Friday, September 21, 2012

Sometimes They Come Back


Credit Wikipedia


UPDATED 9/23/12: See  Details Emerge On (3) Saudi Coronavirus Cases


# 6568


This November will be the 10 year anniversary of the SARS (Severe Acute Respiratory Syndrome) outbreak that began in Guangdong Province, China.  An epidemic that would – over the ensuing six months – move well beyond the borders of China, infecting more than 8,000 people, and killing nearly 800.



Source World Health Organization


The SARS epidemic was eventually contained due to the combined efforts of public health agencies around the globe, helped along no doubt by the fact that – unlike with influenza – patients didn’t appear to be contagious until after symptoms appeared. 


By the summer of 2003, the crisis was over – but the investigation into how it came about was still underway.


SARS appears to have emerged due the penchant of some prosperous Chinese to dine on exotic animals.  These animals were slaughtered, and served, in `Wild Flavor' restaurants, particularly in Guangdong Province.


There you could partake in all sorts of exotic dishes – including dog, cat, civet, muskrat, ferret, monkey, along with a variety of snakes, reptiles, and birds.


What are commonly referred to as `bushmeat’.


For a horrific description of the conditions in these restaurants, I would direct you to an essay by Karl Taro Greenfeld called Wild Flavor which appeared in the Paris Review in 2005.


Greenfeld, you may recall, is also the author of The China Syndrome: The True Story of the 21st Century's First Great Epidemic.  Perhaps the most authoritative (and absolutely riveting) account of the SARS outbreak of 2003, and how it was directly linked to the practice of consuming bushmeat in China.


It was finally determined that a previously unknown coronavirus, which was detected in civet cats served in these establishments, was the cause of the SARS outbreak (see  A Civets Lesson).


Since that time, bats have also been shown to carry this Coronavirus (among others) as well.  The jury is out on whether the virus was transmitted directly to man from bats, or perhaps from bats to civits to humans.


Since 2003 the Chinese government has outlawed the use of civits as a food source, although reportedly it can still be purchased in some eating establishments and live markets.


There have been no new reports of SARS anywhere in the world since 2003, but the threat has certainly not gone away. The virus, presumably, resides in an animal reservoir somewhere, and could potentially re-emerge.


And there is always the possibility that there are other, equally pathogenic coronaviruses, yet to be discovered.


Which is why, a report that appeared yesterday in ProMed Mail has perked up the ears of many infectious disease watchers the world.



It isn’t SARS, but it is a report on a human infection with another, previously unknown coronavirus.


Published Date: 2012-09-20 15:51:26
Subject: PRO/EDR> Novel coronavirus - Saudi Arabia: human isolate
Archive Number: 20120920.1302733


A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Sat 15 Sep 2012

From: Ali Mohamed Zaki [edited]

A new human coronavirus was isolated from a patient with pneumonia by Dr Ali Mohamed Zaki at the Virology Laboratory of Dr Soliman Fakeeh Hospital Jeddah Saudi Arabia.


The virus was isolated from sputum of a male patient aged 60 years old presenting with pneumonia associated with acute renal failure. The virus grows readily on Vero cells and LLC-MK2 cells producing CPE in the form of rounding and syncetia formation.


[The clinical isolate] was initially tested for influenza virus A, influenza virus B, parainfluenza virus, enterovirus and adenovirus, with negative results. Testing with a pancoronavirus RT-PCR yielded a band at a molecular weight appropriate for a coronavirus. The virus RNA was tested also in Dr. Ron Fouchier's laboratory in the Netherlands and was confirmed to be a new member of the beta group of corononaviruses, closely related to bat coronaviruses. Further analysis is being carried out in the Netherlands.



There is a lot we don’t know about this case, including results of any epidemiological investigation, and the patient’s outcome.


Hopefully more details will be forthcoming.


Coronaviruses - of which there are many - are pretty much ubiquitous, as roughly 30% of all `common colds’ are due to either the OC43 or 229E human coronaviruses.


Various coronaviruses are also known to infect bats, cattle, pigs, horses, turkeys, cats, dogs, rats, and mice. 


But it has only been the SARS-Coronavirus – isolated in 2003 – that has been linked to severe respiratory disease in humans.  


At least, until now.


We’ve no reports (thus far) of secondary transmission with this novel coronavirus, so with luck this will prove to be a dead-end infection.


But this reminds us that nature’s laboratory continues to cook up new, and potentially dangerous, human pathogens.


And that influenza, while always atop our list of viruses to watch, isn’t the only possible pandemic threat we need to be wary of.



For more on the SARS virus, you may wish to visit the CDC’s website:


Severe Acute Respiratory Syndrome (SARS)