The usual spelling, outside USA, is "Misirlu." Information in websites all seems anecdotal.

The Wheat in the Barley call it an "ancient Arabic" melody on their cd. The Greeks use it for a circle dance.
Greek words (in our alphabet) at www.sacredcircles.com/THEDANCE/HTML/DANCEPAG/MISERLOU.HTM

Greek and French at this Canadian site: www.cvm.qc.ca/mlandry/folklore/Misirlou-ch.htm.

Here the Americanized song form (Nicholas Roubanis, sheet music) is said to be based on the Greek: www.arkmay.com/esphere/song_info3.php?song=Miserlou

There are two distinctly separate modes; the dance, and the slow, exotic music of the love poem (the inspiration for the Roubanis song "Miserlou," as sung by Carol Bruce).