Metagenomics-Based Diagnosis and Monitoring Treatment of Disseminated Talaromyces Marneffei Infection

Abstract

Background: The diagnosis of T. marneffei infection remains challenging due to its non-specific clinical presentations and the inadequate performance of conventional diagnostic methods. Meanwhile, there is no good indicator to monitor when induction treatment should switch to consolidation treatment.Case summary: A 53-year-old male patient presented with a one-week history of high fever on March 21, 2019, 10 years after a liver transplant. A chest CT showed multiple pulmonary nodules. Blood culture revealed T. marneffei. After two weeks of intravenous treatment of voriconazole and caspofungin, the patient was discharged without fever and was given oral voriconazole on April 8. Two days later, the patient had a fever again. The patient was fever-free soon after intravenous voriconazole. However, a high fever occurred three days later. Cultures of blood and sputum were negative. Metagenomics next-generation sequencing (mNGS) detected T. marneffei sequences in blood and Enterococcus faecium sequences in sputum. Despite the use of caspofungin and linezolid, the patient maintained a daily fever of 38.5°C. Chest CT revealed that pulmonary nodules were growing in size and number. After administering Amphotericin B, the temperature quickly returned to normal. Liposomal amphotericin B was used due to increased creatinine. When the sequence of T. marneffei turned negative in the blood, the patient was discharged on May 24 and received 14-week oral voriconazole without relapse. Conclusion: mNGS can directly detect the sequence of T. marneffei in the blood. Consequently, mNGS is a powerful technique in precise diagnosis and a good monitoring technique for treating disseminated T. marneffei.