Herpes simplex is one of the commonest infections of mankind throughout the world. There are two main types of herpes simplex virus (HSV); type 1, which is mainly associated with facial infections and type 2, which is mainly genital, although there is considerable, overlap.
Both type 1 and type 2 herpes simplex viruses reside in a latent state in the nerves, which supply sensation to the skin. With each attack of herpes simplex the virus grows down the nerves and out into the skin or mucous membranes where it multiplies, causing the clinical lesion.
After each attack it "dies back" up the nerve fiber and enters the resting state again. First attacks of type 1 infections occur mainly in infants and young children, which are usually mild or sub clinical. In crowded, undeveloped areas of the world up to 100% of children have been infected by the age of 5.
In higher socioeconomic groups the incidence is lower, for example less than half of university entrants in Britain have been affected. Type 2 infections occur mainly after puberty, often transmitted sexually.
The initial infection more commonly causes symptoms. The virus can be shed in saliva and genital secretions from individuals without symptoms, especially in the days and weeks following a clinical attack. The amount shed from active lesions is 100 to 1000 times greater.
Spread is by direct contact with infected secretions. Minor injury helps inoculate the virus, especially into the skin. The virus can be inoculated into any body site to cause a new infection, whether or not there has been a previous infection of either type.
The source of the virus may be from elsewhere on the body especially in nail biters or thumb suckers. Examples of inoculation from external sources include lesions of the hand in health-care workers, facial lesions contracted in rugby scrums, and infection of a breast-feeding mother's nipples from the infected mouth of her baby.
Following the initial infection immunity develops but does not fully protect against further attacks. However where immunity is deficient, both initial and recurrent infections tend to occur more frequently and to be more pronounced.
Joke and Humors
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