A Q fever outbreak affected goats on at least 16 farms in Washington and Montana and caused at least 15 human illnesses, federal health officials said.
A report from the Centers for Disease Control and Prevention indicates Coxiella burnetii infection was first detected in April in a goat herd in Washington. A county health department reported May 25 that a person later found to have antibodies against the bacteria had bought goats from the farm in February, and a report two days later indicated that the family of a Montana child seropositive for antibodies against the bacteria had bought goats from the farm in October 2010. The child had become ill May 12, two weeks after a family goat aborted triplets, the CDC report states.
Subsequent investigation found that, of 15 people known to have been sickened because of the outbreak between January and July 2011, four were hospitalized, according to the CDC.
The CDC and Washington state officials reported that C burnetii was detected on 13 farms in Washington and three in Montana through PCR confirmation that the bacteria were shed in feces, vaginal mucous, or milk of 161 of the 667 goats tested.
Public health and agriculture authorities advised goat owners to take steps such as disinfecting birthing areas, limiting visitor access to animal holding areas, and reporting animal abortions and positive Q fever test results, CDC information states.
Dr. Paul Kohrs, Washington's assistant state veterinarian, said goats at the two farms with human illnesses connected with C burnetii were quarantined. The other 11 farms were not under formal quarantine, but their owners received warnings about moving the animals and agreed to management practices intended to avoid the disease's spread. Montana authorities did not return a call seeking additional information.
Q fever can cause acute febrile illness in humans, and serious illness can be associated with complications such as pneumonia and hepatitis, according to the CDC. Endocarditis is one of the most common sequelae of chronic Q fever.
The causative bacteria can be spread by inhalation and persist in the environment, the report notes.
Cattle, sheep, and goats are reservoirs, and the disease can cause late-term abortions and weak offspring in those animals. The bacteria are present in the milk and reproductive fluids and tissues of infected animals.