Abstract
BACKGROUND: In this study, we present a case of Japanese spotted fever (JSF) caused by Rickettsia japonica and use this case to investigate the process of diagnosing and reintegrating traceability of infectious diseases via metagenomic next-generation sequencing (mNGS). METHODS: From data relating to epidemiological history, clinical and laboratory examinations, and mNGS sequencing, a diagnosis of severe JSF was concluded. RESULTS: A detailed field epidemiological investigation discovered parasitic Haemaphysalis longicornis from a host animal (dog) in the domicile of the patient, within which R. japonica was detected, along with a diverse array of other potentially pathogenic microorganisms that could cause other infectious diseases. CONCLUSION: The mNGS provided an efficient method to diagnose JSF infection. This methodology could also be applied to field epidemiological investigations to establish the traceability of infectious diseases.