Eight states have recently been added to the list that now stands at 16, including California, Georgia, Iowa, Idaho, Louisiana, Mississippi, Nevada and Tennessee.
The other states on that list were announced last Wednesday are Alabama, Arkansas, Arizona, Florida, North Carolina, South Carolina, Texas and Utah.
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Under the travel advisory, individuals traveling to or returning to New York, New Jersey and Connecticut from states with increasing rates of COVID-19 are advised to self-quarantine for two weeks. This includes travel by train, bus, car, plane and any other method of transportation, officials said.
The 14-day quarantine travel advisory applies to travel from states identified as those that have a positive COVID-19 test rate higher than 10 per 100,000 residents or have a 10% or higher positivity rate over a seven-day rolling average, officials said.
The self-quarantine is voluntary, but compliance is expected.
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According to officials, the advisory does not apply to any individual passing through designated states for a limited duration through the course of travel. Examples include: stopping at rest stops for vehicles, buses, and/or trains; or layovers for air travel, bus travel, or train travel.
Individuals who are traveling to New York, New Jersey or Connecticut from impacted states for business are exempt.
The travel quarantine announced on June 24 by New York Gov. Andrew Cuomo applies to everyone entering the Tri-State region, including New Yorkers returning home from elsewhere.
Washington was also on the list initially, but the state was removed June 24 after New York officials reviewed the state's data, saying, "There was a temporary discrepancy with Washington State's reporting, however, they have since corrected it and we have removed them from the list of states under travel advisory."
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The quarantine list is based on a formula. If the states have 10 positive cases per 100,000 residents, or if 10% of their total population is infected, states can be added or taken off the list.
This is what has been predicted from the beginning, that there would be a rolling curve with different areas of the country being impacted at different times.
The question on many people's minds now is, how will this be enforced?
The three governors are relying on people to report others who violate the quarantine.
On ABC's "Good Morning America" last week, Connecticut Gov. Ned Lamont described the approach his state is taking.
"What we're going to do is go to every travel agent and say, 'From these regions don't come to Connecticut unless you get tested first or know you have to quarantine,'" said Lamont. "We're going to go to all the hotels, every single site there, let people know from those states you have to quarantine if you come to Connecticut."
Lamont said the state is stopping short of imposing fines for violations, but will ramp up penalties if necessary.
If you're caught in violation in New York, on the other hand, you will face mandatory quarantine and thousands of dollars in fines.
"It's only for the simple reason that we worked very hard to get the viral transmission rate down," said Gov. Andrew Cuomo. "We don't want to see it go up, because a lot of people come into this region, and they could literally bring the infection with them. It wouldn't be malicious or malevolent but it would still be real."
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Because of the high number of cases in the United States, the European Union is considering a temporary ban on American tourists.
The ban would also include those traveling from Brazil and Russia.
The E.U. issued a statement saying in part, "restrictions should remain in place for countries whose situation is worse than in the E.U."
When it comes to those wanting to travel to the Tri-State area after visiting any of the eight states currently on the quarantine list, the governors say there is a simple solution: get a test once returning to find out if you've been exposed.