Here’s another reason to start reading e-books.

Two Belgian researchers testing library books for germs and bacteria found traces of the herpes virus on borrowed copies of the popular “Fifty Shades of Grey” novel.

The best-selling erotic novel was one of the 10 most borrowed books at the Antwerp library.

Each of the most-borrowed volumes underwent bacteria and toxicology tests, and the findings revealed that library books should come with due dates and rubber gloves.

While the concentrations of the herpes virus were not enough to pose a health risk, the results were pretty high on the “eww” scale.

Some of the books even tested positive for cocaine, which could be even more of a problem.

“Today’s testing methods are so sensitive that traces of the drug originating from a contaminated book will be found in your hair, blood and urine,” said Jan Tytgat, a toxicologist from the Catholic University of Leuven.