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Q fever is a zoonotic disease caused by inhalation of the bacterium Coxiella burnetii . Ruminant livestock are common reservoirs for C. burnetii , and bacteria present in aerosols derived from the waste of infected animals can infect humans. The significance of infection from material deposited in the environment versus transmission directly from infected animals is not known. In 2011, an outbreak of Q fever cases on farms in Washington and Montana was associated with infected goats. A study was undertaken to investigate the quantity and spatial distribution of C. burnetii in the environment of these goat farms. Soil, vacuum, and sponge samples collected on seven farms epidemiologically linked to the outbreak were tested for the presence of C. burnetii DNA by quantitative PCR. Overall, 70.1% of the samples were positive for C. burnetii . All farms had positive samples, but the quantity of C. burnetii varied widely between samples and between farms. High quantities of C. burnetii DNA were in goat housing/birthing areas, and only small quantities were found in samples collected more than 50 m from these areas. Follow-up sampling at one of the farms 1 year after the outbreak found small quantities of C. burnetii DNA in air samples and large quantities of C. burnetii persisting in soil and vacuum samples. The results suggest that the highest concentrations of environmental C. burnetii are found in goat birthing areas and that contamination of other areas is mostly associated with human movement.

Infected persons had slept in an infested cabin., In February 2006, a diagnosis of sylvatic epidemic typhus in a counselor at a wilderness camp in Pennsylvania prompted a retrospective investigation. From January 2004 through January 2006, 3 more cases were identified. All had been counselors at the camp and had experienced febrile illness with myalgia, chills, and sweats; 2 had been hospitalized. All patients had slept in the same cabin and reported having seen and heard flying squirrels inside the wall adjacent to their bed. Serum from each patient had evidence of infection with Rickettsia prowazekii. Analysis of blood and tissue from 14 southern flying squirrels trapped in the woodlands around the cabin indicated that 71% were infected with R. prowazekii. Education and control measures to exclude flying squirrels from housing are essential to reduce the likelihood of sylvatic epidemic typhus.

Coxiella burnetii is a zoonotic pathogen that causes Q fever in humans and is transmitted primarily from infected goats, sheep, or cows. Q fever typically presents as an acute febrile illness; however, individuals with certain predisposing conditions, including cardiac valvulopathy, are at risk for chronic Q fever, a serious manifestation that may present as endocarditis. In response to a cluster of Q fever cases detected by public health surveillance, we evaluated C. burnetii infection in a community that operates a large-scale cow and goat dairy. A case was defined as an individual linked to the community with a C. burnetii phase II IgG titer ≥ 128. Of 135 participants, 47 (35%) cases were identified. Contact with or close proximity to cows, goats, and their excreta was associated with being a case (relative risk 2.7, 95% confidence interval 1.3-5.3). Cases were also identified among individuals without cow or goat contact and could be related to windborne spread or tracking of C. burnetii on fomites within the community. A history of injection drug use was reported by 26/130 (20%) participants; follow-up for the presence of valvulopathy and monitoring for development of chronic Q fever may be especially important among this population.

Coxiella burnetii is an endemic bacterial pathogen in the United States and the causative agent of Q fever. Two outbreaks of Q fever occurred in Montana during 2011, which led to the issuance of a health alert urging clinicians to test patients with Q fever-compatible illnesses for C. burnetii infection.We retrospectively evaluated the medical records of patients hospitalized for fever, pneumonia, chest pain, and viral infection of unknown etiologies during the two Q fever outbreaks and following the health alert.A total of 103 patients were included in the analysis. Clinicians assessed1% of patients suffering illnesses compatible with Q fever for known risk factors or C. burnetii infection. Only 1 patient had Q fever excluded as a diagnosis.Clinicians should assess for Q fever risk factors and consider the diagnosis in patients hospitalized with Q fever-compatible illnesses when the etiology of illness is unknown. Work is warranted to evaluate the effectiveness of current healthcare alert practices for zoonotic diseases.

