Are we in an “endemic” moment?
What the term really means.
One silver lining of 2020 for epidemiologists was a newfound public recognition of what we do, or even that we exist. No longer did we need to patiently explain — to friends, family, acquaintances, and strangers — that no, we aren’t skin doctors, and no, we aren’t medical doctors either, but more like population doctors. Epidemiologists, as everyone now knows, are concerned with disease distribution in the aggregate, rather than the presentation of disease in an individual patient (the purview of medical doctors). Along with improving lay knowledge of epidemiologic work, the pandemic has introduced a whole suite of specialized epidemiologic jargon into everyday parlance: incubation period, test positivity, false positive rate, and of course, “endemic.”
Endemicity is en vogue these days. Op-eds ranging in tone from hopeful to monomaniacal assure us that endemic COVID is right around the corner, or exhort us to behave as if it were already here. Before we evaluate these claims, let’s consider what “endemic” means. The words epidemic and endemic both derive from Greek. Epidemic combines demos (people) with the prefix epi- (upon). Endemic swaps the epi- prefix for en-, meaning (you guessed it) in. In the common senses of the words, an epidemic virus is one that is “upon” the population, causing massive outbreaks of the kind we’ve seen with COVID-19. An epidemic virus is often, like COVID-19, a novel virus, to which people in the affected area may have no immunological memory. An endemic virus, by contrast, is one known to be circulating at relatively low levels in a given area — not causing massive outbreaks, but sickening people at a steady or intermittent pace. These concepts are not meaningless for public health practice. A few cases of bubonic plague in Rhode Island would imply different public health actions than the same number of cases in Madagascar, where plague is endemic in parts of the country.
The timbre of op-eds hoping or pushing for “endemicity” is relentlessly positive. A world with endemic COVID is, for these commentators, going to be great. The comparisons chosen in service of this optimism certainly resonate; they tend to evoke other endemic diseases familiar to most Americans like the common cold and seasonal influenza. Though the flu comparisons are inaccurate for several reasons (seasonal and so-called “pandemic” flu are very different; and even so, seasonal influenza causes upwards of 50,000 deaths annually in the United States), a discussion of some other endemic diseases less familiar to American readers puts things into perspective. As we will see, endemicity doesn’t imply anything about reduced virulence, milder symptoms, or attenuated severity.
An epidemic virus is often, like COVID-19, a novel virus, to which people in the affected area may have no immunological memory. An endemic virus, by contrast, is one known to be circulating at relatively low levels in a given area — not causing massive outbreaks, but sickening people at a steady or intermittent pace.
Malaria, an ancient parasitic disease endemic to many regions of the world, was responsible for 241 million infections and nearly 630,000 deaths in 2020. Since malaria is always debilitating but seldom fatal, sometimes the burden of malaria is expressed in other ways. Disability-adjusted life years are a complicated and imperfect measure, but they are meant to quantify years of life affected by illness or disability. One study estimated that malaria is associated with 795 disability-adjusted life years per 100,000 population (by way of comparison, the same study estimated the disability-adjusted life years per 100,000 associated with measles as approximately 81). In fiscal year 2021, as in previous years, the United States earmarked almost $1 billion for malaria research, prevention, and control efforts. Of course, it’s not just malaria. Tuberculosis, rare in the US, is endemic in parts of Africa, Asia, and Europe. Tuberculosis killed 1.5 million people in 2020, making it the second leading infectious cause of death that year (after COVID-19). Tuberculosis is both preventable and treatable, but persists for a variety of complex reasons. One study estimated total health spending on tuberculosis just among low- and middle-income countries at approximately $11 billion in 2017. Another virus endemic almost everywhere, HIV, killed 680,000 people in 2020. Over 36 million people have died of HIV since the emergence of the virus in 1981 — more people than live in the entire state of Texas. Again, considerable research, government spending, and civil society efforts are devoted to mitigating the impacts of the virus. This is not a comprehensive overview of the global burden of infectious disease, but merely an illustration — the transition to endemicity does not mean a return to normal or freedom from the virus. Instead, it means redoubling planning efforts, greatly expanding public health infrastructure, and committing resources to mitigate, treat and cure disease in the long term.
Endemicity doesn’t imply anything about reduced virulence, milder symptoms, or attenuated severity.
Those who anticipate the arrival of endemic COVID and celebrate the carefree life to follow owe the public some clarity on this point. Endemic diseases are, by definition, diseases that continue to sicken and kill people at some level above zero. Endemic diseases also require constant mitigation, vigilance, and investment. However, while not even the most fervent cheerleader for endemic COVID would suggest immediately discontinuing the use of bed nets that repel malaria-carrying mosquitoes, or ceasing distribution of condoms to people at high risk of exposure to HIV, this kind of approach is exactly what they envision for our endemic COVID future. Removing your mask and choosing to live your life “in defiance” of the virus (as if nothing is going on) will not hasten the arrival of endemic COVID; it won’t affect the course of the pandemic at all (except, in some unfortunate cases, to accelerate it). Advocating for a wholesale abandonment of prevention and mitigation measures belies a deeply nihilist outlook on public health coupled with a baffling optimism of the will. An endemic future of low, manageable COVID case counts is not a preordained future. We don’t, and can’t, know that we are going to have low case counts in the future; we can’t anticipate anything about future variants except that gross global vaccine inequity will breed more of them.
Why, then, the preoccupation with establishing COVID as an endemic disease, discursively if not literally? Who stands to win and who stands to lose from this shift in thinking? The winners are the presidential administration and health and government officials, who feel absolved of responsibility, corporations large and small who do not want to expend resources on COVID mitigation and have effectively lobbied to kill federal regulations, and their toadies in the elite classes, particularly in academia and media. Everyone else loses.
The inconvenient and unavoidable fact is that COVID is causing severe illness, debilitating long-term sequelae, and death on a scale that is severely disruptive and unprecedented. The evangelists for endemic COVID don’t realize this, but their future vision is the worst of both worlds: continued debility and death will make it impossible to return to the 2019 version of “normal.”
The endemicity discourse is supposed to trick people into feeling less fear, which the pundits think is the main obstacle to returning to normal. But it isn’t fear that is keeping people out of work and school — in almost all of the country, the most extreme public health measures were lifted by summer of 2020 and never reinstated — it’s COVID. The inconvenient and unavoidable fact is that COVID is causing severe illness, debilitating long-term sequelae, and death on a scale that is severely disruptive and unprecedented. The evangelists for endemic COVID don’t realize this, but their future vision is the worst of both worlds: continued debility and death will make it impossible to return to the 2019 version of “normal.”
For all the talk of the costs associated with public health measures, there has been almost no talk of the obvious cost of endemic COVID — that more people will get sick and more people will die. Discussing endemicity forces us to confront difficult questions about who and how many will suffer long-term debilitating health conditions and continue to die of a preventable disease, and what kinds of investments or changes to “normal” various people’s lives merit. COVID, unlike influenza, continues to be a disease of contestation — we haven’t yet arrived at a societal consensus around COVID as to what constitutes ‘acceptable’ losses. As eliminating COVID becomes less and less likely, it’s time for a real, serious conversation about what living with endemic COVID will entail. It will not look like a return to 2019, and despite the most fervent wishes of some pundits, we can’t end-run around it by appealing to flu or car accidents.