Mechanism Behind Herpes Reactivation

The herpes viruses belong to the family Herpesviridae and include at least 25 viruses that affect humans, including herpes simplex type I and II (HSV 1 and 2), Epstein Barr virus (EBV), Cytomegalovirus (CMV), Varicella Zoster Virus (VZV) and human herpes viruses 6 and 8. For example HSV1, responsible for cold sores, is believed to affect as many as 90% of adults worldwide.

Once a person is infected with a virus belonging to the herpes family, the infection will remain for life. The initial infection (which may or may not manifest with symptoms) is followed by a period of so called “latency or dormancy” when the virus stays dormant and there are no symptoms. Different herpes viruses will stay dormant in different cells. For example, herpes simplex stays dormant in the nerve cells, while other viruses stay dormant in cells involved in the immune system such as T and B lymphocytes. Occasionally, the herpes viruses reactivate. There is no cure for herpetic infections, although anti viral medications can help sometimes to decrease the number of recurrences. Most herpes viruses are easily transmitted from one person to another.

It is not well understood what exactly causes herpes reactivation. For some viruses it is well established what causes the reactivation. For example, in the case of herpes simplex, the reactivation is sometimes associated with febrile infections, menses, stress, fatigue or exposure to sun. However, the exact mechanism of reactivation is not known.

A recent study featured in the November 2012 issue of the “Journal of Leukocyte Biology” revealed significant evidence regarding the mechanism behind the herpes virus reactivation. Scientists from Ohio State University College of Medicine, Columbus, Ohio, explain how the immune system becomes unbalanced and loses control over the herpes virus when the body is exposed to other viruses and bacteria. During this research study, the scientists evaluated a group of mice with latent infection with family cytomegalovirus (CMV), a virus belonging to the herpes family of viruses, during a new infection with bacteria. Interestingly, during these bacterial infections, the subjects exhibited a dramatic reduction of T-cells that are responsible for controlling the CMV infection. Therefore, this new infection basically decreased the body’s ability to control the herpes infection and as an end result, allowed it to reactivate. The researchers also noted that when the herpes infection was reactivated, the memory T-cell  levels returned  to normal and were quickly ready to fight the herpes virus.

This study is likely to have a significant impact in the future management and prevention of  herpetic infections as well as decreasing the risk of transmission from one person to another. Until the exact mechanism or reactivation is elucidated and applied in practice, prevention of  herpetic infections must be considered. Herpes simplex virus infections can be prevented by avoiding skin contact with any person with blisters, avoid sharing personal items such as lip balms or towels and always keep the hands clean. The Epstein-Barr Virus (EBV) is transmitted through saliva, Cytomegalovirus (CMV) are spread through direct contact as well as blood transfusions. Boosting the immune system with natural supplements will reduce the risk of reactivation of herpes viruses.

References:

http://www.sciencedaily.com/releases/2012/10/121031125516.htm
http://www.jleukbio.org/content/92/5/933
http://www.mayoclinic.com/health/cold-sore/DS00358/DSECTION=causes
http://pathmicro.med.sc.edu/virol/herpes.htm