Thank you for the query. Handling of used needle should be done with utmost care (it is considered under Universal precautions). Used needles should never be recapped (which causes the maximum number of pricks). Ideally used needles should be disposed by needle cutters, but these are not always available at home. I would also like to know how deep your prick was (i.e. did you bleed yourself?). Immediately after the prick, you should wash your hands properly with a soap. (do not put the punctured finger in your mouth). If your father in law is suffering from any disease which can be transmitted by blood and blood products (haematological transmission), like Hepatitis B, Hepatitis C and HIV, then the need for concern arises. In that case I would advise you to consult your physician. I don t think it will be a need for concern if he is suffering from Urinary tract infection. However, in future, please use a proper handcare to handle these sharp objects. Hope that helps you.