Acute pneumonia due to Tropheryma whipplei diagnosed by metagenomic next-generation sequencing and pathology: A case report

Tropheryma whipplei (TW) is a rod-shaped, gram-positive bacterium that, when chronically infects humans, can lead to multi-system pathologies, including joint pain, abdominal pain with diarrhea and weight loss, myocarditis, pericarditis, and neurologic inflammation. Moreover, acute infections can lead to bronchopulmonary infections, bacteraemia, and acute diarrhea. However, fewer cases of acute pneumonia due to TW have been reported, and this diagnosis is not well founded. Herein, we report a case of acute pneumonia caused by a TW infection. The patient, a middle-aged man, underwent bronchoscopic alveolar lavage, and the metagenomic nextgeneration sequencing of the lavage fluid suggested TW infection. A lung puncture biopsy tissue specimen was also positive based on periodic acid-Schiff staining. After confirming the diagnosis, the patient was administered ceftriaxone for anti-infection treatment, improving clinical symptoms and lung imaging results. Therefore, in cases where conventional anti-infective treatment is ineffective for patients with acute pneumonia, we should consider the possibility of TW infection, conduct prompt pathogenetic examination, and provide timely treatment after diagnosis to improve overall patient prognosis.