France’s poorest département, Seine Saint Denis, has seen a leap in the number of deaths from Covid-19 – up 63% between 21-27 March.

It is not the worst hit, that’s the eastern département of Haut Rhin, but the virus is taking off at an alarming rate in this working-class area north of Paris, Le Figaro reports.

Local officials say there are fewer intensive care beds than in neighbouring areas and local people have less access to good quality health care. And housing conditions – many large families living in confined spaces, migrant workers’ hostels, slums and shanty towns – also appear to contribute to the spread.

There’s another key factor, according to Gwenaëlle Ferré who runs a health centre in the area. Many residents of Seine Saint Denis work in those poorly paid and little-appreciated jobs, which have now turned out to be indispensable. They work in delivery or are carers in old people’s homes or for local councils and are thus at high risk of exposure to the virus.

In Seine Saint Denis there have been 263 deaths (1.8 per 1,000), 1,310 people hospitalised, 228 in intensive care and 503 cured.

The département I live in, Val de Marne, which also includes a number of working-class areas, has seen 280 deaths (2.0 per 1,000). There are 1,651 people hospitalised, 291 in intensive care and 641 people cured.

The city of Paris has seen 548 deaths (2.6 per 1,000), 2,999 hospitalisations, 809 in intensive care and 1,212 cured.

Tests have started in Paris and elsewhere to see whether blood transfusions from cured patients can help seriously ill patients.

Similar tests have taken place in China and the US.

Researchers are also testing vaccination with an anti-TB drug, BCG.

Only 8% of serious Covid-19 cases and 1% of those who have died in France are below 45 years old, while 22% of serious cases and 73% of deaths are over 75 years old.

Gender is also a key factor – 74% of serious cases in intensive care are men, as are 59% of those who have died. This has yet to be explained.

Saturday’s Covid-19 death toll in France was 441, down from 588 on Friday, the worst day so far. That brings the total recorded death toll to 7,560, with 64,338 serious cases recorded, 6,800 people I intensive care.