infections
Lymphatic Filariasis
Diagnosis of Lymphatic Filariasis
Examination of a blood sample Blood tests Doctors diagnose lymphatic filariasis when they identify microfilariae in a sample of blood or biopsy of lymphatic tissue examined under a microscope. When ultrasonography is done, adult worms can be seen moving in the widened lymph vessels. Blood tests that can rapidly identify signs of infection (such as antibodies to the worm) have been developed. ( Antibodies are proteins produced by the immune system to help defend the body against a particular attack, including that by parasites.) However, the value of blood tests is limited because they cannot distinguish between worms that cause lymphatic filariasis and some other worms nor between past and current infection. 