COVID-19 spreads even before people show symptoms, study says

Agencies
March 15, 2020

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.

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News Network
January 21,2020

Beijing, Jan 21: The Chinese official investigating a pneumonia outbreak stemming from a new coronavirus said the disease can spread from person to person but can be halted with increased vigilance, as authorities on Tuesday confirmed a fourth death.

Zhong Nanshan said there was no danger of a repeat of the Severe Acute Respiratory Syndrome (SARS) epidemic that killed nearly 800 people globally during a 2002-2003 outbreak, which started in China, as long as precautions were taken.

"It took only two weeks to identify the novel coronavirus," state news agency Xinhua quoted Zhong as saying late on Monday.

The outbreak was still in its early stages and China had good surveillance and quarantine systems to help control it, he added.

The outbreak has spread from the central city of Wuhan to cities including Beijing and Shanghai, with more than 200 cases reported so far. Four cases have been reported outside China - in South Korea, Thailand and Japan.

Australia on Tuesday said it would screen passengers on flights from Wuhan amid rising concerns that the virus will spread globally as Chinese travellers take flights abroad for the Lunar New Year holiday starting this week.

Authorities around the globe, including in the United States and many Asian countries, have stepped up screening of travellers from Wuhan.

Chinese authorities confirmed a total of 217 cases of the virus in China as of 6 p.m. (1000 GMT) on Monday, state television reported, 198 of which were in Wuhan.

A fourth person died on Jan. 19, the Wuhan Municipal Health Commission said. The 89-year-old man, who had underlying health diseases including coronary heart disease, developed symptoms on Jan. 13 and was admitted to hospital five days later, it added.

Zhong, who is renowned in China for his work fighting SARS in 2003, confirmed that the virus can pass from person-to-person.

Fifteen medical workers in Wuhan had been diagnosed with pneumonia, with one other suspected case, the Wuhan Municipal Health Commission said. Of the infected staff, one was in critical condition.

In Shanghai, officials on Tuesday confirmed a second case involving a 35-year-man who had visited Wuhan in early January, and said they were monitoring four other suspected cases.

The virus causes a type of pneumonia and belongs to the same family of coronaviruses as SARS. Symptoms include fever and difficulty in breathing, which are similar to many other respiratory diseases and pose complications for screening efforts.

The World Health Organisation (WHO) said on Monday an animal source appeared most likely to be the primary origin of the outbreak and that some "limited human-to-human transmission" occurred between close contacts.

The Geneva-based U.N. agency convened an emergency committee for Wednesday to assess whether the outbreak constitutes an international health emergency and what measures should be taken to manage it.

So far, the WHO has not recommended trade or travel restrictions, but a panel of independent experts could do so or make other recommendations to limit spread.

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Agencies
January 21,2020

Fifty-six journalists were killed in 2019 and most of them died outside conflict zones, a United Nations spokesperson said.

The number dropped by nearly half from the year 2018, but perpetrators enjoyed almost total impunity, Xinhua news agency quoted Stephane Dujarric, spokesperson for UN Secretary-General Antonio Guterres, as saying on Monday citing Unesco figures.

The figure was published in the 'Unesco Observatory of Killed Journalists' on Monday.

In total, Unesco recorded 894 journalist killings in the decade from 2010 to 2019, an average of almost 90 per year. The number in 2019 was 99.

Journalists were murdered in all regions of the world, with Latin America and the Caribbean recording 22 killings, the highest number, followed by 15 in Asia-Pacific, and 10 in Arab States.

"The figures show that journalists not only suffer extreme risks when covering violent conflict, but that they are also targeted when reporting on local politics, corruption and crime - often in their hometowns," the Unesco said.

Almost two thirds (61 per cent) of the cases in 2019 occurred in countries not experiencing armed conflict, a notable spike in a wider trend in recent years, and a reversal of the situation of 2014, when this figure was one third.

More than 90 per cent of cases recorded in 2019 concerned local journalists, consistent with previous years, it added.

In response to these figures, Audrey Azoulay, the Director-General of Unesco, said: "Unesco remains deeply troubled by the hostility and violence directed at all too many journalists around the world.

"As long as this situation lasts, it will undermine democratic debate."

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News Network
May 20,2020

May 20: The novel coronavirus is behaving differently in patients in northeast China who have contracted it recently compared with early cases, indicating it is changing as it spreads, a prominent doctor said.

China, which has largely brought the virus under control, has found new clusters of infections in the northeastern border provinces of Jilin and Heilongjiang in recent weeks, raising concern about a second wave.

Qiu Haibo, an expert in critical care medicine who is part of a National Health Commission expert group, said the incubation period of the virus in patients in the northeast was longer than that of patients in Wuhan, the central city, where the virus emerged late last year.

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"This causes a problem, as they don't have any symptoms. So when they gather with their families they don't care about this issue and we see family cluster infections," Qiu told state broadcaster CCTV in a programme broadcast late on Tuesday.

Patients in the northeastern clusters were also carrying the virus for longer than earlier cases in Wuhan, and they were taking longer to recover, as defined by a negative nucleic acid test, he said.

Patients in the northeast also rarely exhibited fever and tended to suffer damage to the lungs rather than across multiple organs, he said.

He said the virus found in the northeastern clusters was probably imported from abroad, which could account for the differences.

He did not say where he though they might have come from but both Jilin and Heilongjiang border Russia.

China reported five new coronavirus cases on Wednesday, down from six a day earlier.

Four of the new cases were local transmissions and one was imported by a traveller coming from abroad, the commission said in a statement, compared with three imported cases reported the previous day.

China's total number of coronavirus infections stands at 82,965, while the death toll 4,634. 

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