A genus of hard ticks widely distributed in the tropics. The dog tick (R. sanguineus) can suck the blood of man and is commonly involved in the transmission of diseases caused by rickettsiae.
A surgical procedure in which selected nerve roots are cut at the point where they emerge from the spinal cord. In posterior rhizotomy the posterior (sensory) nerve roots are cut for the relief of intractable pain in the organs served by these nerves. An anterior rhizotomy, the cutting of the anterior (motor) nerve roots, is sometimes done for the relief of severe muscle spasm.
A genus of ticks belonging to the family Ixodidae. Several species, especially R. sanguineus, are vectors for the organisms of spotted fever, boutonneuse fever, and other rickettsial diseases.