Which herpes simplex virus type is historically associated with genital‑urinary tract infections, HSV‑1, HSV‑2, HSV‑3, or HSV‑4?

HSV-2 is Historically Associated with Genital-Urinary Tract Infections

HSV-2 (herpes simplex virus type 2) is the herpes simplex virus type historically and classically associated with infections of the genital-urinary tract. 1, 2

Note: There are only two types of herpes simplex virus—HSV-1 and HSV-2. HSV-3 and HSV-4 do not exist. 3

Historical Classification and Association

• The traditional paradigm established that HSV-2 causes genital and urogenital tract infections, while HSV-1 causes orolabial disease. 3

• The International Classification of Diseases specifically codes anogenital herpesviral infections under code A60, with A60.0 designated for "Herpesviral infection of genitalia and urogenital tract," reflecting the historical association with HSV-2. 1

• HSV-2 establishes latency in the sacral ganglia following genital infection, with recurrences arising from viral reactivation at these sites. 1, 4

Epidemiological Evidence

• Historically, HSV-2 accounted for the vast majority of genital herpes cases, with an estimated 29 million cases in men and 12.3 million cases in women in eastern Europe and central Asia as of 2003. 1

• HSV-2 is efficiently transmitted through intimate genital tract contact and causes persistent infection with frequent subclinical shedding from genital surfaces. 2

Important Modern Caveat

• While HSV-2 remains the classic genital pathogen, the epidemiology has shifted significantly in recent decades. 5

• HSV-1 now causes a substantial proportion of genital infections, particularly in young women, due to oro-genital sexual practices. 6, 5, 7

• In one prospective study of young women, HSV-1 caused more primary genital infections than HSV-2 (3.7% vs 1.6%), with 84% of recognized disease cases being genital. 5

• However, the clinical manifestations of genital HSV-1 versus genital HSV-2 disease are indistinguishable, though HSV-2 typically causes more frequent recurrences. 4, 5

• Laboratory typing (viral culture, HSV DNA PCR, or HSV antigen detection) is essential because typing has prognostic implications for recurrence frequency. 4