Nigerian airplane crash: All 153 on board dead

New York, Jan 10: The US's National Transportation Safety Board (NTSB) announced that it has accepted an invitation from Tehran to participate in its investigation into the crash of a Ukrainian plane amid speculations that an Iranian missile might have brought down the plane.

The federal agency said in a statement on Thursday that the Iran Civil Aviation Organization has notified them that they could take part in the investigation of the plane crash that occurred shortly after taking off from Tehran on Wednesday, killing all 176 people on board, reports the Efe news.

"The NTSB has designated an accredited representative to the investigation of the crash," said the independent US government agency tasked with investigating transport accidents.

Since the aircraft was a US-made Boeing 737-800, international regulations allow Washington to be a part of the accident investigation.

However, it remains unclear to what extent the NTSB representative will be able to play an active role in the probe, as US sanctions complicate cooperation with Iran, and the two countries have no diplomatic relations.

The NTSB announcement came hours after US intelligence sources told several media outlets that the Kiev-bound Ukrainian International Airlines (UIA) flight 752 could have been accidentally shot down by an Iranian missile.

Canadian Prime Minister Justin Trudeau later confirmed that his government had "evidence" indicating that the aircraft "was shot down by an Iranian surface to air missile", although he added it may have been unintentional.

The accident occurred on the same day after Iran launched more than a dozen ballistic missiles at two US military bases in Iraq, in retaliation for the killing of Iranian Major General Qasem Soleimani in an American drone attack in Baghdad on January 3.

However, the Iranian authorities have denied that they had accidentally shot down the plane and claimed the accusations were a part of a psychological warfare campaign against Tehran.

Iranian foreign ministry spokesman Abbas Mousavi said they welcomed the presence of experts from countries whose citizens have died in the tragic accident, and requested Trudeau and any other government to provide any information they had regarding the crash.

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.