North Dakota’s health department said it is monitoring five individuals who were exposed to a sick hantavirus cruise ship member abroad. None of these five people were on the cruise ship, the department said.

There are now 11 state health departments monitoring a total of at least 23 people, none of whom have symptoms.

The other states monitoring people are Texas, California, Georgia, Virginia, Arizona, New Jersey, Maryland, Washington, Kansas and Minnesota.

-ABC News’ Youri Benadjaoud

Three people in Kansas who have been under monitoring by the state's health department for potential hantavirus infection have been transported to a hospital for observation, a department spokesperson told ABC News.

It is not clear why they were transported and if any of the three have shown signs of symptoms.

Kansas’ health department initially announced on Tuesday that these three people -- who were not cruise ship passengers -- were exposed to an infected individual abroad. The department said their exposure was "high risk" and said at the time that they were not showing any signs of illness.

-ABC News’ Youri Benadjaoud

Dr. Stephen Kornfeld, who identified himself as the first American who initially tested positive for hantavirus from samples taken on the cruise ship, has now tested negative in subsequent testing, he told ABC News.

The testing was originally listed as inconclusive per the World Health Organization because of a positive and negative test result returned from a Dutch lab. Health officials had proceeded with caution and labeled him as a positive case.

Kornfeld was moved from the Nebraska Biocontainment Unit to the National Quarantine Unit, alongside his fellow passengers, according to a statement from Nebraska Medicine.

-ABC News' Youri Benadjaoud and Vera Drymon

Officials with the U.S. Centers or Disease Control and Preventionupdated the public on the hantavirus situation and reiterated the risk to the U.S. population remains low.

Dr. David Fitter, the incident manager for CDC’s hantavirus response, told reporters in a telephone news conference that the agency has over 100 staff working full time on the outbreak.

Dr. Brendan Jackson, the CDC team lead in Nebraska where some of the U.S. passengers of the MV Hondius are quarantining, said that the one passenger who tested positive did his tests abroad but they were inconclusive.

"We got a positive and a negative abroad, so we want to redo the test here in the U.S.," he said.

The CDC is awaiting the results of that new test, Jackson said.

-ABC News' Eric Strauss