Molecular and serological diagnosis of multiple bacterial zoonoses in febrile outpatients in Garissa County, north-eastern Kenya.

Bacterial zoonoses are diseases caused by bacterial pathogens that can be naturally transmitted between humans and vertebrate animals. They are important causes of non-malarial fevers in Kenya, yet their epidemiology remains unclear. We investigated brucellosis, Q-fever and leptospirosis in the venous blood of 216 malaria-negative febrile patients recruited in two health centres (98 from Ijara and 118 from Sangailu health centres) in Garissa County in north-eastern Kenya. We determined exposure to the three zoonoses using serological (Rose Bengal test for Brucella spp., ELISA for C. burnetti and microscopic agglutination test for Leptospira spp.) and real-time PCR testing and identified risk factors for exposure. We also used non-targeted metagenomic sequencing on nine selected patients to assess the presence of other possible bacterial causes of non-malarial fevers. Considerable PCR positivity was found for Brucella (19.4%, 95% confidence intervals [CI] 14.2-25.5) and Leptospira spp. (1.7%, 95% CI 0.4-4.9), and high endpoint titres were observed against leptospiral serovar Grippotyphosa from the serological testing. Patients aged 5-17 years old had 4.02 (95% CI 1.18-13.70, p-value = 0.03) and 2.42 (95% CI 1.09-5.34, p-value = 0.03) times higher odds of infection with Brucella spp. and Coxiella burnetii than those of ages 35-80. Additionally, patients who sourced water from dams/springs, and other sources (protected wells, boreholes, bottled water, and water pans) had 2.39 (95% CI 1.22-4.68, p-value = 0.01) and 2.24 (1.15-4.35, p-value = 0.02) times higher odds of exposure to C. burnetii than those who used unprotected wells. Streptococcus and Moraxella spp. were determined using metagenomic sequencing. Brucellosis, leptospirosis, Streptococcus and Moraxella infections are potentially important causes of non-malarial fevers in Garissa. This knowledge can guide routine diagnosis, thus helping lower the disease burden and ensure better health outcomes, especially in younger populations.

Cross-Sectional Study of Q Fever Seroprevalence among Blood Donors, Israel, 2021.

We evaluated Q fever prevalence in blood donors and assessed the epidemiologic features of the disease in Israel in 2021. We tested serum samples for Coxeilla burnetii phase I and II IgG using immunofluorescent assay, defining a result of >200 as seropositive. We compared geographic and demographic data. We included 1,473 participants; 188 (12.7%) were seropositive. The calculated sex- and age-adjusted national seroprevalence was 13.9% (95% CI 12.2%-15.7%). Male sex and age were independently associated with seropositivity (odds ratio [OR] 1.6, 95% CI 1.1-2.2; p = 0.005 for male sex; OR 1.2, 95% CI 1.01-1.03; p<0.001 for age). Residence in the coastal plain was independently associated with seropositivity for Q fever (OR 1.6, 95% CI 1.2-2.3; p<0.001); residence in rural and farming regions was not. Q fever is highly prevalent in Israel. The unexpected spatial distribution in the nonrural coastal plain suggests an unrecognized mode of transmission.

Seroepidemiologic evidence of Q fever and associated factors among workers in veterinary service laboratory in South Korea.

The incidence of Q fever has rapidly increased in South Korea since 2015. This study was undertaken to investigate the seroprevalence and seroreactivity of Q fever and the risk factors associated with its seroprevalence among workers in the veterinary service laboratory (VSL) in South Korea. This seroepidemiologic study was conducted in a total of 661 human subjects out of 1,328 subjects working in 50 VSL existing in South Korea between July 15 and July 29, 2019. Data were collected by administering survey questionnaires and by analyzing collected blood samples to determine the presence of antibodies against Coxiella burnetii. The seroprevalence and seroreactivity of C. burnetii infection were determined based on serum titers as (phase II IgG ≥1:256 and/or IgM ≥1:16) and (phase II IgG ≥1:16 and/or IgM ≥1:16) as determined by indirect immunofluorescent assay. Work, work environment, behavioral risk and protective factors associated with seroprevalence of Q fever were assessed by employing multivariable logistic regression analysis. Among the 661, the seroprevalence and seroreactivity of C. burnetii infection were 7.9% and 16.0%, respectively. Multivariate logistic regression analysis showed the risk factors significantly associated with seroprevalence were the antemortem inspection of cattle, goats, or sheep (APR (adjusted prevalence ratio), 2.52; 95% CI, 1.23-4.70)), animal blood splashed into or around eyes (APR, 2.24; 95% CI, 1.04-4.41), and contact with animals having Q fever (APR, 6.58; 95% CI, 3.39-10.85) during the previous year. This study suggests the need for precautions when contact with cattle, goats, or sheep is expected, especially during the antemortem inspection, when dealing with C. burnetii infected animals, or when there is a risk of ocular contact with animal derivatives. Therefore, we recommend the consistent use of appropriate personal protective equipment and other protective measures including PPE treatment and washing of body surfaces after work to prevent C. burnetii infections among VSL staff in South Korea.

