In Italy the entire population of a small town was tested for Covid 19. Of those infected, one in three people with no symptoms had the virus. And from China researchers found many people carried the virus – even before authorities there began tracking its spread. The findings suggest vulnerable people may contract the virus from those without symptoms.

And we’ve news of a breakthrough - new tests looking at Covid 19 antibodies, These should help provide a picture of developing immunity to the virus.

However as growing numbers of people fall ill there are concerns over a potential shortage of hospital ventilators globally, These are needed to treat the most severe cases. However a crowdsourcing project has been set up to try and kick start the manufacturing of a variety of different types of ventilator that could be built around the world. If you have knowledge of ventilators or their use and would like to get involved more information is available here. http://bit.ly/frontiertech4COVIDaction

Many of us are fascinated by our ancestry: knowing where our families came from can give us a sense of identity and roots. Tracing your family tree is a time-honoured tradition, but several companies now sell DNA tests that offer you insights into your heritage: so you might find out you’re 70% Nigerian, 39% Italian, or 11% South Asian, for example.

There’s no doubt that genes contain clues about your family history, but how reliable are these commercial tests? That’s what CrowdScience listener Karen wondered after an update of her test results showed her going from 39% Scandinavian to 2% Norwegian. How confident can she be in her results now? And what does it actually mean to be 2% Norwegian, in terms of your family tree?

Presenter Alex Lathbridge delves into his own African and European ancestry, talks to some of the companies offering these tests, and unpicks the complex relationship between genetic science and family trees. We meet a woman who found her long-lost uncle with a combination of a DNA test and old-fashioned archive research; and look to the Americas to ask whether genetic testing can restore ancestral ties erased by the inhumanity of the transatlantic slave trade.

(Image: AFP/Getty Images)