West African study shows HIV-2 less pathogenic than HIV-1.

A survival study conducted in West Africa confirms that HIV-2 is less pathogenic than HIV-1, with the mortality rate for HIV-2 infected patients found to be two-thirds that for those with HIV-1 infection.

HIV-2, which is endemic in West Africa, has long been assumed to be less pathogenic than HIV-1, which is now spreading in the region.

"The assumption is based largely on anecdotal reports or on cross-sectional laboratory data which show that immunological markers, such as CD4+ count, are more abnormal in HIV-1-infected patients," researcher Hilton Whittle and colleagues wrote ("HIV-2- Infected Patients Survive Longer than HIV-1-Infected Patients," AIDS, …