Correction appended, July 19

Nearly a dozen delegation staffers from California who are in Ohio for the Republican National Convention have become sick with the norovirus.

The 11 members of the California Republican Party who have come down with the highly contagious digestive illness are staying at the Kalahari Resort in Sandusky, Ohio, which is about 60 miles from where the GOP convention is being held in Cleveland, USA Today reports.

The staffers brought the illness from their home state and have been isolating themselves from the public at their hotel, Erie County Health Commissioner Peter Schade told the newspaper.

Norovirus, which inflames the stomach and intestines, can be contracted through an infected person, contaminated food or water or tainted surfaces, according to the Centers for Disease Control and Prevention. Symptoms include stomach pain, nausea, and diarrhea and vomiting.

Correction: A previous version of this article misstated the role of those who became sick.

[USA Today]

Get our Health Newsletter. Sign up to receive the latest health and science news, plus answers to wellness questions and expert tips. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.