CD4 and cryptosporidiosis: Although syphilis is not an opportunistic infection such as cryptosporidiosis, cryptococcosis, pneumocystis carinii, or cytomegalovirus (50 < CD4 < 100 cells/ml) and mycobacterium avium complex (CD4 < 50 cells/ml), our study suggests that high HIV-1 viral load and relatively compromised immune status in HIV patients may play a role in ocular manifestation of syphilis [31].