June 12 (UPI) -- Twelve cases of the flesh-eating fly called the New World screwworm have been detected in the United States as of Friday and what took decades to eradicate only took a few years to return. Since first being detected in Texas earlier this month, the screwworm has spread to southeastern New Mexico, found in a dog. All 12 cases remain active. The Cochliomyia hominivorax, also known as the New World screwworm, is a parasitic bloatfly that feasts on living tissue. It is the only