Amebiasis:
Clinical:
Approximately 1 to 10% of the worlds population are thought to be infected with Entamoeba histolytica, however, up to 90% of infected individuals may be asymptomatic. Infection with Entamoeba histolytica typically results in a colitis. Hepatic involvement can occur in up to 25% of infected individuals due to intestinal mucosal invasion and spread of the infection via the portal circulation. After the liver, pleuropulmonary involvement is the next most common site of extra-intestinal disease [2]. Pleuropulmonary complications occur almost exclusively in patients with liver abscess- approximately 15-35% of patients with liver disease will have pleuropulmonary disease.Patients can develop a sterile, sympathetic, exudative pleural effusion due to the presence of an unruptured liver abscess near the diaphragm. Rupture of an amebic abscess through the diaphragm into the pleural space (amebic empyema) is the most common route of pleuropulmonary infection [2]. Less commonly a lung abscess can occur due to hematogenous dissemination of the organism. Bronchohepatic fistula is a rare complication, but is characterized by the production of "anchovy paste" sputum. Metronidazole is the treatment of choice.
X-ray:
A small to moderate right pleural effusion is the most common abnormality (30% of patients with liver abscess), an elevated right hemidiaphragm is found in 27%, and right basilar atelectasis in 13%.REFERENCES:
(1) Seminars in Respiratory Infections 1997; Lyche KD, et al. Pleuropulmonary amebiasis. 12 (2): 106-112
(2) Radiographics 2005; Martinez S, et al. Thoracic manifestations of tropical parasitic infections: a pictoral review. 25: 135-155
