Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Lymphatic filariasis ?
    ### Response:
    Lymphatic filariasis is a parasitic disease caused by microscopic, thread-like worms that only live in the human lymph system, which maintains the body's fluid balance and fights infections. It is spread from person to person by mosquitoes. Most infected people are asymptomatic and never develop clinical symptoms.
    