Lassa Fever in West Africa A Systematic Review and Meta-Analysis of Attack Rates Case Fatality Rates and Risk Factors

The authors describe a systematic review and meta-analysis of observational studies on Lassa fever between 1969 and 2025. They found a pooled attack rate of 21 percent and a case fatality rate of 27 percent. High risk factors included environmental (poor housing, presence of rodent burrows, uncovered food storage, proximity to refuse) and occupational exposures. They also found a shift over time in disease transmission from rural to urban and peri-urban settings.