Most people initially are not aware that they have lymphatic filariasis. Filariasis is not life threatening infection but it can cause lasting damage to the lymph system and kidneys. In the initial stages the disease causes no symptoms and the problems start after the adult worms die. Damage to the lymph system leads to fluid collection and swelling in the arms, breasts and legs. The swelling is called lymphedema. In men, the scrotum can become swollen. It is called hydrocele. The swelling in the leg, arm, or genital area can be several times its normal size.
Swelling of the limb and damage to the lymphatic system increases the risk of bacterial infections of the skin and lymph system. Repeated infections lead to hardening and thickening of the skin, known as elephantiasis. Rare manifestations of filariasis include tropical pulmonary eosinophilia and chyluria. The commonly used method to diagnose filariasis includes direct demonstration of the parasite (almost always microfilariae) in blood or skin specimens. As microfilariae have nocturnal periodicity the blood sample is usually taken at night. Other tests used to diagnose filariasis include detection of antibodies by immunodiagnostic tests, and detection of circulating filarial antigen (CFA).