Hello doctor I would like to narrate some incidents that occurred last few months back please help me and give me elaborate answers it my kind request doctor I am really depressed for past few months because following incidents I would like to narrate case 1: last month for 4-5 days I constantly rubbed my penis between two steel rods until I ejaculate but yesterday while rubbing I found that some part of penis skin got removed and I am not sure whether blood was coming out of it or not I noticed it while having bath. On steel rods there were some reddish brown coloured spots and I am also not sure whether they are of rust or blood. The place was dirty and unclean and had some black coloured spots of previously ejaculated semen my worry is if some person other than me is doing the same rubbing activity will I get infected with hiv case 2: my second query is my leg got wounded because of steel rod present on drainage chamber I didn't notice the wound and it got exposed to unclean and waste water, I think dirty sewage water (there might be presence of urine) will I get hiv because of such exposure to sewage and dirty waste water case 3: I went for shopping in city area in wholesale grocery market with relatives, to reach that market we need to pass through red light area filled with prostitutes my query is by just passing i.e walking through red light area will I get infected with hiv case 4: doctor, I work as a design engineer in automotive firm for past two years I working with my manager yesterday I came to know that he was hiv positive till I didn't knew about his hiv status, during meeting we often shake hand, also share drinks and food and also often travel in car for seminar. By keeping casual contact will I be infected with hiv doctor why I am worried is because I have shared water bottles so many times with him and I am not sure whether saliva was there or not will this cause any harm I have also shared toilets with him and also might have eaten his food that might be mixed with saliva I am not sure about it and doctor what about coughing and sneezing action near my mouth will this cause any hiv transmission case 5: my last question is I travel a lot by train are there any chances of getting hiv by use of unclean and dirty toilets because I am not sure whether there is urine on floors on taps, etc if some person with hiv has used it and touched the taps.