The single most important component of an effective response to the Covid-19 pandemic is rapid use of data.
I recently highlighted 19 critical data gaps regarding the novel coronavirus that we need to address. Now, with Covid-19 continuing to spread rapidly in the United States and elsewhere, the US Centers for Disease Control and Prevention (CDC) and other public-health specialists must urgently answer three questions in particular.
Children and school
First, do people without symptoms and children spread the novel coronavirus?
If we are to know who to test and who to quarantine, it is crucial to understand whether asymptomatic people spread infection.
If kids don’t account for a substantial proportion of the spread of the Covid-19 virus, as they do with seasonal influenza, then there is much less reason to close schools, and perhaps those that are closed can reopen sooner.
Although children up to at least age 18 appear to become very ill with Covid-19 less often, they may be able to spread infection. We need to know how much risk infected children pose to the older and more medically vulnerable people around them, especially because many of these people may be called on to provide childcare during school closures.
Investigating the risk of spread to contacts from patients who never developed symptoms, or from patients who later developed symptoms, can clarify the risk of spread from asymptomatic people.
Public-health specialists need to investigate clusters of cases and see how many have a child as an index (that is, first) case. Is this proportion lower than would be expected statistically? And in family and other clusters, are there chains of transmission that start with kids?
Second, how is the virus spreading in hospitals?
We urgently need to protect health-care workers and also to preserve scarce infection-control resources so that we can maintain or expand capacity to provide intensive care to patients who need it.
For example, whereas Covid-19 infections spread rapidly to patients and hospital staff in Wuhan, China, and in northern Italy, Singapore has apparently yet to report a single infection of a health-care worker, despite diagnosing nearly 250 cases (one who did become infected was a non-medical contact of a confirmed case).
Care of a severely ill patient in Singapore, including intubation and intensive care before he was diagnosed, resulted in the exposure of 41 health workers, most of whom used only surgical masks; none became infected.
The number of Covid-19 cases is likely to exceed the supply of protective equipment for health-care professionals, so we need to know which items are most important.
For example, regular surgical masks may be sufficient for health-care workers in most settings, except where there is a risk of aerosolisation (such as during bronchoscopy, sputum induction, and intubation).
Investigating known transmission of Covid-19 within nursing homes and hospitals can identify the sources and routes of the virus’s spread. That would enable us to establish best practices to protect health-care workers and other patients in higher- and lower-resource settings.
Who will die?
Third, who is most likely to die from Covid-19?
To reduce illnesses and deaths among people infected with the virus, our highest priority must be protection and services for people who are most likely to become severely ill if infected – and who therefore should stay at home and avoid contact with others to the greatest extent possible.
Although older people and those with underlying health conditions are at greater risk from Covid-19, we don’t know the precise age at which the risk actually increases, or the extent to which specific comorbidities elevate that risk.
If, for example, a 62-year-old with well-controlled hypertension and no other illness is not at elevated risk, as seems possible, then we can focus resources on people who need them more.
Analysis should cover only patients diagnosed at least 30 days earlier, and calculate mortality by age, gender, and health status. This might indicate which conditions predict severe illness – for example, obesity, hypertension, diabetes (both well- and poorly controlled), specific medication use, or other factors.
These studies might already be underway – I certainly hope so. Much of the early US public-health response to Covid-19 was derailed by the need to deal with infections on cruise ships and repatriate travelers.
It’s now crucial that public-health specialists at the CDC and state and local health departments focus on getting answers to these and other critically important questions.
By responding rapidly to the data, we can design and implement measures to prevent the further spread of Covid-19, improve outcomes among those infected, and reduce societal harm.
Good data on Covid-19 is a precious resource, and it needs to be much less scarce. Answering epidemiological questions isn’t a matter of intellectual curiosity; the knowledge we gain could mean the difference between life and death. And we’re now at the point where every minute counts.
Tom Frieden, is former director of the US Centers for Disease Control and Prevention and former commissioner of New York City Health Department. © Project Syndicate 2020.
The views expressed are those of the author and do not necessarily reflect those of FMT.