Camelid Brucellosis: A Review

Camel brucellosis has been diagnosed in all camel-rearing countries except Australia. In many countries the infection is on the rise in Old World camels (OWCs) due to the uncontrolled trade of live animals. Knowledge of camelid brucellosis has increased over the last decade through field investigations, experimental infection trials and comprehensive laboratory testing. Infection with Brucella melitensis is frequent in OWCs and rare with B. abortus. New World Camels (NWCs) rarely contract brucellosis. In East African countries the seroprevalence of brucellosis can reach 40% (herd level) and depends on the management system. The highest incidence is found when camels are kept together with infected small ruminants. Only a combination of serological methods can detect all serological reactors. However, many brucellosis antibody ELISAs for serum or milk are not suitable for diagnosis. Culturing the pathogen is still the preferred test method, although several assays based on polymerase chain reaction have been developed. through milk. Also, the blood of dromedary calves was negative in culture and Polymerase Chain Reaction (PCR). Interestingly, camel calves of serologically positive dams were all serologically negative, using RBT and cELISA techniques, at the age of six months. The calves therefore do not appear to be at risk for an acute brucellosis infection even after the disappearance of maternal antibodies. However, for confirmation of these findings, further investigations need to be performed [9]. Ostrovidov [37], and Solonitsyn and Pal’gov [38], proposed separating calves from their dams at the age of seven to eight months, when their maternal antibodies have disappeared. If this does not occur, they may contract infection from infected dams at the next parturition. The Brucella-negativity of female camel calves from chronically infected dams is controversially discussed among Dubai-based veterinarians and some researchers believe that confirmation of the Brucella-negativity can only be confirmed when camel calves remain serologically negative after parturition. In males, it is an even more complicated unsolved issue.