British PM Boris Johnson moved to ICU after coronavirus symptoms worsen

Houston, Mar 15: Researchers, studying the novel coronavirus, have found that the time between cases in a chain of transmission is less than a week, and over 10 per cent of patients are infected by someone who has the virus, but does not show symptoms yet, a finding that may help public health officials contain the pandemic.

The study, published in the journal Emerging Infectious Diseases, estimated what's called the serial interval of the coronavirus by measuring the time it takes for symptoms to appear in two people with the virus -- the person who infects another, and the infected second person.

According to the researchers, including those from the University of Texas at Austin, the average serial interval for the novel coronavirus in China was approximately four days.

They said the speed of an epidemic depends on two things -- how many people each case infects, and how long it takes cases to spread.

The first quantity, the scientists said, is called the reproduction number, and the second is the serial interval.

Due to the short serial interval of the disease caused by the coronavirus -- COVID-19 -- they said, emerging outbreaks will grow quickly, and could be difficult to stop.

“Ebola, with a serial interval of several weeks, is much easier to contain than influenza, with a serial interval of only a few days,” said Lauren Ancel Meyers, study co-author from UT Austin.

Meyers explained that public health responders to Ebola outbreaks have much more time to identify and isolate cases before they infect others.

“The data suggest that this coronavirus may spread like the flu. That means we need to move quickly and aggressively to curb the emerging threat,” Meyers added.

In the study, the scientists examined more than 450 infection case reports from 93 cities in China, and found the strongest evidence yet that people without symptoms must be transmitting the virus -- known as pre-symptomatic transmission.

More than one in ten infections were from people who had the virus but did not yet feel sick, the scientists said.

While researchers across the globe had some uncertainty until now about asymptomatic transmission with the coronavirus, the new evidence could provide guidance to public health officials on how to contain the spread of the disease.

“This provides evidence that extensive control measures including isolation, quarantine, school closures, travel restrictions and cancellation of mass gatherings may be warranted,” Meyers said.

The researchers cautioned that asymptomatic transmission makes containment more difficult.

With hundreds of new cases emerging around the world every day, the scientists said, the data may offer a different picture over time.

They said infection case reports are based on people's memories of where they went and whom they had contact with, and if health officials move quickly to isolate patients, that may also skew the data.

“Our findings are corroborated by instances of silent transmission and rising case counts in hundreds of cities worldwide. This tells us that COVID-19 outbreaks can be elusive and require extreme measures,” Meyers said.

Washington, Apr 28: US President while addressing a news conference on coronavirus pandemic said his administration has launched "very serious investigations" into China's response to the novel coronavirus.

"And we are not happy with China, we are not happy with that whole situation, because we believe it could have been stopped at the source," he said. "It could have been stopped quickly and it wouldn't have spread all over the world," the BBC reported.

Trump has been critical of China as the pandemic has progressed and has frequently touted his decision to close the US borders to China in an effort to curb the outbreak. Some health experts have said the effort bought time for the US to prepare, but the Trump administration has been accused of squandering the opportunity.

"Nobody except one country can be held accountable for what happened," Trump said.

"Nobody's blaming anybody here, we're looking at a group of people that should've stopped it at the source."

The US will never forget those who were "sacrificed for a reason of incompetence or something else other than incompetence," he added.

"They" - referring to China - "could've protected the whole world - not just us - the whole world," he said.

At the starting of the conference Trump said COVID-19 cases are declining or stablising across the country.

"In all cases getting better," he said. "Really a horrible situation that we've been confronted with, but they're moving along."

He added there's a "hunger" to get back to work.

"Ensuring the health of our economy is vital to ensuring the health of our nation - these goals work in tandem."

The president has suggested an unnamed individual "a long time ago" could have stopped the "unnecessary death[s]" due to COVID-19.

"There has been so much unnecessary death in this country," he said.

"It could've been stopped and it could've been stopped short, but somebody a long time ago, it seems, decided not to do it that way and the whole world is suffering because of it."

He did not say who he was referencing and gave no other details.

Trump was asked if he has considered delaying the November presidential election.

"I never even thought of changing the date of the election," he answered. "Why would I do that? November 3rd. That's a good number."

Trump called the suggestion "made up propaganda" and said that "sleepy Joe" Biden - his presumptive Democratic rival - was likely unaware his campaign had put the statement out.

Former Vice-President Joe Biden said at a virtual fundraiser last week that he thought Trump would "try to kick back the election somehow".

The president has frequently levelled insults at his Democratic opponent by questioning the former vice-president's mental fortitude.

"I look forward to that election," Trump said.

The president responded to a question criticising Health Secretary Alex Azar's early downplaying of the disease by saying it was "unfair". He claimed Democrats did the same, including Speaker of the House of Representatives Nancy Pelosi.

"I was very fortunate through luck or whatever that we closed the border, we put a ban on China," he said.

"But I could tell you that Nancy Pelosi was dancing in the streets in Chinatown. She wanted to go, let's go out and party. That was late in February."

Back in February, Pelosi had encouraged people to visit San Francisco's Chinatown to help struggling businesses. She did not propose any parties, as the president suggested.

The city issued a stay-at-home order in March.

A reporter asked: If an American president loses more Americans over the course of six weeks than died during the entirety of the Vietnam war, does he deserve to be reelected?

Trump took the question in stride.

"So, yeah, we've lost a lot of people but if you look at what original projections were, 2.2 million, we're probably heading to 60,000 - 70,000," he said.

"It's far too many - one person is too many for this. I think we've made a lot of really good decisions," he added. "The big decision was closing the border, doing the ban on people coming in from China."

He also brings up the "unbelievable" job his administration did with ventilators.

"I think we've done a great job. And I will say this - one person is too many."