A Cass County man in his 50s has tested positive for the new coronavirus, making him the 11th known case in Nebraska, officials said.

The man recently flew back to Nebraska from Minnesota on the same connecting flight as the woman who is Nebraska’s first case of COVID-19. The man’s been self-isolating at his home since last Saturday, the Nebraska Health and Human Services Department said in a news release Thursday night.

The 36-year-old Omaha woman tested positive March 6. Health officials said she had recently traveled to the United Kingdom with her father and first started showing symptoms of a respiratory illness on Feb. 24. She returned to Nebraska on Feb. 27.

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.

According to the World Health Organization, people with mild illness recover in about two weeks, while those with more severe illness may take three to six weeks to recover.