HERPES SIMPLEX

The Herpes simplex virus (HSV) is a member of the Herpesviridae family, of which two types are known: type 1 (HSV-1) and type 2 (HSV-2) which present slight antigenic differences. HSV-1 causes chiefly oral-facial lesions, while HSV-2 is mainly responsible for genital lesions, but this distinction is not binding, both types occasionally causing infection in either anatomical site. HSV may also cause a form of ocular cheratitis, and lesions of the central nervous system. HSV can affect practically the whole population. The primary infection is often in a subclinical form and is rarely diagnosed. After a latency period of variable duration, reactivation may occur and viral replication may or may not give rise to clinical lesions. Infection contracted during birth is of particular interest, this being an important cause of morbidity and mortality. It is therefore important to determine the immunitary state of women during pregnancy in order to detect serum conversion. The assay of specific IgG is important to establish the serological state of the patient. The assay of specific IgM is important for the diagnosis of neonatal infection and encephalitis caused by HSV. Moreover, the presence of specific IgM indicates viral activity in progress, although it is not possible to distinguish between primary infection and reactivation.