Jan 27, 2020

Americans still have low risk of coronavirus infection, CDC says

National Center for Immunization and Respiratory Diseases Director Nancy Messonnier speaks during a press conference on the coordinated response to the coronavirus outbreak. Photo: Samuel Corum/Getty Images

The risk of U.S. residents becoming infected by the coronavirus that's devastating China remains low right now, public health officials said Monday, even as there's growing pressure to ramp up U.S. and international pandemic preparedness.

The latest: There are at least 2,886 confirmed cases of 2019-nCoV in 16 countries or regions and 82 deaths in China. The U.S. has five confirmed cases with 110 people in 26 states under investigation so far, 32 of whom tested negative, according to the Centers for Disease Control and Prevention.

"At this time in the U.S., the virus is not spreading in the community ... the risk remains low."
— Nancy Messonnier, director of the CDC's National Center for Immunization and Respiratory Diseases, at a press briefing

Reality check: At the moment, the influenza outbreak is more dangerous to Americans. The CDC says flu activity remains high — this season so far has an estimated 15 million illnesses, 140,000 hospitalizations and 8,200 deaths (including 54 children) in the U.S. as of Jan. 18.

"Absolutely, the flu is a bigger risk for Americans than the coronavirus, right now."
— Melissa Nolan, an infectious disease expert, tells Axios

Yes, but: Because this is a new coronavirus, and there are many "unknowns" about it, there's the potential for a pandemic, which the CDC acknowledged on Sunday.

  • And, if the Chinese health ministry is correct when they say people begin shedding the virus before showing symptoms, this could be a game-changer.
  • "This would be very unusual, and very concerning," as a similar coronavirus, SARS, was not contagious before symptoms appeared, Nolan says.
  • But, Messonnier says they have not seen this in the U.S., where so far all confirmed cases have been people who've traveled in Wuhan.

What's happening now: The U.S. will continue screening passengers coming indirectly from Wuhan at five airports, conduct contact tracing for all confirmed patients to monitor for new infections, and publicize research via GenBank so labs can develop targeted diagnostics, treatments and vaccines.

What we know so far: It's early days in investigating this virus, so some reports may be based on too few samples or show an incomplete picture.

  • It "doesn't look like the virus has mutated" yet, at least when the U.S. compares the genetic sequences of China's initial sequencing of the virus and the first two American cases, Messonnier says. If it continues to mutate slowly, diagnostics, treatments and vaccines are likely to be more effective.
  • The incubation period appears to be around 2–14 days, she adds.

What we don't know: Per Nolan, who is an assistant professor at the University of South Carolina’s School of Public Health, researchers need to determine...

  • What is the animal "reservoir" where the virus first transmitted to humans, so it can be culled.
  • How contagious is this virus — such as looking at how fast it "reproduces," called R-naught. One initial report says the average infection rate is about 2.6 people per infected person — this is higher than SARS' rate of 2.0 but less contagious than measles, which is around 12-18. "In general, you want the R-naught to be below one," Messonnier says.
  • Whether super-spreaders, or people who shed the virus more than most, are transmitting the virus to others. Reports point to the possibility that one person infected 15 health workers in China.

Go deeper:

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6 Americans now confirmed with coronavirus, CDC says

Stuart Marcus, chief clinical officer of Amita Health Chicago, briefs the media regarding the second confirmed case of Wuhan Coronavirus in the U.S., Jan. 24, outside St. Alexius Hospital in Hoffman Estates, Illinois. Photo: Derek R. Henkle/AFP via Getty Images

Six Americans — in California (2), Arizona, Washington state, and Chicago (2) — have the novel coronavirus that's been spreading from China, as of Thursday according to the Centers from Disease Control and Prevention.

What they're saying: "We need to prepare as if this is a pandemic, but we hope it is not," Nancy Messonnier, director of CDC's National Center for Immunization and Respiratory Disease told a press conference on Sunday.

Go deeperArrowUpdated Jan 30, 2020

China to admit international experts to examine coronavirus

Alex Azar speaks during a Jan. 28 press conference on the coordinated public health response to 2019-nCoV, with Robert Redfield (L), Nancy Messonnier and Anthony Fauci. Photo: Samuel Corum/Getty Images

China agreed on Tuesday to allow international experts, expected to include Americans, to work on the ground with their scientists on the fast-spreading coronavirus.

Why it matters: Roughly 60 cases are outside mainland China, where the outbreak has infected at least 4,633 people. While China quickly provided global access to the virus genome, the epidemiology of how the virus works is hard to determine from outside China with little public data.

Go deeperArrowJan 28, 2020

Coronavirus may be "at the brink" of a global pandemic

Illustration: Sarah Grillo/Axios

The coronavirus outbreak may be "at the brink" of a global pandemic, Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, tells Axios.

What's new: Signs people are infecting each other in a more sustainable fashion in China, an uptick in confirmed cases in Japan and Singapore, and research showing people without symptoms may be able to infect each other are fueling concerns that COVID-19 will develop into a pandemic.

Go deeperArrowFeb 19, 2020 - Health