It is difficult to make predictions, said Niels Bohr with wry humor – especially about the future. The questions we are all asking ourselves now are: How long will this Covid-19 pandemic last and what impact will it have in terms of premature deaths and the economy?
In Greek mythology, the god Apollo promised Casandra the power to see the future, in exchange for her favors. Upon receiving them, Apollo punished her by making no one believe her prophecies. This is how epidemiologists feel today. So be it, I will nevertheless share with you here my recommendations based on projections.
To know in a country the number of new cases (incidence) or the proportion of the infected population (prevalence) with the new coronavirus (SARS-CoV-2), good epidemiological surveillance is required. This involves early identification of all possible infected persons and their contacts, and diagnostic testing. If there are not enough tests, or if samples are only taken from seriously ill or hospitalized patients – the tip of the iceberg – we won’t know what lies beneath.
Of the total number of infected cases, a high proportion (about 70%) have moderate or light symptoms, but they are still infectious. On average, an infected person infects 3 other people. This is known as the reproduction rate (R0). For an epidemic to end, R0 must be less then 1. The only way to achieve this reduction is through physical distancing of the general population and isolation of infected people. The key is to break the chain of transmission. This is the only way to avoid the sudden emergence of cases that would exceed the capacity of the system. That is, flatten the growth curve and gain time while therapies and vaccines emerge.
As of yesterday (March 23), 367 confirmed cases of Covid-19 had been reported in Mexico. If we know that the number of cases in the current phase doubles every 60 hours (exponential growth), this implies that in one week we will have 2,300 cases and in 15 days, 18,785 cases. 6% of these cases will require intensive care. Official figures assume that just 0.2% of the Mexican population will be infected in the first phase, but this is a gross understatement.
There are three strategies to combat this pandemic: containment (already too late); mitigation (we’d need to rush) and suppression (draconian measures).
Mexico is a week or two behind the epidemic in Spain: We still have in Mexico a brief window of opportunity to influence the growth curve. Acting early and aggressively is the key to achieving it. We have the additional aggravating factor of the extremely high prevalence of obesity and diabetes in the country, which are risk factors for fatality due to Covid-19. Hence the urgency to act now, before we find ourselves in crises like those in Wuhan, Italy and Spain.
There are several bottlenecks that exist in our health system as we try to contend with the epidemic. There are not enough reagents or devices to carry out diagnostic tests, and private laboratories have been until now barred from conducting them. There aren’t enough mechanical ventilators or intensive care beds. Like all countries, this pandemic finds us poorly prepared. An urgent need, for example, is to acquire supplies to protect health personnel. Even in the United States there is a serious shortage.
I am confident that we will not find ourselves torn about whether to save lives or save the economy. Delaying distancing and isolation measures could benefit the economy, but at the cost of many premature deaths. The economic impact will no doubt be brutal, but the most important thing is to save lives.
Physical distancing does not mean social distancing; on the contrary, we need social support and solidarity. The new coronavirus is a social equalizer – it affects the poor and the rich equally. In a country so divided and with so much inequality, we need to be more united than ever.
This essay was originally published in Reforma