Q Fever 2004

Table 1. Q Fever Cases by Race and Sex, Indiana, 2005

  2005 2001-2005
Cases Rate* Cases
Total 4 0.06 7
   White 4 0.07 5
   Black 0 0 0
   Other 0 0 0
   Not Reported 0 - 2
   Male 3 0.10 5
   Female 1 0.03 2
   Not Reported 0 - 0

*Rate per 100,000 population based on the U.S. Census Bureau’s

Q fever is caused by the bacteria Coxiella burnetii and is a zoonotic disease affecting several species of animals including humans. Ticks are the primary reservoir and maintain disease cycles in rodents, other mammals, and birds. Cattle, sheep, and goats can carry the infection without signs or symptoms and shed high levels of bacteria when birthing. Birth products (placenta and fluids) are often highly contaminated. The bacteria are highly resistant to natural degradation and can persist in the environment for weeks to months. Q fever may result from infection by a single organism and the low infectious dose enhances transmission efficiency.

Human infections generally occur through inhalation of aerosols of contaminated barnyard dust, by handling of birthing products from shedding animals, or by drinking unpasteurized milk. Humans may have an asymptomatic, acute, mild to severe disease that can be highly fatal or result in chronic infection that can cause significant morbidity, if untreated.

In 2005, 4 cases of Q fever were reported in Indiana, for a rate of less than 1 case per 100,000 population (Table 1). This represents the highest reported number of cases in Indiana. The increased reporting is likely due to better recognition of Q fever signs and symptoms.

Q fever is classified as a Category B potential bioterrorism agent because of its ability to cause infection with a low number of organisms, resistance to environmental degradation, and the ability to cause infection via aerosolization.

You can learn more about Q fever by visiting the following website: