The coverage on this live blog has ended — but for up-to-the-minute coverage on the coronavirus, visit the live blog from CNBC's Asia-Pacific team. All times below are in Eastern time. Total confirmed cases: More than 82,500

Total deaths: At least 2,810

6:03 pm: CDC to test more suspected cases after revising guidelines

The Centers for Disease Control and Prevention said it revised its guidelines to allow clinicians across the U.S. to test more people suspected of carrying the new coronavirus. Under the prior federal guidelines, clinicians could test suspected COVID-19 patients if they had traveled recently from China or had been in contact with someone known to be infected. Some lawmakers criticized the CDC's previous guidance as too restrictive. The new guidelines, which were posted to the CDC's website Thursday, appear to place more power in the hands of local health practitioners to determine who should get tested. —Feuer

5:25 pm: US CDC chief says aggressively evaluating whether coronavirus survives on surfaces

Robert Redfield, director of the U.S. Centers for Disease Control and Prevention, told the U.S. Congress on Thursday that his agency is aggressively evaluating how long coronavirus can survive and be infectious on surfaces. "On copper and steel its pretty typical, it's pretty much about 2 hours," Redfield said at a House of Representatives hearing on the government response to the fast-spreading virus. "But I will say on other surfaces — cardboard or plastic — it's longer, and so we are looking at this." He said infections contracted from surfaces rather than through the air could have contributed to the outbreak on the Diamond Princess cruise ship. —Reuters

4:20 pm: Dow plunges nearly 1,200 points

Stocks fell sharply in volatile trading as investors worried the coronavirus may be spreading in the U.S. A slew of corporate and analyst warnings on the virus also dragged down the major averages. The Dow Jones Industrial Average plummeted 1,190.95 points, or 4.4%. Thursday marked the Dow's biggest one-day point decline in history. The S&P 500 also closed below 3,000 for the first time since last October. Those losses put the Dow, S&P 500 and Nasdaq in correction territory, down more than 10% from their record closes. It took the Dow just 10 sessions to tumble from its all-time high into a correction. The S&P 500 and Nasdaq set record highs last week. —Imbert

4 pm: Goldman Sachs asks some clients to skip New York conference

Goldman Sachs is asking customers to skip a conference hosted by its investment bank next week if they've recently traveled to countries worst hit by the coronavirus. The warning, for Goldman's eighth annual housing and consumer finance conference held at the bank's New York headquarters, was just added to the event's registration website. "In light of the recent outbreak of the novel coronavirus, COVID-19, Goldman Sachs has enacted several precautionary measures to ensure the wellbeing of our clients and our people," the bank said. —Son

3:18 pm Dow falls 700 points

U.S. stocks continued their free fall in volatile trading as investors grow increasingly worried the coronavirus may be spreading in the U.S. A slew of corporate and analyst warnings on the virus also dragged down the major averages. The Dow Jones Industrial Average was down 716 points, or 2.7%, after plummeting more than 900 points earlier in the session. The S&P 500 slid 2.3% while the Nasdaq Composite dropped 2.5%. The Dow was on pace for its worst weekly performance since the financial crisis, falling more than 8% this week, along with the S&P 500. —Imbert

2:52 pm: Corona will continue controversial promotion for hard seltzer

Constellation Brands will continue a marketing push for its new Corona Hard Seltzer following backlash to a Twitter post that featured a video promising new Corona hard seltzer flavors are "coming ashore soon." Constellation, whose portfolio includes Corona Extra, Modelo Especial and Svedka Vodka, said last month it planned to spend more than $40 million in marketing its four new seltzer flavors, which is already appearing on shelves. But in the meantime, concerns about the spread of the coronavirus have surged. —Graham

2:26 pm: British region of Northern Ireland confirms first case

Northern Ireland authorities confirmed their first case of coronavirus, with the British region's chief medical officer Michael McBride telling journalists that the patient had traveled from Italy via Dublin. The case is in addition to the 15 cases confirmed in the United Kingdom by England's chief medical officer Chris Whitty earlier on Thursday. —Reuters

1:58 pm: California is monitoring at least 8,400 people for the coronavirus

California Gov. Gavin Newsom said the state is currently monitoring 8,400 people for COVID-19, a day after health officials confirmed the first apparent community transmission of the coronavirus in a Solano County resident. "This is a fluid situation right now and I want to emphaize the risk to the American public remains low," said Dr. Sonia Y. Angell, California Department of Public Health Director and State Health Officer during a press conference. "There have been a limited number of confirmed cases to date." —Lovelace

