HSV-1 encephalitis is a devastating disease with significant morbidity and mortality, despite available antiviral therapy. The pathogenesis, clinical manifestations, diagnosis, and treatment of HSV-1 encephalitis will be reviewed here. Neonatal infections with herpes simplex virus (HSV) were first reported in the mid-1930s, when Hass described the histopathologic findings of a fatal case (35) and when Batignani reported a newborn with herpes simplex keratitis (14). Additional improvements in the outcomes of neonates with HSV disease have been achieved through advances in the diagnostics available to clinicians, the most powerful of which is the application of PCR to patients with neonatal HSV disease (46). In infants with CNS disease, mortality is usually caused by devastating brain destruction, with resulting acute neurologic and autonomic dysfunction. Improvements in morbidity rates with antiviral therapies have not been as dramatic as have improvements in mortality rates. Herpes simplex encephalitis (HSE) is a life-threatening condition with high mortality as well as significant morbidity in survivors.
The diagnosis of neonatal HSV can be difficult, but it should be suspected in any newborn with irritability, lethargy, fever or poor feeding at one week of age. Neonatal herpes simplex virus infections can result in serious morbidity and mortality. When diagnosis is delayed, mortality is high despite antiviral therapy. The incidence of neonatal HSV infection is estimated at 1 per 3,000 to 20,000 live births. Between 20 and 40 of infants infected with HSV are born preterm. Approximately 50 of neonates who have disseminated disease die despite antiviral therapy. Herpes simplex encephalitis (HSE) is a devastating disease. This method has been available for routine clinical use since 1991. The main conclusion of our study is that, despite the development of highly effective antiviral therapy in the past 2 decades, the level of morbidity following HSE is still high, and the mortality associated with HSE remains considerable, underscoring the need to expand our knowledge of the pathogenesis of HSE to direct more effective antiviral and antiinflammatory treatments.
In the adult, the therapy of choice for herpes simplex encephalitis is acyclovir. In addition to the development of more effective antiviral drugs and less invasive diagnostic techniques, prevention of these often devastating infections will be important in reducing morbidity and mortality. The few anecdotal reports of the use of vidarabine and acyclovir in herpes zoster encephalitis and the histopathologic evidence suggesting viral invasion of the CNS in many cases of zoster-associated neurologic syndromes makes the use of specific antiviral therapy in zoster encephalomyelitis more rational. Despite treatment, the mortality rate remains high, ranging from 20 to 30 1. Patients with HSV-1 encephalitis may complain of headache and fever of rapid onset; In the United States, HSV-1 encephalitis accounts for about 10 to 20 of the annual viral encephalitis cases11,12 and is associated with significant morbidity and mortality. Survivors may have significant behavioral and cognitive impairments despite treatment.13,18 Early and aggressive antiviral therapy with acyclovir may help prevent fatality and limit the severity of potential neurobehavioral and neuropsychiatric problems. Silent but Deadly: 45 of Heart Attacks Lack Symptoms. Disseminated neonatal herpes simplex virus infection usually presents with multi-organ involvement. Disseminated neonatal HSV infection characteristically presents as a sepsis syndrome with fever, hepatitis, and pneumonia with or without encephalitis. Prompt diagnosis and early initiation with antiviral therapy can be life-saving, but early recognition of the infection is difficult in infants with non-specific symptoms. Neonatal HSV infection, a potentially devastating disease with a high rate of morbidity and mortality, occurs between 1/12,500 and 1/1700 live births in the United States 2.
Neonatal Herpes Simplex Virus Infections