Table 1.

When should CMV drug resistance be considered? (Adapted from Le Page et al. [50••] and Drew [53])

Been on an anti-CMV agent for >6 weeks

Viral load rises while on treatment

Viral load plateaus at high level despite treatment

Viral load declines then rises again (though there has been no cessation of therapy in a compliant patient)

Viral load does not fall by >0.5 log per week

Disease is progressing (e.g. new area of retina involved)

CMV cytomegalovirus