Novel coronavirus (NCoV) deadlier than SARS?

[alert]

I don't know if I agree with this assessment. It is possible the higher reported CFR might be due to missed milder cases; many of the NCoV fatalities had significant co-morbidities, far more than one might expect in a random sample of 17 individuals. It might be that only the most severe cases are being discovered, and those would likely be in those individuals who were sicker prior to infection.

http://www.scmp.com/news/hong-kong/...erious-new-coronavirus-could-be-deadlier-sars

New coronavirus appears deadlier than Sars, says HKU
Mysterious coronavirus, though not less infectious, has a higher mortality rate and infects many species, Hong Kong researchers find

.Thursday, 28 March, 2013, 5:58am

The mysterious new coronavirus that emerged in the Middle East and has killed 11 people is potentially more deadly than Sars and also more "promiscuous" - able to infect many different species - University of Hong Kong research has found.

Unlike Sars (severe acute respiratory syndrome), the new coronavirus can affect many different organs in the body and kills cells rapidly, the researchers say.

The source of the new infection is still unknown, but the virus appears to have originated in bats, a team of European experts wrote in the journal mBio.

The HKU research listed animals including monkeys, pigs, civet cats and even rabbits that could be hosts of the virus before it found its way to humans. Lead researcher Yuen Kwok-yung, a microbiologist, said this meant the source of human infection would be difficult to trace.

The World Health Organisation announced yesterday that the disease had killed two more people - a 73-year-old from the United Arab Emirates and a Briton who had visited Saudi Arabia and Pakistan - bringing the death toll to 11. The WHO has confirmed 17 cases to date.

Yuen told the South China Morning Post that the virus could cause a deadly pandemic if it mutated further. "It could be more virulent [than Sars]", he said. "The Sars coronavirus infects very few human cell lines. But this new virus can infect many types of human cell lines, and kill cells rapidly."

The findings, tested in human cell lines, suggest the virus could cause widespread organ infection. It could attack the lower airway, liver, kidneys and intestines as well as tissue macrophages - cell clusters that "eat" bodily debris such as dead cells.

The report, published by the Journal of Infectious Diseases this week, says the new virus "is markedly different" from the other non-Sars human coronaviruses that usually have little ability to move among different cells, and cause self-limiting upper respiratory tract infections.

This may explain why patients with the new coronavirus can suffer multiple organ failure, resulting in a high mortality rate of 56 per cent - in contrast to 11 per cent for Sars.

[snip]

 

[alert]

Re: Novel coronavirus (NCoV) deadlier than SARS?

More on the study done in Hong Kong:

http://www.cidrap.umn.edu/cidrap/content/other/sars/news/mar2713corona.html

Novel coronavirus lab studies hint at wide tissue susceptibility
Lisa Schnirring Staff Writer


Mar 27, 2013 (CIDRAP News) – Experiments by Hong Kong researchers to gauge the susceptibility of several human and animal cell lines to novel coronavirus (NCoV) found signs that it can infect a broad range of tissues, which might shed light on the disease's seemingly high mortality rate.

Though many questions remain about the source of the new virus and how it spreads, health officials know that it can cause severe clinical illness in some patients, including severe pneumonia and renal failure, the group wrote. They added that until more is known about the disease, lab studies could help provide clues.

The tests they conducted with NCoV and the cell lines are surrogates of virus growth in the tissues. They measured viral load in the cultures, nucleoprotein expression, and cytopathic effect. They published their findings yesterday in an early online edition of the Journal of Infectious Diseases (JID).

The group used an autopsy NCoV virus sample obtained from the first known case-patient, a Saudi Arabian man who died from the disease in June. They used 27 cell lines from different tissues and organs in their susceptibility tests, 14 from humans and 13 from animals.

Tests suggested that NCoV can infect human respiratory, kidney, and liver cells, as well as histiocytes. The impact on neuronal cells and monocytes was much less.

Researchers suggested that the range of human tissues that are susceptible to infection appears to be broader than all other human coronaviruses, including the SARS (severe acute respiratory syndrome) virus. The team said this finding might help explain the disease's pathogenesis and high mortality.

Human upper-airway cells did not seem to support the growth of the novel virus, which the investigators said isn't surprising, given that many of the lab-confirmed cases had severe acute pneumonia. However, more data on infected patients is needed to determine if the clinical pattern is similar to SARS, in which the virus was also shed in the upper airways, which played a role in human-to-human transmission.

More studies are needed to explore the histopathologic changes in the kidneys of patients infected with NCoV, the group wrote. They also noted that research is needed to determine the viral load in patients' urine specimens, because acute renal failure might be a mortality risk factor for NCoV, as it was for SARS.

Experiments on the animal cell lines suggested that NCoV can infect cells from non-human primates, pigs, civets, and rabbits, results that they said add to earlier findings showing the virus can infect bat cells. They wrote that their findings strengthen the suspicion that the virus can jump interspecies barriers.

"The presence of a receptor utilized by the virus which is common in bats, primates, pigs, civets, rabbits, and humans might imply a broad species tropism, which is unique among all the currently known human coronaviruses," the group wrote.

In an editorial in the same issue of JID, Kenneth McIntosh, MD, with the division of infectious Diseases at Boston Children's Hospital, wrote that aside from extensive genetic sequence data and a report on receptor usage in tissue culture, little has been published on the biology or pathogenicity of NCoV in humans or animals.

McIntosh noted that in the current study infectious virus wasn't measured in any of the cell lines and that evidence of viral replication was measured more indirectly, based on detection of viral RNA or viral nucleoprotein.

Though virologists have used in vitro tests to guide them oin what cells to tests for in vitro growth and understanding more about pathogenesis, he wrote that there are several examples, including those involving coronaviruses, in which viruses didn't behave as expected in the organisms.

