Thanks for writing in.
You need to know whether the person has any disease that is transmissible by syringes. These include HIV, Hepatitis B
and Hepatitis C
. If the elderly gentleman did not have these diseases you need not worry, if he has any of these I recommend you see your local doctor for post exposure prophylaxis for these diseases.
Hope I have answered your query. If you have any further questions I will be happy to help
Dr. Om Lakhani
http://www.healthcaremagic.com/doctors/dr-om-lakhani/60313 (online expert diabetes