Dateline: October 13, 2005

State health officials warn of tularemia

By Roger  Estlack, Clarendon Enterprise

State health officials are warning Donley County residents not to touch any dead rabbits or prairie dogs after the discovery of tularemia here recently.

Tularemia is caused by a bacterium known as Francisella tulareniss and can affect over 250 species of wild and domestic mammals, birds, and fish as well as humans.

“It is definitely contagious from animals to humans,” said Dr. Guy Ellis of the Clarendon Veterinary Hospital, “and it can spread in every way – by air, by skin contact, by ingesting.”

The disease was found here after a dead cottontail rabbit was discovered in a residential yard near Lake Greenbelt two weeks ago. An analysis of the rabbit by scientists at the Centers for Disease Control in Ft. Collins, Colo., determined last week that the cause of death was tularemia.

Ellis said the finding was a surprise because there was no previous indication that this disease was in the area.

“I’ve never seen it before,” he said.

In humans tularemia can cause high fever with or without other symptoms such as dry cough, shortness of breath, sore throat, eye infections, ulceration of the skin, swollen glands, vomiting, and diarrhea. Incubation is one to 14 days with most cases developing within a three to five day timeframe. Symptoms usually depend on the route of the organism’s entry.

People should avoid contact with sick rabbits, prairie dogs, and other small wild mammals. Anyone hunting rabbits should not handle a rabbit that appears sick.

Since skin contact with fluids and tissues from sick animals is a significant risk, gloves and long sleeves should be worn when processing wild rabbits.

The organism may also be inhaled, ingested, or enter through the membranes of the eyes. A filtering mask and eye protection are recommended.

Tularemia may also be transmitted by ticks and through inhalation of contaminated dust or ingestion of contaminated food or water. Dust stirred up by mowing in areas where the disease is common has resulted in human infections as has accidentally running over a rabbit with a lawnmower.

Ill rabbits, squirrels, prairie dogs, and other small mammals may exhibit weakness and death. If white spots are seen on the liver of a rabbit or squirrel being processed for food or if swollen lymph nodes are found, the animal should be discarded, preferably by burying, or placing in at least two plastic bags and putting the carcass in a garbage can.

Cats that eat wild game, such as rabbits or prairie dogs, may become infected. They may exhibit general weakness, ulcers in the mouth, and swollen lymph nodes, especially in the throat area.

Dogs are usually resistant to tularemia infection, but both dogs and cats can serve as hosts for ticks that are vectors for the causative bacterium.

For more information, contact the Texas Department of State Health Services.