RESUMEN
We present the results of a study on myiasis in Panama during the first years of a Cochliomyia hominivorax eradication program (1998-2005), with the aim of investigating the behavior of the flies that produce myiasis in animals and human beings. The hosts that registered positive for myiasis were cattle (46.4 percent), dogs (15.3 percent), humans (14.7 percent), birds (12 percent), pigs (6 percent), horses (4 percent), and sheep (1 percent). Six fly species caused myiasis: Dermatobia hominis (58 percent), Phaenicia spp. (20 percent), Cochliomyia macellaria (19 percent), Chrysomya rufifacies (0.4 percent), and maggots of unidentified species belonging to the Sarcophagidae (3 percent) and Muscidae (0.3 percent). With the Dubois index, was no evidence that the absence of C. hominivorax allowed an increase in the cases of facultative myiasis.