Bronchoalveolar Lavage Fluid Metagenomic Second-Generation Sequencing Assists in Guiding the Treatment of Visceral Leishmaniasis: A Case Report.

Purpose: The incidence of visceral leishmaniasis (VL), a global infectious disease, has been on the rise in China's Hebei province. When patients achieve clinical cure, they often do not reach an etiological cure, which may lead to recurrence of the disease. Here, we report a case of visceral leishmaniasis with a negative blood smear and bone marrow cytology.

Patients and methods: A 65-year-old man and bronchoalveolar lavage fluid mNGS.

Results: A 65-year-old man developed a chronic fever, anorexia, splenomegaly, and pancytopenia. The blood metagenomic second-generation sequencing (mNGS) revealed Leishmania sequence readings, which led to the diagnosis of VL. After sodium antimony gluconate treatment, the blood smear and bone marrow cytology revealed no Leishmania bodies. However, pancytopenia and respiratory failure did not fully subside, and cardiotoxic damage emerged. The bronchoalveolar lavage fluid (BALF) mNGS was performed to detect the pathogen. Through BALF mNGS, Leishmania sequence was still detectable. Therefore, after the ECG returned to normal, antimony sodium gluconate was administered as a next course of treatment.

Conclusion: BALF mNGS may assist in evaluating the therapeutic efficacy of VL with respiratory failure, especially in patients with negative blood and bone marrow cytology.