S.

At least 33 states and the District of Columbia have confirmed over 500 cases and more than 20 deaths.

100 countries are not reporting cases, and Italy, one of the hardest hit, has placed millions on lock down.

Now, one of the nation's top outbreak expert says something similar could happen here.

We also learned there's a quarantine plan for the thousands of passengers and crew who have been stuck on a cruise ship off the coast of California.

The State Department also advising Americans, especially those with underlying medical conditions to stay off cruise ships are.

Steve Patterson has a very latest tonight, after nearly a week adrift in isolation and without answers.

Finally, an end in sight agreement has been reached to bring our ship into the Port of Oakland.

The Grand Prince says, is expected to dock Monday.

Already, 21 people are positive for Corona virus, including 19 crew members, thousands still untested tomorrow in Oakland, California.

Those passengers will be transferred to four military bases to in California, one in Texas, in one in Georgia, where there will be screen tested and quarantined for two weeks.

Passengers say it's been miserable.

It's like being in a little prison cell at sea.

We are not allowed out of our room at all.

For Gina Kolata and Mike Nikki, being trapped on board is a matter of life or death.

My husband is, um, actually, as of today, running out of his diabetic medications in Oakland.

Worry from residents as news spreads that the ship is coming in.

It's going to just have the whole bear.

You're scrambling at this point that's gonna wake everybody up.

I think it would be a tough situation off the coast of South Florida.

Another cruise liner stuck it see while officials test two crew members and another in Egypt.

Quarantine with Americans on board today, a member of President Trump's Corona Virus task force with this urgent warning.

If you're a person with an underlying condition and you are particularly an elderly person with an online condition, you need to think twice about getting on a plane on a long trip and not only think twice, just don't get on a cruise ship.

Meanwhile, near Seattle, at the heart of the nation's Corona virus outbreak Maur Deaths announced today a wake up call for the community.

Now even more cautious.

Church this morning was from a distance.

We're not touching each other.

We're change some of our basic practices around communion and greeting each other.

Steve Anderson is if the Port of Oakland Steve, is it just the passengers getting off that ship tomorrow?

Well, Jose, the answer to that is yes, but officials say that crew of 1100 will remain quarantine on board this ship and treated as necessary.

And as soon as those passengers disembark, that ship leaves the bank chief Patterson in Oakland, Thank you very much.

And in Italy tonight, 16 million people are under a luck down in the region known as the country's financial hub, NBC's Bill Neely is in Rome with the very latest the drastic locked on sent thousands rushing for trains out of Milan.

16 million people are not quarantined.

Ah, quarter of Italy's population.

No one can leave or enter hospitals, air being overwhelmed by the virus, said the prime minister.

It's an emergency.

Milan today look deserted.

Italy, now the worst hit country in the world, 133 new deaths in just one day 366 now in all on today, more than 1400 new infections.

Venice, too, is now locked down on deserted today, Pope Francis said prayers by video link to deter crowds at the Vatican still appeared briefly at a window.

The Vatican's museums on its Sistine Chapel now closed like museums across Italy.

It is a growing crisis here in Italy and in the U.

S.

But globally, more people have now recovered from the virus than are ill with it.

China today closed one temporary hospital, all patients discharged, the rate of new cases and deaths falling fast.

But in Egypt, two dozen Americans are the latest quarantined on a cruise ship, this one trapped on the Nile.

At least one American has tested positive, the rest scared.

It's an overwhelming feeling off being helpless.

We have no control over anything.

Italy's new rules will be tested tomorrow as millions begin a new work week, its richest region not closed for a month.

Billy, NBC News, Rome and in Washington state.

Tonight we learned those new deaths were tied to a nursing home.

Many have already died from the virus.

The state's health care system is under immense strain, and there's concern that other states could soon face the same challenges.

There's Cathy Park tonight, growing frustration in Seattle at the nursing home now linked to 16 Corona virus Dance, the facility where residents are at high risk saying they need more help.

Cathy Jackson believes she may have been exposed to the Corona virus at the life care center at Kirkland, the 71 year old self quarantine after noticing symptoms.

But more than a week later, she's still waiting for results.

I was not ready for being hung up on I was not ready for the run around, she says.

The path to getting tested was the hardest part.

Call after call to the local health department turned into a chase for answers, delaying her diagnosis.

