With the development of commercial diagnostic tests for Severe Acute Respiratory Syndrome (SARS) progressing slower than initially hoped, the United Nations World Health Organization (WHO) said its network of laboratories are working to expedite the process by providing critical specimen to scientists.
With the development of commercial diagnostic tests for Severe Acute Respiratory Syndrome (SARS) progressing slower than initially hoped, the United Nations World Health Organization (WHO) said its network of laboratories are working to expedite the process by providing critical specimen to scientists.
The development of diagnostic tests has been stalled partly because unusual patterns of the virus complicate the task, WHO said. Most viral diseases excrete the greatest quantities of the causative agent during the initial phase of illness – usually in the first few days following the onset of symptoms during which patients pose the greatest risk of infecting others – while viral shedding is comparatively low at the onset of SARS.
Available tests are unable to reliably detect the SARS virus or its genetic material during the earliest days of illness because the viral load peaks at around 10 days after onset of clinical illness. This poses a particular challenge for SARS control, as patients are still capable of infecting others during that initial phase.
The WHO collaborating network has made critical biological materials and reagents available to other laboratories, including the commercial sector. Such specimens are needed to assess how well a test will perform with real patient specimens, as opposed to artificial laboratory conditions.
In return for the supply of these exclusive materials, recipients of WHO support have agreed to offer test kits, once available, at preferential prices to developing countries.
Meanwhile, WHO expressed concern over the sharp drop, virtually to zero, of new SARS cases in China, raising questions about the counting method used. This comes at a time China has been cooperating more with the agency, after an earlier credibility problem arising out of that country’s initial reporting of its SARS situation.
WHO stressed, however, that if the current drop is indeed good news, then China should be applauded rather than treated with suspicion.
As of today, a cumulative total of 8,398 probable SARS cases and 772 deaths have been reported from 29 countries.