A potentially nasty biological agent has infected 13 people in Utah.

Tularemia, also known as rabbit fever, a naturally occurring Class-A biological agent, is being blamed for 13 cases of serious illnesses that have sent victims repeatedly to the emergency room.

The victims were from three different counties spread across the state; however, they all have one thing in common. All 13 people are believed to have been camping on the west side of Utah Lake sometime between the end of July and the first week of June.

The Utah Department of Health has only confirmed that two of the cases are Tularemia. The remaining 11 cases are "suspect" with the patients showing all appropriate clinical signs of the bacteria infection. Positive confirmation can not be made until bacterial culture growths can be completed for testing.

Symptoms of the disease can include sudden fever, headaches, ulcers on the skin or mouth, swollen and painful lymph glands -- sometimes filled with puss, swollen and painful eyes, and a sore throat. If left untreated, Tularemia can be fatal.

Lance Madigan, a spokesman for the Utah County Health Department, said that Tularemia is fairly uncommon, with the state seeing only two or three cases per year.

"This is one of those semi-exotic diseases," he said.

According to the Centers for Disease Control, the relative rarity of the disease often delays diagnosis and proper treatment as doctors may try several other antibiotics more common to general skin conditions before trying the medications that target this particular bacteria.

The Utah cases took about two weeks for the diagnosis to be made -- a delay which, according to Madigan, caused a patient to make several trips to the emergency room.

Once treated, however, the bacteria generally responds well to treatment with antibiotics.

The bacteria is generally spread through several different methods. The most common is handling of rabbit or other animal carcasses. Also, being bit by infected ticks, horseflies, deerflies, or simply being exposed to their fluids can cause infection. Drinking contaminated water or food can also result in infections exposure. Inhalation also is possible, but according to the CDC that is more rare than contraction through handling contaminated materials.

Tularemia is not known to be spread from person to person. Persons infected with the disease are not generally believed to be a danger to others.

While Tularemia has the potential to be weaponized, the Utah County Health Department does not believe, given the location, that there are any indications of terrorism.

According to Madigan, almost all cases of Tularemia on record in Utah County are contracted on the West Side of Utah Lake.

To protect yourself, the Health Department and the CDC recommends wearing insect repellent with DEET, covering up with long sleeves, avoiding walking in brush, staying on trails, and not handling dead animals.

Nathan Johnson can be reached at 344-2543 or at njohnson@heraldextra.com.

This story appeared in The Daily Herald on page D1.