Disease Vectors

Carriers (Vectors) of Disease

Welcome to the "Vector" page. A vector is an organism that unwittingly carries a disease that normally is not harmful to itself, but is harmful to other organisms. Vectors come from a wide range of organisms. They can be insects, arachnids, amphibians, reptiles, birds, and mammals. Below is a partial list of vectors. When you have finished with this page, use the "BACK" button from your browser to return you to the referring page.


Mammals
		Multimammate Rat
	Any of several species of the genus Mastomys. Mastomys rodents breed very frequently, produce large numbers of offspring, and are numerous in the savannas and forests of West, Central, and East Africa. Some species, like M. huberti, prefer to live in human homes. Multimammate rats are known carriers of Lassa virus. While the exact number and type of Mastomys rodents which carry the virus is uncertain, at least two species carry Lassa virus in Sierra Leone: M. huberti and M. erythroleucus. Click your back button to return to your referring page.
		The Deer Mouse
	(Peromyscus maniculatus) is a deceptively cute animal, with big eyes and big ears. Its head and body are normally about 2 - 3 inches long, and the tail adds another 2 - 3 inches in length. You may see it in a variety of colors, from gray to reddish brown, depending on its age. The underbelly is always white and the tail has sharply defined white sides. The deer mouse is found almost everywhere in North America. Usually, the deer mouse likes woodlands, but also turns up in desert areas. Click here to see a map of where the deer mouse has been found in the United States.
		Cotton Rat
	Sigmodon hispidus), which you'll find in the southeastern United States (and way down into Central and South America), has a bigger body than the deer mouse—head and body about 5 - 7 inches, and another 3 - 4 inches for the tail. The hair is longer and coarser, of a grayish brown color, even grayish black. The cotton rat prefers overgrown areas with shrubs and tall grasses. Click here to see a map of where the cotton rat has been found in the United States.
		The Rice Rat
	Oryzomys palustris) is slightly smaller than the cotton rat, having a head and body 5 - 6 inches long, plus a very long, 4- to 7-inch tail. Rice rats sport short, soft, grayish brown fur on top, and gray or tawny underbellies. Their feet are whitish. As you might expect from the name, this rat likes marshy areas and is semiaquatic. It's found in the southeastern United States and in Central America. Click here to see a map of where the rice rat has been found in the United States.
		White-footed Mouse
	(Peromyscus leucopus) is hard to distinguish from the deer mouse. The head and body together are about four inches long. Note that its tail is normally shorter than its body (about 2 - 4 inches long). Topside, its fur ranges from pale brown to reddish brown, while its underside and feet are white. The white-footed mouse is found through southern New England, the Mid-Atlantic and southern states, the midwestern and western states, and Mexico. It prefers wooded and brushy areas, although sometimes it will live in more open ground. Click here to see a map of where the white-footed mouse has been found in the United States.
		House Mouse
	The common house mouse, Mus musculus, is the most frequently observed species and is the ancestor of the white mice that are raised for scientific experimentation. In its wild state the house mouse is slightly less than 17 cm (less than 6.5 in) long including the tail, which is slightly more than 8 cm (more than 3 in) long; domestic mice, because of better nutrition, are often considerably larger. The house mouse is yellowish-gray above, sometimes streaked with black, and lighter gray beneath. It breeds every 10 to 17 weeks throughout the year, producing five to ten young in a litter.

Arthopods
Arthropod-borne viruses, i.e., arboviruses, are viruses that are maintained in nature through biological transmission between susceptible vertebrate hosts by blood feeding arthropods (mosquitoes, psychodids, ceratopogonids, and ticks). Vertebrate infection occurs when the infected arthropod takes a blood meal. The term 'arbovirus' has no taxonomic significance. Arboviruses that cause human encephalitis are members of three virus families: the Togaviridae, Flaviviridae, and Bunyaviridae.
		Aedes (Mosquitos)
	Ae. albopictus is a potential vector of epidemic dengue. It is unclear what effect the presence of this species might have on transmission dynamics in the Americas. Ae. albopictus may also affect the disease potential for yellow fever in Brazil by bridging the ecological niche between jungle and urban transmission cycles. Mosquitos also are vectors for encephalitus. Click your "Back" button to return you to the referring page or click here to return to the top of this page.