HERPESVIRIDAE

There are 8 types of Herpes virus:

• Herpes in Greek means “creep”. This is because it reflects the creeping or spreading nature of the skin lesions caused by many herpes virus types.
  
  https://healthlibrary.epnet.com/GetContent.aspx?token=c5987b1e-add7-403a-b817-b3efe6109265&chunkiid=11950

• Herpes viruses quite ubiquitous in nature (ubiquitous means everywhere) and they are prevalent (means common/widespread).
  
• Herpes viruses are the leading cause of human viral disease just second to the influenza virus.
  
• Herpes viruses can be found mammalian and non mammalian vertebrates and non vertebrates.
  
• Structure of Herpes virus:

from left:

http://stdgen.northwestern.edu/stdgen/bacteria/hhv2/herpes.diagram.jpg

http://stdgen.northwestern.edu/stdgen/bacteria/hhv2/herpes.diagram.jpg

- Envelope: Found in the outside of the herpes virus particle. Contain numerous glycoproteins.

- Tegument: It is the space between envelope and the capsid. The tegument is a protein-filled region which contains protein and enzyme which are involved in the beginning of the replication process.

- Glycoprotein spikes: It determines the cell that can be infected due to the availability of the suitable receptors.

- Capsid: Protein shell of the herpes virus. It has an icosahedral structure.

- Genome: Contains linear double stranded DNA.

Herpes Simplex Virus 1 (HSV1) and Herpes Simplex Virus 2 (HSV2):

Similarities
- Both share about 50% of their DNA.
- Most people infected with HSV1 or HSV2 do not have any symptoms or any noticeable symptoms.
- Both infect the mucosal surfaces of the body.

Differences
- HSV1 causes the sores around the mouth and it is also known as “cold sores”.
- HSV2 infects the genital and it is also known as “genital herpes”.
- HSV1 establish latency in the trigeminal ganglion.
- HSV2 establish latency in the sacral ganglion.

Causes of HSV1 and HSV2
- People get infected with HSV1 by touching infected saliva mucous membrane or skins.
- For HSV2, people get infected during sex with an infected partner.

Stages of Infection

1. Primary infection
   When people get infected with either HSV1 or HSV2, they usually do not know of the condition since most of the time there are no symptom or noticeable symptom.
2. Latent infection
   After the herpes viruses infect the host, it will remain inactive for a long period of time. It hides within in the cells and the nerves tissue. By hiding, the herpes virus protects itself from being destroyed by the antibodies that is produced by the immune system.
3. Recurrent infection
   This happens when the herpes virus reactivates. Reactivation occurs due to various factors like sunlight, stress and menstruation. Infections can recur throughout life.

References:

• http://biommed.Isu.edu/onlinefiles/BIOL4190/LECT-6-Herpesviruses/SLIDES-herpesviridae-TIM-FOSTER.pdf
• http://chealth.canoe.ca/channel_section_details.asp?text_id=1364&channel_id=1020&relation_id=8287
• http://www.globalherbalsupplies.com/herpes/scinfo.html
• http://www.microbiologybytes.com/virology/Herpesviruses.html