Varicella

Varicella, better known as chicken pox, is a viral disease caused by the varicella-zoster virus. Although considered a benign childhood disease, varicella may be particularly severe in newborns, adults who have not contracted the disease during childhood, and immunodepressed individuals. (29)

Symptoms of varicella

Following a mean incubation period of 15 days, moderate fever usually precedes the onset of a rash. The first lesions usually appear on the face and scalp, before spreading to the trunk and the rest of the body. The initial macular (red spots) lesions subsequently become vesicular before drying out into scabs. Successive crops of lesions usually appear.

The severe forms of the disease are treated using an antiviral.

Epidemiology and vaccination against varicella

The virus is transmitted through the respiratory route or by direct contact with the lesions. Patients are usually contagious several days before the onset of the rash and up to the formation of scabs.

Varicella vaccines are available.

References:

29 - Varicella vaccines. WHO position paper. WER 1998, 73:241-248

http://www.who.int/immunization/wer7332varicella_Aug98_position_paper.pdf