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Rabies occurs in more than 150 countries and territories, resulting in at least 55,000 human deaths per year worldwide according to World Health Organization estimates. Rabies is a vaccine-preventable viral disease caused by numerous lyssaviruses that are found in a variety of animal species throughout the world. Rabies virus infects the central nervous system, causing disease in the brain with almost 100% mortality once clinical symptoms manifest.

Within recent years, point-of-care (POC) testing has allowed for many individuals to be screened for and provided with HIV test results. It is critical to be able to accurately detect acute HIV infections as this is a stage where the risk of transmission is great. Additionally, early HIV detection could lead to less high-risk behavior, thereby reducing transmission. Currently, there are no rapid, cost-effective diagnostic tests sensitive enough to detect acute HIV-1 infections for the POC setting.

Currently available identification methods for antigen-specific antibodies require live pathogens, antisera (that are only available for a limited number of species), and species-specific secondary antibodies (also a limited resource). Thus, detection or surveillance of pathogens in wild avian species or zoo animals, for example, is complex and cumbersome.

The core proteins of HIV-1 are secreted into the environment during replication in the human body. The detection of the core protein p24 (molecular mass of 24 kilodaltons) serves as an indicator of early HIV-1 infection, and assays detecting it have been available since the late 1980s. However, the development of a rapid assay for the detection of HIV-1 p24 has only recently become available.

Mosquito-transmitted dengue virus is one of the leading causes of illness in the tropics and subtropics. There is currently no vaccine available and a number of DENV diagnostic and research applications depend on the production of large amounts of these viruses. However, due to the slow growing nature of DENVs these protocols are very time-consuming.

CDC scientists have developed a novel enzyme immunoassay for the simultaneous detection of hepatitis C virus (HCV) core antigen and circulating HCV antibodies. Serological testing procedures for HCV circulating antibodies are well established. There is, however, a window of time between HCV infection and seroconversion that generates an opportunity for false negative results. This period varies from two months in immunocompetent subjects to six to twelve months in immunodeficient patients.

CDC researchers have developed a potent immunogenic enhancer polypeptide useful for improving flavivirus vaccines. Flaviviruses such as dengue virus (1, 2, 3 and 4), Japanese encephalitis virus, Murray Valley encephalitis virus, St. Louis encephalitis virus, yellow fever virus and tick-borne encephalitis virus are a great burden on public health. This technology describes an identified CD4+ T cell epitope occurring within the E-glycoprotein of West Nile virus and methods of using this polypeptide to increase vaccine immunogenicity in monovalent vaccines.

This CDC-developed technology entails a nucleic acid-based HIV-2 in vitro diagnostic assay that is well-suited for use in mobile testing units/vehicles or resource-limited settings, for example, many areas of West Africa. Because HIV-2 requires unique treatment regimens, accurate, early diagnosis is crucial for effective care and directing treatment. Recently, new HIV testing recommendations have been proposed for laboratory settings, which include the use of a HIV-1/HIV-2 discriminatory assay.

CDC researchers have developed improved Loop-Mediated Isothermal Amplification (LAMP) assays for the nucleic acid-based diagnosis of malaria in field settings. The approach employs Plasmodium genus-specific LAMP primers and a portable tube scanner to run the LAMP reaction and measure fluorescence signal (e.g., SYBR green) as a measure of DNA amplification in real time. Using this platform, the researchers were able to detect several different species of the human malaria parasites.

CDC researchers have identified and characterized discrete flavivirus cross-reactive epitopes useful for improving serodiagnosis and vaccination of flaviviruses, such as dengue virus, yellow fever virus, Japanese encephalitis virus, West Nile virus and the tick-borne encephalitis viruses.