Natural reservoir or nidus (the latter from the Latin word for "nest") refers to the long-term host of the pathogen of an infectious disease. It is often the case that hosts do not get the disease carried by the pathogen or it is carried as a subclinical infection and so asymptomatic and non-lethal. Once discovered, natural reservoirs elucidate the complete life cycle of infectious diseases, providing effective prevention and control. Examples of natural reservoirs are:
- Field mice, for hantaviruses and Lassa fever
- Marmots, black rats, prairie dogs, chipmunks and squirrels for bubonic plague
- Armadillos and opossums for Chagas disease and several species of New World Leishmania
- Ticks for babesiosis and Rocky Mountain spotted fever
- Ground squirrels, porcupines, and chipmunks for Colorado tick fever
- Snails for schistosomiasis and swimmer's itch
- Pigs for cestode worm infections
- Raccoons, skunks, foxes and bats for rabies
- Shellfish for cholera
- Fowl (ducks and geese) for avian influenza
- Bats, the reservoir for nipah, hendra, rabies and severe acute respiratory syndrome (SARS)
- Dogs and wild canids for Leishmania infantum, the cause of infantile visceral leishmaniasis
- Cats, for Bartonella (aka Cat scratch disease)
- Gerbils for Leishmania major, the causative agent of cutaneous leishmaniasis in the Old World
- Rock hyrax for Leishmania aethiopica and, probably, certain strains of Leishmania tropica, the causative agents of cutaneous leishmaniasis in the Old World
Some diseases have no non-human reservoir: poliomyelitis and smallpox are prominent examples.
The natural reservoir of some diseases remain unknown. This is the case of the Ebola disease, which is caused by a virus.
Famous quotes containing the words natural and/or reservoir:
“If everybody is looking for it, then nobody is finding it. If we were cultured, we would not be conscious of lacking culture. We would regard it as something natural and would not make so much fuss about it. And if we knew the real value of this word we would be cultured enough not to give it so much importance.”
—Pablo Picasso (1881–1973)
“It’s very expressive of myself. I just lump everything in a great heap which I have labeled “the past,” and, having thus emptied this deep reservoir that was once myself, I am ready to continue.”
—Zelda Fitzgerald (1900–1948)