CDC Develops New Test for Dengue Virus

The Centers for Disease Control and Prevention (CDC) has developed a new diagnostic test to detect the presence of dengue virus in people with symptoms of dengue fever or dengue hemorrhagic fever. The test, called the CDC DENV-1-4 Real Time RT PCR Assay, has been authorized by the Food and Drug Administration for use in the United States and can be performed using equipment and supplies many public health laboratories already use to diagnose influenza.

The new test will help diagnose dengue within the first seven days after symptoms of the illness appear, which is when most people are likely to see a health care professional and the dengue virus is likely to be present in their blood. The test can identify all four dengue virus types. 

This is the first FDA-approved molecular test for dengue that detects evidence of the virus itself. The other available FDA-approved test detects a certain type of antibody (immunoglobin M (IgM) class antibodies) to dengue virus.  Most patients begin to develop these antibodies four days after they become ill.  However, because not everyone develops these antibodies until seven days after they get sick, the antibody test might not recognize dengue early in a patients illness.    

The need for the new dengue diagnostic test was high, says Jorge L. Munoz-Jordan, PhD, chief of the Molecular Diagnostics and Research at the CDC Dengue Branch. Patients will be diagnosed sooner than before, and public health laboratories will have a clearer picture of the true number of dengue cases.  Dengue is now a reportable disease in the United States, and the availability of state-of-the-art dengue diagnostics will improve patient management and the public health response to dengue.

One of the new tests most important features is that it can be performed using equipment and supplies that many public health laboratories already use to diagnose influenza. This makes it possible to begin using the test in the many laboratories in the United States and internationally that already run influenza Real-Time PCR assays, a frequently used flu test also developed by CDC. The new test will be available to clinical and public health laboratories within the United States and internationally. Kits will be available for distribution beginning July 2, 2012 (see http://www.cdc.gov/Dengue/ for more information).

Dengue is caused by any of four dengue viruses, which are transmitted by Aedes mosquitoes. Dengue is a major public health problem in the tropics and subtropics, which includes Puerto Rico and the U.S. Virgin Islands, where thousands of U.S. citizens develop dengue every year. Dengue is leading cause of fever in travelers returning from Asia, the Caribbean and Latin America. Transmission has occasionally occurred in the continental United States in areas where Aedes mosquitoes are found.

Symptoms of dengue include high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash and mild bleeding involving the nose or gums, and easy bruising. Severe infections can result in hemorrhage, shock, and death.

Although there are no FDA-licensed vaccines to prevent dengue and no medicines specifically approved to treat the disease, timely medical care can greatly reduce the possibility of death. People who believe they have dengue should immediately contact a health care professional. Early identification may be very helpful in determining the best course of treatment.