HERNDON, Va. -- Focus Technologies announced today FDA clearance of its IgM and IgG ELISA antibody detection diagnostic kits based on a West Nile Virus (WNV) recombinant protein antigen licensed by the Centers for Disease Control and Prevention (CDC).
The West Nile Virus products are third generation assays developed by Focus and currently in use in the company's infectious disease reference laboratory in Cypress, California. Extensive in-house testing and clinical trials on patients with meningioencephalitis demonstrated superior performance, with sensitivity and specificity ranging from 91% to 99%. The two ELISA tests satisfy CDC recommendations for laboratory diagnostic testing to detect antibodies of West Nile Virus. To date 2003 has been another epidemic year for this mosquito- borne disease with over 7,328 reported cases and 153 deaths in the United States.
"We are pleased to be the first company to bring both IgG and IgM diagnostic products to the marketplace to aid in the clinical laboratory diagnosis of West Nile Virus infection. It is our hope that these products will allow for an ever-increasing number of laboratories to properly test for this important disease," said Charles C. Harwood, Jr., president and CEO of Focus Technologies. "As with many other emerging infectious diseases Focus has been in the forefront with WNV. We expect to continue development efforts this area for some time to come."
West Nile virus has emerged in recent years in temperate regions of Europe and North America, presenting a threat to public and animal health. The most serious manifestation of West Nile virus infection is fatal encephalitis in humans and horses, as well as mortality in certain domestic and wild birds. The disease is transmitted by an infected mosquito and not directly from humans or animals. The incubation period ranges from 3 to 14 days. An estimated 10 percent to 20 percent of the people who become infected will develop West Nile fever: mild symptoms include fever, headache, and body aches, occasionally with a skin rash on the trunk of the body and swollen lymph glands. Symptoms of mild disease will generally last a few days. Symptoms of severe disease may last several weeks, although neurological effects may be permanent. Less than 1 percent of those infected develops severe symptoms, most typically encephalitis. Persons over 50 years of age have the highest risk of severe disease and have a higher case-fatality rate. Overall case-fatality rates in severe cases are about 10 percent.
Laboratory diagnosis of WNV infection is through detection of IgM and/or IgG antibodies to WNV in serum. Viral detection using PCR is also available. PCR is highly specific but may not yield positive results at the time patients show clinical symptoms. Focus' reference laboratory performs WNV serology and PCR, as well as PRNT (plaque reduction neutralization test) to confirm specific antibodies detected for WNV versus St. Louis Encephalitis (SLE), another flavivirus that is genetically similar and cross reactive with WNV.
Source: Focus Technologies