1:48 pm: The air-travel boom could come to an end

Air-travel demand had been growing at twice the pace of the global economy, but that bright spot is now at risk. U.S. airlines and other travel stocks have tumbled more than the broader market in this week's rout. The NYSE Arca Airline Index, which tracks 16 carriers in North America, Latin America and budget carrier Ryanair, has dropped more than 15% this week as of Wednesday's close, putting it on pace for its biggest weekly percentage loss since March 2009 — during the last recession. —Josephs

1:17 pm: Facebook cancels its annual developer conference

Facebook announced its decision to cancel its annual F8 software developer conference due to concerns surrounding the COVID-19 coronavirus outbreak. "This was a tough call to make — F8 is an incredibly important event for Facebook and it's one of our favorite ways to celebrate all of you from around the world — but we need to prioritize the health and safety of our developer partners, employees and everyone who helps put F8 on," Facebook Director of Platform Partnerships Konstantinos Papamiltiadis said in a blog post. —Rodriguez

1:04 pm: Nancy Pelosi calls stock market plunge 'disturbing'

House Speaker Nancy Pelosi called the stock market sell-off "disturbing" Thursday as she criticized the Trump administration's response to the global coronavirus outbreak and outlined conditions for an emergency funding proposal. The California Democrat also pushed back on President Donald Trump's suggestion — during a Wednesday evening White House briefing on the health crisis — that the stock plunge was at least in part the fault of Democratic presidential candidates. "Lives are at stake," she said. "This is not a time for name-calling or playing politics." —Breuninger

1:01 pm: This week's stock shock is just the start of the economic pain if coronavirus hits American wallets

Jitters over the outbreak have wiped $2 trillion from the stock market just this week. Many retail stocks, such as Macy's, Under Armour and Gap, are taking a beating on fears that consumer spending could slow. Investors may not be wrong. The market slide shows the virus doesn't need to run rampant in the U.S. to start wearing down consumer sentiment. In China, cities are being described as ghost towns. A widespread outbreak here would could similarly disrupt consumer spending, which accounts for 70% of the economy.

12:25 pm: Elizabeth Warren wants to use Trump's border wall money to fight coronavirus

Sen. Elizabeth Warren, D-Mass., unveiled a bill to divert money from President Donald Trump's border wall to the U.S. coronavirus response. As concerns rise about the outbreak spreading in the U.S., the 2020 Democratic presidential candidate argued the $1.25 billion in emergency funding sought by the president is inadequate. With the proposal, Warren not only aims to confront a budding public health crisis but also looks to knock a Trump policy she has called racist and divisive. —Pramuk

11:31 am: WHO warns Iran outbreak could be worse than thought

Iran, which had just two cases a week ago, confirmed 245 infections as of Thursday morning, but the outbreak could be even more widespread in the Islamic Republic than is currently known, said Dr. Mike Ryan, executive director of the World Health Organization's emergencies program. "This disease came unseen and undetected into Iran, so the extent of infection may be broader than what we may be seeing," Ryan told reporters. —Feuer

11:20 am: Starbucks reopens most China stores

Starbucks CEO Kevin Johnson said in a letter to employees that 85% of the global coffee chain's cafes in China are operating again. Starbucks closed more than half of its roughly 4,300 Chinese stores in January due to the COVID-19 outbreak.The company did not share any updates on the expected financial impact of the temporary closures. China accounted for 10% of Starbucks' revenue during its first quarter. —Lucas

People wait to pick up their orders at a Starbucks outlet in Hangzhou in east China's Zhejiang province Thursday, Feb. 13, 2020. Barcroft Media | Getty Images

11:10 am: US health secretary says at least 40 labs can currently test for coronavirus

U.S. Health and Human Services Secretary Alex Azar said that at least 40 public health labs are able to test specimens for coronavirus and that could more than double as soon as Friday. Azar, speaking before the House Ways and Means Committee, said the Centers for Disease Control and Prevention had tested 3,625 specimens for the fast-moving virus as of Thursday morning. He said at least 40 labs have test kits that were previously manufactured by the CDC and modified to test for coronavirus. He said a newly manufactured CDC test can be sent to 93 public health labs as soon as Monday, and a privately manufactured test based on the new CDC test could be sent to those same labs as early as Friday, pending FDA clearance. —Reuters

