The Regional Mixed Migration Secretariat (RMMS), the secretariat of the Mixed Migration Task Force which HAART is a member of, has conducted research on human trafficking in East Africa and Middle East. You can find more information about RMMS at http://www.regionalmms.org/index.php?id=2.
RMMS conducted research on Mixed Migration (including human trafficking) in Kenya (published in 2013). You can read the research results here:
RMMS has also conducted research on human trafficking in Saudi Arabia, which is a major destination country for Kenyan victims of trafficking. The document has information about migration policies in Saudi Arabia and you can access it here:
RMMS has also recently studied migration from the Horn of Africa to the West. Going West is available here:
Another RMMS study focusing on Ethiopian migrants is Blinded by Hope which is available here: