Effective treatment also means that some people living with HIV are achieving an undetectable viral load. This means that the virus exists in such small quantities in their blood that it does not affect their health and there is zero risk of transmitting the virus on to others. But remember that if you stop taking your medication then your viral load will go back up again. It is now recommended that people living with HIV start antiretroviral treatment straight away. This is being implemented in an increasing number of countries. In some places, the decision about when to start treatment is still dependent upon a CD4 count test, which looks at how many CD4 cells are in a small amount of blood.