A comprehensive review of the epidemiology and research gaps of Crimean-Congo Haemorrhagic Fever in Nigeria

Abstract Crimean-Congo Haemorrhagic Fever virus (CCHFV) has circulated in Nigeria for over five decades, yet its public health significance remains underestimated despite recurrent serological and molecular detection in livestock, ticks, and humans. This review synthesizes epidemiological evidence, bibliometric trends, and S-segment clade diversity to clarify the virus’s burden, research progression, and emerging risks. Published literature from PubMed, Google Scholar, and AJOL, totalling 18, reveals persistent enzootic transmission driven by livestock movement, pastoralism, agricultural expansion, and intensifying human-animal-vector interfaces. The absence of confirmed clinical cases likely reflects surveillance blind spots, limited diagnostic capacity, subclinical infections among high-risk occupational groups, and systemic underreporting rather than a true absence of transmission. Bibliometric analysis shows extremely low national research output, averaging one publication yearly over nearly six decades, with international collaboration. Molecular assessment of 132 S-segment sequences demonstrates global predominance of clades IV and V, while Clade III circulates in Nigeria, indicating notable viral heterogeneity and reinforcing the need for routine genomic monitoring. Structural gaps remain substantial, including the lack of dedicated tick surveillance, weak integration of CCHFV into priority zoonotic disease frameworks, inconsistent vector control, and inadequate laboratory capacity. Broader health-system constraints, such as insecurity in livestock-producing regions and limited access to diagnostic tools for viral haemorrhagic fevers, further heighten national vulnerability. Strengthening preparedness will require a coordinated One Health approach, emphasizing systematic sero-surveillance, expanded molecular diagnostics, improved clinical recognition, integrated vector monitoring, and sustained research investment.