Diseases & National Health Programme
Which of the following is true regarding Varicella-zoster virus infection: (AIPG 11)
|A||Rash has centrifugal distribution|
|B||Incubation period is of 30-100 days|
|C||Secondary attack rate is about 50%|
|D||Scabes are not infectious|
Varicella-zoster virus causes two distinct clinical entities: varicella, or chickenpox, and herpes zoster, or shingles.
a. The incubation period of chickenpox ranges between 10 and 21 days but is usually between 14 and 17 days.
b. Rash is pleomorphic i.e. different stages of rash are seen at one given time, because rash appears in successive crops.
c. Secondary attack rates in susceptible siblings Within a household are between 70 and 90 percent.
d. Rash has centripetal distribution.
e. The communicability period of patients ranges from 1-2 days before the appearance of rash and 4-5 days thereafter. The virus tends to die out before the pustular stage.