Abstract: Lassa fever is a febrile infectious disease caused by the Lassa virus (LASV). This disease was first reported in Nigeria in 1969 and subsequently became endemic in the West African region. LASV is mainly transmitted to humans through urine or feces of rats and may also be transmitted from person to person through contact with the blood, feces, or other bodily secretions of infected persons. Common symptoms of Lassa fever include fever, headache, vomiting, abdominal pain and cough. This article reports on the first confirmed case of Lassa fever in China, where the patient had been working in Guinea, West Africa, prior to the onset of the disease. After the onset, both the Lassa virus serum fluorescent quantitative PCR test and the IgG antibody test were positive, confirming the diagnosis of Lassa fever. Following the diagnosis, the patient received treatment with ribavirin in combination with symptomatic supportive therapy, which led to a gradual improvement in condition. The article provides a comprehensive review of the case's epidemiological history, clinical symptoms, diagnostic process, treatment measures, and outcome, with the hope of raising medical staff and vigilance about this infectious disease. Through an in-depth analysis of this case, the article summarizes the lessons learned and offers a scientific basis for the rapid identification and effective response to similar cases in the future, thereby enhancing the public health system's capacity to prevent and control the importation of infectious diseases.

Key words: Lassa fever, Clinical symptoms, Epidemiology, Diagnosis, Treatment, Prevention