ABSTRACT
Objective To explore the characteristics of human plague using a sero-epidemiologic method in the source of the three rivers area in Qinghai for possible plague control strategies. Methods Investigate human plague sero-epidemiologically in the source of 4 counties in the three rivers area in Qinghai. The human serum would be tested to confirm the sew-positive rate for plague F1 antibody using indirect hemagglutination assay(IHA). Results A total of 2508 local participants were tested in 4 counties, the overall plague sero-positive rate was 2.31%(58/2508). This represents a statistically significant difference with 4 counties(X2=19.30,P<0.01). The sew-positive rate for males and females were 2.54% (32/1261) and 2.09% (26/1247), respectively. There were no statistically significant differences between males and females(X2= 0.65,P 0.05). The sero-positive rate in herdsman, cadre, Tibetan, Hart nationalities were 3.54% (44/1243), 6.47% (11 / 170), 2.40% (56/2335) and 1.47% (2/136), respectively. The sero- positive rate increased with age. The highest titre for human plague serum antibody was 1 : 640. Conclusion There were occult infections of plague in the population on source of three rivers area in Qinghai. Sero-epidemiologic data revealed that the human plague sero-positive rate was closely correlated with the local animal plague.