Anais Legand, the technical officer with the World Health Organization, briefed the press Friday about the organization's efforts to screen the M/V Hondius' crew and passengers after the ship arrives in the Canary Islands.

Health teams will work with national authorities and each boat member will be assessed by trained medical staff, he said.

Epidemiologists will review individual exposure histories and interactions, according to Legand.

"So this is a way for us to get all the pieces together and have the maximum information to be able to assess any risk for this person and give them the right recommendation," he said.

-ABC News' Othon Leyva

An official at the Centers for Disease Control and Prevention confirmed to ABC News that the agency will be dispatching personnel to the Canary Islands, where the M/V Hondius -- the cruise ship at the center of a suspected hantavirus cluster -- is scheduled to arrive on Sunday.

Teams will then escort those Americans to the National Quarantine Unit in Nebraska.

-ABC News' Youri Benadjaoud

No U.S. residents have experienced any signs of illness as of Friday morning, according to health officials. However, six states are tracking nine residents for possible hantavirus infections.

Health officials in Texas, New Jersey and Georgia are monitoring two people while officials in California, Virginia and Arizona say they each are monitoring one person.

Two New Jersey residents -- who were not passengers on the cruise ship M/V Hondius -- are being monitored for possible hantavirus infections.

The state's health department was notified by the Centers for Disease Control and Prevention that the residents were potentially exposed to an infected cruise ship passenger during a flight. Neither individual is reporting symptoms.

This brings the total of U.S. residents under monitoring to at least nine across six states. None have shown any signs of illness at this time.

-ABC News' Youri Benadjaoud

Twelve U.S. residents are under monitoring by state health departments for hantavirus, according to officials. None of these 12 people have symptoms, officials said.

Seven of the 12 were cruise ship passengers who disembarked before the outbreak was declared: two are in Texas, two are in Georgia, one is in Virginia, one is in Arizona and one is in California.

The other five people were exposed to an infected individual during air travel, officials said. Two are in New Jersey, two are in Maryland and one is in California, officials said.

-ABC News’ Youri Benadjaoud