NEW YORK — The number of physical books sold dropped 10 percent from the previous week, the latest sign of the effect of the coronavirus on the publishing industry.

NPD BookScan , which tracks around 85 percent of physical sales, reported big drops in children’s fiction and adult nonfiction books. The biggest gains were in nonfiction books for kids, notably workbooks purchased by parents whose children are now home from schools that have been closed.

The BookScan numbers were released at a time when tours were being called and some of the country’s top independent sellers, among them Powell’s Books in Portland, Oregon, and the Tattered Cover in Denver, were laying off employees. Barnes & Noble has been cutting back its hours and closing some stores, but otherwise is reporting “relatively strong sales considering the situation, both in our stores and online, especially of kid’s books and fiction, including notably home study aids,” according to a statement Wednesday.

Such traditional spring events as the PEN World Voices festival and the Mystery Writers of America awards dinner have been canceled. And the country’s largest publisher, Penguin Random House, announced Wednesday that it would not attend the BookExpo national convention in late May in Manhattan. A spokeswoman for BookExpo said an announcement on the convention’s status would be made early Thursday.

For most people, the new coronavirus causes only mild or moderate symptoms, such as fever and cough. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia.