Abstract: Objective To investigate the co-infection of hepatitis B virus,human immunodeficiency virus and treponema pallidum in patients with chronic hepatitis C. Methods HBV markers and anti-TP and preliminary screening of anti-HIV were detected by ELISA,and anti-HCV was detected by chemiluminescence,and western blot was applied to confirm the HIV infection. Results In 169 patients with HCV infection,25（14.8%） had HBsAg,4（2.4%） had anti-HIV,9（5.3%） had anti-TP,2（1.2%） had HBsAg and anti-TP,and 2（1.2%） had HBsAg and anti-HIV positive;The co-infection with HIV（6.7%） and TP（11.1%） in intravenous drug users were higher than those in patients without history of intravenous drug use（P<0.05）;The proportion of co-infection with HBV（19.7%） in male patients was higher than that in female patients（3.8%,P<0.01）;The proportion of co-infection with TP（11.5%） in female patients was higher than that in male patients（2.6%,P<0.05）;The patients older than 40 years were mainly co-infected with HBV （20.9%）,and the proportions of co-infection with HIV （3.9%） and TP （7.8%） increased significantly in the younger patients. Conclusions It is not uncommon in patients with chronic hepatitis C co-infected with other blood-borne pathogens.

Key words: Hepatitis C, Hepatitis B virus, Human immunodeficiency virus, Treponema pallidum, Co-infection