Filling knowledge gaps about NCoV based on in vitro tests is tempting, but difficult and risky, McIntosh wrote. However, he added that the Hong Kong group's work is useful for showing wide tissue tropism in the lab.

ECDC airs geographic considerations
In other developments, the European Centre for Disease Control and Prevention (ECDC) updated its epidemiologic assessment today, as four new cases have been reported since its last report on Feb 22.

It noted that three of the four cases were reported by Saudi Arabia's health ministry, with the last one reported on Mar 25 by Germany's Robert Koch Institute, the 73-year-old man from the United Arab Emirates who died in a Munich hospital yesterday.

The ECDC noted that six case-patients so far have been diagnosed and treated in Europe, three of whom were transferred from Arabian Peninsula countries where they were infected.

Though the number of NCoV infections increased over the past month, most cases continue to have links to the Arabian Peninsula, where contact tracing and epidemiologic investigations are under way, the group wrote.

Also, the ECDC issued a separate document that addresses the World Health Organization's (WHO's) NCoV surveillance update, which was published on Mar 18. Though the latest version from the WHO is more comprehensive, the ECDC took issue with one of the testing recommendations.

It noted that for testing, the WHO no long distinguishes between countries in which unexplained sporadic cases have occurred and those, such as in Europe, that have detected imported cases or infections linked to imported cases.

It said the November version of the WHO guidance specifically referenced countries in the Arabian Peninsula and their neighbors. However, the ECDC said it and the US Centers for Disease Control and Prevention (CDC) are retaining that recommendation. The CDC lists the countries considered in the Arabian Peninsula and neighboring areas as Bahrain, Iraq, Iran, Israel, Jordan, Kuwait, Lebanon, Oman, Palestinian territories, Qatar, Saudi Arabia, Syria, the United Arab Emirates, and Yemen.

"In ECDC's view, at present there is not a case for considering European countries epidemiologically the same as those countries in the Middle East where indigenous sporadic infections and clusters have been detected," the statement says.

The ECDC added that a strong case can be made for EU countries to continue using geography as one risk factor for testing patients for NCoV and for healthcare workers to remain vigilant when caring for patients with respiratory infections who are evacuated from Arabian Peninsula and neighboring countries.

Chan JF, Chan K, Choi GK, et al. Differential cell line susceptibility to the emerging novel human betacoronavirus 2c EMC/2012: implications on disease pathogenesis and clinical manifestation. J Infect Dis 2013 Mar 26 [Abstract]

McIntosh K. A new virulent human coronavirus: how much does tissue culture tropism tell us? (Editorial) J Infect Dis 2013 Mar 26 [Full text: http://jid.oxfordjournals.org/content/early/2013/03/24/infdis.jit125.short]

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I have put the full link for the above paper. It is worth reading in full, as the author points out many cautions about this line of reasoning and why this conclusion about the true severity of NCoV may not be justified. - alert

 

[Ronan Kelly]

Re: Novel coronavirus (NCoV) deadlier than SARS?

Link to PDF - Differential cell line susceptibility to the emerging novel human betacoronavirus 2c EMC/2012: implications on disease pathogenesis and clinical manifestation

and another published paper (PDF); A new virulent human coronavirus: How much does tissue culture tropism tell us?

Questions arise whether in vitro studies can be translated to in vivo situations.

 

[Pathfinder]

Re: Novel coronavirus (NCoV) deadlier than SARS?

Hattip Alert

<IFRAME height=360 src="http://www.youtube.com/embed/Gp5recIznH0" frameBorder=0 width=480 allowfullscreen></IFRAME>

New coronavirus not SARS: Thomas Tsang (26.9.2012)

http://www.youtube.com/watch?v=Gp5recIznH0&feature=player_embedded


Dr. Thomas Tsang is the former controller of the city's Center for Health Protection

 

[Pathfinder]

Re: Novel coronavirus (NCoV) deadlier than SARS?

Hong Kong, Shaken by SARS Outbreak in ?03, Keeps Wary Eye on New Virus

By KEITH BRADSHER

Published: March 28, 2013
...
Hong Kong University researchers are now expressing growing concern about the new coronavirus that has emerged in the Middle East, known as novel coronavirus. Dr. Malik Peiris, a co-discoverer of SARS who is the director of the center for influenza research at Hong Kong University, warned in a speech on Tuesday that while SARS faded away after a year, with 8,445 cases and 790 deaths worldwide, two other coronaviruses had jumped from animals to people in the past two centuries and become endemic.

Both of those coronaviruses cause common colds. One of the concerns about the novel coronavirus is that it seems deadlier, having killed more than half of the people with confirmed cases. A study published this week in The Journal of Infectious Diseases by Dr. Yuen and 12 colleagues in Hong Kong and mainland China found that the new virus also infects a wider range of human tissue types than the SARS virus and kills them more quickly.
...
One big question is whether far more people are being infected without detection, in which case the disease may kill a lower percentage of victims but also be more transmissible. Dr. Yuen said that when 2,400 people were screened recently in Saudi Arabia for antibodies to the virus, none had them.

That suggests that the virus is periodically infecting people from an unknown animal host, but it has not developed the ability to pass easily from person to person, he said...

The H5N1 avian influenza virus has been periodically jumping from birds to people and causing sporadic deaths for 16 years without developing sustained transmissibility among people. On the other hand, the SARS virus appears to have developed transmissibility after only a few months of sporadic infections of people in southern China in late 2002.

For the new virus, ?we may be at the 2002 situation at this time, and that would be very, very bad,? Dr. Yuen said. ?But this also may be like H5N1.?

Full text:
http://www.nytimes.com/2013/03/29/world/asia/hong-kong-prepares-for-new-coronavirus.html?_r=0