11 am: IMF likely to downgrade global growth

The International Monetary Fund said it is likely to downgrade its global economic growth forecast because of the fast-spreading coronavirus. "Clearly the virus is going to have an impact on growth," IMF spokesman Gerry Rice said without giving specific details. He said he expected a decision soon on the impact of the coronavirus for the IMF and World Bank spring meetings in April, noting that many options were under consideration. Reuters reported Wednesday that officials were considering scaling back the meetings or holding them by teleconference. —Reuters

10:46 am: Dow on pace for worst weekly performance since financial crisis

The Dow is on pace for its worst weekly performance since the financial crisis, falling more than 9% week to date. The benchmark index wsa down 950 points or 3.5%, at midmorning Thursday as investors worried about the spread of the coronavirus outside China and its economic impact. The S&P 500 slid 3.3% while the Nasdaq Composite dropped 3.7%. —Imbert

10:24 am: WHO advising Tokyo Olympics organizers

The World Health Organization said it is advising the organizers of the Tokyo Olympics and that no decision has been made to cancel the major sporting event in the midst of the coronavirus outbreak. "To my understanding, no decision has or will be taken in the near term regarding the future of the Olympics," said Dr. Mike Ryan, head of WHO's Health Emergencies Programme. He said that WHO was working "extremely closely" with event organizers and is providing them with risk assessment and management advice. —Newburger

10:18 am: European stocks enter correction territory

European stocks slid into correction territory as the rapid spread of the coronavirus weighed heavily on market sentiment. The pan-European Stoxx 600 fell 4% and officially entered correction territory as it was off more than 10% from its record high notched on Feb. 19, 2019. Germany's DAX and Italy's FTSE MIB were also in correction territory. —Smith, Ellyatt

People wearing protective face masks, following an outbreak of the coronavirus, are seen in front of the Giant Olympic rings at the waterfront area at Odaiba Marine Park in Tokyo, Japan, February 27, 2020. Athit Perawongmetha | Reuters

10:15 am: US Senate to take up funding legislation to fight coronavirus spread

Senate Majority Leader Mitch McConnell said he expects appropriators to produce funding legislation within the next two weeks to fight the spread of coronavirus in the United States. McConnell, speaking on the Senate floor, said he has faith that bipartisan discussions on the Senate Appropriations Committee would agree on "the right sum ... at this time to ensure our nation's needs are fully funded." —Reuters

10:05 am: Dow drops 500 points, stock market enters correction territory

Wall Street stocks fell sharply again as investors worried the coronavirus may be spreading in the U.S. A slew of corporate and analyst warnings also dragged down the major averages.The Dow Jones Industrial Average plummeted 529 points, or 2%. The S&P 500 slid 2.1% while the Nasdaq Composite dropped 2.4%. Those losses put the Dow in correction territory, down 10% from its from its record close to where it's trading at now. The S&P 500 was in correction territory on an intraday basis. —Imbert

9:31 am: WHO says failure to prepare for an outbreak 'could be a fatal mistake'

World Health Organization officials warned on Thursday that member nations need to prepare for COVID-19's arrival after seven countries in the last day reported their first cases. "Every country must be ready for its first case," said Tedros Adhanom Ghebreyesus, director-general of WHO. "No country should assume it won't get cases. That could be a fatal mistake. This virus does not respect borders." Tedros said the biggest concerns now are what's happening outside China, where the growth in cases have slowed. Brazil, Georgia, Greece, North Macedonia, Norway, Pakistan and Romania reported their first coronavirus cases in the last day, Tedros said. —Lovelace

9:11 am: PayPal warns coronavirus will have a negative impact on Q1 revenue

PayPal said the outbreak could have a negative impact on its revenue expectations and warned that revenue for the first quarter would be toward the lower end of the guidance it gave when it reported earnings in January. "We currently estimate the negative impact from COVID-19 to be an approximate one percentage point reduction, on both a spot and foreign currency-neutral basis, to PayPal's year-over-year revenue growth for the first quarter, as compared to the revenue guidance provided on January 29, 2020," the company said. —Bursztynsky

