Foscarnet Resistance HSV (Phenotype)

The Foscarnet Resistance HSV (Phenotype) assay evaluates HSV-1/HSV-2 susceptibility to foscarnet by plaque reduction, reporting the inhibitory dose that reduces plaque formation by 50% (ID50). Findings assist in determining phenotypic resistance and guide use of foscarnet (Foscavir) for management of herpes simplex virus infections when an actively growing isolate can be tested, including use cases commonly referred to as Foscavir resistance testing or HSV phenotyping for foscarnet.

Herpes simplex virus types 1 and 2 are widespread human pathogens that cause vesicular lesions of mucocutaneous surfaces and then persist in a latent state, with potential for intermittent reactivation, particularly during stress or immunosuppression. HSV-1 is most often associated with orolabial disease and HSV-2 more commonly with anogenital infection, although either type may be found at either site. Transmission occurs through direct contact and can happen even when lesions are not clinically evident. Severe manifestations, including disseminated infection and encephalitis, may occur in neonates and in immunocompromised individuals.