Coach Rigobert Song was forced to select from home-based players, none of whom are in contention for a World Cup squad place, because the match fell outside the FIFA window for international matches.
Veteran striker Vincent Aboubakar (30), who plays his club football in Saudi Arabia, was the only player likely to go to Qatar available to play and he captained the side.
Justin McMaster (23) put Jamaica ahead after an hour and Cameroon substitute Djamal Kaiba (19) equalised 17 minutes from time.