Over the past several months, coronavirus disease 2019, known as COVID-19, has emerged onto the world stage and quickly shifted from a distant public health threat to something that affects day to day life in countries around the world.

As I’ve watched events unfold, I can’t help but be transported back to the beginning of my career in infectious disease epidemiology, when I was working on my doctorate studies in the Andean mountains of Peru. I chose to study cutaneous leishmaniasis, a parasitic zoonotic infection that is transmitted to humans by sand flies via wild and domestic mammal reservoirs. I quickly began to realize that diseases such as leishmaniasis have more than just a disease or public health dimension. Villagers from the study site I was working in would regularly go from the mountains to the Amazon forest in order to pursue economic activities. There, they would contract not only leishmaniasis, but also malaria, yellow fever, or dengue. Upon their return to the mountains, health workers wondered why they were seeing cases of a type of leishmaniasis more commonly seen in the Amazon as well as diseases such as yellow fever, given that they were not typically prevalent there. In some instances, if the vector was present, local transmission cycles would get established, creating an additional public health challenge for the local health system due to health care workers’ unfamiliarity with some of these new diseases.

RTI scientist Richard Reithinger, shown in a photo from his time in graduate school, examines an animal in Peru.

Richard Reithinger, Vice President for Global Health at RTI, pictured left, went to Peru during his doctoral studies to study cutaneous leishmaniasis, a parasitic zoonotic infection that can be transmitted to humans via dogs and other infected mammals.

We have seen through history, when infections have emerged such as avian influenza, Zika, and Ebola to name a few, the ability of countries to respond and contain these new public health threats has depended on the strength of their health systems and their governments’ preparedness to face these threats. But my experiences in Peru opened my eyes to the fact that while we study a specific disease, there are so many other factors involved in the system of a disease’s epidemiology, such as socioeconomics, human behavior, or population mobility. For example, population density and mobility as well as the ability of urban populations to adopt and enact preventive behaviors and measures have played a large role in the spread of COVID-19 since it first emerged in China at the end of 2019.

RTI scientist Richard Reithinger, shown in a photo from his time in graduate school in Peru.

Studying in Peru taught RTI scientist Richard Reithinger about the many factors involved in the system of a disease’s epidemiology, including socioeconomics, human behavior, and population mobility.

The rapid global spread of COVID-19 underscores the importance of not only continuing to invest in health systems strengthening and public health emergency preparedness and response, but it brings to light other key elements that must be considered in response to this and future emerging pandemic threats. Below I highlight a few that I believe are critical for an effective, adaptive, and timely response to the COVID-19 pandemic.

Yes, strong health systems are the foundation of a strong response, but ripple effects across the health system need to be considered.

We can and should focus on COVID-19, but it’s likely that it will have ripple effects for other diseases and conditions. For example, in Guinea, Liberia and Sierra Leone, there were fears that the Ebola epidemic would cause thousands of excess deaths from malaria because services would be interrupted and people with malaria would not receive adequate treatment. However, those fears were not realized as community health worker platforms continued to engage with communities, adapting case management approaches to the new programmatic context, treating cases, and continuing to provide seasonal malaria chemoprevention. The ability to respond to COVID-19 and continue to provide essential services to address other diseases and conditions will be a direct result of countries’ investment into the core building blocks of health systems, namely service delivery; health workforce; health information systems; access to essential medicines as well as health-related equipment and materials; financing; and governance. This investment should consider how the system would respond and continue to operate in the event of an emergency. Some examples include ensuring that health workers are adequately trained on infection prevention and control measures, putting plans in place for mobilizing additional health workers, and having enough stockpiles of essential medicines, equipment, and materials that can be dispatched strategically to areas most in need.

Equitable and non-fragmented health systems may be better positioned to tackle COVID-19.

A health system’s ability to prepare and respond is also linked to how equitable and fragmented it is. Thus, here in the U.S., large proportions of the population will have difficulty accessing health services because they are uninsured or live in areas where health services are not readily available. The cost of services—especially if uninsured—could also mean that people may not want to access services if not critically ill. Additionally, coordinating a system like the U.S.’s which is fragmented on a number of levels, including with regards to different service providers (public, academic, and private); the type of services provided (clinical care and laboratory services); and different insurance coverage that people may or may not have (public versus private insurance, and basic versus premium coverage) will be more difficult compared to a non-fragmented system that provides universal health care to the entire population. Such fragmentation challenges the availability of inter-operable data systems and platforms, which are crucial for disease surveillance and outbreak detection and response.

Strong leadership beyond the health sector is crucial, from all levels of government to the economic sector.

As demonstrated previously with avian influenza, SARS, or Ebola, and again with COVID-19, public health emergencies require leaders across all sectors to have a coordinated, collaborative, and transparent emergency response, as a failure to do so can result in an ineffective response and confusion for the general public. This is complimented by a government’s and by extension the population’s trust in public institutions, science, and expertise. The media—often referred to as an informal branch of a government and necessary to inform the populace in a healthy functioning democracy—as well as other influential institutions like religion are essential in strengthening trust and can also seriously undermine it. Thus, the Liberian response to Ebola in 2014–2015 is often heralded as exemplary. The president at the time, Ellen Johnson Sirleaf, declared a national emergency, mobilized national and international resources, and ensured that Liberian government leaders were overseeing and coordinating the multitude of national and international stakeholders in the response. Communication was consistent and evidence based. Such characteristics also seem to have played an important role in South Korea, Taiwan and New Zealand, all countries which arguably have—to date—responded well to COVID-19.

Sectors outside of health have a critical supporting role to play in emergency preparedness and response.

Wildlife conservation and counter wildlife trafficking can help limit exposure to wildlife infectious agents and thus spillover of these agents to the human population. Similarly, food safety and regulation of meat processing, preparation and consumption—whether in public markets, food stalls and restaurants, or at home—will also mitigate and contain spillover events and agent spread. The entertainment and tourism industries attract large and mobile crowds contained in small and dense physical spaces, whether in a concert hall, at a sports event, or on a cruise ship, and thus need to be rapidly included in public health response efforts to contain the amplification and spread of any outbreak.

Finally, we need to rethink how we rank countries on their ability to prepare and respond to public health emergencies.

In the early phase of COVID-19, much emphasis was placed on various indices—such as the National Health Security Preparedness Index, the Global Health Security Index, and the Infectious Disease Vulnerability Index—which weigh a variety of factors in order to calculate rankings for countries based on their ability to withstand a public health emergency like COVID-19. While very comprehensive, these indices do not include factors such as leadership and trust in public institutions, health system equity and fragmentation, or the presence of a comprehensive social safety net. As a result, many of the countries that we see responding well to the COVID-19 pandemic, including Taiwan and South Korea, were ranked lower than countries that are currently major hotspots such as Italy, the U.K., and the U.S. Having infectious disease indices that reflect these additional factors will help the global community better understand how to prepare for these threats in the future as well as identify more accurately which countries may need additional support.