Pleuropulmonary amebiasis

Amebiasis is the third leading parasitic cause of death in the world. Approximately 500 million people worldwide are infected with Entamoeba histolytica. Invasive disease is more common in the immunosuppressed, pregnant women, children, and alcoholics. Amebic colitis and liver abscess are the most common intestinal and extraintestinal manifestations of E. histolytica infection. Pleuropulmonary complications occur almost exclusively in individuals with a liver abscess. Common pleuropulmonary complications include right-sided sympathetic effusions, empyema, basilar atelectasis, lung infiltration, and lung abscess. Bronchohepatic fistula is an unusual and distinctive problem characterized by expectoration of sputum that may resemble anchovy paste. Left hepatic lobe abscesses occasionally produce left-sided pleuropulmonary complications and may result in lethal rupture into the pericardium. Diagnosis is based on demonstration of the organism in clinical specimens; however, false-negative microbiological study results commonly occur even with active infection. Serological studies can confirm the diagnosis in the appropriate clinical setting, and newer immunological tests on blood, fluid, and tissue specimens show promise. Metronidazole remains the treatment of choice, and although surgical drainage is contraindicated, percutaneous drainage of abscesses and empyema may occasionally be indicated.