Cytomegalovirus and the acquired immunodeficiency syndrome.

The acquired immunodeficiency syndrome (AIDS) is complex in nature with one major aetiological factor but with numerous other agents exploiting the immune incompetence. Cytomegaloviruses (CMV) form a little-defined group of viruses which naturally persist in man and respond readily to the relaxation in immune surveillance. A role for CMV and other herpesviruses in potentiating the underlying infection with human immune deficiency virus (HIV) cannot be totally excluded but CMV is well established as a major opportunist in AIDS. They are considered responsible for a range of diseases in AIDS patients including retinitis, gastrointestinal disease, pneumonitis and, less frequently, encephalitis. The pyrophosphate analogue foscarnet (phosphonoformate) and the deoxyguanosine analogue ganciclovir have both been used to treat CMV infections in AIDS patients. Results of uncontrolled studies have indicated efficacy with both drugs but the work with ganciclovir is particularly encouraging. This communication provides a review of CMV infections in AIDS patients with special reference to the experiences to-date in the use of ganciclovir and foscarnet.