Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Human T-cell leukemia virus type 2 ?
    ### Response:
    What causes human T-cell leukemia virus, type 2? Human T-cell leukemia virus, type 2 (HTLV-2) occurs when a person is infected by the human T-cell leukemia retrovirus. HTLV-2 is spread by blood transfusions, sexual contact and sharing needles. It can also be spread from mother to child during birth or breast-feeding.
    