<s>[INST] My brother is a regular blood donner. In last july he went to donate blood to his wife. In cross matching hospital informed him that his is positive. And advised to contact with dermatologist. As pre advice by dermatologist tpha and vdrl tested. Test reports shows that tpha is positive, vdrl is reactive and titre is 1:1. Doctor adviced for penicillin 1.2 million for 3 injection in 3 week and take test after one month. After 1 month in test report found vdrl is reactive and titre is 1:1. Note that he do not have any symptoms for syphilis in his body. Asking your advice. [/INST] it takes months to years for a positive vdrl to become negative. so far there has been no evidence of resistance of the syphilis bacteria to penicillin so he can relax. </s>