When he travelled to the strife-torn Central African Republic in February, Issouf Sanogo witnessed an extraordinary scene after a visit by President Samba Panza. "As her car revs up to leave, dozens of women and children start running behind it, jumping with joy, laughing and yelling," he writes. "That brief explosion of joy, captured on camera, is such a relief, so different from the atrocities I have been photographing."