Herpes Simplex Virus 2 (HSV‑2) is an enveloped double‑stranded DNA virus in the genus *Simplexvirus* of the Alphaherpesvirinae subfamily. It primarily causes genital herpes and establishes latent infection in the sacral sensory ganglia.
Virology and Infection Characteristics
HSV‑2 has an icosahedral capsid surrounded by a tegument layer and an envelope studded with glycoproteins that bind to heparan sulfate and nectin‑1 on mucosal epithelial cells. After entry, the linear double‑stranded DNA genome circulates in the nucleus and expresses immediate early, early and late genes. Viral DNA replication produces concatemeric intermediates that are cleaved and packaged into preformed capsids, and mature virions acquire tegument and envelope components as they exit the cell. HSV‑2 replicates efficiently in genital mucosa and establishes latency in the sacral dorsal root ganglia where the genome persists as an episome with limited gene expression. Reactivation can be triggered by fever, stress, ultraviolet light or immunosuppression, leading to anterograde transport of virions back to the skin or mucosa. Transmission occurs mainly through sexual contact and vertical transmission from mother to infant during delivery.
Clinical Significance and Public Health
Primary HSV‑2 infection often presents as painful vesicular lesions on the external genitalia, perineum or buttocks that progress to ulcers. Constitutional symptoms such as fever, headache and inguinal lymphadenopathy can accompany the first episode. Recurrent outbreaks tend to be milder but occur more frequently than recurrences of HSV‑1 infection. Many infected people remain asymptomatic yet shed virus intermittently, contributing to spread. HSV‑2 is a major cause of aseptic meningitis and can cause severe disseminated disease in neonates, particularly when the mother has a primary infection near term. The virus also increases susceptibility to HIV acquisition and transmission. Seroprevalence varies by region but remains high globally, with notable burden in sub‑Saharan Africa. Management focuses on suppressive therapy with nucleoside analogues such as acyclovir, valacyclovir or famciclovir to reduce symptom duration and recurrence frequency. Safe sexual practices and antiviral prophylaxis during pregnancy are key preventive measures, and vaccine candidates are under investigation but none are yet licensed. HSV‑2 continues to be a significant cause of genital ulcers worldwide. Although antivirals mitigate symptoms and reduce transmission, the virus persists for life, making prevention strategies essential for public health. Related Terms: herpes simplex virus 1, genital herpes, latency, antiviral therapy, neonatal herpes