How does a vaccination for dogs work? One of the 195 Americans evacuated from Wuhan, China, was placed under mandatory quarantine after trying to leave the facility where the evacuees were supposed to stay for 72 hours of voluntary monitoring, Reuters reported Thursday, citing public health officials.
A study of a cluster of five infections in a family in Shenzhen identified a child who was infected with the virus but did not show any symptoms 3 If such asymptomatic cases are common and these individuals can spread the virus, then containing its spread will be much more difficult, researchers say.
The attack rate or transmissibility (how rapidly the disease spreads) of a virus is indicated by its reproductive number (Ro, pronounced R-nought or r-zero), which represents the average number of people who will catch the disease from a single infected person.
WHO Director-General Tedros Adhanom Ghebreyesus, right, with WHO Health Emergencies Program head Michael Ryan at a press conference following a WHO Emergency committee to discuss whether the new chinatown constitutes an international health emergency, on January 30, 2020, in Geneva.
Additionally, estimates suggest that cases of 2019-nCoV infection may have spread from Wuhan to multiple other major Chinese cities as of January 25, including Guangzhou (111 cases), Beijing (113), Shanghai (98), and Shenzhen (80; figure 3). Together these cities account for over half of all outbound international air travel from China.
One way to determine whether symptom-free people can spread the virus would be to study its spread in individual households in China, says Sheila Bird, a biostatistician at the University of Cambridge, UK. By closely monitoring all the members of a household in which one person is infected, it should be possible to determine who else contracts the virus and how.
But three times so far in the 21st century, novel coronaviruses have emerged that could potentially cause a deadly pandemic—SARS (severe acute respiratory syndrome) in 2003, MERS (Middle East respiratory syndrome) in 2012, and now 2019-nCoV emanating from Wuhan, China.
The World Health Organization ( WHO ) has declared a global health emergency over a new coronavirus that has killed at least 361 people in China following an outbreak in the central city of Wuhan, forcing a government lockdown in almost 20 cities that, in effect, has quarantined an estimated 56 million people.
On Friday, the Trump administration announced that foreign nationals who visited China within the past 14 days will be barred from entering the U.S., while Americans who visited the Chinese province at center of outbreak will be quarantined upon their return to the U.S. Several U.S. airlines suspended flights to China.
Background: In December, China notified the World Health Organization of several cases of human respiratory illness, which appeared to be linked to an open seafood and livestock market in the city of Wuhan The infecting agent has since been identified as a novel coronavirus , now called 2019-nCoV.