Cytomegalovirus infection in patients with HIV infection

Cytomegalovirus (CMV) is responsible for the most common viral opportunistic infection in persons with acquired immunodeficiency virus syndrome (AIDS). Clinical disease due to CMV has been recognized in up to 40% of patients with advanced HIV disease. The most common presentation is retinitis, although colitis, esophagitis, pneumonitis and neurological disorders are also reported frequently. CMV retinitis is usually diagnosed clinically, and serological testing for CMV immunoglobulin is useful to support the diagnosis. Parts of the gastrointestinal tract (esophagus and colon) are the most common extraocular sites of CMV infection in AIDS patients. Therapy with systemic agents, including intravenous ganciclovir, intravenous foscarnet, and intravenous cidofovir, is effective. Ganciclovir is associated mainly with hematological toxicity, while foscarnet and cidofovir are nephrotoxic. Intravitreal injections with these antiviral agents are also effective, but inconvenient, and there is a need for repeated injections. Intraocular implants that slowly release ganciclovir have been effective for both acute therapy and long-term maintenance, but the occurrence of contralateral ocular and extraocular disease is a serious concern. New agents, as for example an anti-sense agent against CMV, appear promising.