Genital herpes simplex virus afects an estimated 50 million adolescents and adults (Workowski, 2015). Most women are unaware of their infection, but HSV-2 seroprevalence among non-Hispanic white females in the United States was 15.3 from 2007 to 2010 and among black females, it was 53 percent (Fanfair, 2014; Schulte, 2014). In one study of nearly 16,000 pregnant women from 2000 to 2010, the overall seroprevalence of HSV-2 was 16 percent, and for HSV-l, it was 66 percent (Delaney, 2014). Seronegative pregnant women have a 4 to 5 percent risk to acquire HSV-l or -2 during pregnancy (Brown, 1997; Kulhanjian, 1992). For those who are HSV-l seropositive, acquisition risk for HSV-2 approximates 2 percent (Brown, 1997).
Once transmitted by contact, HSV-l or -2 replicates at the entry site. Following mucocutaneous infection, the virus moves retrograde along sensory nerves. It then remains latent in cranial nerves or dorsal spinal ganglia, but recurrences are common. HSV infections may be categorized into three groups.
First episode primary inection describes the case in which HSV-l or 2 is isolated from a lesion in the absence of HSV-l or -2 serological antibodies. The typical incubation period of 6 to 8 days (range 1 to 26 days) may be followed by a papular eruption with itching or tingling, which then becomes painful and vesicular. Multiple vulvar and perineal lesions mayror may not coalesce, and then ulcerate (Fig. 65-5). Associated inguinal adenopathy can be severe. Many women do not present with typical lesions. Instead, a pruritic or painful abraded area or knife-cut may be found. Cervical involvement is common, although it may be inapparent clinically. Transient systemic influenza-like symptoms are frequent and are presumably caused by viremia. Some cases are severe enough to require hospitalization. Hepatitis, encephalitis, or pneumonia infrequently develop, and disseminated disease is rare. After 2 to 4 weeks, all signs and symptoms of infection disappear. Instead of these classic symptoms, the percentage of asymptomatic primary HSV-2 genital infections may be as high as 90 percent (Fanfair, 2013).
FIGURE 65-5 First-episode primary genital herpes simplex virus infection. Vesicles and knife-cut lesions are indicated by arrows. Small ulcers rim the anus. Similar lesions can typically be seen on the vulva.
First episode nonprimay inection is diagnosed when one HSV type is isolated from a lesion in a woman who has only the other serological HSV-type antibody present. In general, compared with primary infection, nonprimary infections are characterized by fewer lesions, less pain, fewer systemic manifestations, and briefer duration of lesions and viral shedding. This is likely because of some immunity from cross-reacting antibodies, for example, from childhood-acquired HSV-l infection.