Can syphilis patient get HIV by own.

Hello, i am 28, unmarried. I had Syphilis was treated by 3 shots of penicillin in mumbai. later after 3 moths i migrated to gulf here in TPHA test it was detected 1:640 nd VDRL was Non Reactive so I was given Vibramycin 100 mg (doxcyline) for 15 days after 3 months again in TPHA test it was detected 1:340 & VDRL was Non Reactive. But now after 5 months i did TPHA test again & now again it is detected 1:640 & VDRL is Non Reactive & again my Dr have given me Vibramycin 100 mg (Doxycyline) for 15 days course and told me to do test again after 1 month of finishing the cource.. So i want to know if i am cured by syphilis or not yet & will i ever get rid of this syphilis thing and one thing that m very much concern about is that a syphilis patient have more chances to get HIV in future but can a X syphilis patient (cured) can get HIV by own without getting exposed or contacted to a HIV positive patient? How does it happens?  Please answer the last question about HIV.  Thankyou!!!