PRECAUTIONS
Standard for encephalitis and mucocutaneous, recurrent; Contact for neonatal and mucocutaneous (disseminated or primary, severe) until lesions dry and crusted; "Also, for asymptomatic, exposed infants delivered vaginally or by C section and if mother has active infection and membranes have been ruptured for more than 4 to 6 hrs until infant surface cultures obtained at 24-36 hrs. of age negative after 48 hrs incubation." [CDC 2007 Guideline for Isolation Precautions]
COMMENTS
FINDINGS:
HSV-2 infections cause genital ulcers and tender, inguinal adenopathy. Primary HSV-1 infections may cause a mononucleosis-like syndrome with pharyngitis, cervical lymphadenopathy, and fever. Seizures and localizing signs are early symptoms in encephalitis. [Guerrant, p. 355-9, 1034] Complications of genital herpes include aseptic meningitis, transverse myelitis, and severe neuralgia of the sacral nerves. Genital HSV may cause urinary retention and constipation. [Merck Manual, p. 1621-2; ID, p. 1348] A clue to the diagnosis of HSV pharyngitis is the presence of esophagitis with chest pain and dysphagia. It is usually diagnosed in the immunocompromised, but may occur in healthy young adults. Other symptoms are nausea, vomiting, GI bleeding, and weight loss. [PPID, p. 828, 1342] About 9% of patients with primary HSV-2 infections have extragenital lesions, usually of the buttocks. Cutaneous dissemination occurs in some cases and is often associated with aseptic meningitis, hepatitis, or pneumonitis. Primary genital HSV-2 infection may be complicated by transverse myelitis, monoarticular arthritis, thrombocytopenia, adrenal necrosis, and myoglobinuria. HSV hepatitis is uncommon in healthy people. Candida and HSV infections often occur together. AIDs patients with HSV esophagitis have painful swallowing, substernal pain, and weight loss. [PPID, p. 1835-7] About 75% of cases of erythema multiforme may be caused by herpes simplex. Chorioretinitis may occur in neonates and AIDS patients. [Harrison ID, p. 740-1]
EPIDEMIOLOGY:
Individuals infected with HSV-2 shed the virus about 3-4% of the time, may be asymptomatic, and pose a risk of infection to sexual partners. [Cecil, p. 1843] Culture and PCR studies of patients have shown that HSV is frequently present when recognized lesions are absent. Genital HSV-2 infections have a recurrence rate ten times that of genital HSV-1 infections. [Cohen, p. 572, 1436]
GENITAL ULCERS:
In the US, virtually all cases are caused by HSV-1, HSV-2, and T. pallidum with the first two being the most common. [Cecil, p. 1842] A study of US urban patients in 1996 (PCR testing of genital ulcer specimens) found HSV in 62% of patients, T. pallidum in 13%, and H. ducreyi (chancroid) in 12-20%. The bacterial agents of lymphogranuloma venereum and granuloma inguinale cause genital ulcers in developing countries. [Harrison ID, p. 329] "Recurrent painful ulcers preceded by vesicles is usually HSV." [ABX Guide: Genital Ulcer Adenopathy Syndromes]
CNS INFECTIONS:
Type 1 and 2 herpes viruses cause aseptic meningitis, transverse myelitis, sacral radiculopathy, or encephalitis. Fever, headache, leukocytosis, stiff neck, confusion, stupor, coma, and focal neurological deficits are findings in encephalitis. [CCDM, p. 276] Type 2 is a common cause of acute viral meningitis. Type 1 is a common cause of acute viral encephalitis. [Harrisons, Table 194-3 & 4] MRI is the preferred neuroimaging technique in cases of viral encephalitis. "Bitemporal and orbitofrontal areas of increased signal are seen in HSV encephalitis, but are not diagnostic." [Harrisons, p. 1059] Focal neurological findings in encephalitis include dysphasia, weakness, and paresthesias. [PPID, p. 1176] Brain biopsy has been largely replaced by detection of HSV DNA in CSF. [Harrison ID, p. 741] The early use of acyclovir has reduced the mortality rate of herpes simplex encephalitis from 75% to less than 30%. [ID, p. 1291]