I received some more information from Jamey Allen, a bead expert who says (with some editing by myself):

To accurately identify glass beads, the first step is to determine method of manufacture. The bead in question is drawn, and not composed from manipulated powder glass. It is a drawn striped and twisted bead.

My best guess is that the bead is a transplanted jatim. Nowadays, it is not so unusual to find Javanese (jatim) beads in West Africa--where they are passed-off as "African" beads. (This has happened since the 1990s, but is more frequent in recent years.). It also might be a Middle Eastern bead, but also transplanted to W. Africa (recently)--as opposed to beads that may have been taken to W. Africa, say, 1000 years ago.