Q fever endocarditis in the United States.

A patient with Q fever endocarditis, which is almost unknown in the United States, was followed for a total of 32 months; the study was begun 3 1/2 months before aortic valve replacement. Diagnosis was confirmed by serology, visualization of Coxiella burnetii in excised aortic valve tissue by direct and immunofluorescence staining, and isolation of C. burnetii from aortic valve tissue. Serum antibodies against phase I and phase II antigens of C. burnetii were identified. Almost all phase I and phase II antibodies were IgG. These findings are compared with those in an uncomplicated case of acute Q fever. New findings on the immune response to chronic Q fever are presented.     

Q fever in humans and animals in the United States

Coxiella burnetii, the etiologic agent of Q fever, is a worldwide zoonotic pathogen. Although Q fever is present in the United States, little is known about its current incidence or geographic distribution in either humans or animals. Published reports of national disease surveillance, individual cases, outbreak investigations, and serologic surveys were reviewed to better characterize Q fever epidemiology in the United States. In national disease surveillance reports for 1948-1986, 1,396 human cases were reported from almost every state. Among published individual case reports and outbreak investigations, occupational exposures (research facilities, farm environments, slaughterhouses) were commonly reported, and sheep were most frequently implicated as a possible source of infection. In studies conducted on specific groups, livestock handlers had a significantly higher prevalence of antibodies to C. burnetii than did persons with no known risk. Animal studies showed wide variation in seroprevalence, with goats having a significantly higher average seroprevalence (41.6%) than sheep (16.5%) or cattle (3.4%). Evidence of antibody to C. burnetii was reported among various wild-animal species, including coyotes, foxes, rodents, skunks, raccoons, rabbits, deer, and birds. This literature review suggests that C. burnetii is enzootic among ruminants and wild animals throughout much of the United States and that there is widespread human exposure to this pathogen. Sheep and goats appear to be a more important risk for human infection in the United States than cattle or wild animals, and research studies examining the natural history and transmission risk of Q fever in sheep and goats in this country should be encouraged.     

An outbreak of Q fever affecting postal workers in Oxfordshire

Twenty-five people in Oxfordshire were found to have had clinical illness due to Q fever in the 3 months from April to June 1983. Twelve cases were diagnosed through the routine laboratory diagnostic service. Five of these were postmen, four of whom worked in a sorting office where an outbreak of illness similar to influenza had been noted by the Occupational Health Nurse. Thirteen cases were diagnosed by active case-finding in this sorting office but investigation failed to define the source of the outbreak. Nine of the 18 postal workers were found to have antibodies to phase I Coxiella burnetii antigen. The significance of these antibodies is discussed. Surveillance for over 2 years has not revealed anyone with symptoms or signs suggestive of chronic Q fever. An outbreak of Q fever among postal workers has not previously been described. We recommend continued surveillance for this enigmatic condition.     

Sheep-associated outbreak of Q fever, Idaho

Between Feb 1 and Aug 31, 1984, an outbreak of 18 symptomatic cases of Q fever occurred in Idaho; these numbers represent an increase over the three cases reported in 1982 and the five reported in 1983. Four of the patients in the outbreak required hospitalization for two to five weeks; there were no fatalities. Eight of the cases had documented Q fever hepatitis, and one had pneumonia. All 18 of the 1984 cases for whom information was available were epidemiologically linked to visiting or working at a sheep research station and/or being exposed to animals from this research station. In this outbreak, patients typically had a hepatitislike illness associated with fever and severe headache. Severity of illness ranged from asymptomatic to life threatening. Cases of pneumonia and hepatitis due to Q fever continue to occur in the United States, especially among persons exposed to livestock.     

An outbreak of Q fever probably due to contact with a parturient cat

Thirty-three cases (24 definite, nine probable) of Q fever were diagnosed in Victoria County, Cape Breton, Nova Scotia from May to August, 1985. Twenty-six of the cases occurred in residents of Baddeck (population 900, attack rate 2.8 percent), and 21 of the cases occurred during the month of June. There was geographic clustering of the cases: 14 of the 33 (42 percent) lived or worked in four buildings located side by side in the center of town. A case control study revealed that 25 of 29 cases were exposed to a cat that gave birth to stillborn kittens on June 8, 1985 and had bled per vaginum for three weeks prior to delivery. The cat lived in one of the buildings where geographic clustering occurred and frequently visited the other buildings. None of the 40 control subjects was so exposed (p less than 0.001). This cat had an antibody titer of 1:512 to Coxiella burnetii phase 1 antigen and a titer of 1:1024 to phase 2 antigen. Exposure to cattle, sheep and goats, the traditional reservoirs of Q fever, was uncommon among patients and control subjects and none of eight cattle tested had antibodies to C burnetii phase I antigen. We conclude that the infected parturient cat was probably responsible for this outbreak of Q fever affecting 2.8 percent of the population of the town of Baddeck.     

National surveillance and the epidemiology of human Q fever in the United States, 1978-2004

Although Q fever is considered enzootic in the United States, surveillance for human Q fever has been historically limited. From 1978 through 1999, 436 cases (average = 20 per year) of human Q fever were reported. After Q fever became nationally reportable in 1999, 255 human Q fever cases (average = 51 per year) were reported with illness onset during 2000 through 2004. The median age of cases was 51 years, and most cases were male (77%). The average annual incidence of Q fever was 0.28 cases per million persons, and was highest in persons 50-59 years of age (0.39 cases per million). State-specific incidence ranged from a high of 2.40 cases per million persons in Wyoming, to 0 cases in some states. Since Q fever became reportable, case reports have increased by more than 250%. Surveillance for Q fever is essential to establish the distribution and magnitude of disease and to complement U.S. bioterrorism preparedness activities.     

