The Cryptic “Five Mouthed” Parasite: A Case Report

Abstract

INTRODUCTION: A middle-aged male presented with acute urinary-retention. Upon further evaluation, an interesting incidental finding of multiple sub-centimeter ring-like calcifications in the liver, spleen, lung, and intestine were discovered. CASE PRESENTATION: A 60 year old male with history of hypertension and BPH was admitted for acute urinary-retention. CT-abdomen/pelvis revealed multiple sub-centimeter liver, spleen, lung, and intestinal calcifications(many with ring like appearance). The patient had no pulmonary or gastrointestinal symptoms. He was an ex-smoker, had no pet or occupational exposures, and had emigrated from Nigeria more than 3-decades ago. Physical exam was unremarkable other than a pansystolic aortic murmur. Labs were unremarkable, including negative tests for schistosoma/histoplasma/quantiferon-TB/HIV, blood parasite(thick/thin) smear, and Syphillis. CT-images are shown. After review of CT images and of endemic infections from northwestern Nigeria, a focused history of prior food habits was obtained. He stated that his home area/family used to eat snakes routinely as part of their diet, but does not remember the time of his last ingestion. Based on this, a diagnosis of Pentastomiasis was made. DISCUSSION: Pentastomiasis is an unusual parasitic zoonosis caused by larval stages of several species of pentastomes(â€ætongue worms†), mostly Armillifer-armillatus and Linguatula-serrata. The adult stages are parasites of the respiratory tract of snakes and carnivorous mammals. Humans are a secondary-host and can become infected accidentally by ingesting eggs from soil, vegetation, contaminated water, or directly by ingesting raw or undercooked snakes, or drinking fresh blood of serpent with contaminated eggs. Larvae penetrate through the gut wall and migrate for several days along the peritoneum and pleura before becoming encysted in various tissues. A fully developed third-stage larva reaches a dead end in man and usually dies and calcifies within two years of infection. The majority of infections are asymptomatic and manifest as incidental radiological, surgical, or autopsy findings. The radiological appearance of calcified nymphs of A. Armillatus is among the most characteristic of all soft tissue calcifications: multiple comma shaped/ring like calcifications. No serology/PCR has been established for the diagnosis. CONCLUSIONS: Based on the detailed personal history obtained, clinical presentation and imaging studies, we conclude that our patient had this rare and intriguing parasitic infection, pentastomiasis. Although endemic to Africa and Asia, physicians in the US should be aware of this condition. Our case illustrates the importance of obtaining a detailed personal history including food habits.