Coronavirus and other deadly epidemics
The novel coronavirus pandemic, soon to pass the milestone of one million deaths, has a higher toll compared with other modern viruses although its ravages to date are far less than the Spanish flu a century ago.
21st century viruses
SARS-CoV-2, the virus responsible for COVID-19 infection, has been the deadliest of the 21st century viruses.
In 2009, the H1N1 virus, or swine flu, caused a global pandemic and left an official death toll of 18,500.
This was later revised upwards by the medical journal The Lancet, to between 151,700 and 575,400 dead.
In 2002-2003, the SARS virus (Severe Acute Respiratory Syndrome) that emerged from China was the first coronavirus to spark global fears, but killed just 774 people in the final toll.
The COVID-19 toll is often compared to that of deadly seasonal flu, though the latter rarely makes the headlines.
Globally, seasonal flu accounts for up to 650,000 deaths, according to the World Health Organization (WHO).
In the 20th century, two major non-seasonal flu pandemics—Asian flu in 1957-1958 and Hong Kong flu in 1968-1970—each killed around one million people, according to tolls carried out afterwards.
Both pandemics occurred in different circumstances to COVID-19, before globalisation intensified and accelerated economic exchange and travel—and with it the rapid spread of deadly viruses.
The greatest catastrophe of modern pandemics to date, the flu pandemic of 1918-1919 also known as Spanish flu, wiped out some 50 million people according to research published in the 2000s.
The death toll from the new coronavirus is already far higher than that of the haemorrhagic fever Ebola, which was first identified in 1976 and in its latest 2018-2020 outbreak killed nearly 2,300 people.
In four decades, periodic Ebola outbreaks have killed some 15,000 people, all in Africa.
Ebola has a far higher fatality rate than COVID-19: around 50 percent of people who are infected die from it, and this has risen to 90 percent in some of the epidemics.
But Ebola is less contagious than other viral diseases, namely because it is not airborne but transmitted through direct and close contact.
Dengue fever, which can also be deadly, has a lower toll. This flu-like illness spread by the bite of an infected mosquito has been on the rise for two decades but causes just a few thousand deaths per year.
Other viral epidemics
AIDS is by far the most deadly modern epidemic: almost 33 million people around the world have died of the disease which affects the immune system.
First detected in 1981, no effective vaccine has been found.
But retroviral drugs, when taken regularly, efficiently stop the illness in its tracks and heavily reduce the risk of contamination.
This treatment has helped bring down the death toll from its peak in 2004 of 1.7 million deaths to 690,000 in 2009, according to UNAIDS.
The hepatitis B and C viruses also have a high death toll, killing some 1.3 million people every year, most often in poor countries.
Main data source: World Health Organization (WHO).
© 2020 AFP