An outbreak of travel-associated Legionnaires disease and Pontiac fever: the need for enhanced surveillance of travel-associated legionellosis in the United States.

Travel-associated outbreaks of legionnaires disease (LD) and combined outbreaks of LD and Pontiac fever (PF) are rarely identified. During one travel-associated combined outbreak at a hotel, a cohort study of potentially exposed persons and an environmental investigation were performed. Two LD and 22 PF cases were identified. Legionella pneumophila serogroup 6 (Lp6) isolates from the index patient and the hotel whirlpool spa were found to be identical by amplified fragment-length polymorphism typing. Disease occurred in 10 of 26 guests who were exposed to the spa versus 2 of 29 guests who were exposed only to the pool area (38% vs. 7%; P=.005). Immunoglobulin M (IgM) antibody to the outbreak Lp6 strain was more common among persons with PF (4 of 9) than among non-ill persons (2 of 32) (44% vs. 6%; P=.02). Spa exposure correlated with disease (P=.001) and IgM seropositivity (P=.007). New laboratory techniques facilitate outbreak investigation; to expedite outbreak interruption and measure the impact of travel-associated legionellosis, surveillance must be improved.     

Parvovirus arthropathy outbreak in southwestern United States

OBJECTIVE: We describe an outbreak of parvovirus (PV) arthropathy that was detected in a rheumatology clinic in San Antonio, Texas, during the winter of 1994. Parvovirus B19 causes acute symmetric polyarthritis (ASPA) in adults. In the US, the majority of cases described are from the northern US. METHODS: An outbreak of PV arthropathy was monitored in a San Antonio area rheumatology clinic. RESULTS: Of the 16 affected patients, 69% were female, ages ranging from 23 to 60 years; 75% had close contact with children, 58% of whom were exposed to children with clinical PV. All patients noted an acute arthritis except for 2 patients with polyarthralgias. The most common presentation was ASPA (9/16), with 10/16 complaining of viral prodrome, and 5/16 having a nonspecific rash, but none with the typical "slapped cheek" appearance. Eleven patients had an ASPA at some time in their illness. Of these, 3 had a true migratory arthritis that developed into an ASPA and another 2 were additive. Two additional patients had persistent asymmetric polyarthritis. The most common joints involved were the metacarpophalangeals, proximal interphalangeals, wrists, and knees. Most patients' syndromes lasted < 6 weeks, but 3 patients had symptoms that lasted longer than 6 months. Eight of 10 had elevated erythrocyte sedimentation rate. Rheumatoid factor was detected in 3 patients and antinuclear antibody in 2. All patients were treated symptomatically with nonsteroidal antiinflammatory drugs and a few also received low dose corticosteroids. Because of suspicious clinical presentations, 2 patients were presumed to have gonococcal arthritis before PV titers were available. CONCLUSION: This is the first large series on adults with PV arthropathy reported in the southern US. In contrast to the usual features of ASPA, the outbreak appears unique in that almost 40% of cases presented with a true migratory arthritis.     

Coxiella burnetii, the agent of Q fever, in domestic sheep flocks from Wyoming, United States

Coxiella burnetii, the agent of Q fever, is an intracellular bacterial pathogen. It has a nearly cosmopolitan distribution. We conducted a serological survey of domestic sheep herds for infections with C. burnetii in Wyoming following reports of abortion and open ewes. Based on the serologic evidence, there was no link between reproductive problems and exposure to C. burnetii. However, the overall prevalence of C. burnetii in WY sheep was 7%, which indicates that the agent is present in the environment and could pose a threat to public health.     

Pigeon pneumonia in provence: a bird-borne Q fever outbreak.

Q fever is a widespread zoonosis caused by Coxiella burnetii, an obligate intracellular bacterium, which humans usually acquire through the inhalation of infected dust from subclinically infected mammals. Human infection commonly takes place when an infected mammal gives birth, since high concentrations of the organism are found in the products of conception. Worldwide, cattle, sheep, and goats are the most common reservoirs for C. burnetii. A few investigators have also reported parturient cats and dogs as the sources of human outbreaks of Q fever. During a 10-day period in May 1996, all five members of one family living on a farm in Provence, in the south of France, became ill with fever, general malaise, and cough. All of them had acute Q fever. An epidemiological investigation suggested that this outbreak resulted from exposure to contaminated pigeon feces and ticks.     

The epidemiology of tick-borne relapsing fever in the United States

Each year, many residents of and visitors to endemic regions of the western United States are exposed to the vector of tick-borne relapsing fever (TBRF), an underrecognized and underreported disease. Through review of report forms and literature review, we identified 450 cases of TBRF acquired in the United States in 11 western states (and in British Columbia by a U.S. resident) from January 1977 to January 2000. Exposure sites were in forested areas, at varying elevations, in mountainous regions (Cascade, Rocky Mountain, San Bernardino, and Sierra Nevada ranges) of the United States and Canada and in limestone caves in central Texas. Only 13 counties accounted for approximately 50% of all cases. Forty percent of the cases were not residents of the state where TBRF exposure occurred, including 7% from 11 states where TBRF is not endemic. TBRF is endemic in the United States and is a disease affecting travelers, who may return home with the disease to areas where physicians are not familiar with it.