Dengue hemorrhagic fever

DHF is a more severe form of dengue. It can be fatal if unrecognized and not properly treated. DHF is caused by infection with the same viruses that cause dengue. With good medical management, mortality due to DHF can be less than 1%.Dengue is transmitted to people by the bite of an Aedes mosquito that is infected with a dengue virus. The mosquito becomes infected with dengue virus when it bites a person who has dengue or DHF and after about a week can transmit the virus while biting a healthy person. Dengue cannot be spread directly from person to person.

The principal symptoms of dengue are high fever, severe headache, backache, joint pains, nausea and vomiting, eye pain, and rash. Generally, younger children have a milder illness than older children and adults.

Nature

Nature, in the broadest sense, is equivalent to the natural world, physical universe, material world or material universe. "Nature" refers to the phenomena of the physical world, and also to life in general. The term generally does not include manufactured objects and human interaction unless qualified in ways such as, e.g., "human nature" or "the whole of nature". Nature is also generally distinguished from the spiritual or supernatural. It ranges in scale from the subatomic to the galactic.

The word "nature" derives from the Latin word natura, or "the course of things, natural character."Natura was a Latin translation of the Greek word physis, which originally related to the innate way in which plants and animals grow of their own accord, and to the Greek word for plants generally.The concept of nature as a whole, the physical universe, is a more recent development that gained increasingly wide use with the advent of modern scientific method in the last several centuries.