, the World Health Organization warned that the number of dengue cases globally could reach historic levels, resulting from the expanding geographic spread of mosquitoes because of global warming.
Previously, it was known where malaria diagnostics needed to be distributed, "but that's not necessarily going to be a given" anymore, Bausch said. One consequence of this is that diagnostic tools for these diseases may need to be more readily available across a broader geography, even though pipelines currently are "not necessarily set up" for those diagnostics in places where certain infectious diseases used to be uncommon, he said.
Ben Beard, the deputy division director of the US Centers for Disease Control and Prevention's Division of Vector-Borne Diseases, emphasized that climate change has caused the number of vector-borne diseases to rapidly increase as more people are exposed. There is a "clear and present danger for us," he said, adding as winters get milder, ticks and mosquitoes can survive farther north, and earlier springs and later frosts provide longer transmission seasons for other diseases, such as West Nile virus.
In addition, diseases that are rarer and for which good diagnostic tests may not be available could become more common, which would require additional research and development to create better diagnostic tests, Bausch noted. But as those diseases expand into new places, the diagnostics industry may not be prepared for a significant uptick in cases of a previously rare disease.
For now, climate change is just beginning to enter the consciousness of many diagnostic firms. Indeed, while some companies have taken tangible steps to address climate change, many are aware of the potential threat but do not have specific strategies in place to address global warming.
The problem, as Bausch sees it, is that the diagnostics ecosystem has "often been very entrenched" without much motivation to develop tests for diseases, such as Ebola, that affect small or less-affluent areas. Such areas could bear the brunt of new, emerging diseases due to climate change.
An outbreak could be "a tragedy for a small village somewhere, but not something where there's a lot of motivation for industry to get engaged," Bausch noted, although that mindset is changing. While test development can occur relatively quickly, as highlighted during the COVID-19 pandemic and the monkeypox epidemic, distribution of those assays is a different story. There's "not necessarily a pipeline to get [diagnostics] to all the places that need it," Bausch said.
Companies need a nimbler approach to manufacturing, a more distributed manufacturing base, and quick validation, he said. In particular, there is a need for broader manufacturing bases in Africa, where many tropical diseases are prevalent and where diagnostic testing infrastructure is not as widespread, so countries don't have to rely on tests coming through distribution channels that are continents away.
The economic market is largely what shapes manufacturing and distribution decisions, and the diagnostic industry needs to think creatively about economic factors to make distribution viable in such markets, Bausch said. One option he suggested is agreements from nongovernmental organizations to purchase a set number of diagnostic tests in advance to incentivize companies and ensure that the industry knows there is a fixed price for certain kinds of tests, making the R&D efforts to create those tests worth it because companies know they will be paid.
But a key question is whether there is commercial interest and incentive, Beard added, and a company must know how widespread a disease is and how many tests need to be produced.
For outbreak-prone diseases, the cost for developing diagnostics should be included in emergency funds provided by organizations like the World Health Organization and the CDC in the same way vaccine development costs are accounted for, according to Bausch.
The challenge, he said, is that even when there is money available for test development, no one is interested in producing tests that aren't needed, so it may take between six and eight months to make the necessary assays available in the correct locations. It's important to be able to "flip the switch back and forth more easily," but we're still not good at figuring out what's needed and when, said Bausch.
As an industry, diagnostics developers have been largely reactive, rather than proactive, when it comes to disease outbreaks. But a gradual change may be afoot. For example, earlier this year, Abbott announced that it had joined the Climate Amplified Disease and Epidemics consortium, a group of more than 100 scientists that uses data science technology and diagnostic testing to determine and mitigate the impact climate change has on disease outbreaks.
Through its work with CLIMADE, the company will collaborate with researchers and public health institutions to leverage information gathered on the ground and use climate data research to predict where conditions would be "ripe for an outbreak," said Gavin Cloherty, the company's head of infectious disease research for its diagnostics business. Abbott's role will be to provide resources, including diagnostic tests and sequencing data, to identify known pathogens and prepare for new outbreaks that crop up. As a founding member, the company is also looking for other partners with a variety of other skill sets to join the consortium, he said.
CLIMADE's first focus will be in Africa, but Cloherty emphasized that it intends to expand to other geographies, including South and Central America, as well as a variety of diseases such as influenza, vector-borne acute febrile illness, and hemorrhagic fevers, to ensure nothing is missed. "There's a cocktail of these pathogens that are going around the world all the time," he said. "We really have to keep our eye on all of them."
