Severe fever with thrombocytopenia syndrome complicated by invasive pulmonary aspergillosis and septic shock: a case report highlighting the role of mNGS.

Background: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne viral hemorrhagic fever associated with high mortality, and no specific antiviral therapy is currently available. Patients with SFTS often develop immune dysfunction, rendering them susceptible to secondary opportunistic infections, particularly invasive pulmonary aspergillosis (IPA). Early diagnosis of this co-infection is critical but remains challenging due to nonspecific clinical manifestations and radiological findings. Case presentation: A 61-year-old male farmer from a hilly region presented in July 2024 with fever, dyspnea, and altered consciousness. On admission, he exhibited septic shock and multiple-organ dysfunction, including severe thrombocytopenia, leukopenia, liver injury, and acute kidney injury. Metagenomic next-generation sequencing (mNGS) of blood and bronchoalveolar lavage fluid rapidly identified SFTS virus, Conclusion: This case highlights the diagnostic value of mNGS in critically ill patients with SFTS and suspected co-infections, as it enables early pathogen identification and targeted therapy. Clinicians in endemic areas should maintain a high index of suspicion for SFTS and IPA in patients presenting with unexplained fever, thrombocytopenia, and organ dysfunction. However, the favorable outcome cannot be attributed solely to mNGS, as multiple supportive interventions were administered concurrently; the clinical improvement likely reflects a synergistic effect of timely targeted therapy and comprehensive intensive care.