Paris (AFP)

The toll of the Covid-19 pandemic has crossed the threshold of one million deaths, already well above those of other recent emerging viruses, but well below that of the terrible "Spanish flu" a century ago .

The tally, which only includes officially counted deaths, is only provisional as the pandemic continues.

But it gives benchmarks for comparing the new coronavirus to other viruses, current or past.

- Emerging viruses of the 21st century -

The human toll of Sars-Cov-2 far exceeds those of emerging virus epidemics of the 21st century.

Sparking a pandemic alert and a global mobilization in 2009, the influenza A (H1N1) epidemic, known as "swine", thus officially killed 18,500.

But this record was then revised upwards by the medical journal The Lancet with an assessment between 151,700 and 575,400 dead.

A virus emerging from China and the first coronavirus to trigger global fear, the SARS epidemic (Severe Acute Respiratory Syndrome) ultimately only caused 774 deaths in 2002-2003.

- Influenza epidemics -

Regularly, the toll of Covid-19 has been compared to those of the seasonal flu that silently kills each year, without making headlines.

“Globally, these annual epidemics are responsible for around 5 million severe cases, and 290,000 to 650,000 deaths,” says the WHO.

In the twentieth century, two major influenza pandemics linked to new viruses (not seasonal), that of 1957-58 known as the Asian flu and that of 1968-70 known as the Hong Kong flu, each killed around one million people, according to counts made a posteriori, even if they have remained in the oblivion of history.

However, they took place in a very different context, since globalization has since shaken the planet, marked by much more intense economic exchanges and a much greater and faster circulation of people (and therefore of viruses).

The great flu of 1918-1919, known as "Spanish" (also caused by a new virus) had done terrifying damage: in three "waves", it killed a total of 50 million people according to work published at the beginning from the 2000s.

- Tropical viruses -

The death toll from the new coronavirus is already much higher than that of the formidable Ebola, whose emergence dates back to 1976.

The latest outbreak of "Ebola virus disease" killed nearly 2,300 people in the Democratic Republic of Congo (DRC) between August 2018 and the end of June 2020. If we add up all the Ebola epidemics for more than forty years, this virus has in total about 15,000 deaths, exclusively in Africa.

Ebola, however, has a much higher case fatality rate than that of the Sars-Cov-2 coronavirus: around 50% of people affected die from it and up to 90% for some epidemics, according to the WHO.

But this virus is less contagious than other viral diseases: it is transmitted by direct and close contact and cannot be spread by air.

Other tropical viruses such as dengue fever, or "tropical flu", the severe form of which can lead to death, also have less serious consequences.

This infection transmitted by mosquitoes has been progressing for 20 years, but only causes a few thousand deaths per year (4,032 in 2015).

- Other viral epidemics -

Another killer virus, HIV-AIDS, for which 50 years after its appearance there is still no effective vaccine, for its part caused real deaths at the worst of the epidemic between the 1980s and 2000.

Thanks to the generalization of anti-retroviral therapies, the annual toll of people dying from AIDS has fallen steadily since the peak in 2004 (1.7 million deaths).

In 2019, the death toll was 690,000 according to UNAIDS.

But AIDS, which is now treatable but cannot be cured, has resulted in the death of nearly 33 million people since its onset.

As for the hepatitis B and C viruses, they show a very heavy toll, killing around 1.3 million people annually, most often in poor countries, by cirrhosis or liver cancer (900,000 deaths for hepatitis B and 400,000 for hepatitis C).

Main data source: World Health Organization (WHO).

© 2020 AFP