Same Disease, Different Transmission
Ezzell, Carol, Science News
On the U.S. West Coast, the bacterium responsible for Lyme disease is transmitted through a more complex network of infected animal hosts and tick vectors than on the East Coast, according to a new study. This finding has important implications for controlling the spread of this disease, which causes severe arthritis-like symptoms.
On the East Coast, white-footed mice serve as the reservoir of infection for the Lyme-causing bacterium, Borrelia burgdorferi. The bacteria thrive in the mice and are picked up by the deer tick Ixodes dammini when young tick nymphs feed on the blood of the mice during early summer. The infected nymphs then spread the infection to other animals, including humans (SN: 3/25/89, p.184).
On the West Coast, the process is much more involved, reports entomologist Robert S. Lane of the University of California, Berkeley. Wood rats, not mice, serve as the reservoir for B. burgdorferi in northern California, he says, so efforts to control the disease in that region must target these animals. Moreover, the ticks that transmit the bacterium to humans in northern California do not belong to the same species as the ones that spread it among the wood rats. …