- Hello, Jeff -- The CDC believes that a NEW Coronavirus
may cause SARS. Of course, more testing is ongoing and a definite diagnosis
forthcoming.
-
- Patricia
-
-
- From ProMED-mail promed@promedmail.org
-
- CDC Lab Analysis Suggests New Coronavirus May Cause SARS
-
- A CDC Press Release
-
- The Centers for Disease Control and Prevention (CDC)
announced today that a previously unrecognized virus from the coronavirus
family is the leading hypothesis for the cause of severe acute respiratory
syndrome (SARS). Two coronaviruses that are known to infect humans cause
one third of common colds and are also a common cause of health care-associated
upper respiratory infections in premature infants.
-
- "This is encouraging news from our laboratories
at CDC," said Tommy G. Thompson, Secretary of Health and Humans Services.
"These and other excellent scientists all over the world have been
working around the clock for days and their hard work is paying off. They
continue to look at other possible causes of SARS, but this is a key finding
in our efforts to identify the cause of this global outbreak."
-
- Additional steps needed to confirm this hypothesis include
further culturing of the virus from appropriate specimens, sequencing the
viral genome, and examining specimens from patients at different stages
of their illness.
-
- "This collaboration among scientists led by the
World Health Organization (WHO) is unprecedented," said CDC Director
Dr. Julie Gerberding. "We certainly have more work to do, but we think
we are on the right track. And our systems to identify cases and investigate
them are working too, thanks to all the frontline clinicians and state
and local health departments around the country."
-
- As of Mon, 24 Mar 2003, CDC is reporting 39 suspected
SARS cases in 18 states. WHO is reporting 456 cases and 17 deaths.
-
- Since the outbreak of SARS was first reported two weeks
ago, CDC has responded in these ways:
-
- Activated the agency's Emergency Operations Center.
-
- Alerted public health partners in cities and states by
issuing electronic messages.
-
- Prepared and distributed more than 60,000 health alert
cards to travelers returning from Southeast Asia.
-
- Provided guidance to public health departments, health
care facilities, and clinicians in monitoring and identifying potential
cases.
-
- Provided safe specimen-handling guidelines to laboratories.
-
- Deployed more than a dozen CDC staff members, including
medical officers, epidemiologists, infection control specialists, and pathologists
to support the World Health Organization in the global investigation.
-
- Provided regular media briefings to report on progress
of the investigation.
-
- http://www.cdc.gov/od/oc/media/pressrel/r030324.htm
-
- Pro Med Comment -
-
- (This report does not provide much clarity but rather
adds to the confusion regarding the nature of the infectious agent responsible
for SARS. The candidates so far include, an unspecified paramyxovirus,
the recently discovered human metapneumovirus (representing the two subfamilies
of the family _Paramyxoviridae_, and now an unspecified coronavirus (representing
the family _Coronaviridae_). A common feature of the families _Paramyxoviridae_
and Coronaviridae_ is that they contain viruses that are ubiquitous respiratory
tract pathogens. Consequently it would not be unexpected to detect such
viruses in clinical samples entirely fortuitously, particularly where a
diagnostic technique of limited discriminatory potential such as electron
microscopy is employed.
-
- The paramyxoviruses and coronaviruses are quite distinct
viruses with different biological potential. The paramyxoviruses are negative-sense
RNA viruses, which do not recombine, whereas the coronaviruses are positive-sense
RNA viruses, which undergo recombination at high frequency.
-
- In the UK, at least, coronaviruses are second only to
rhinoviruses as causes of the common cold. In the case of the four types
of human parainfluenza viruses (sub-family _Paramyxovirinae_), human respiratory
syncytial virus and human metapneumovirus (sub-family _Pneumovirinae_)
infection occurs in infancy and early childhood, but does not confer prolonged
immunity. In the case of human respiratory syncytial virus it has been
estimated that reinfection occurs on average every 36 months.
-
- The outcome of infection can be serious in infancy (bronchiolitis)
and in the elderly (pneumonia), At other ages infection is usually asymptomatic
or mild URTI. The recently discovered human metapneumovirus appears to
behave similarly, but is less prevalent than respiratory syncytial virus
(see: Human metapneumovirus infections in young and elderly adults by Falsey
et al., in Journal of Infectious Diseases, 187, (5), 785-790, 2003). These
authors conclude that: "Human metapneumovirus infection occurs in
adults of all ages and may account for a significant portion of persons
hospitalized with respiratory infections during some years."
-
- Continued caution is required in evaluation of the competing
claims of identification of the etiologic agent of SARS. - Mod.CP)
-
- ProMED-mail promed@promedmail.org
-
-
- Patricia A. Doyle, PhD Please visit my "Emerging
Diseases" message board at: http://www.clickitnews.com/emergingdiseases/index.shtml
Zhan le Devlesa tai sastimasa Go with God and in Good Health
|
