Five years of molecular epidemiology of Lassa virus from human cases in Nigeria

• Applicant: Dr. Sophie Duraffour
• Subject Area: Virology
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 513978232

Lassa fever is a viral haemorrhagic fever caused by Lassa virus (LASV). It is endemic in West Africa, with Nigeria being the most affected country. Every year, thousands of people contract Lassa fever, with a wide range of clinical manifestations. The mortality rate of hospitalised patients is about 20%. LASV is an RNA virus whose genome is subject to rapid evolution. Over the hundreds or thousands of years that it has circulated in its animal reservoir, its genome has diversified enormously. Currently, several genetic lineages are known. Sequence analysis of the virus can be used to reconstruct LASV transmission routes and the spatial and temporal spread of the virus. Possible correlations between genetic or phylogenetic markers and the severity of the disease can also be elucidated. This has been speculated previously, but could never be proven due to a lack of data. Comprehensive sequence analysis also allows the detection of rare or newly emerging viral variants or genetic lineages that might be linked to unknown reservoir animals. We aim to address these research questions by generating the largest dataset of more than 500 LASV sequences and metadata so far. The viruses to be sequenced are from patient samples collected between 2018 and 2022 in collaboration with our partner institution in Nigeria. The sequence data will be combined and analysed with the corresponding clinical data, viral load, disease progression and geographical origin of the patient. The new data on viral diversity, dispersal dynamics and potential correlation between genetic viral markers and clinical manifestation (virulence) will contribute to the control of outbreaks in endemic regions and the development of modern molecular diagnostics as well as prophylactic and therapeutic strategies.

• DFG Programme: Research Grants
• International Connection: Belgium, Nigeria
• Cooperation Partners: Dr. Cyril Oshomah Erameh; Liana Kafetzopoulou, Ph.D.; Professor Philippe Lemey, Ph.D.