No evidence to suggest SARS is airborne: WHO No evidence to suggest SARS is airborne: WHO

MANILA, Oct. 20 (Xinhuanet) -- There is no evidence to suggest that SARS (severe acute respiratory syndrome) is an airborne virus, the World Health Organization (WHO) said Monday in a report.

The report, summarizing international research on SARS, concluded that at all outbreak sites, the main route of transmission was direct contact, via the eyes, nose and mouth, with infectious respiratory droplets, the WHO regional office for the Western Pacific said in a statement.

"The finding that each patient infected on average three others is consistent with a disease spread by direct contact with virus-laden droplets rather than with airborne particles," the WHO said, noting that in airborne diseases such as influenza or measles, one person can infect an entire room by coughing.

The report, which found health workers at special risk of SARS and children rarely affected, said health workers accounted for 21percent of all cases. In some cases, transmission occurred even though they were wearing masks, eye protection, gowns and gloves.

The report said children were rarely affected, with only two reported cases of transmission from children to adults and no reports of transmission from children to other children. No evidence has been found to show SARS transmission in schools, or in infants whose mothers were infected during pregnancy. On the other hand, research found no evidence that patients transmit the infection 10 days after fever has subsided.

The risk of a person transmitting the disease is greatest at around day 10 of the illness, when a maximum virus excretion from the respiratory tract occurs, then declines, the report said.

Research also showed that five international flights were associated with the transmission of the disease, but found no evidence of transmission on flights after the March 27 travel advisory in which the WHO recommended exit screening and other measures.

The report was released at the start of four consecutive SARS meetings being hosted in Geneva by the WHO starting Monday through Nov. 1, which will address priorities for scientific research, laboratory issues, clinical treatment protocols, and prospects forvaccine development.

More than 8,000 SARS cases and over 800 deaths in nearly 30 countries were reported between February and July, when the disease was brought under control. Over 95 percent of these cases occurred in the Western Pacific Region.

OTHER SARS NEWS

Orthoreovirus Co-infection in SARS patients

On Fri 17 Oct 2003, Dr. Steve Berger drew attention to a recently-published finding that 1.2 to 2.9 percent of healthy individuals tested in Guangdong were seropositive for SARS-associated coronavirus.

A study published in China in July 2003 may be of interest in light of this apparent anomaly. The study, conducted by the Academy of Military Medical Sciences (AMMS), states that while the SARS coronavirus "has been confirmed" as the cause of SARS, the presence of reovirus in 24 of 38 serum samples taken from SARS patients, and only 1 of 35 subjects in a healthy control group, suggests the possibility of co-infection. The authors conclude, with due caution, that SARS could be a combination of the [SARS] coronavirus and [a] reovirus.

This week, following a conference on SARS in Guangzhou on 14 Oct 2003, Chinese media has given extensive coverage to this study, labeling reovirus the other possible "culprit" behind SARS. The AMMS study is available online in English in the Chinese Science Bulletin:

The study in the Chinese Science Bulletin (Vol. 48 No. 13 1293-1296, 2003), referred to above by Dan Silver, states that the initial diagnosis of reovirus infection was on the basis of electron microscopy. Subsequently primers designed to detect reovirus (presumably the orthoreoviruses types 1, 2 and 3, which infect mammals) amplified several genome fragments, one of which was sequenced (an S2 -- core protein -- gene fragment), confirming the presumption of reovirus co-infection. Preliminary animal experiments showed that inoculation of the orthoreovirus into mice caused death with atypical pneumonia.

The significance of these data is unclear. It is conceivable that the expression of the disease known as SARS is dependent on the presence of one or more co-factors, which may or may not be other infectious agents.

Previously published data have suggested that Human metapneumovirus, a common respiratory virus, might be such a co-factor, but this has not been universally substantiated. The evidence for identification of an orthoreovirus as a co-factor is similarly circumstantial; certainly the frequency of detection of orthoreovirus in SARS patients was greater than that in the normal population, but not all (14 of 38) SARS patients were orthoreovirus-positive.

The concern is that viruses such as human metapneumovirus and the 3 types of mammalian orthoreovirus are ubiquitous in the normal population. Whereas an orthoreovirus might be a good candidate for inclusion in a general class of co-factors, it is less likely to be a specific co-factor.

The transmission of orthoreoviruses is by the enteric or respiratory route. Orthoreoviruses infect a wide range of animals and are distributed worldwide.

Human orthoreoviruses are generally benign, but may cause upper respiratory tract illness or rarely -- in infants and children -- enteritis. Experimentally in mice, orthoreoviruses may cause a wide spectrum of disease, and viruses isolated from primates have been associated with neurological disease. Avian orthoreoviruses can cause severe disease outbreaks in domestic flocks but do not infect mammals.

SARS May be More Common than Thought

October 17, 2003

A surprising number of Chinese animal traders were infected with the virus that causes SARS, a new study reported Friday.

The study suggested to health officials the outbreak of severe acute respiratory syndrome may have been far more common than believed and many people may have had it without showing symptoms.

The research also strengthens the likelihood the new virus crossed to humans from a yet-to-be-determined animal source, the Milwaukee Journal Sentinel said.

The study, done by Chinese researchers and reported by the Centers for Disease Control and Prevention, is the most extensive yet involving blood samples tested for severe acute respiratory syndrome.

Until now, health officials had thought the virus caused only the severe cases of pneumonia that came to light during the outbreak last spring.

What's surprising about this study, said Dennis Maki, chief of infectious diseases at the University of Wisconsin-Madison, is the high rate of infection in people who weren't sick.

I remembered your arguments from the very early threads, the more we know the more you seem right. To: Mother Abigail

My concern is that the paramyxovirus, serious as it is, might only be part of the key, that something(and it might not be the virus but something, another virus, another bacteria or a fungi that is symbiotic somehow with the paramyxovirus or something totally extraneous and common)...that this something rapidly triggers the immune system into further systemic attack...or that there is something else, some other agent undetected that is causing this. I hope and pray it is only the paramyxovirus...we can deal with this.

44 posted on 03/22/2003 5:55 PM PST by Domestic Church (AMDG...)

In looking back for this quote I reread the "Causative agent of SARS virus isolated from lung tissue - test is reliably identifying cases" thread. What a wonderful read.

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