Paris (AFP)

The daily counting of the victims of Covid-19, whose official number has exceeded 100,000 dead, is a delicate exercise, the collection of data in real time being only fragmented and the methods varying according to the countries.

Place of death, way of identifying the causes of death, different timeframes for reporting information: several elements can have an impact on these accounts, which are necessarily undervalued but essential for monitoring the evolution of the pandemic.

This is a real "statistical challenge", emphasizes the French institute for demographic studies, INED.

- Hospitals and retirement homes -

While Spain and South Korea count all deaths of people who test positive for Covid-19, whether in or out of the hospital, this is not the case in all countries. Iranian figures, for example, appear to only include hospital deaths.

Until recently, deaths in retirement homes were also not included in official French and British figures. They are however far from being marginal, since they now represent more than a third of the balance sheet in France.

In the United States, the deaths taken into account vary from state to state: New York State includes retirement homes, California does not.

Even in Italy, which officially has the heaviest death toll in the world (more than 18,000 dead), not all deaths in retirement homes have been recorded. If a large epidemic focus is detected in an establishment, tests are carried out and deaths counted, but if an establishment is less affected, it is likely that this will not be the case, explains the Civil Protection.

- Covid-19 or some other disease? -

While some countries, such as South Korea, Italy, Spain and the United Kingdom, include in their figures all people who tested positive for coronavirus, even those who died from complications of a preexisting disease, other countries are more selective.

In Iran, patients who test positive but die from another "serious respiratory illness" are excluded from the assessments.

In the United States, there are increasing testimonies from people whose relatives have died, officially of pneumonia, before the tests were available or at a time when they were difficult to obtain.

- Lack of tests and deadlines -

During an epidemic, "the ascent and processing of information, even accelerated, is done with a few days of delay and does not cover all deaths. It takes several weeks or several months to be able to precisely count all the dead", estimate Gilles Pison and France Meslé, demographers at INED, on The Conversation site.

In the United States, even in the absence of a test, death certificates must state whether Covid-19 is the "probable" cause of death, but these certificates take time to ascend and cannot be taken into account for real-time reports.

In Spain, the civil registers and the number of burials show an excess mortality much higher than that which should result from the official balance sheet of the Covid-19.

Due to lack of tests, Spain performs very few post-mortem screenings. Thus, if a person has not been screened before dying, he is not counted by the health authorities. Judicial data, which is less restrictive, suggests a much better balance sheet: for example, the Superior Court of Castile-La Mancha registered in March 1,921 death certificates "the cause of which is due to Covid or to a suspicion of Covid", ie nearly three times more than the 708 dead (positive for Covid-19) as of March 31 by health authorities.

Another illustration: in Bergamo, in Lombardy, were recorded, during the first half of March, 108 more deaths (+ 193%) than a year earlier ... but only 31 deaths linked to Covid-19.

- China and Iran accused of lying -

Sometimes the very sincerity of the figures published is called into question.

In Iran, official reports have been challenged, particularly at the start of the epidemic, by provincial officials and parliamentarians. Even the official Irna agency has sometimes released figures higher than those of the authorities, the balance sheets then denied by the government. Outside of the country, Washington, in particular, criticized Tehran for making up its figures.

Regarding China, the cradle of the epidemic, a confidential report of American intelligence, quoted by the Bloomberg agency, accused Beijing of having intentionally undervalued its balance sheet. His figures were also questioned by several Iranian officials, but the health ministry spokesman was forced to correct his remarks after calling the Chinese record "a joke in bad taste".

burs-jah / ber / cds / mm

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