Abstract
The flagellate protozoan parasite known as Lophomonas blattarum primarily infects the respiratory tract. Infections in humans are infrequent but have been observed, especially in immunocompromised individuals. Our study presents the first case of L. blattarum infection in the lungs of a patient from Ahvaz Province in Khuzestan. A 63-year-old man who had previously suffered from pulmonary embolism presented with persistent symptoms of chronic cough, hemoptysis, and dyspnea. Radiographic studies revealed the presence of bilateral pulmonary infiltrates. L. blattarum trophozoites in the sputum were identified by examining the morphology and motility of the trophozoites. Subsequent treatment with metronidazole resulted in significant improvement in the patient's condition. This case highlights the importance of considering L. blattarum as a potential respiratory pathogen, especially in regions with a high prevalence of cockroach infestation.