Viral dementia hand test, a diphtheria scare and Brexit blocking research — how well did you follow this week's health news?

This week's health quiz: from a viral social media hand-test to a fatal diphtheria case — let's see how closely you were paying attention.

1. A ten-second hand test spreading on social media is claimed to indicate what?
2. Why are New York State and City tightening inspections of cooling towers?
3. What discovery did researchers make in zebrafish for multiple sclerosis research?
4. According to Annie Jacobsen's new book, what makes biological warfare more insidious and harder to stop than nuclear war?
5. How many people in Hungary are estimated to live with a rare disease?
6. What happened in Italy after a four-year-old girl died of diphtheria?