We describe the case of a man presumptively diagnosed and treated for Rocky Mountain spotted fever following exposure to multiple ticks while riding horses. The laboratory testing of acute and convalescent serum specimens led to laboratory confirmation of acute Q fever as the etiology. This case represents a potential tickborne transmission ofCoxiella burnetiiand highlights the importance of considering Q fever as a possible diagnosis following tick exposures.

Coxiella burnetii has recently gained military relevance given its potential as a bioterrorism agent, and the multiple cases reported among U.S. military personnel deployed to the Middle East. Sexual transmission of Q fever is rare but has been reported in the literature. We describe the possible sexual transmission of Q fever from a returning serviceman from Iraq to his wife. In a recent editorial commentary, Dr. Raoult wrote about the reemergence of Q fever after September 11, 2001 (Raoult 2009). Indeed, C. burnetii has gained military relevance given its potential as a bioterrorism agent and the multiple cases reported among military personnel deployed in Southwest/Central Asia and North Africa (Botros et al. 1995 , Meskini et al. 1995 , Leung-Shea and Danaher 2006 ). Human serosurveys in these geographic areas have reported prevalence rates for Q fever ranging from 10% to 37% in contrast to the United States, which has an estimated Q fever seroprevalence of 3.1% (Botros et al. 1995, Meskini et al. 1995, Anderson et al. 2009). There is no data available for Q fever seroprevalence in Iraq. As a consequence, native populations in these regions may be more likely to possess immunity, and newcomers, such as U.S. military personnel, would be vulnerable to acute infection (Derrick 1973). We report on the possible sexual transmission of C. burnetii from a serviceman in the late recovery of acute Q fever to his wife.

