This page has moved. Click here to view.

 

Herpes Simplex Virus Infections

Herpes is a member of the herpesvirus family, which includes varicella zoster virus, Epstein-Barr virus, and cytomegalovirus herpes, herpe, cold sore. Like all herpesviruses, herpes tends to establish latent infection and eventually it reactivates and becomes infectious. Most herpes-infected patients have asymptomatic infections or the symptoms are only mildly uncomfortable. However, a substantial number of patients experience frequent painful 

Virology and pathogenesis

Two types of herpes exist: herpes-1 and herpes-2. Both types can infect any 

herpes-1 may cause asymptomatic infection, oral lesions, nonoral or non-genital skin lesions, encephalitis, neonatal disease, and genital lesions

herpes-2 may cause asymptomatic infection, genital lesions, neonatal disease, nonoral, nongenital skin lesions, meningitis, and oral lesions

During epithelial cell infection, herpes infects the regional sensory or autonomic nerves, traveling via the nerve axon to the neuron, where it establishes a latent infection. The virus may reactivate at a

Transmission

herpes-1 and herpes-2 are transmitted from person to person through contact with infected skin lesions, mucous membranes, and secretions. The incubation period is 1 to 26 days, and both types may be

Asymptomatic virus shedding may transmit the disease. Women who have had previous genital herpes-2 infection shed virus on 2% of 

Oral/facial herpes infections

herpes-1 infection is extremely common in infants and children. The most common clinical manifestation of primary herpes-1 infection is gingivostomatitis, characterized by fever, malaise, myalgia, pharyngitis, irritability, and cervical adenopathy. The illness is self-limited and usually of short duration.

Recurrent herpes-1 infections are most frequently characterized by oral and lip lesions. Many individuals who have oral herpes lesions have no known history of prior gingivostomatitis.

herpes-2 also may cause oral lesions and pharyngitis, particularly in sexually active individuals.

Genital herpes infections

Many herpes infections are asymptomatic, but they can also cause papular, vesicular, or ulcerative lesions with pain, itching, urethral or vaginal discharge, and dysuria.

Primary infections cause more severe symptoms and signs, including extensive skin lesions, tender inguinal adenopathy, and extragenital lesions. Primary infections are often associated with fever, headache, malaise, abdominal pain, and

Eighty percent of persons who have a first episode of herpes-2 genital infection will experience a recurrence in the first year. Thereafter, most patients who have genital herpes infection have few

herpes encephalitis

herpes encephalitis is the most common viral infection of the CNS. The incidence peaks at 5 to 30 years and at more than 50 years. Ninety five percent of cases are caused by herpes-1. herpes encephalitis is

Neonatal herpes infections

Infection in neonates results from vertical transmission during the peripartum period in 85%; in utero or postpartum transmission rarely occurs. Seventy percent of untreated infants will progress to disseminated or CNS disease. Most neonatal infections are caused by herpes-2, although 30% of cases

Skin, eye, mouth (SEM) disease accounts for 45% of peripartum infections.

SEM disease most commonly presents in the first or second weeks of life with vesicular skin lesions which may occur anywhere on the body. Skin lesions have an erythematous

Central nervous system disease is manifest as encephalitis, and it accounts for 35% of peripartum infections.

Neonatal herpes CNS disease most commonly presents in the second to third week of life. Only 60% will develop skin lesions during the illness. herpes CNS disease has a 50%

Disseminated disease is characterized by hepatitis, pneumonitis, and disseminated intravascular coagulation, and it accounts for 20% of peripartum infections.

herpes disseminated disease presents in the first week of life. Bilateral patchy infiltrates are indicative of pneumonitis. Skin lesions may not be present initially.

Disseminated herpes disease should be considered in any infant presenting with sepsis that is unresponsive to antibiotic therapy, or who has both pneumonitis and hepatitis. Without treatment, disseminated herpes infection has an 80% mortality rate. With treatment, the

Eye infections

herpes is the most common cause of corneal blindness. herpes keratitis is characterized by conjunctivitis and dendritic lesions of the cornea.

Management of  herpes infection in pregnancy

The most reliable predictor of the risk of perinatal transmission is whether a woman has active genital

Management of infants exposed to herpes at delivery

Virus cultures of the infant’s conjunctivae, pharynx, skin folds, CSF, and rectum at 24-48 hours can indicate whether herpes has been transmitted. Infants who are culture positive for herpes from any site after 24 hours of life are given antiretroviral therapy with acyclovir.

During the time when herpes-exposed infants are in the hospital, they should be placed in contact isolation. Circumcision is

Diagnosis of herpes infection

herpes-1 and herpes-2 can be isolated by virus culture from active skin, eye, and genital lesions. In cases of recurrent disease, virus shedding may be too brief to be detected by virus culture. Herpes simplex is rarely is recovered from

Although less sensitive and specific than culture, staining for virus antigens with fluorescent antibodies

PCR is a useful diagnostic procedure for herpes encephalitis, with a sensitivity of 75% and a specificity of 100%.

Therapy for herpes infections

Acyclovir is the treatment of choice for most cases of serious herpes infection and for prophylaxis. Acyclovir interferes with viral DNA polymerase.

Parenteral acyclovir is indicated for severe or potentially severe infections, such as neonatal herpes infection, herpes encephalitis, and non-localized infections in immunocompromised patients. Oral acyclovir decreases new lesion formation and improves symptoms in first episode genital herpes. Oral acyclovir has limited effect on the resolution of recurrent herpes disease.

Topical acyclovir is not effective for skin or oral lesions. The ophthalmic solution is useful for herpes keratitis, in combination with IV acyclovir.

Acyclovir ( Zovirax)

For serious infections, such as neonatal disease and encephalitis, 5-10 mg/kg IV is given q8h for 10 to 21 days. Doses up to 20 mg/kg IV q8h are used for infants who have CNS or 

Acyclovir is well tolerated. The most common adverse effect is gastrointestinal upset. Nephrotoxicity can be avoided by keeping the

Valacyclovir ( Valtrex) is an ester of acyclovir that has better oral absorption; 1000 mg orally twice a day for 5 days. It has a more convenient dosage schedule than acyclovir and is approved for

Famciclovir ( Famvir) has a more convenient dosage schedule than acyclovir and is approved for adolescents. Dosage for first episodes of genital herpes infection is 250 mg q8h for 5 days, and for

Sexually active individuals known to have genital herpes infection should be advised to use latex condoms even