The First Imported Case of Lassa Fever - China, 2024

Abstract

What is already known about this topic?: Lassa fever, an acute viral hemorrhagic illness caused by Lassa virus, is primarily transmitted through contact with rodents, particularly Mastomys species. The disease is endemic to West Africa and is not classified as a notifiable infectious disease in China. Prior to August 2024, no cases of Lassa fever had been reported in China.

What is added by this report?: The clinical manifestations of Lassa fever (LF) are nonspecific and may closely resemble those of other febrile illnesses, posing challenges for detection at points of entry and during medical evaluations. In this severe case, the patient experienced coma and developed persistent hearing loss even after discharge, emphasizing the critical importance of early diagnosis and treatment.

What are the implications for public health practice?: For cases with unclear diagnoses, healthcare providers should prioritize obtaining a detailed 30-day travel history to assess the potential risk of imported infectious diseases. Public health strategies in Africa must prioritize: 1) community-tailored health education campaigns, 2) enhanced syndromic surveillance coupled with pathogen-specific research, and 3) sustainable stockpiling of rapid diagnostic tests (RDTs) for endemic infections alongside accelerated vaccine development pipelines.

Keywords: Lassa fever; imported cases; public health emergency.

Figure 1

Epidemiological timeline of the first imported Lassa fever case in China, 2024. Note: “−” means LASV negative; “+” means LASV positive.Abbreviation: PCR=Polymerase Chain Reaction; NGS=Next-Generation Sequencing; CSF=Cerebrospinal fluid; LASV=Lassa virus.