Improving HIV service delivery for people who inject drugs in Kazakhstan: study protocol for the Bridge stepped-wedge trial oleh Tara McCrimmon, Louisa Gilbert, Timothy Hunt, Assel Terlikbayeva, Elwin Wu, Meruyert Darisheva, Sholpan Primbetova, Azamat Kuskulov, Alissa Davis, Anindita Dasgupta, Bruce R. Schackman, Lisa R. Metsch, Daniel J. Feaster, Baurzhan Baiserkin, Nabila El-Bassel