Important Facts for Zoonotic Illnesses - Tularemia Cases

Definition

Rate of reported tularemia cases in Utah per 100,000 persons per year. A case of tularemia is defined as a person who has a clinically compatible presentation of the disease and meets specific laboratory criteria: isolation of ''F. tularensis'' in a clinical or autopsy specimen, elevated serum antibody titer(s) to ''F. tularensis'' antigen, detection of ''F. tularensis'' in a clinical or autopsy specimen by polymerase chain reaction (PCR), or detection of ''F. tularensis'' in a clinical or autopsy specimen by fluorescent assay.

Numerator

Number of reported tularemia cases in Utah per year.

Denominator

Total Utah population per year.

Why Is This Important?

Tularemia is a potentially serious illness that occurs naturally in the United States. It is caused by the bacterium ''Francisella tularensis'', which is commonly found in animals (especially rabbits, hares, and rodents). People can be infected by the bacteria in a number of ways. The most common mode of transmission is by the bite of a blood-sucking insect, such as a deer fly or tick that had previously bitten an infected animal. People can also get tularemia through direct contact with infected animals and animal products. This includes exposure to blood or tissue of infected animals or exposure through handling or eating meat (e.g. from an infected rabbit) that is not cooked well. Drinking contaminated water or breathing dust containing the bacteria may also put a person at risk of becoming ill. Person-to-person transmission of the disease does not occur. Symptoms of tularemia may include sudden fever, chills, headache, diarrhea, muscle aches, joint pain, dry cough, and progressive weakness. People can also catch pneumonia and develop chest pain and/or bloody sputum and can have trouble breathing and sometimes even stop breathing. Other signs and symptoms of tularemia depend on how a person was exposed to the bacteria. These can include ulcers on the skin or mouth, swollen and painful lymph glands, swollen and painful eyes, or a sore throat. Tularemia is an urgently notifiable disease in Utah and is considered a Category A Bioterrorism Disease. This category of diseases includes high-priority agents that pose a risk to national security because they can be easily disseminated, result in high mortality rates and have the potential for major public health impact, may cause public panic and social disruption, and/or require special action for public health preparedness.

How Are We Doing?

In the U.S., tularemia is now much less common than it once was in the early 20th century. The rate of disease decreased substantially in the 1950s and 1960s and has remained relatively constant since that time. In fact, in 1995 tularemia was dropped from the list of nationally notifiable diseases because it was so uncommon. However, because of fears that the bacteria could be used as a bioterrorism agent, tularemia was reinstated as a notifiable disease in 2000.

How Do We Compare With the U.S.?

In Utah, tularemia incidence rates had been historically higher than national rates. However, in recent years, Utah's incidence rates have been comparable to national rates (see graph).

What Is Being Done?

Tularemia is an urgent notifiable disease in Utah. Upon notification of a suspected case, the Office of Communicable Diseases assists local health departments in case investigation and implementation of control measures as needed to prevent additional cases.