The plague has hit San Diego. No, I don’t mean the Carolina Panthers, although they might as well have been the plague after defeating the Chargers yesterday. I mean the actual plague. The plague is the bacterial infection from rats that killed as as many as 100 million people throughout the world in during Medieval times.Plague is an infection caused by Yersinia pestis a bacterium. As every grammar school kid learns, the plague is transmitted by fleas. The bacterium infects rodents, notoriously rats, but also squirrels, groundhogs, and chipmunks. Although no person has been infected here in California, the bacterium has been detected in squirrels, which are natural carriers of the disease. It is not unusual for squirrels or groundhogs to be infected here in the Western US.
Bubonic plague is one of the diseases caused by Yersinia pestis. The bacterium is highly infective and is transmitted from infected rodents to humans by bites from infected fleas. Once in the body, the bacterium multiplies and travels to the lymph nodes. The infection causes tremendous swelling and bleeding into the lymph nodes causing black lumps or “buboes” in the skin. In addition to people and rodents, family pets can also be infected. This is important because domestic dogs or cats that are infected at campsites can carry the infection home and infect the whole family. In addition to flea bites, humans can become infected by direct contact with an infected animal. About a dozen people are infected by plague in the US every year, usually in rural areas.
Unlike in ancient times, the plague is now easily treatable with antibiotics. It can, however, still cause significant illness, including pneumonia. It is advised that people hiking or camping in the mountainous regions of San Diego avoid any contact with squirrels, chipmunks or other rodents.
In humans the first sign of illness is fevers, chills, sweats, and painful tender swollen lymph nodes under the arms or in the groin. Symptoms usually occur within 3-7 days of a bite from an infected flea.
If you or your family pet becomes ill within a week of camping or hiking in endemic areas, you should see your physician and bring your pet to the vet as soon as possible.
This post is written by Jeffrey Benabio, MD