As a senior editor at Discover Magazine, science journalist Pamela Weintraub had covered myriad scientific dramas throughout her career. But it was her own family’s medical odyssey with Lyme disease — and the book she wrote about it, Cure Unknown: Inside the Lyme Epidemic — that brought her to speak on Monday to about 60 people on Martha’s Vineyard, where tick-borne illness is one of the most serious and prevalent health concerns.