Reports of Q fever on upswing

Increased attention to pathogens that could be used in a terrorist attack, combined with the growing number of soldiers returning from Iraq -- a locale where Q fever is prevalent -- have led to increases in reported cases of the disease.

This topic was detailed in a March 1 editorial in the journal Clinical Infectious Diseases (link).

"We need to know more about this disease," said Ruth Berkelman, MD, director of the Center for Public Health Preparedness and Research at Emory University in Atlanta. She co-wrote a study in the same issue examining the incidence of Q fever in veterinarians (link).

This zoonosis is endemic to Iraq, and 26 people were sickened by it in the United States in 2001, according to reports received by the Centers for Disease Control and Prevention. This number grew 6.5-fold to 169 in 2006. Most experts suspect that these figures reflect a small percentage of the true number, since most cases are asymptomatic or mild.

Dr. Berkelman's study suggests that people who spend a lot of time with animals may be another group at increased risk. The authors tested 508 veterinarians attending the American Veterinary Medical Assn.'s 2006 annual convention in Honolulu. Slightly more than 22% tested positive for antibodies to Coxiella burnetii, the bacteria that cause Q fever. Those who were older than 46 or had regular contact with ponds, cattle, swine or wildlife were most at risk.

"People working with animals, especially ... with farm animals, are at higher risk of exposure to these infections. Physicians should be considering the risk of zoonotic infections in their patients," Dr. Berkelman said.

Data from the 2003-04 National Health and Nutrition Examination Survey suggest that the national prevalence is around 3%, although it may be as high as 16% in soldiers returning from Iraq. Scientists are concerned about the numbers in certain populations, because about 5% of cases become chronic and lead to heart damage. Latent infections also may cause pregnancy complications.

Meanwhile, as part of its preparedness efforts, including plans to respond to outbreaks caused by the deliberate release of an infectious agent, the American Medical Association launched its Center for Public Health Preparedness and Disaster Response in 2003. The Center's Disaster Medicine and Public Health Preparedness journal was launched in 2007 and is available online (link).

Also, the AMA is participating in the American Veterinary Medical Assn.'s One Health Initiative, which will help raise awareness about preventing and managing zoonotic disease outbreaks.