Parasitic Infections in Pulmonary and ICU Patients: Presentation, Diagnosis, and Treatment

Parasitic infections in the United States are mostly seen in immigrants and travelers. In many cases, pulmonary and intensive care physicians fail to consider parasitic disease, which can result in delayed diagnosis and adverse outcomes. Almost 2,000 cases of imported malaria are diagnosed in the United States each year. Severe cases can be confused with bacterial sepsis (shock, lactic acidosis, pneumonia, renal failure, respiratory failure, and jaundice). In contrast to bacterial sepsis, survival is improved by restrictive fluid therapy. Parenteral artesunate is licensed to treat severe cases but may not be readily accessible. Strongyloidiasis is endemic in warm and most tropical regions. Chronic strongyloidiasis causes few symptoms and can persist for decades after the patient leaves the endemic region. Treatment with corticosteroids may lead to hyperinfection, which may present with bacteremia and meningitis caused by enteric organisms, pulmonary hemorrhage, and gastrointestinal pain, bleeding, or obstruction. Treatment with ivermectin can be curative if initiated early. Cystic echinococcosis can present as pulmonary mass. Paragonimus presents with hemoptysis, pulmonary nodules, or pleural effusions, and usually with eosinophilia. Endemic regions include not only East Asia but also Southeast Asia, West Africa, the Pacific coast of Latin America, and even North America. Other parasitic infections can involve the lungs. This article aims to provide awareness of the most clinically relevant parasitic infections seen in pulmonary and critical care medicine.