Although diagnostic testing is an essential component of CLIMADE, bioinformatics tools also play a major role, particularly when it comes to information garnered from sequencing. "With sequencing, you're creating all of this data, and if you don't have bioinformatic tools to process and analyze that, you're going to run into a dead end," Cloherty said.
Those tools can flag important information and can be rapidly scaled up in the case of an outbreak, and the consortium is making sure that what it develops can respond quickly if another pandemic occurs, he said. "Those early days and weeks are critically important; we don't want to lose them."
Abbott's participation in the group is "partially an evolution" of its Global Surveillance Program, which has been in place for 30 years, Cloherty said. That collaborative program began with HIV but has since broadened to "build the best solutions that are dealing with what we have today but also into the future."
The firm is also drawing on its Pandemic Defense Coalition, which started in 2021 and is headed by Cloherty, for this work. The goal of the PDC is to identify the causative agent of someone's illness and build tests to understand the nature of the discovery, he said. It asks whether the virus matters and then distributes that information through a global network of collaborators to understand the nature of what has been discovered.
Like Abbott, Siemens Healthineers is also including data as it attempts to address the potential impacts of climate change. In Siemens' view, "digitally connected healthcare data could pave the way for the next leap in preventative public health," said Ranga Sampath, the head of R&D strategy for the firm's Center for Innovation in Diagnostics. "By building intelligent monitoring systems that detect anomalies as they unfold, we can potentially identify the underlying problems and design and deploy appropriate interventions early enough to mitigate some of their worst effects."
Sampath noted that Siemens is partnering with biostatisticians at Harvard University to use artificial intelligence, machine learning, and other data analytics models to address some of the challenges of using diagnostic data for public health.
High-quality diagnostic data, he noted, is "subject to considerable regulation and lies mostly with companies and hospitals." Using that same data for public health monitoring "could maximize the utility of the data for the public good while at the same time protecting patient privacy." However, using that data "requires navigating a complex web of legal, commercial, intellectual, and ethical considerations."
Sampath also emphasized the importance of collaboration with other stakeholders outside of industry. "Building structures that incentivize collaboration among the public, private, and academic sectors could catalyze the development of the tools we need to keep future threats from snowballing from threat to disaster."
Another company taking a more proactive stand is Revvity subsidiary Euroimmun, which is investing in research and development to address climate change's impact on infectious diseases, Maite Sabalza, the firm's senior scientific affairs manager, and Stephanie Franco, the senior product manager for tuberculosis and infectious diseases, said via email. They noted that Euroimmun is the only provider of tests for the detection of antibodies against rare diseases Mayaro virus and Powassan virus, and that the firm also offers a test for latent tuberculosis.
"Despite the current low numbers of many vector-borne diseases and other diseases impacted by climate change, we recognize the potential need for these products and will proactively develop detection assays in the event that disease incidence increases," Sabalza and Franco said.
Further, the firm is working on expanding its test menu using dried-blood spot samples, which can help conduct seroprevalence studies to investigate increases in antibody concentrations against specific pathogens and detect new outbreaks.
Euroimmun prioritizes its diagnostics development efforts toward infectious diseases with a high prevalence or those with significant public health implications. It also collaborates with academic institutions, public health agencies, reference laboratories, and industry partners to focus its development efforts, Sabalza and Franco said. Its collaborations also grant the company access to "unique samples that may otherwise be hard to come by, which play a critical role in the validation and testing of new assays," they noted.
Some of its efforts are influenced by geographic considerations, they added. "For example, while working on developing a specific assay for a pathogen in an endemic region, our scientists and developers might identify an antigen associated with a different pathogen that is also endemic in that particular area. In such cases, we evaluate the need for diagnostics for the newly discovered pathogen, considering factors such as whether it is an emerging or re-emerging disease."
That evaluation is important because "emerging or re-emerging diseases often present new challenges that require the development of novel diagnostic tools to effectively address them," they said.
Sabalza and Franco also noted the importance of government regulatory agencies in developing and distributing tests for new diseases, which was particularly critical during the COVID-19 pandemic, emphasizing the need for industry and regulators to work together and proactively to, among other things, establish international standards and make samples available to manufacturers to develop and standardize assays. Such steps, they said, would prevent the spread of disease caused by climate change.
