Thanks Seeker, that saved me some explaining.
As per aidsmeds.com,
“HIV is a very fragile virus. Its outer membrane is very sensitive to minute changes in moisture content, pH levels and temperature. Its favoured environment is INSIDE the human body and once it is outside this environment, it quickly becomes damaged and unable to infect. To infect, it must actually latch on to specific types of cells in the body. In order for it to be able to latch on to these cells, not only must it bump into these specific cells by chance, but its outer membrane must also be intact and in good condition.”