Prevalence of Coxiella burnetii in Hungary: Screening of Dairy Cows, Sheep, Commercial Milk Samples, and Ticks

Abstract Q fever is an important zoonotic disease caused by Coxiella burnetii. There are few reliable data about C. burnetii infection available. The aim of this study was to assess the importance and potential infectious sources of Q fever in Hungary. A total of 215 milk samples (10 individual samples from each herd and 1 bulk tank milk sample from each cattle herd), and 400 serum samples (20 from each herd) were tested from 15 dairy cattle herds and 5 sheep flocks located in different parts of Hungary. The study found 19.3% (58/300) and 38.0% (57/150) seropositivity in cattle, and 0% (0/100) and 6.0% (3/50) seropositivity in sheep, by complement fixation test (CFT) and enzyme-linked immunosorbent assay (ELISA), respectively. C. burnetii DNA was detected by IS1111 element-based TaqMan real-time polymerase chain reaction (PCR) in 8.7% (13/150) of individual dairy cow milk samples, 4.0% (2/50) of individual sheep milk samples, and 66.7% (10/15) of dairy bulk tank milk samples. Samples taken from nine different commercially-available pasteurized cow milk products from different Hungarian producers were also tested for the presence of C. burnetii DNA, and eight of these samples were found to be positive (88.9%). The real-time PCR examination of 5402 ixodid ticks collected from different parts of the country yielded negative results. Knowledge of the true prevalence of Q fever is crucial for policymakers involved in evidence-based decision making.     

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.     

Exposure to parturient cats: a risk factor for acquisition of Q fever in Maritime Canada

Over a 34-mo period we studied 51 patients with Q fever and 102 control subjects (with various lower-respiratory-tract infections) who were matched for age, sex, and time of onset of infection. By univariate analysis (not adjusted for multiple comparisons), cases differed significantly from controls in the following activities: working on a farm; slaughtering or dressing animals; and contact with cats, cattle, and sheep. The strongest association was with exposure to stillborn kittens--11 of 51 cases vs. none of 102 controls (P less than .00000)--and with exposure to parturient cats (odds ratio, 10.3; 95% confidence interval, 3.5-31.8). Exposures to newborn animals (chiefly kittens) and stillborn kittens were significant risk factors by multivariate analysis, as were rural residence and slaughtering or dressing animals. In 13 Q fever incidents following exposure to parturient cats, 80 people became ill, 52 of whom had serological evidence of recent Coxiella burnetii infection (most of the others were not tested).     

Outbreak of Q fever in Lohra-Rollshausen,Germany, spring 1996

Q fever is an acute (and sometimes chronic) febrile illness caused by the rickettsial organism Coxiella burnetii. The commonest animal reservoirs for C. burnetiiare cattle, sheep, and goats. Infected animals shed the organisms, which resist desiccation, i     

Q Fever in the United States: Summary of Case Reports from Two National Surveillance Systems, 2000–2012

Q fever is a worldwide zoonosis historically associated with exposure to infected livestock. This study summarizes cases of Q fever, a notifiable disease in the United States, reported to the Centers for Disease Control and Prevention through two national surveillance systems with onset during 2000–2012. The overall incidence rate during this time was 0.38 cases per million persons per year. The reported case fatality rate was 2.0%, and the reported hospitalization rate was 62%. Most cases (61%) did not report exposure to cattle, goats, or sheep, suggesting that clinicians should consider Q fever even in the absence of livestock exposure. The prevalence of drinking raw milk among reported cases of Q fever (8.4%) was more than twice the national prevalence for the practice. Passive surveillance systems for Q fever are likely impacted by underreporting and underdiagnosis because of the nonspecific presentation of Q fever.     

