Primary infection and late-stage infection were estimated to be 26 and 7 times, respectively, more infectious than asymptomatic infection. High infectiousness during primary infection was estimated to last for 3 months after seroconversion, whereas high infectiousness during late-stage infection was estimated to be concentrated between 19 months and 10 months before death.

HIV-1 Transmission, by Stage of Infection. 
The Journal of Infectious Diseases 2008 vol. 198   DOI: 10.1086/590501
T. Déirdre Hollingsworth, Roy M. Anderson, and Christophe Fraser

(My emphasis)