सनदेरथाव सम - फारिया जाहाबनाया नुजानायनि थाम सानफोर फ्राम आगोलनिफ्राय गासै सिथरफोरा दाखोन महर - लानाय सिमहालागै जोरो ।
The infectious period lasts from about three days before the rash appears until all the blisters have formed scabs .