Iowa announced its first three cases of the coronavirus Sunday evening as the deadly outbreak continues to spread across the United States.

The patients, two seniors and a middle-aged adult, recently took a cruise ship to Egypt, Iowa Gov. Kim Reynolds (R) and state health officials said. The three are recovering at their homes.

“Iowa has been proactively preparing for the likelihood of a positive test in Iowa with strategic planning and safety measures. While these are the first cases, it may not be the last and it’s why Iowans must continue to practice safe habits like hand washing and staying home from work when sick,” Reynolds said in a Sunday evening statement.

“My team is engaged through the President’s Coronavirus Task Force, led by Vice President Mike Pence, as well as the nation’s governors to work collaboratively to limit the spread of COVID-19,” she added.

On Sunday, the State Department and the Centers for Disease Control and Prevention (CDC) recommended that Americans, not to travel by cruise ship amid the outbreak.

“U.S. citizens, particularly travelers with underlying health conditions, should not travel by cruise ship,” said the State Department. “While the U.S. government has evacuated some cruise ship passengers in recent weeks, repatriation flights should not be relied upon as an option for U.S. citizens under the potential risk of quarantine by local authorities.”

The Grand Princess, which has confirmed 21 corona cases, will dock in Oakland, California, on Monday after spending days on the the Northern California coast.

Data via Johns Hopkins Univerity shows over 500 U.S. cases and 22 deaths have been confirmed.

There are at least 100,000 cases and over 3,000 deaths linked to the illness that originated in Wuhan, China.