[Lophomonas blattarum infection in a patient without identified risk factors: Case report]

Pulmonary infection with Lophomonas blattarum is a rare infestation in healthy individuals. In Mexico, this disease has only been reported in immunocompromised patients.

A 30-year-old male patient presented with chronic respiratory symptoms, including a productive cough and hemoptysis, which did not improve with antibiotics. After several unsuccessful treatments and a bronchoscopy, the protozoan Lophomonas blattarum was identified, leading to a diagnosis of pulmonary lophomoniasis. He received treatment with metronidazole, but the symptoms persisted and recurred. A second bronchoscopy confirmed the recurrence. Months later, due to persistent cough, an allergist diagnosed a moderate obstructive pattern. The patient finally found symptomatic relief with a long-acting bronchodilator and an inhaled corticosteroid, adjusting his treatment after remission.

Pulmonary lophomoniasis infection should be considered in the differential diagnosis of patients with pulmonary symptoms who are receiving various treatment regimens without achieving the expected improvement, even with risk factors such as immunosuppression, rural living, poor hygiene, and recurrent symptoms. It is also important to suspect and identify underlying respiratory conditions, especially in patients with poorly controlled asthma or those receiving conventional medications.