Outbreak of Q fever associated with a horse-boarding ranch, Colorado, 2005

Coxiella burnetii is a bacterium located worldwide that can cause Q fever when inhaled. We describe an outbreak of Q fever associated with a horse-boarding ranch that had acquired two herds of goats. We conducted case finding and cohort studies among persons who boarded horses on the ranch and ranchers and among residents in the surrounding community, and conducted sampling of the goats and environment, to determine risk factors for infection and guide public health interventions. Sixty-six ranchers and persons who boarded horses on the ranch were interviewed; 62 (94%) were not professional ranchers. Twenty persons (53%) of 38 persons tested had evidence of infection with C. burnetii. Contact with goats was associated with seropositivity, including having helped birth goats (relative risk [RR] 2.4, 95% confidence interval [CI] 1.6-3.6), having had contact with newborn goats (RR 2.3, CI 1.2-4.3), having vaccinated goats (RR 2.1, CI 1.3-3.5), having had contact with stillbirths or newborns that died (RR 2.1, CI 1.2-3.7), and having fed goats (RR 2.1, CI 1.0-4.3). Among 138 tested persons living within 1 mile of the ranch, 11 (8%) demonstrated evidence of C. burnetii infection; eight seropositive persons (73%) had no direct contact with the ranch. Testing of the soil and goats with an IS1111 polymerase chain reaction (PCR) assay confirmed the presence of C. burnetii among the herd and in the environment. This outbreak of Q fever was caused by exposure to infected goats, but exposure to the environment likely played a secondary role. Laypersons should not participate in the birthing process of goats; professionals who come into contact with birthing goats should be educated on reducing their infection risk. This is the first time an IS1111 PCR assay has been used in an outbreak investigation in the United States.     

The serologic prevalence of Q fever (Coxiella burnetii) complement-fixing antibodies in the Peninsular bighorn sheep of Southern California

Q fever is a rare illness in the Southern California desert. During the past 34 years only 6 patients have been diagnosed with the disease at the Eisenhower Medical Center, a referral center for much of the desert and surrounding mountains. In all but 2 instances, Q fever was identified in patients who have been in contact with imported domestic sheep who are brought to the desert to graze and lamb in the fall and winter. The sheep are sent back to Idaho, Wyoming, and Montana in the spring. With frequent infection by Coxiella burnetii established in domestic sheep, we elected to study the prevalence of complement fixing antibodies to Coxiella burnetii in native bighorn sheep who reside in the lower levels of the mountains surrounding the desert. From 1992 to 1999, of 268 serum samples drawn from male and female lambs and adult sheep, 27 tested positive (10%), which is strikingly low when compared with Dall sheep in Alaska (12 of 15), kangaroos, wild rabbits, and brown rats. Because changes have been made in Peninsular bighorn sheep habitat since the animals were listed as endangered in 1998, further follow-up in Q fever serology testing will be of interest.     

Prevalence of Coxiella burnetii antibodies among febrile patients in Croatia, 2008-2010

Despite the widespread distribution of Q fever, the prevalence in humans is not accurately known, because many infected people seroconvert without symptoms or with a mild febrile disease. The aim of this study was to determine the seroprevalence of Q fever in different regions of Croatia. During a 2-year period (2008-2010), serum samples from 552 febrile patients with prolonged cough aged 1-88 were tested for the presence of Coxiella burnetii antibodies by using indirect immunofluorescent assay. Sera from 27.5% patients showed IgG antibodies. Serological evidence of C. burnetii infection was found in patients from all parts of Croatia. Seroprevalence rates significantly differed among regions from 21.5% to 41.2% (p=0.001). Men were more often seropositive (31.6%) than women (22.2%; p=0.016). According to age, a progressive increase in the IgG seropositivity rates was observed as ranging from 6.7% in children less than 10 years of age to 39.2% in patients aged 40-49 (p=0.001). Above the age of 50, the IgG seroprevalence remained stable. Patients from rural areas were more often seropositive than patients from urban areas (40.8% vs. 19%), p<0.001). Acute Q fever was confirmed in 5.8% of patients. Cases occurred throughout the year. A majority of cases were reported during summer months.     

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.     

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.     

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.     

Coxiella burnetii pneumonia.