No one disputes the importance of the government in identifying, diagnosing, and managing disease, and planning for outbreaks. FIND's Bausch, however, said that even government power and reach has its limitations. For example, while stockpiling tests is an option, they have expiration dates and there is "always the risk it expires before you can actually use it." Countries have to be engaged, but other stakeholders like NGOs must also be involved — everyone has a "vested interest" in keeping outbreaks contained, he said.
Surveillance can be the first step to curtailing potential outbreaks, particularly for vector-borne diseases, according to Kristie Ebi, a professor of global health at the University of Washington. She noted that it can take time after a vector first appears for a specific disease to appear, which provides the opportunity to monitor for potential outbreaks, set up early warning systems, and have resources — including diagnostic tests — on hand.
For the CDC, expanding human and ecological surveillance is one of a few priorities for vector-borne diseases and climate change. The others are identifying and validating effective prevention and control measures that are tailored to specific communities; developing and maintaining the capacity to detect, diagnose, and respond to emerging disease threats and working with public health agencies to have tools to detect new pathogens; and conducting outreach to increase awareness of changing disease patterns due to climate change and other environmental factors, Beard said.
When it comes to surveillance, the agency is committed to collecting long-term data and building out its capacity to model and forecast where potential outbreaks could occur based on trends that have been seen, he said.
The agency is also looking at a range of diseases that could be introduced and determining what kinds of diagnostic tests would be needed, such as pathogen-agnostic tests with the capacity to detect something new, he said. Beyond the CDC, the US Department of Health and Human Services' Biomedical Advanced Research and Development Authority is working with multiple companies to develop next-generation sequencing-based tests to detect all known and unknown respiratory viruses.
Outside of work by government and research organizations, companies such as Roche also have invested in surveillance efforts. According to Michael Hombach, the disease area lead for infectious diseases at Roche Diagnostics, the company's epidemic response structure allows it to quickly react to epidemic outbreaks and develop solutions.
The program is coordinated through its vector-borne infections and epidemic preparedness areas, which prioritize and design tests that need to be developed, he said, adding Roche is setting up a modeling approach with external partners to explain the effect of deploying diagnostic tools on public health measures in various outbreak scenarios, which will help guide future product design.
Additionally, Roche has a working group that analyzes the impact of global warming on the spread of infectious diseases into new ecosystems and provides strategic recommendations that reflect unmet or increased diagnostic needs.
The firm has both prioritized and begun R&D programs related to climate change that include the discovery of new biomarkers and expanding its portfolio to include more comprehensive options for malaria, dengue, chikungunya, Zika, and Lyme disease. Hombach noted that the company sees a need to offer "holistic patient management solutions that may include host response biomarkers and digital solutions."
Roche considers a number of factors when deciding where to focus its efforts, Hombach noted, including unmet medical needs, geography, and prevalence and incidence of a disease. Also factored in are available infrastructure of healthcare systems, reimbursement structures, patient access to diagnostics, and customer needs of laboratories, physicians, and patients. Roche also has an interdisciplinary team that monitors and analyzes information about emerging infectious diseases and outbreaks. It uses a variety of criteria to determine the need for and guide the design of diagnostics, including mode of transmission, mortality, therapeutic options, animal reservoirs, and immunity, Hombach said.
Even if private industry isn't focusing on developing new tests for diseases that have yet to appear, the CDC's Beard noted, they play an essential role as disease patterns mutate amid climate changes. For uncommon diseases, the CDC takes the lead on developing tests, but for more common diseases, such as Lyme disease, commercial tests may already exist, allowing the center to focus on other efforts.
Stakeholders in the industry emphasize the importance of collaboration to prepare for the threat of climate change and the diseases it will impact. "No one group can do it on their own," Abbott's Cloherty said. "We have to find a way to connect all of these networks."
Diagnostic firms also point out the need to use past information and lessons learned from prior outbreaks to ensure any new ones caused by climate change can be handled quickly. "I really am passionate about us not reliving the same mistakes of the past and trying to get ahead of emerging outbreaks and emerging potential pandemics … and climate is a key area involved in that," Cloherty said. "We can't ignore the impacts that it is having on human movement, animal movement … we have to remain vigilant."