Whole Blood Interferon γ Release Is a More Sensitive Marker of Prior Exposure to Coxiella burnetii Than Are Antibody Responses.

For the zoonotic disease Q fever, serological analysis plays a dominant role in the diagnosis of Coxiella burnetii infection and in pre-screening for past exposure prior to vaccination. A number of studies suggest that assessment of C. burnetii-specific T-cell IFNγ responses may be a more sensitive tool to assess past exposure. In this study, we assessed the performance of a whole blood C. burnetii IFNγ release assay in comparison to serological detection in an area of high Q fever incidence in 2014, up to seven years after initial exposure during the Dutch Q fever outbreak 2007-2010. In a cohort of >1500 individuals from the Dutch outbreak village of Herpen, approximately 60% had mounted IFNγ responses to C. burnetii. This proportion was independent of the Coxiella strain used for stimulation and much higher than the proportion of individuals scored sero-positive using the serological gold standard immunofluorescence assay. Moreover, C. burnetii-specific IFNγ responses were found to be more durable than antibody responses in two sub-groups of individuals known to have sero-converted as of 2007 or previously reported to the municipality as notified Q fever cases. A novel ready-to-use version of the IFNγ release assay assessed in a subgroup of pre-exposed individuals in 2021 (10-14 years post exposure) proved again to be more sensitive than serology in detecting past exposure. These data demonstrate that C. burnetii-induced IFNγ release is indeed a more sensitive and durable marker of exposure to C. burnetii than are serological responses. In combination with a simplified assay version suitable for implementation in routine diagnostic settings, this makes the assessment of IFNγ responses a valuable tool for exposure screening to obtain epidemiological data, and to identify previously exposed individuals in pre-vaccination screens.

Seroprevalence of brucellosis and Q fever infections amongst pastoralists and their cattle herds in Sokoto State, Nigeria.

Brucellosis and Q fever are neglected zoonoses of global health importance, with unknown true prevalence in occupationally vulnerable settings, partly due to misdiagnosis for other febrile conditions and poor access to primary health care. We examined the seroprevalence of these diseases and associated factors amongst pastoralists and their cattle in Sokoto State, a hub of cattle and pastoral populations in Nigeria. Serum samples randomly collected from 137 pastoralists and 366 cattle from 27 herds in three selected Local Government Areas (LGAs) in the state were analysed for antibodies to Brucella abortus using Rose Bengal Plate Test (RBT) and competitive Enzyme-Linked Immunosorbent Assay (cELISA) as well as antibodies to Coxiella burnetti using indirect ELISA. Consenting pastoralists' knowledge, perception and practices about the diseases were assessed using a semi-structured questionnaire. Data were analysed using descriptive statistics and bivariate analysis at p ≤ 0.05 level of significance. Brucellosis adjusted individual seroprevalence were 0.83% (95%CI: 0.04-4.59%) and 0% among pastoralists; 2.28% (95%CI: 1.16-4.43%) and 5.70% (95%CI: 3.68-8.74%) in cattle by RBT and cELISA, respectively. Adjusted herd-level seroprevalence for brucellosis were 23.20% (95%CI: 11.07-42.54%) and 42.00% (95%CI: 25.27-61.11%) by RBT and cELISA, respectively. For Q fever, higher seroprevalence of 62.57% (95%CI: 54.04-70.46%) and 2.98% (95%CI: 1.57-5.58%) were recorded amongst the pastoralists and their cattle, respectively. with adjusted herd-level seroprevalence of 40.36% (95%CI: 22.57-63.17%). The LGAs of sampling were significantly (OR: 0.2; 95%CI: 0.02-1.00) associated with Q fever infection, though marginal. The majority of the pastoralists had poor knowledge, perception and practices towards the diseases. This is the first study establishing the presence of brucellosis and Q fever at the human-animal interface in Sokoto State, Nigeria. The pastoralists' poor knowledge, perception and practices about these diseases are worrisome and are important factors for consideration in disease control.

