Try looking in the library science literature - where information-needs
studies are often done. I did a quick keyword search for "health
information needs Africa" in the Library Literature database (Wilson
databases) and found this title, which is somewhat related. Perhaps there
Title: Meeting basic health information needs in Africa (at the
Medical Library of the University of Zimbabwe; presented at a
meeting in London, July 1994).
Source (jrnl): Information Development. v. 11, June '95, p. 94-8.
Subject: Information-needs: Zimbabwe.
Named Body: University-of-Zimbabwe: Library.
Also, try asking people at SatelLife: http://www.healthnet.org/
(Perhaps you already have).