Endoscopic Diagnosis of Hookworm Infection in a Previously Deployed U.S. Military Member

Abstract

Purpose: Hookworms are soil-transmitted intestinal helminthes and are a primary cause of iron deficiency anemia worldwide, with an estimated global prevalence of nearly 750 million infected persons. We report a case of a U.S. military service member with an endoscopic diagnosis of Ancylostoma duodenale during an evaluation for iron deficiency anemia. Case: A 24-year-old active duty male deployed in 2011 in support of Operation Enduring Freedom in Afghanistan sustained an improvised explosive device (IED) blast injury complicated by an open left foot fracture and pseudomonas aeruginosa osteomyelitis following internal fixation. He initially had mild anemia attributed to polytrauma and osteomyelitis, but, additionally, was noted to have a peripheral eosinophilia of 3706/mcL. A subsequent serologic parasite work-up was negative, as were stool examinations for ova and parasites. He had persistent mild normocytic anemia through 2012 after an elective left below-the-knee amputation for ongoing complications. He re-presented in 2013, complaining of fatigue with vigorous physical therapy. At that time, he had severe iron-deficiency anemia, with hemoglobin 6 g/dL, MCV 66 fL, iron 14 mcg/dL and ferritin 1.8 ng/mL, and ongoing eosinophilia of 2414/mcL. Colonoscopy demonstrated numerous 1.5-cm long worms. Based on exposure in Afghanistan, severity of progressive anemia, gross examination, and four hook-like teeth at the caudal end of the adult worm, Ancylostoma duodenale infection was diagnosed. The patient improved, following treatment with albendazole and iron replacement. While well-described hookworm outbreaks occurred in U.S. forces during the Second World War and, more recently, in Grenada, hookworm infections are rare in contemporary military operations. There are no prior documented cases of Ancylostoma infection in military service members returning from U.S. operational support in the Middle East or central Asia. Comprehensive public health and hygienic practices are necessary to prevent this and other enteric diseases in the deployed setting.Figure: Hookworms visualized during colonoscopy. A worm was removed via biopsy forceps to facilitate identification.