SEROLOGICAL EVIDENCE OF COXIELLA BURNETII INFECTION IN THE WHITE RHINOCEROS (CERATOTHERIUM SIMUM) IN SOUTH AFRICA.

Coxiellosis, or Query (Q) fever, a disease caused by the intracellular bacteria Coxiella burnetii, was recently described in a managed breeding herd of white rhinoceros (Ceratotherium simum) in the southeastern United States. Clinical disease often results in abortion and could represent a conservation challenge for this species. In addition to the reproductive and herd management consequences, coxiellosis is also a zoonotic disease. Infection or clinical disease in any free-ranging rhinoceros species in a national park setting has not been previously described. In this study, evidence of prior infection was measured by immunofluorescent antibody titers in 89 serum samples collected from white rhinoceros within private reserves and a national park in South Africa. Total seropositivity was 48/89 (53.9% [95% CI, 43.6-63.9%]). Animals on private reserves had a seropositivity of 21/51 (41.1% [95% CI, 27.1-55.2%]), and national park rhinoceros had a higher rate of seropositivity at 71.0% [95% CI, 55.9-86.2%] (27/38; P= 0.004). Adults had a higher seropositivity compared with subadults (P= 0.03). There was no difference in seropositivity between sexes (P > 0.05). Results demonstrate that South African white rhinoceros populations are exposed to Coxiella, which could result in underrecognized reproductive consequences. Further studies should investigate potential implications for public health and conservation management of this species.

Long-term serological follow-up after primary Coxiella burnetii infection in patients with vascular risk factors for chronic Q fever.

We evaluated the long-term serological follow-up of patients with vascular risk factors for chronic Q fever that were previously Coxiella burnetii seropositive. C. burnetii phase I IgG titers were reevaluated in patients that gave informed consent or retrospectively collected in patients already deceased or lost to follow-up. Of 107 patients, 25 (23.4%) became seronegative, 77 (72.0%) retained a profile of past resolved Q fever infection, and five (4.7%) developed chronic Q fever. We urge clinicians to stay vigilant for chronic Q fever beyond two years after primary infection and perform serological testing based on clinical presentation.

Analysis of recombinant proteins for Q fever diagnostics.

Serology is essential for Q fever diagnostics, a disease caused by the bacterial pathogen Coxiella burnetii. The gold standard test is an immunofluorescence assay utilizing whole cell antigens, which are both dangerous and laborious to produce. Complexities of the antigen coupled with the subjective nature of the assay lead to decreased uniformity of test results and underscore the need for improved methodologies. Thirty-three C. burnetii proteins, previously identified as immunoreactive, were screened for reactivity to naturally infected goat serum. Based on reactivity, 10 proteins were analyzed in a secondary screen against human serum from healthy donors. Assay sensitivity and specificity ranged from 21 to 71% and 90 to 100%, respectively. Three promising antigens were identified based on receiver operating characteristic curve analysis (CBU_1718, CBU_0307, and CBU_1398). Five multiplex assays failed to outperform the individual proteins, with sensitivities and specificities ranging from 29 to 57% and 90 to 100%, respectively. Truncating the top antigen, CBU_1718, had no effect on specificity (90%); yet sensitivity decreased dramatically (71% to 21%). Through this study, we have expanded the subset of C. burnetii immunoreactive proteins validated by enzyme-linked immunosorbent assay and demonstrate the effect of novel antigen combinations and protein truncations on assay performance.

Apparent prevalence and risk factors of coxiellosis (Q fever) among dairy herds in India.

