Two more Nebraska residents have tested positive for the new coronavirus disease, bringing the Nebraska total to five, health officials said.

A Douglas County woman in her 40s was added to the list Tuesday, the Douglas County Health Department said. She had recently traveled to California and Nevada and is recovering at home. State officials were awaiting case confirmation from the federal Centers for Disease Control and Prevention.

A person from northeast Nebraska will be treated at the Nebraska Biocontainment Unit on the University of Nebraska Medical Center campus in Omaha, the state Health and Human Services Department said. It's unclear whether the person's infection is travel-related or related to any of the other four.

The patient is a student at Crofton High School, said the North Central District Health Department. The Crofton district announced that classes, events and activities would be canceled for the rest of the week to limit exposure.

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.

The vast majority of people recover from the new virus. 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. In mainland China, where the virus first exploded, more than 80,000 people have been diagnosed and more than 58,000 have so far recovered.

An American who was exposed to the new coronavirus on a Japanese cruise ship and who was being monitored at an Omaha hospital was released from quarantine Tuesday.

The University of Nebraska Medical Center said the patient tested negative for COVID-19 three times and was cleared to leave quarantine. Seven others who were exposed to the virus on the Diamond Princess were released from quarantine in Omaha last week.

Seven other passengers who were evacuated from the ship have tested positive for COVID-19, and they remain at the Omaha hospital. One of them was being treated in the hospital's biocontainment unit and was in good condition Tuesday. The other six remain in the hospital's National Quarantine Unit.