Serosurvey of Crimean-Congo Hemorrhagic Fever Virus in dromedary camels (Camelus dromedarius) in Egypt

Abstract

Crimean-Congo hemorrhagic fever virus (CCHFV) is recognized as one of the most severe zoonotic viruses, marked by gastrointestinal disturbances and hemorrhagic symptoms in its more severe forms. Transmission occurs mainly through ticks of the genus Hyalomma or through contact with infected animal tissues. A wide range of animals can be asymptomatically infected, and the presence of antibodies against CCHFV in these animals poses a significant risk to individuals who are in close contact with livestock. Globally, research on CCHFV is scarce, and this is particularly true in the case of Egypt. This study aimed to evaluate the exposure of camels to CCHFV in Egypt and to compare seroprevalence across different geographic regions. In this investigation, a total of 513 serum samples were collected from apparently healthy camels across Egypt, representing the key northern and southern parts of the country, and tested using an enzyme-linked immunosorbent assay (ELISA). Surprisingly, a total of 511 samples (99.61%) tested positive for CCHFV antibodies, representing the highest seroprevalence rate of CCHFV reported at both national and international levels. Seropositivity was consistently observed across all sampled regions. The observed high seroprevalence indicates frequent exposure of camels in Egypt to CCHFV or antigenically related viruses. Camels may therefore represent an important component of viral circulation among livestock populations. Given the close contact between camels and humans during husbandry, transport, and slaughter, these findings support the need for improved surveillance at the camel-human interface. In conclusion, this study provides interesting serological evidence of widespread exposure of camels to CCHFV in Egypt. Further large-scale serological and molecular investigations in livestock and humans, together with the characterization of circulating viral strains and assessment of tick infestation, are required to better define CCHFV transmission dynamics and potential implications for human health.