Ascaris lumbricoides: A Startling Discovery during Screening Colonoscopy

Intestinal parasitic infections are a major public health issue across the world and particularly in rural and urban areas of tropical and subtropical countries. Those at increased risk include inhabitants of poor and disadvantaged regions, which are more likely to have inadequate environmental sanitation, insufficient water supply, greater contact rates with reservoirs of infection, limited health literacy, and socioeconomic disparities. Of the intestinal nematodes (roundworms) that parasitize the human gastrointestinal tract, Ascaris lumbricoides is the largest in terms of size. It causes ascariasis, a "neglected tropical disease," or NTD, that is among the most common helminthic human infections worldwide with an estimated 800 million to 1.2 billion people infected. It causes more than 60,000 deaths annually. However, in more than 85% of cases, infections do not result in symptoms - especially in individuals infected with a small number of worms. Thus, many individuals with intestinal ascariasis remain undiagnosed for years until either they experience symptoms and seek medical attention, the macroscopic adult worms are passed with the stool, or the adult worms are incidentally discovered during routine endoscopic procedures. Here, we present an interesting case of an elderly Bangladeshi man with seemingly innocuous complaints of intermittent mild abdominal symptoms and no recent travel history, who was discovered to have intestinal ascariasis during a screening colonoscopy.