Who knows.
Only injecting has any bearing on HIV, so Musket is just raising a spurious issue.

"Research in the UK29 that explored drug use levels among
MSM within the previous 12 months reported levels ranging
from 39.4% for poppers, 27.7% for cannabis, 18.5% for ecstasy
and 4.7% for methamphetamine (with significant regional
variations evident and highest usage in London.)30"
http://www.ihra.net/files/2012/09/04/Chapter_3.3_MSM_.pdf


Injectable drugs not even on the scale.
A wholly spurious issue.