Rigorous scientific investigation has only just begun in the communities hit by the epidemic, and relatively few facts have been established, but scientists are coming up with what they believe to be a credible hypothesis. 
Uchunguzi zaidi wa kisayansi umeanza tu katika jamii zilozo adthiriwa na ugonjwa, na ukweli mchache kuanzishwa, lakini wanasayansi nwamezindua kile wanachokiamini kuwa wazo la kuaminika.