Herpes simplex virus 1 transmission is primarily oral, and herpes simplex virus 2 primarily genital. Transmission requires intimate contact. However, most primary herpes infections are asymptomatic, meaning that
there are no symptoms and therefore infection control more difficult.
- There are two types with slightly different pathogenicity
- Herpes simplex virus (HSV) 1 or HSV-2
- Can cause brain, oral, genital and ocular infections
- Predominantly causes ulceration
- Herpesviruses have a unique four-layered structure
- A core containing the large, double-stranded DNA genome
- This is enclosed by an icosapentahedral capsid composed of capsomers.
- The capsid is surrounded by an amorphous protein coat called the tegument
- It is encased in a glycoprotein-bearing lipid bilayer envelope.
- Alpha herpesvirus group.
- It is an enveloped virus that is approximately 160 nm in diameter
- A linear, double-stranded DNA genome
Spread by close contact
- HSV1: kissing/saliva
- HSV2: sexual contact. 23% of adults in the UK and US having antibodies to HSV-2.
Herpes simplex 1
- Herpes stomatitis with ulcers, fever, lymph node enlargement
- Herpetic whitlow : vesicles on fingers from contact common among health care workers. Lesions appear on abraded skin of the fingers
- Keratoconjunctivitis: dendritic ulcers best detected by fluorescein staining
- Acute Encephalitis: hemorrhagic necrosis of the inferiomedial portion of the temporal lobe
- Disseminated infection in immunocompromised: pneumonitis, oesophagitis, hepatitis, colitis, and disseminated cutaneous disease. Extensive perineal or orofacial ulcerations.
Herpes simplex 2
- Sexual Genital herpes
- Anorectal infection
- Neonatal herpes simplex virus infection: 70% are HSV2
- Herpes simplex virus identified by positive viral culture
- Polymerase chain reaction (PCR) on Serum/CSF etc...
- Aciclovir, valaciclovir and famciclovir are all licensed therapeutics
- Mild: Aciclovir (200 mg five times a day) PO should be started within 5 days of the start
- Severe: Aciclovir 10 mg/kg 8-hourly