ForPneumocystic cariniipneumonia, standard treatment is trimethoprim-sulfamethoxazole, but promising results have been reported for dapsone and trimethoprim, inhaled pentamidine, effects of trimethoprim-sulfamethoxazole include chemical hepatitis, neutropenia, and methemoglobinemia. Prophylaxis includes trime-thoprim-sulfamethoxazole and inhaled pentamidine. In treatment of cryptococcal meningitis, the role of fluconazole is being studied. In studies of histoplasmosis, a new radioimmunoassay has been developed forHistoplasma capsulatum.In candidiasis, a relationship between site of mucosal candidiasis and CD4 count has been identified. Tuberculosis may be the first opportunistic infection to manifest in HIV-infected persons. InMycobacterium aviumcomplex infection, impressive results have been demonstrated for a regimen consisting of rifabutin, clofazimine, ethambutol, and isoniazid, and a regimen consisting of amikacin, ciprofloxacin, ethambutol, and rifampin. Ganciclovir is effective treatment for cytomegalovirus infection. For both herpes simplex infection and varicella zoster infection, acyclovir resistance is a problem. Alternatives to acyclovir include foscarnet, and for varicella zoster, vidarabine.