Cross-Sectional Analysis of Serologic Response to Arthropod-Borne and Hemorrhagic Fever Viruses in Ghanaian Livestock Herders

Abstract

Zoonotic diseases account for more than 60% of emerging infectious diseases, and they are the leading cause of pandemics. As humans and livestock become increasingly transient and the environment and climate change, disease vectors expand into previously untouched geographical regions, spreading pathogens. In this study, we assessed the seroprevalence of arthropod-borne and hemorrhagic fever viruses of similar clinical presentation and endemicity in high-risk populations in Ghana (animal handlers). Using a microneutralization assay, we compared total IgG prevalence with live virus neutralizing response. In total, 300 blood samples were collected from consenting healthy adults at five military and three civilian sites across Ghana. The observed seroprevalence rates for Rift Valley fever virus (RVFV), Crimean-Congo hemorrhagic fever virus (CCHFV), Ebola virus, Lassa virus, and Marburg virus were 14.7%, 7.0%, 2.3%, 1%, and 0%, respectively. Microneutralization data further verified virus-specific neutralization positives of the total IgG positives. Among animal handlers who had recently skinned livestock, 19 (25.3%) were exposed to RVFV, and 20 (28.6%) of those in the coastal savannah ecological zone were also more likely to be exposed to RVFV compared with those in the other ecological zones (P = 0.002). Animal handlers younger than 25 years old had a higher exposure rate to CCHFV than those older than 25 years old (P <0.001). These data help us better understand the risk of exposure to zoonotic and vector-borne diseases in the region. Moreover, this study establishes methods for assessing seropositivity in a multiplexed format for higher-throughput sample analysis.