Coxiella burnetii is a highly infectious zoonotic pathogen infecting wide range of mammals, including humans. In the present study, a total of 711 blood samples from bovines [cattle (n = 543) and buffaloes (n = 168)] from eight farms at different geographical locations in India were screened for C. burnetii targeting the IS1111 and the com1 genes. The anti-C. burnetii antibodies in serum samples were detected using indirect-ELISA kits. Also, a total of 21 parameters pertaining to animal health and farm management were identified to assess their role as possible risk factors for coxiellosis among the targeted farms. The apparent prevalence (positive for PCR and/or ELISA) for coxiellosis was reported to be 24.5% in cattle and 8.9% in buffaloes. In cattle, the detection rate of C. burnetii employing the IS1111 gene (8.5%) was found to be significantly higher (p<0.05) as compared to the com1 (6.5%) gene. The seropositivity by ELISA was higher among cattle (17.7%) than in buffaloes (8.3%). Further, on univariable analysis of risk factors, species (cattle) (OR:3.31; 95%CI:1.88-5.82), inadequate floor spacing (OR:1.64; 95%CI:1.10-2.43), mastitis (OR:2.35, 95%CI:1.45-3.81) and reproductive disorders (OR:2.54; 95%CI:1.67-3.85) were significantly (p<0.05) having high odds for coxiellosis. The multivariable logistic regression analysis of the animal level risk factors revealed that species and age were found to be significantly associated with coxiellosis. However, since the number of screened farms is limited; further research is needed with a higher number of animals to confirm the farm level odds ratio of risk factors. Quarantine and biosecurity measures including farm hygiene operations were observed to be inadequate and also the lack of awareness about coxiellosis among the farm workers. In absence of vaccination program for coxiellosis in India, robust surveillance, farm biosecurity measures and the awareness for the disease among risk groups can play an important role in the disease prevention and subsequent transmission of the pathogen.

Comparison of three serological tests for the detection of Coxiella burnetii specific antibodies in European wild rabbits.

BACKGROUND: Coxiella burnetii causes Q fever, a zoonotic bacterial disease with a multi-host cycle and reservoirs in wild and domestic animal species. Q fever has a significant impact on the Australian public health and economy but its ecology and contributing reservoir species remain poorly understood. In Europe, rabbits (Oryctolagus cuniculus) were identified as a major reservoir of C. burnetii and it is possible that they play a similar role in Australia. In absence of commercial kit available for rabbit, the Thermo Fisher - PrioCHECK™ Ruminant Q fever Ab Plate Kit was adapted to successfully screen rabbits population in Europe. However, this assay is not accessible in Australia and we assessed the equivalency of two commercially available kits in Australia - IDEXX - CHEKIT Q Fever Antibody ELISA kit and IDVet - ID Screen® Q Fever Indirect Multi-species with the Thermo Fisher kit (reference kit). RESULTS: A total of 94 rabbit sera were screened by all three ELISA kits using the same confirmed positive and negative controls. While the IDEXX kit failed to agree the other two assays (concordance correlation coefficient, rb < 0.77), IDVet kit showed satisfactory equivalency with Thermo Fisher (rb = 0.927). CONCLUSION: IDvet kit provides the best alternative for Thermo Fisher in the detection of C. burnetii specific antibodies in rabbits in Australia. Further trials are required to confirm these preliminary results due to the low seroprevalence of Coxiella burnetii observed in the study sera.

First Serological & Molecular Study of Coxiella burnetii in Stray, Domestic Cats, and Their Owners in Iran.

Coxiella burnetii, the agent of Q fever, is recognized as a worldwide zoonosis a wide host and potentially complex reservoir systems. Infected ruminants are the main source of infection for humans, but cats also represent a potential source of infection. The prevalence of C burnetii in cats in Iran is unknown and the risks of transmission to humans are undetermined. This study aimed to determine the prevalence of C burnetii in domestic cats and their owners. An Enzyme-linked immunosorbent assay was used for detection of anti-C burnetii antibodies in both cats and humans. Cats serum samples and humans serum samples (n = 85) were tested with indirect ELISA. C burnetii was diagnosed using real time- polymerase chain reaction. Antibodies were detected in 19 sera of 85 (22.35%) samples in stray cats, 9 sera of 78 (11.53%) samples of domestic cats and 4 sera of 78 (5.12%) samples of their owners. This first study of C burnetii prevalence in cats in Iran has indicated that positive samples can be found throughout the country and these results confirm that Iranian cats have been exposed to C burnetii. Moreover, this study demonstrates that cat owners, breeders and veterinary personnel might be at higher risk of exposure of C burnetii.

