An haemonhagic fever is an epidemic disease that has a female tiger mosquito as a carrier. A patient gets virusy from masquito stinging. Usually ,the viruses stay in a stomach and a salivary gland of the mosquito. The viruses increase numbers in 8-10 days. The disease, called dengue five , is spread in rainy season .The carrier prays in the daytime and lays eggs in utensils that have clean water in not in ponds , canals or rivers.