Serological and bacteriological study of brucellosis in camels in Central Saudi Arabia

Sera from 2,630 apparently normal adult camels (Camelus dromedarius) raised in central Saudi Arabia (Riyadh and Al-Kharj cities) were examined serologically by the Rose Bengal and standard United States of America Brucella plate agglutination tests. The overall seroprevalence of brucellosis in the restricted populations of tested camels was 8%. The seroprevalence of brucellosis among camels raised in small numbers in the backyards of 24 houses in Riyadh and those intensively raised on one large camel farm near Al-Kharj were 4.3% and 8.6% respectively. Fresh milk samples from 100 brucellosis seropositive camels from Riyadh and Al-Kharj were cultured on Brucella-selective media. Brucella melitensis biovars 1 and 2 were isolated and identified from 26 camels. Epidemiologically, brucellosis in camels in central Saudi Arabia appeared to be connected with B. melitensis infection of sheep and goats, and also represents a serious public health risk.