Identification of risk factors associated with Coxiella burnetii infection in cattle and buffaloes in India.

The etiological agent Coxiella burnetii is a highly infectious gram-negative bacterium that can affect multiple species. Many reports confirm its presence in humans, domestic ruminants and rodents in India. This study was aimed to investigate the risk factors associated with C. burnetii infection in bovine populations in Punjab, India. This study was conducted using a stratified two-stage random sampling approach. Twenty-two villages representing all districts of the state were selected. Bovine farmers were interviewed and detailed information about their management and husbandry practices was collected using a structured questionnaire. Blood, milk and genital swab samples were collected from the cattle and buffaloes owned by the farmers. An animal was declared C. burnetii infected by using a combination of tests in parallel, i.e. if it was positive in serological or molecular tests (IgG indirect ELISA or Trans-PCR assay). A herd was considered positive if at least one animal in the herd was declared C. burnetii infected using the above definition. Three binomial logistic regression models were constructed to evaluate the association of (a) geographical location, herd characteristics, and farm management practices with the herd status (herd model), (b) individual animal related factors with the C. burnetii infection status (individual animal model), and (c) production and health related factors with C. burnetii infection status in adult females (adult female model). We collected a total of 610 blood, 610 genital swabs and 361 milk samples from 378 cattle and 232 buffaloes in 179 herds/households. The practice of throwing away aborted materials outside the farm as compared to burial/burning (adjusted odds ratio [OR] 3.0, 95 % confidence interval [CI] 1.14-7.87, p = 0.02) was associated with larger odds of being a C. burnetii infected herd. On the other hand, separation of the animals from the rest of the herd during parturition had a protective effect for being a C. burnetii infected herd (adjusted OR 0.31, 95 % CI 0.18-0.77, p = 0.01). Being cattle as compared to buffalo (adjusted OR 3.37, 95 % CI 1.23-9.20, p = 0.02) and older (adjusted OR 3.37, 95 % CI 1.23-9.20, p = 0.02) were associated with larger odds of C. burnetii infection. The current study highlights that farm practices such as improper aborted material disposal and not separating the animals from the rest of the herd during parturition are important risks for the occurrence of C. burnetii infection in the bovine populations in the state.

Molecular detection of Coxiella burnetii in livestock farmers and cattle from Magdalena Medio in Antioquia, Colombia.

Coxiella burnetii causes Q fever in humans and coxiellosis in animals. In humans, it causes acute febrile illnesses like influenza, pneumonia, hepatitis, and chronic illnesses such as endocarditis, vascular infection, and post-infectious fatigue syndrome. It is widely distributed worldwide, and its main reservoirs are sheep, goats, and cattle. This study aimed to determine the frequency of C. burnetii infection using molecular detection and to identify the associated factors in livestock farmers and cattle from the Magdalena Medio region of Antioquia, Colombia. Using real-time polymerase chain reaction (PCR), molecular detection was performed for the IS1111 insertion sequence of C. burnetii using genomic DNA collected from the peripheral blood of 143 livestock farmers and 192 cattle from 24 farms located in Puerto Berrío, Puerto Nare, and Puerto Triunfo. To confirm the results, bidirectional amplicon sequencing of 16S rRNA was performed in four of the positive samples. Additionally, factors associated with C. burnetii were identified using a Poisson regression with cluster effect adjustment. Real-time PCR showed positive results in 25.9% and 19.5% of livestock farmer samples and cattle samples, respectively. For livestock farmers, factors associated with C. burnetii were the area where the farm was located [Puerto Berrío, adjusted prevalence ratio (aPR): 2.13, 95% confidence interval (CI): 1.10-4.11], presence of hens (aPR: 1.47, 95% CI: 1.21-1.79), horses (aPR: 1.61, 95% CI: 1.54-1.67), and ticks (aPR: 2.36, 95% CI: 1.03-5.42) in the residence, and consumption of raw milk (aPR: 1.47, 95% CI: 1.26-1.72). For cattle, the factors associated with Coxiella genus were municipality (Puerto Nare; aPR: 0.39, 95% CI: 0.37-0.41) and time of residence on the farm (≥49 months; aPR: 2.28, 95% CI: 1.03-5.20). By analyzing sequences of the 16S rRNA molecular marker, C. burnetii infection was confirmed in livestock farmers. However, in cattle, only the presence of Coxiella-type bacteria was identified. Further research is necessary to determine the potential role that these types of bacteria have as etiological agents for disease in livestock farmers and cattle from the study area.

