15.3.1.1.1.1: Herpes Simplex 1 and 2 (HHV 1 and 2)
- Page ID
- 46694
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)
Virus
- Genetic material: double-stranded linear DNA
- Virion structure: Enveloped, icosahedral capsid
Replication
- DNA enters host nucleus and circularizes
- Remains separate from host genome as episome
- After initial infection, viral DNA remains in ganglia near initial infection site
- Replication of virus (and therefore disease) can recur, usually due to stress, immune suppression, other disease, or exposure to factors which can cause DNA damage, such as sunlight (UV)
Transmission
- Transmitted through close contact with infected individual, usually active lesions
- HSV-2 (HHV-2) can be shed even when there are no active lesions
Epidemiology
- Anyone is susceptible to infection, but HSV-2 (HHV-2) is typically sexually transmitted
Clinical Disease
- Oral herpes
- also called cold sores or fever blisters
- recurrence of lesions is triggered by illness/stress
- painful, itchy lesions on the lips
- usually caused by HSV-1 (HHV-1)
- virus goes latent in trigeminal and brachial ganglia
- also called cold sores or fever blisters
- Genital herpes
- painful, itchy lesions in/on genitalia
- usually caused bby HSV-2 (HHV-2)
- virus goes latent in sacral ganglia
- Neonatal herpes
- infection of infant during birth
- 30% fatal if cutaneous or oral infection, 80% if CNS infection
- to prevent, mother should be tested for HSV and give birth by Caesarean section if infected
- Whitlow
- infection of wound or cut
- most at risk are healthcare workers who may come in contact with lesions or young children who suck their thumb
Treatment and Prevention
- Antivirals such as acyclovir, valacyclovir or other nucleoside analogs
- Prevention of contact with active lesions (gloves, condoms)
- Caesarean delivery for infected women
- Abstinence/monogamy