In the United States, specialized molecular, serologic, and rapid diagnostic tests are found in research and some public health laboratories. The FDA has not cleared these tests for clinical use. Rather, the methods mentioned below are used primarily in endemic, developing countries for research and for epidemiology purposes.
Molecular methods that have been described in the literature include:
Real-time PCR
LAMP (loop-mediated isothermal amplification)
DNA sequencing
Filarial antigen detection: Antigen tests use venous blood to test for specific circulating filarial antigens (most common with W. bancrofti); these are useful for monitoring response to treatment. Cross-reactivity with antigens of other common helminths is problematic.
Filarial antibody detection: An IgG4 assay has been developed for use in testing for Wuchereria bancrofti. Useful for ruling out infection; serologic tests are not able to discern past from current infections.
Rapid tests: Immunochromatographic tests (ICTs) are used for monitoring parasite elimination epidemiologic studies.
Serum immunoglobulin concentrations: Serum IgE and IgG occur with an active filarial infection. This test is under development.