To the Editor: Q fever is a zoonotic disease caused by the rickettsialike organism Coxiella burnetii. The disease has a worldwide distribution and can infect many different species, although cattle, sheep, and goats are the primary reservoirs (1). Transmission to humans usually occurs by inhaling dust or aerosols from infected animals, and approximately half of infected persons manifest clinical symptoms. In acute Q fever infection, the 3 main sets of symptoms are flulike syndrome, pneumonia, and hepatitis (2,3). Q fever has military relevance not only in its potential use as a bioterrorism agent, but also because of the risk for natural infection in deployed military personnel. Thousands of cases of Q fever have been seen in military personnel since the disease was first reported in the 1930s (4). Since the most common mode of transmission is airborne, personnel do not need to have direct contact with infected animals to be exposed. C. burnetii was first recognized as an infectious disease threat to US military troops serving in Iraq in 2003 during a pneumonia outbreak investigation. Nineteen cases of severe pneumonia, including 2 deaths, occurred from March 1 to August 20 (5). A case was defined as occurring in a patient with bilateral alveolar infiltrates that required intubation and mechanical ventilation. This investigation involved extensive serologic testing for possible infectious causes of pneumonia, including C. burnetii. Of 19 patients with severe pneumonia tested for C. burnetii, 3 had positive antibody titers by immunofluorescence assay (IFA). No other infectious cause was confirmed for the remaining cases of pneumonia. Although C. burnetii was not determined to be the cause of the pneumonia outbreak, the finding of 3 patients with positive antibody titers launched an effort to ascertain other cases of Q fever among military personnel who served in Iraq during that time. Approximately 62 cases of pneumonia, both severe and nonsevere, occurred in Iraq from March 1 to August 20, 2003. A pneumonia case was defined as occurring in a patient with a chest radiograph suggesting pneumonia and ≥1 of the following symptoms: fever, cough, or shortness of breath. The Defense Medical Surveillance System (DMSS) was queried to determine how many patients had both predeployment and postdeployment serum samples available for Q fever testing. The Army Medical Surveillance Activity, which operates DMSS, also maintains the Department of Defense Serum Repository and stores serum from service members after mandatory HIV testing and deployment processing (6). Predeployment sera must be collected within the year before deployment. Twenty-two soldiers had predeployment and postdeployment sera available; samples were tested for phase I and phase II antibody to Q fever by using IFA. Results showed 5 additional soldiers in whom pneumonia was diagnosed while serving in Iraq and who seroconverted to C. burnetii before postdeployment serum draws (Table). All predeployment antibody titers for both immunoglobulin (Ig) G and IgM were negative in these 5 soldiers, with an IFA titer of 1:16 as a cutoff. Table Postdeployment serum antibody titers to phase II antigen for Q fever in 8 US military personnel who served in Iraq, March 1–August 20, 2003* The initial 3 Q fever patients ascertained through the pneumonia outbreak investigation were extensively interviewed for possible exposures. All 3 patients first experienced symptoms while in northern Iraq and reported contact with domestic animals, including dogs, cats, sheep, goats, and camels. Two of the patients reported tick bites within 30 days before becoming ill, and 1 reported drinking raw sheep's milk. The 5 other patients who became ill with pneumonia also first sought care while in northern Iraq. Predeployment sera from these 3 patients were also tested for C. burnetii by IFA, and all samples were negative for both IgG and IgM. Extremely limited information is available on Q fever disease prevalence in Iraq, either in animals or humans. Iraq is primarily an agricultural country, and nomadic herding takes place countrywide, except in the northernmost regions and along the eastern border, where adequate land is available for grazing livestock. The most common livestock in Iraq are cattle, sheep, and goats (7). Although herds of infected animals may exist in any region of Iraq, larger concentrations of livestock may exist in northern areas, where land is suitable for ruminants to graze. This concentration could lead to a higher risk for transmission to humans because the chance of contact with infected animals would be greater. These data indicate the potential importance of C. burnetii as an infectious disease threat to US military troops in Iraq. Healthcare providers should include Q fever in their differential diagnosis of community-acquired pneumonia and consider adding doxycycline to a combined antimicrobial drug regimen to presumptively treat severe pneumonia. Future studies to be completed include case ascertainment to locate US troops who were infected with Q fever while in Iraq and in whom pneumonia or other clinical manifestations of illness may have developed. Research was conducted in compliance with the Animal Welfare Act and other federal statutes and regulations relating to animals and experiments involving animals and adheres to principles stated in the Guide for the Care and Use of Laboratory Animals, NRC Publication, 1996 edition.

In February 2001, episodes of acute gastroenteritis were reported to the Wyoming Department of Health from persons who had recently vacationed at a snowmobile lodge in Wyoming. A retrospective cohort study found a significant association between water consumption and illness, and testing identified Norwalk-like virus (NLV) in 8 of 13 stool samples and 1 well. Nucleotide sequences from the positive well-water specimen and 6 of the positive stool samples were identical. This multistrain NLV outbreak investigation illustrates the importance of NLV as a cause of waterborne illness and should encourage monitoring for NLVs in drinking water.

In February 2000, an outbreak of gastroenteritis occurred among employees of a car dealership in New York. The same meal was also supplied to 52 dealerships nationwide, and 13 states reported illness at dealerships where the banquet was served. A retrospective cohort study was conducted to identify risk factors associated with the illness. Stool samples were collected to detect Norwalk-like virus, and sera were drawn and tested for immunoglobulin A antibodies to the outbreak strain. By univariate analysis, illness was significantly associated with consumption of any of four salads served at the banquet (relative risk = 3.8, 95% confidence interval: 2.5, 5.6). Norwalk-like virus was detected by reverse transcription-polymerase chain reaction assay in 32 of 59 stool samples from eight states. Nucleotide sequences of a 213-base pair fragment from 16 stool specimens collected from cases in eight states were identical, confirming a common source outbreak. Two of 15 workers at caterer A had elevated immunoglobulin A titers to an antigenically related Norwalk-like virus strain. This study highlights the value of molecular techniques to complement classic epidemiologic methods in outbreak investigations and underscores the critical role of food handlers in the spread of foodborne disease associated with Norwalk-like virus.