A method for treating infection by a flaviviridae virus is disclosed. The method includes administering to a subject in need thereof an effective amount of a compound having the formula: AwBxCyDz, in which A is Li, Na, K, Rb, or Cs; B is As, Sb, or Bi; C is an oxygen or sulfur atom; D is a monodentate ligand, a bidentate ligand, or a tridentate ligand; w is 0, 1, 2, or 3; x is 1, 2, 3, or 4; y is 0, 1, 2, 3, 4, or 5; z is 0, 1, 2, 3, 4, or 5; and provided that at least one of y and z is not 0.