AK Ajith Kumar, Bhutta Beenish S., Mendez Magda D.
Manipal Hospitals
Sheikh Zayed Hospital, Lahore
Herpetic infections have been well-documented, as far back as ancient Greek literature. Herpes viruses are large double-stranded DNA viruses. Eight types of herpes viruses affect humans (human herpes virus—HHV). Symptoms of central nervous system infection include fever, headache, seizures, focal neurological signs, and impaired consciousness. Herpes simplex encephalitis is an acute or subacute illness associated with focal or global cerebral dysfunction caused by herpes simplex viruses belonging to either type 1 (HSV-1) or type 2 (HSV-2). Most herpes simplex encephalitis is caused by HSV-1, with HSV-2 constituting less than 10% of infections. Almost all herpes encephalitis beyond the neonatal period is caused by herpes simplex type 1 (HSV-1), the most common cause of fatal encephalitis, occurring in a sporadic and non-seasonal pattern across the globe. Herpes encephalitis in neonates could be due to HSV-1 or HSV-2, though the latter is more common. HSV-2 can also cause encephalitis in immunocompromised patients. HSV-1 in adults is associated with significant morbidity and mortality despite treatment with antiviral therapy. Herpes simplex encephalitis has a nonspecific and insidious onset in children and can be devastating, irrespective of treatment. Herpes simplex encephalitisis a rare condition, but if left untreated, it can result in a mortality rate of up to 70%, and only a minority of individuals recover fully without residual deficits. Neonatal encephalitis caused by HSV-2 involves the brain in a more global distribution, resulting in a greater incidence of neurologic sequelae.
疱疹感染早在古希腊文学中就有详尽记载。疱疹病毒是大型双链DNA病毒。八种类型的疱疹病毒会感染人类（人类疱疹病毒——HHV）。中枢神经系统感染的症状包括发热、头痛、癫痫发作、局灶性神经体征和意识障碍。单纯疱疹性脑炎是一种急性或亚急性疾病，与1型（HSV-1）或2型（HSV-2）单纯疱疹病毒引起的局灶性或全身性脑功能障碍有关。大多数单纯疱疹性脑炎由HSV-1引起，HSV-2引起的感染不到10%。几乎所有新生儿期后的疱疹性脑炎都是由1型单纯疱疹病毒（HSV-1）引起的，这是致命性脑炎最常见的病因，在全球呈散发性且无季节性规律。新生儿疱疹性脑炎可能由HSV-1或HSV-2引起，不过后者更常见。HSV-2也可在免疫功能低下的患者中引起脑炎。尽管采用抗病毒治疗，成人的HSV-1感染仍会导致显著的发病率和死亡率。单纯疱疹性脑炎在儿童中起病非特异性且隐匿，无论是否治疗都可能具有毁灭性。单纯疱疹性脑炎是一种罕见疾病，但如果不治疗，死亡率可达70%，只有少数患者能完全康复且无残留缺陷。由HSV-2引起的新生儿脑炎累及大脑的范围更广，导致神经后遗症的发生率更高。
