SPECIAL ARTICLES: REVIEW OF LITERATURE: GENERAL INFECTIOUS DISEASES
HERPES SIMPLEX VIRUS INFECTIONS [Whitley RJ, Roizman B. Lancet 2001;357:1513]:
Two major authorities in HSV review the topic with the following highlights:
Epidemiology: Positive serology for HSV-1 by age 5 years in 20%; incidence among university students of 5%–10%/year. Positive serology for HSV-2 in 20%–30% by age 15–29 years, and 35%–60% by age 60 years. Asymptomatic shedding of HSV-2 on 3%–5% of days in women, but this rate increases to 28% with PCR detection [JCI 1997;99:1092].
Diagnosis: (1) Culture of vesicle scraping; (2) serology (helpful only to determine prior exposure; serology to distinguish HSV-1 and HSV-2 now being licensed); and (3) PCR as the preferred method for CSF (persistently positive for up to 1 week).
Symptoms: The incubation period is about 4 days. Both HSV-1 and -2 are often asymptomatic. HSV-1 primary oral infections are often characterized by oral lesions lasting 2–3 weeks and accompanied by fever; recurrent lesions generally involve only the vermilion border and last up to 8–10 days. Primary genital herpes may be associated with paresthias of legs and perineum, dysuria, inguinal adenopathy, and malaise as well as typical skin lesions.
Neonatal HSV: Three factors influence transmission rates: (1) primary infection is transmitted to 30%–50% with vaginal delivery; recurrent HSV is transmitted at a rate of 3% or less; (2) transplacental maternal HSV-2 antibodies appear to protect and to reduce the severity of infection; and (3) the risk is increased with ruptured membranes for >6 hours.
HSV encephalitis: Without treatment the mortality rate is 70%, and only 2.5% of surviving patients return to normal neurologic function.
Treatment: Treatment for the most common treatable forms of HSV are summarized in Table 7:
Prophylaxis: Daily acyclovir has reduced the frequency of recurrences by up to 80% and totally prevents recurrence in 25%–30%. The dose should be titrated. Viral shedding is reduced, but persists so that transmission can still occur.
Acyclovir resistance: Acyclovir-resistant HSV is also resistant to famciclovir, valacyclovir, and penciclovir. The basis for most resistance is thymidine-kinase deficiency and it is found in immunocompromised patients almost exclusively.
This section of IDCP features summaries of publications relevant to the practice of HIV/AIDS. In most cases, a comment is provided from the editor concerning interpretation, impact or further relevant information on the topic reviewed. This represents a modification of selected entries in the “What’s News” section of the Johns Hopkins website for ID HIV/AIDS (reprinted from http://www.hopkins-aids.edu with permission).