This report reviews the pulmonary and extrapulmonary manifestation of infections due to Coxiella burnetii. Q fever, a zoonosis, is due to infection with C. burnetii. This spore-forming microorganism is a small gram-negative coccobacillus that is an obligate intracellular parasite. The most common animal reservoirs are goats, cattle, sheep, cats, and occasionally dogs. The organism reaches high concentrations in the placenta of infected animals. Aerosolisation occurs at the time of parturition and infection follows inhalation of this aerosol. There are three distinct clinical syndromes of the acute form of the illness: nonspecific febrile illness, pneumonia, and hepatitis. The chronic form of Q fever is almost always endocarditis, but occasionally it is manifest as hepatitis, osteomyelitis or endovascular infection. The pneumonic form of the illness can range from very mild-to-severe pneumonia requiring assisted ventilation. Multiple round opacities are a common finding on chest radiography. Treatment with doxycycline or a fluoroquinolone is preferred. Susceptibility to macrolides is variable. In conclusion, Coxiella burnetii pneumonia should be considered when there is a suitable exposure history and when outbreaks of a pneumonic illness are being investigated.     

Seroprevalence to Coxiella burnetii among residents of the Hunter New England region of New South Wales, Australia

Exposure to Coxiella burnetii is a risk in the Hunter New England (HNE) region of New South Wales (NSW), Australia, based on yearly reported cases of Q fever. We assessed seroprevalence of phase II antibodies to C. burnetii by indirect immunofluorescence assay (IFA; screening at 1/50 dilution) of residents of 24 local government areas (LGA) of the HNE region of NSW. A total of 2,438 randomly selected sera sent to the Hunter Area Pathology Service for routine diagnostic purposes (not Q fever testing) during the period of 2006-2009 were tested. The overall seroprevalence in sample group was 7%. The proportion of males (59%) was higher than females (41%). In age distribution, the largest proportion (37%) of seropositives was in the > 60 years age group. Lower prevalence was observed in 0-9 years (1%) and 10-19 years (5%) age groups. The seroprevalence in different LGAs varied between 0.5% and 22%. It was highest in Guyra (22%), Gunnedah (21%), Tenterfield (18%), and Narrabri (16%), with Newcastle (0.5%), Port Stephens (2%), Lake Macquarie (3%), and Singleton (3%) being the lowest. In most of the LGAs, seroprevalence was between 6% and 12%. This report indicates a considerable exposure to C. burnetii of residents in rural areas of the HNE region and is consistent with the high notification rate for Q fever in this part of Australia.     

Coxiella burnetii seroprevalence of shepherds and their flocks in the lower Saint-Lawrence River region of Quebec,Canada

OBJECTIVE:

To determine the seroprevalence of Coxiella burnetii among the shepherds and their sheep in the lower Saint-Lawrence River region (LSLRR) of Quebec, Canada.

DESIGN:

A prospective human-animal comparative study was conducted with 81 shepherds from 46 farms and a control group matched for sex and age. All participants answered a standardized questionnaire to evaluate their risk factors for Q fever, including a specific section on the work practices of the shepherds. All human subjects had a blood sample taken for serology to phase I and phase II antigens of C burnetii performed by indirect immunofluorescence assay. At each participating farm, seven to nine sheep had blood samples taken for C burnetii serology to be assessed by the complement fixation test.

RESULTS:

The seroprevalence to C burnetii was higher in the group of shepherds (28.4%) than the control group (1.2%) (P<0.005). Among the group of shepherds, spending more than 5 h/week in the sheep barn (P=0.06) and buying and/or trading sheep within the past six months (P=0.004) were associated with positive C burnetii serology. A total of 137 of 334 sheep (41%) were seropositive for C burnetii. These positive sheep were distributed in 41 of the 46 flocks (89%). No correlation could be demonstrated between a serology for C burnetii in the herds and the shepherds.

