Roche Accelerates Effort to Develop PCR Blood Screening Assay for West Nile Virus
In response to a recent challenge by the United States Food and Drug Administration (FDA) and the Centers for Disease Control (CDC) to develop effective nucleic acid amplification testing (NAT) to screen blood donations for the West Nile virus, Roche Molecular Diagnostics (RMD) today announced that is has implemented plans to accelerate research and product development efforts to create a polymerase chain reaction (PCR) assay for the West Nile virus.
Speaking at a breakout session of the Annual Meeting of the American Association of Blood Banks, RMD representatives said they had formed a dedicated product development team and initiated efforts to produce a solution to screen blood donations for the West Nile virus. The company believes it can have a PCR (NAT) assay ready to meet FDA's call for assays by the second quarter of 2003.
The West Nile virus is a 'flavivirus,' commonly found in Africa, West Asia, and in the Middle East. CDC scientists estimate the disease has been in the United States since the early summer of 1999, possibly longer. In the New York area in 1999, the West Nile virus caused seven deaths. 2002 saw a surge in West Nile virus cases throughout the United States. The latest CDC statistics indicate 3,391 laboratory-positive cases and 188 West Nile virus deaths have occurred in 2002.
Mosquitoes remain the most common means of West Nile virus transmission. Symptoms are generally flu-like, but for some infected individuals, symptoms can progress to West Nile encephalitis, West Nile meningitis, or West Nile meningoencephalitis. All of these conditions can be fatal, and are of greatest danger to people over 60 years of age or immunocompromised individuals.
At a September press conference, the FDA and CDC indicated that the West Nile virus was very likely to have spread through blood transfusions and tissue donations. RMD has an extensive history in creating PCR-based assays to screen blood donations for infectious diseases, such as HIV*, the hepatitis C virus (HCV)*, and the hepatitis B virus (HBV)*. The company recently announced the start of comprehensive clinical trials of its COBAS AmpliScreen ™ HBV Test under IND permission from the FDA.
Using NAT technology such as PCR to create an assay is an important step in screening blood donations for the West Nile virus, because PCR can amplify a single molecule billions of times to directly detect the presence of West Nile virus genetic material.
The development of an effective antibody screen for West Nile virus is expected to be difficult because of potential false-positive results. This underscores the importance for developing NAT- based screening tests. And because mosquitoes are the most common form of transmission, there is pressure to create viable screening tests by next summer, when the mosquito season reaches its peak in the United States.
Source: Roche Diagnostics View latest company information
Posted: November 8, 2002
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