Landscape analysis of Lassa virus diagnostic tests: Challenges, innovations and future directions

Effective Lassa fever management relies on diagnostics; however, diagnostic gaps have been documented, particularly for point-of-care (POC) tests for use in remote settings where Lassa fever virus (LASV) is endemic. We assessed the current LASV diagnostic landscape to determine whether these gaps persist.

Commercially available and pipeline diagnostic tests for LASV diagnosis were identified via databases, news platforms, internet queries, and manufacturer outreach. Literature searches identified LASV development of molecular tests, immunoassays, and supportive sample management protocols, as well as independent performance evaluations, external quality assurance studies, and prior diagnostic landscapes.

Twenty-four commercial LASV tests were found to be currently on the market, with only four of the molecular tests having documented regulatory approval. Two LASV molecular tests could be implemented at the near-POC level. Lateral flow LASV immunoassays for true-POC that had been in development or evaluation are now discontinued; available data indicate that POC performance failed to meet an acceptable diagnostic accuracy. Several innovative but early-stage LASV technologies were identified in the literature, none of which show a clear pathway to commercialization. Compared to prior reviews, this diagnostic landscape noted improvements for LASV lineage inclusivity but currently no diagnostic tools for true-POC settings.

Key gaps revealed in this landscape impact the "diagnostic readiness" for LASV outbreak management in endemic areas, particularly for early detection in non-laboratory settings. Diagnostic testing at the true-POC level remains a critical unmet need.