Ascaris lumbricoides: To Expect the Unexpected during a Routine Colonoscopy

Ascaris lumbricoides is a common nematode infecting humans worldwide with increased prevalence in tropical and subtropical areas of less developed countries. Recently, it has been estimated that over one billion individuals are infected with ascariasis worldwide with 7% in USA. Although most of these cases are due to increasing immigration and travel outside America it is worth recognizing that prevalence of ascariasis is high in southeastern parts of USA due to their temperate climate. Infections of A. lumbricoides are largely asymptomatic, and hence a large population of people carrying this worm remains undetected for years until they develop some symptoms. Due to a large group of asymptomatic individuals with intestinal ascariasis, these worms are occasionally and unexpectedly identified during routine endoscopic procedures. Here, we present a case of an intestinal ascariasis found during routine colonoscopy in an African-American man from the Bronx with perianal itching. He denied any history of travel outside USA but reported frequent visits to South Carolina. This case illustrates the fact that ascariasis should be suspected even if immigration or travel outside USA is not involved. It should be suspected even in cases of travel within USA to the south east where endemic cases are reported.