Syndemic

The Strange Case Of The Disappearance Of ‘Flu

Apparently, according to WHO figures, influenza cases from Week 15 (April) of 2020 have declined by 98% compared to 2019, whilst Covid-19 cases have correspondingly soared. This is very strange, you have to admit. Here are the figures:

So what on earth is going on? Is it a conspiracy? Have health departments all across the world been wrongly assigning ‘flu cases as Covid-19 cases, in effect faking the entire Covid-19 pandemic? Has the emergence of SARS-CoV-2 somehow ‘driven out’ ‘flu since April, preventing people from being infected with the ‘flu virus if they are already infected with SARS-CoV-2? Has mass mask wearing and social distancing prevented the spread of the ‘flu but not, bizarrely, the spread of SARS-CoV-2? All these explanations seem a little far fetched.

But we need an explanation. The transition from ‘flu to Covid is stark indeed. Here are the case statistics for North America and Northern Europe:

It’s ridiculous isn’t it. How can ‘flu just suddenly disappear? My guess is it did not. Flu and pneumonia are still mentioned on plenty of death certificates. My guess is that the focus on testing for Covid-19 has meant that ‘flu cases are being sidelined, but that moreover, people presenting with severe respiratory disease and dying from severe respiratory disease are those same people who, in a normal year would have presented with the ‘flu and died from it. SARS-CoV-2 appears to have usurped the role of ‘flu in the vulnerable population this year and carried off the susceptible. Not only that, it did so in many countries in a much shorter period, around March and April. It also carried off those who would have died naturally from other diseases too, like cancer, heart disease, stroke etc.

In this respect, Covid-19 is not a pandemic, but a syndemic. It has killed people all over the world by acting in synchrony with – and in some cases by displacing, as with ‘flu – other known morbidities. Very few healthy people under 60 have died directly from Covid-19. Here is what Richard Horton in the Lancet has to say and I believe it is very significant:

As the world approaches 1 million deaths from COVID-19, we must confront the fact that we are taking a far too narrow approach to managing this outbreak of a new coronavirus. We have viewed the cause of this crisis as an infectious disease. All of our interventions have focused on cutting lines of viral transmission, thereby controlling the spread of the pathogen. The “science” that has guided governments has been driven mostly by epidemic modellers and infectious disease specialists, who understandably frame the present health emergency in centuries-old terms of plague. But what we have learned so far tells us that the story of COVID-19 is not so simple. Two categories of disease are interacting within specific populations—infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and an array of non-communicable diseases (NCDs). These conditions are clustering within social groups according to patterns of inequality deeply embedded in our societies. The aggregation of these diseases on a background of social and economic disparity exacerbates the adverse effects of each separate disease. COVID-19 is not a pandemic. It is a syndemic. The syndemic nature of the threat we face means that a more nuanced approach is needed if we are to protect the health of our communities.