CONCLUSION:

Q fever is highly prevalent in the LSLRR of Quebec, affecting 89% of the flocks and 28% of the shepherds. Shepherds in this region are at increased risk for C burnetii infection in comparison to the general population.Key Words: Coxiella burnetii, Flock, Q fever, Quebec, Serology, Seroprevalence, Sheep, ShepherdQ fever is a worldwide zoonosis caused by an intracellular rickettsial agent, Coxiella burnetii. This bacteria shows a characteristic phase conversion: the virulent phase I is directly isolated from infected animals, and the avirulent phase II is obtained after successive passages on cellular cultures of embryonated eggs (1,2). Q fever is predominantly transmitted to humans by inhalation of contaminated aerosols from infected animal litters (3-5). The parturition products and the feces and urine of sheep, cats, goats and dogs are the more common sources of transmission of the bacteria (6-9). Although these animals rarely show any symptoms of the infection (10,11), abortions in sheep, goats and cattle can be seen in some cases (5,6,12-14).Human Q fever is often asymptomatic or manifests as a mild illness. Atypical pneumonia and hepatitis are the principal clinical manifestations of the acute symptomatic infection, while endocarditis is the most frequent presentation of chronic Q fever (1,3,15,16). Very few studies in North America have addressed the issues of prevention of Q fever. In Australia, a highly effective vaccine (Q-Vax, Commonwealth Serum Laboratories, USA) is available for workers with occupational exposition to C burnetii (17,18).Seroprevalence studies conducted in Canada have shown that 5% to 36% of blood donors (19,20), 20% of slaughterhouse workers of the Mauricie region of Quebec (12), 25% of personnel of the animal pathology laboratory in Rimouski in the lower Saint-Lawrence River region (LSLRR) (M Rochette, unpublished data) and 49% of veterinarians in Nova Scotia (21) were positive for C burnetii.Epizootiological studies have also been done on animal populations in Canada. A seroprevalence study in the Mauricie region of Quebec showed that C burnetii had infected 26.7% of the cats, 11.5% of the cattle and 7.7% of the sheep (22). Cats were reported as important vectors of transmission of C burnetii to humans in the Mauricie region of Quebec and in Nova Scotia (23,24). In Ontario, a seroprevalence study demonstrated that 21.3% of the sheep were positive for antibodies to C burnetii (25).Q fever is a notifiable disease in Quebec. From January 1990 to December 1998, 43 (36.1%) of 119 reported cases were from the LSLRR, which had the highest incidence rate of the province, although it represents only 5% of the population. A review of the cases of Q fever from the LSLRR between 1991 and 1999 showed that 67% of the Q fever cases were related to exposure to sheep (P Jutras, unpublished data). It is noteworthy that an important rise in the number of sheep was observed in LSLRR, with an increase from 11,000 animals distributed in 110 flocks in 1983, to more than 33,000 in 180 flocks in 1999 (Union des producteurs agricoles of Quebec, personal communication).To evaluate the association between Q fever and exposure to ovine in the LSLRR, a prospective human-animal seroprevalence study was undertaken to compare the seroprevalence of C burnetii between the shepherds, their flocks and the general population. The work practices of the shepherds were also evaluated.     

Q fever in the Southern California desert: epidemiology, clinical presentation and treatment

Despite the absence of a natural reservoir for Q fever in the desert of Southern California, six cases have been identified during the past 32 years. During that period of time, two areas have been used by northern sheep ranchers from Idaho and Wyoming to import sheep to an area in the Coachella Valley through 1985. Thereafter, because of housing development, the sheep area was moved to Blythe along the Colorado River. All but two of these patients probably acquired infection by Coxiella burnetii by living or working in close proximity to these grazing areas but not directly involved with the sheep. The shift of infected patients from the Coachella Valley to Blythe (100 miles distant) seems to support that supposition. All patients with acute Q fever developed antibodies primarily to phase II antigen, whereas the only person with chronic Q fever developed phase I antibodies. All patients presented with granulomatous hepatitis. One also had a pulmonary infiltrate, and the single individual with chronic Q fever also had a mitral valve prosthesis, although echocardiography could not define endocarditis. All patients with acute infections responded to 3-5 weeks of therapy with doxycycline, whereas the patient with chronic disease failed 3 years of therapy with combination regimens. Further studies at the Eisenhower Medical Center on the prevalence of infection in Blythe, CA, and elsewhere are anticipated.     