8:50 am: WHO officials hold press conference on the outbreak

World Health Organization officials are holding a press conference to update the public on the outbreak. WHO officials declared the COVID-19 a global health emergency last month, while urging the public against over-reacting to the virus. In the past week, the virus has spread substantially beyond China and is now circulating in at least 37 countries across the world. As the virus spreads, WHO Director-General Tedros Adhanom Ghebreyesus is calling the international community to action before it's too late. "The window of opportunity is still there, but our window of opportunity is narrowing," he said last week. "We need to act quickly before it closes completely." Watch the live 8:45 a.m. press conference here. —Feuer

8:13 am: Former FDA chief calls for greater investment in medical research

The world needs to invest billions of dollars in medical research to find effective treatment for the coronavirus, former Food and Drug Administration Commissioner Scott Gottlieb told CNBC. "We have to prepare that this is not something that's going to start and stop," he said. "This could become something that we have to live with and what's going to inevitably be a backstop against it's going to be a therapeutic or a vaccine. We need to invest very heavily in that right now." —Feuer Disclosure: Scott Gottlieb is a CNBC contributor and is a member of the boards of Pfizer and biotech company Illumina.

7:30 am: Chinese government releases new data about the economic impact

7:20 am: Dow is set to drop on report of first US case of unknown origin

U.S. stock futures morning pointed to declines at the day's open even after President Donald Trump tried to calm fears over the coronavirus outbreak. Futures slipped after the Centers for Disease Control and Prevention confirmed the first U.S. coronavirus case of unknown origin in Northern California. —Imbert

7:10 am: CDC confirms first possible community transmission in the US

People wear surgical masks while shopping at a grocery store in Cupertino, California, United States on January 23, 2020 before the start of Lunar New Year. There are now 8,235 confirmed cases of coronavirus, with 171 death and 143 recovered. Yichuan Cao | NurPhoto | Getty Images

U.S. health officials late Wednesday confirmed the first possible community transmission of the coronavirus in America, a troubling sign that the virus could be spreading in local cities and towns. The Centers for Disease Control and Prevention doesn't know exactly how the California patient contracted the virus. The individual is a resident of Solano County and is receiving medical care in Sacramento County. The patient didn't have a relevant travel history or exposure to another patient with the virus, the CDC said. "At this time, the patient's exposure is unknown," it said. "It's possible this could be an instance of community spread of COVID-19, which would be the first time this has happened in the United States." —Lovelace

6:35 am: China's central bank 'very worried' about impact on global economy

"International organizations are worried about the negative impact of the [virus] to the global economy," Liu Guoqiang, a vice governor of the People's Bank of China, said Thursday, according to a CNBC translation of his Mandarin-language remarks. "I'm also very worried," he said, "and this worry has become a reality." Liu noted how China, the world's second-largest economy, is one of the few countries in the world that has not resorted to "unconventional monetary policy." As a result, he said, "China has relatively larger space for policy action, and has the ability to cope with various challenges, something which should be cherished and maintained." He noted how domestic interest rates, as guided by the loan prime rate, have room to fall further. —Cheng

6:25 am: Japan's Abe to ask schools to close from March 2 through to spring break

Elementary school students walk on the snow-covered street in Sapporo, Hokkaido, Japan, February 26, 2020. Issei Kato | Reuters

Japanese Prime Minister Shinzo Abe said Thursday the government will ask all elementary, junior high and high schools to close from March 2 through to spring break. Abe's comments, according to Reuters, came at a meeting of the government's task force as part of efforts to contain the coronavirus outbreak. Spring break in Japan typically ends around late March. —Meredith

6:10 am: Iran's health ministry confirms 245 coronavirus cases; death toll at 26

Iran's health ministry has confirmed 106 additional cases of the coronavirus in the last 24 hours, bringing the total number of infections there to 245. Iran's death toll as a result of the COVID-19 outbreak has also been raised to 26, Kianoush Jahanpour, a spokesperson for the Islamic Republic's health ministry, said Thursday. Iran is at the epicenter of the outbreak in the Middle East, having recorded the highest number of coronavirus fatalities outside China. Health authorities from Afghanistan, Bahrain, Iraq, Kuwait, Oman, and the United Arab Emirates have all reported cases of the coronavirus that stemmed from Iran. Earlier on Thursday, Saudi Arabia announced it would temporarily suspend the entry of foreigners for pilgrimage and tourism purposes. —Meredith

4:45 am: South Korea confirms record spike of cases, outnumbers China for daily infections