This is the advise I've recieved since being dx'd in 1989!
1989, While I was in hospital, it was single use, after I got home I was told to use reuse my syringes, I was also instructed to cut my BM test strips into 2 perferably 3!
I was also told to wripe the rubber bung of my insulin vial with surgical spirit/alcohol swap before drawing up my insulin, plus as swap the injection site before injecting..
About 1996 I was informed that I didn't need to swap my vials or my injection site just insure it was clean..
2007 I found myself preganat, put onto the bolus/regime given 2 insulin pens, told that I could leave my needles on the pens until I needed to change needles, guidence the same as my syringes..
sadly I misscarried, but kept on the new regime and had to buy my own needles, (£12 a box)
2008, January changing needles and injecting through cloths was disgused on the DAFNE course I attended, The advise given yes to same guidance on reusing needles, but adivised not to reuse more than 5 times... Injecting through cloths, it wasn't something they encouraged but if you were injecting through clean light cloth then shouldn't pose a lot of problems, but if you did injet through clothing to change the needle before the next injection!
Now it's not a case of failing to change habits, it's a bit of common sense about risk factors and the likelyhood of something might happen...
I am in more danger from getting an infection from a papercut, being prick by a rose bush thorn or the thistle while gardening.. Or the verious other minor cuts or abrasions that I recived then reusing a needle that started sterile and the only thing it's been in contact with is my skin and the securely covered...
If I have a contaminate on my skin that is going fester for several hours on my needle and cause problems on the following injection a fresh needle won't change a thing the problem already existed on my skin!