Epidemiology and associated factors of Lophomonas blattarum infection in patients undergoing bronchoscopy: a cross-sectional study

Abstract Background and aim: Pulmonary infection caused by Lophomonas blattarum has been increasingly recognized as an emerging parasitic disease in several Asian countries, including Iran. This flagellated protozoan is a commensal organism of the intestinal tract of insects and, under certain conditions, may act as an opportunistic pathogen leading to respiratory infections, particularly among patients with chronic pulmonary disorders. This study aimed to evaluate the prevalence and to characterize the clinical, epidemiological, and therapeutic features of Lophomonas infection in patients with chronic respiratory diseases undergoing bronchoscopy. Methods present cross-sectional descriptive-analytical study included 88 patients with chronic respiratory diseases who underwent bronchoscopy. Data were obtained through systematic medical record review and structured telephone follow-up. Statistical analyses were performed using SPSS software. Results Of the 88 patients, 23 (26.1%) were diagnosed with Lophomonas blattarum infection. No statistically significant association was observed between infection status and demographic variables such as age or sex (P > 0.05). However, exposure to potential vectors, including cockroaches, birds, and rodents, was significantly associated with infection (P = 0.001). The most frequently reported respiratory symptoms were cough (79.5%), dyspnea (72.7%), and sputum production (51%). Among infected patients, 82.6% showed a favorable response to metronidazole therapy, while age and sex did not significantly influence treatment outcomes. Conclusion Lophomonas infection demonstrates a notable prevalence among patients with chronic respiratory diseases, particularly in populations with increased environmental exposure to potential vectors. Early recognition and appropriate treatment, especially with metronidazole, may result in significant clinical improvement. These findings underscore the necessity for improved diagnostic accuracy, enhanced screening strategies, and effective environmental control measures for the prevention and management of this emerging infection.