Abstract
The ancient ectoparasitic diseases share many features in common with newly emerging infectious diseases, such as Lyme disease, including hyperendemic causative agents afforded selective advantages by changing ecological or socioeconomic conditions; origination as zoonoses; transmission by competent arthropod vectors; and introduction into new, susceptible host populations. Many ectoparasites are also developing increased resistance to medical therapies, including the safest insecticides. Over the past two decades, there have been several reports of outbreaks of ectoparasitic diseases, principally myiasis, scabies, and tungiasis, both in regional communities and in travelers returning from developing nations. Today ectoparasitic diseases infest not only executives and tourists returning from travel to developed and developing nations, but also individuals immunocompromised by advancing age and institutionalization, chronic infectious and malignant disease, malnutrition and homelessness. Ectoparasitic diseases are no longer infestations of children and socioeconomically disadvantaged populations in tropical countries; they have re-emerged as unusual, but not uncommon, infectious diseases worldwide.