Serology of Orthopoxvirus cameli infection in dromedary camels: Analysis by ELISA and western blotting

An enzyme-linked immunosorbent assay (ELISA) was developed, together with a Western blotting technique, for the detection of total and IgG and IgM antibodies to camelpox virus (Orthopoxvirus cameli) in camel (Camelus dromedarius) sera and for identifying the seroreactive antigens of the virus. A total of 520 camels from different regions in Libya were tested. The overall seropositivity rate in the examined herds was 9.8%, and varied between herds from 0 to 30%. Two viral antigenic determinants (31 and 35 kDa) were shared by the Western blotting patterns of all the positive camel sera tested. The developed ELISA assay showed ability to differentiate between orthopox and parapoxvirus infections in camels. It is considered that the ELISA technique is justified for serodiagnosis of camelpox in the camel and could be easily modified and usefully applied to other species at risk of poxvirus infection.