Filarial antibody testing is done by serologic assays such as ELISA (including IgG and IgG4‑specific tests) and rapid lateral‑flow/strip tests (e.g., Brugia Rapid) that detect antibodies to Wuchereria or Brugia species. These assays are used for surveillance and exposure detection; they may stay positive after past infection and do not reliably distinguish active infection—antigen tests or night blood smears confirm active filariasis.

A positive filaria IgG indicates your immune system has made antibodies to filarial parasites, suggesting past or recent exposure (for example lymphatic filariasis). It does not confirm active infection because antibodies can persist after treatment. Further evaluation—clinical exam, travel history, blood tests for microfilariae or antigen, eosinophil count and specialist review—is needed to confirm active disease and guide treatment.

Costs vary by country and provider. In India private labs typically charge about ₹400–₹1,200 for a filaria IgG/IgM test. In the UK the test is provided free to patients on the NHS, while private clinics may charge around £30–£80. In the US out‑of‑pocket prices commonly range from about $50–$200. Prices vary by lab, test panel and insurance coverage.

Do you mean the complement fixation assay (CFA), a blood test that detects specific antibodies to diagnose infections? If yes, I’ll provide a 50–75 word explanation. If you mean a different CFA, please specify which test.

The best time to test for lymphatic filariasis depends on the method. For microfilariae detection by blood smear, collect blood at night—typically between 10:00 PM and 2:00 AM (midnight–2:00 AM often optimal). Circulating filarial antigen tests (rapid antigen assays) and molecular PCR tests can be done any time of day and do not require nocturnal sampling.

If filariasis is left untreated, parasitic worms damage lymphatic vessels causing chronic lymphatic obstruction. This leads to progressive limb and genital swelling (lymphedema, elephantiasis, hydrocele), recurrent bacterial skin infections, painful inflammation, skin thickening and deformity. Long-term consequences include disability, reduced mobility, social stigma and secondary infections; some cases progress to severe irreversible disfigurement and impaired quality of life.