The problem is that they're just They were totally called epidemiologists in virologist Joseph Fair PhD Mph says.

Across the country, the demand on health care providers is surging.

We're going to see a complete overwhelming of the entire medical system for the United States if you're showing symptoms possibly linked to the virus.

Fair suggests not going to the emergency room.

If you go to an e.

R, you are by nature exposing everyone else to covert 19.

Who might be there If you're feeling sick, health officials say.

First, call your doctor who can then alert the health department if they believe you're at high risk.

My guidance is this.

If you're feeling ill or if you're in the high risk category, avoid as much contact as you can with others.

Kathy What is the King County Public Health Department say about the Jackson case and others potentially exposed?

Yeah, they didn't actually address her case specifically, but did say that they are working around the clock and providing guidance of thousands of people who were reaching out.

Now they're calling this an unprecedented and challenging situation.

Kathy Park.

Thank you very much.

There's a lot of fear and confusion about the Corona virus.

Here's what we know tonight there are more than 20 deaths in the United States.

There is no vaccine and ah, delay getting those test kits.

It's especially dangerous for the elderly conditions.

And while President Trump is trying to reassure Americans, other officials are taking a more urgent tone.

Holland's Nichols explains tonight, mixed messages on the threat of Corona virus with one of the most public faces of President Trump's task force, warning that the most difficult days, maybe ahead.

Clearly, I'm concerned about community spread.

You have to realistically be concerned about community spread, but the surgeon general painting a more optimistic picture.

And so we actually feel pretty good that some parts of the country have contained it.

You know you don't want to alarm people, but given the spread we've seen, you know anything is possible.

And that's the reason why we've got to be prepared to take whatever action is appropriate to contain and mitigate the outbreak.

Adding to the confusion, Dr Ben Carson claiming that the administration has a plan for tomorrow's arrival of the Grand Princess.

The plan will be in place by that time before acknowledging that the plan hasn't been finalized.

We shouldn't have 16 people saying what the plan is okay, but it has a bit of a particular when it hasn't been fully formulated and President Trump taking to Twitter that he has a perfectly coordinated and fine tune plan for our tack on Corona virus and last night the president saying he was not worried about the virus coming to the White House, but blasting The New York Times as an embarrassment to journalism after it published a story that described internal White House debates on how to confront the virus with the surgeon general acknowledging the challenge of accurately informing the public.

Messaging, quite frankly, is hard.

Hans Nichols joins us now.

Any concern the president may have been in direct proximity to someone who has contracted Corona virus?

Well, both the president and the vice president spoke at a conference last week where one attendee has since tested positive.

But the White House says there's no indication that either met with or was in close proximity to that affected individual tonight, many concerned about Corona virus or wondering how to stay safe when they fly.

Here's NBC's Sam Brock Fly or Not to fly.

With cases of Corona virus spreading worldwide, travelers are on edge, doing everything they can to stay safe in the skies.

I'm really weird about just being in the airport because you get people all over.

You never know if you're coming in contact.

Did you feel safer wearing the musk, but our masks effective the CDC says they should be considered for sick travelers with respiratory symptoms like coughing and sneezing, and for passengers sitting near others with respiratory symptoms.

While a lot of flights to affected areas have been canceled for anyone who does decide to travel, doctor say precautions on planes are key.

It's safe to get on a plane, but use your hand hygiene.

Try to avoid people who are coughing and sneezing.

But if you're older, if you have underlying illnesses, you have to ask yourself, Is this really an essential trip?

But what else can you d'oh.

What a perfect world you'd be sitting next to the window because obviously your exposure here is the least if you sit in the middle seat thistles the worst because you have people on both sides of you.

In fact, no matter where you're seated, the CDC says people who are within six feet of a traveler with Corona virus are at medium risk of getting the disease.

And what about what you're breathing on board?

According to the International Air Transport Association, there's filters on planes that actually get out of a 99.9% of airborne microbes, which means the air quality on the cabin here is actually as good or better than your office.

Also before takeoff, pay special attention to cleaning surfaces anyplace other passengers have touched, including arm rests, those metal seat buckles, plus the front and backs of tray tables and digital screens on the seat backs.

Finally use a tissue or a wife on the handle, opening the bathroom doors, flushing the toilet and turning the water on and off in the sink.

Small tips that could make a big difference for a healthier time in the skies.

Sam Brock, NBC News.