Analysis of Q fever in Uruguay

The first outbreak of Q fever in Uruguay occurred in 1956. The infection, which is caused by Coxiella burnetti, occurs in sheep, cattle, swine, and horses, but not in fowl or guinea pig. Most of the cases studied have been traced to cattle. Fourteen outbreaks of this disease were studied between 1975 and 1985. All of the 1,358 clinically suspected cases (814 serologically confirmed) reported in Uruguay occurred in workers at meat-processing plants. Diagnoses of cases and serologic surveys were made by use of complement fixation, capillary agglutination, and layer microagglutination techniques.     

Urban outbreak of Q fever,Briancon, France,March to June 1996

Q fever is an ubiquitous zoonosis caused by the rickettsial organism Coxiella burnetii. Both sporadic cases and epidemics occur in areas where sheep and goats are bred. The main route of transmission is by inhalation of aerosols from the environment (soil     

Markers of cell-mediated immunity after vaccination with an inactivated, whole-cell Q fever vaccine

A clinical trial of Q fever vaccine in four South Australian abattoirs showed apparently complete protection against natural infection; however, only 50%-60% of vaccinees developed complement-fixing or immunofluorescent antibody after vaccination. Cell-mediated immunity to Coxiella burnetii antigens, as measured by an index of lymphoproliferative responses (LSI) of peripheral blood mononuclear cells, was therefore assessed. Eighty-five percent of 13 subjects with "low risk" of exposure to Q fever and with an initially negative LSI converted to a positive LSI after vaccination; conversion was noted nine to 13 days after vaccination, and positive values were obtained for at least 96 d. Only 35% of this group seroconverted. In a "high-risk" group (abattoir workers), higher rates of positive LSI (greater than 95%) and of antibody (50%-70%) were observed after vaccination; greater than 95% of vaccinees in this group, who had been vaccinated five years previously, had positive LSI values.     

Q fever in children in Greece

The aim of this study was to investigate the incidence, epidemiology, and clinical manifestations of Q fever among hospitalized children in Greece. During a two-year period, 1,200 children with various clinical manifestations were prospectively tested for Coxiella burnetii infection by indirect immunofluorescence. Acute Q fever was diagnosed in eight (0.67%) patients. No chronic case of infection was detected. Multivariate analysis showed that children 11-14 years old and children reporting consumption of cheese from rural areas were at increased risk for this illness. Clinical manifestations of acute Q fever were pneumonia (two patients), meningitis (two), prolonged fever (two), hepatitis (one), and hemolytic-uremic syndrome (one). Q fever accounted for 2.9% of the cases with prolonged fever, 1.2% of the cases of meningitis, and 0.5% of the cases of pneumonia. Fever and headache were the most common symptoms at presentation. Our study indicates that Q fever is a rare cause of hospitalization during childhood.     

Zoonotic infections among veterinarians in Turkey: Crimean-Congo hemorrhagic fever and beyond.

OBJECTIVES: We aimed to determine the seroprevalence of Crimean-Congo hemorrhagic fever (CCHF) virus, Brucella spp, and Coxiella burnetii among veterinarians in a highly endemic and a non-endemic region for these infections in Turkey. METHODS: The antibody levels against these three infections were surveyed. Eighty-three veterinarians were included from two distinct geographic regions. RESULTS: CCHF IgG positivity (3% vs. 0%) and Brucella agglutination titer of > or =1/160 (33% vs. 5%) were more common in the endemic region, whereas the rates of Coxiella burnetii antibodies were similar (7% and 8%). A history of tick bite was significantly more common in the endemic region (35% vs. 12%, p=0.011). A multivariate analysis was performed among the veterinarians living in the endemic area, and percutaneous injuries were found to be associated with Brucella infection (OR 1.8, CI 1.09-3, p=0.022). CONCLUSIONS: Veterinarians should protect themselves against tick bites, and should use masks to prevent transmission by inhalation of zoonotic infections in endemic countries.