 Patients in studies have displayed a shorter lag between seroconversion and experiencing an AIDS-defining clinical condition or death.However, it is unclear whether this rapid conversion is a direct effect of superinfection, or a result of a weaker immune response to the virus caused by superinfection.It is difficult to gain accurate estimations of the frequency of HIV superinfection because most studies are performed on patients infected with the HIV-1 B subtype, and recombinant strains are difficult to distinguish from the original strain for this subtype.