Serum C-reactive protein and procalcitonin values in acute Q fever, scrub typhus, and murine typhus.

BACKGROUND: Although C-reactive protein (CRP) and procalcitonin (PCT) are widely used inflammatory markers for infectious diseases, their role and potential application for rickettsioses were rarely studied. METHODS: A retrospective chart review and serological study were conducted in patients with rickettsioses. The clinical presentations, characteristics, laboratory data, and treatment responses were recorded and their associations with CRP and PCT values were analyzed. RESULTS: A total of 189 cases of rickettsioses, including 115 cases of acute Q fever (60.8%), 55 cases of scrub typhus (29.1%), and 19 cases of murine typhus (10.1%) were investigated. Both CRP and PCT values increased in the acute phase and declined in the convalescent phase. In the acute phase, mean CRP and PCT values were 78.2 ± 63.7 mg/L and 1.05 ± 1.40 ng/mL, respectively. Percentages of patients falling under different cut-off values of CRP and PCT were calculated systematically. Only 10.8% of CRP was > 150 mg/L and 14.2% of PCT was > 2.0 ng/mL. Patients with delayed responses to doxycycline treatment (> 3 days from treatment to defervescence) had significantly higher CRP values (102.7 ± 77.1 vs. 72.2 ± 58.2 mg/L, p = 0.041) and more PCT > 1.0 ng/ml (48.4% vs. 26.0%, p = 0.019) in the acute phase; higher CRP values (19.1 ± 37.4 vs. 3.6 ± 13.1 mg/L, p = 0.049) and more PCT > 0.5 ng/ml (19.2% vs. 1.4%, p = 0.005) in the convalescent phase. Correlation analysis was conducted for patients with acute Q fever. CRP and PCT values were positively correlated to each other, and both markers also had a positive correlation with serum aspartate transaminase values. Both CRP and PCT values and white blood cell counts were positively correlated to the days needed from doxycycline treatment to defervescence. CONCLUSION: CRP and PCT values might be useful in clinical investigations for patients with suspected rickettsioses and in predicting the response to doxycycline treatment for rickettsioses.

Who is at risk of occupational Q fever: new insights from a multi-profession cross-sectional study.

OBJECTIVES: Q fever is a zoonosis caused by the bacterium Coxiella burnetii. It is recognised as an occupational hazard for individuals who are in regular contact with animal birth products. Data from the literature are not comparable because different serological assays perform very differently in detecting past infections. It is therefore essential to choose the right assay for obtaining reliable data of seroprevalence. Obstetricians are another profession potentially at risk of Q fever. They can be infected from birth products of women with Q fever during pregnancy. There is little data, however, for Q fever in this occupational group. Our study therefore had two purposes. The first was to obtain reliable seroprevalence data for occupational groups in regular contact with animal birth products by using an assay with proven excellent sensitivity and specificity for detecting past infections. The second purpose was to obtain primary data for obstetricians. DESIGN: We carried out a cross-sectional study. SETTING: The study included shepherds, cattle farmers, veterinarians and obstetricians from Thuringia. PARTICIPANTS: 77 shepherds, 74 veterinarians, 14 cattle farmers, 17 office employees and 68 obstetricians participated. The control group consisted of 92 blood donors. PRIMARY OUTCOME MEASURE: The primary outcome measure was C. burnetii phase II specific IgG. The assay used was evaluated for this purpose in a previous study. RESULTS: Of the 250 blood samples we analysed, the very highest seroprevalences (64%-77%) occurred in individuals with frequent animal contact. There were no significant differences between shepherds, cattle farmers and veterinarians. The seroprevalence in people working in administration was lower but still significantly greater than the control. No obstetricians or midwives tested positive. CONCLUSIONS: Shepherds, cattle farmers and veterinarians have a high risk of C. burnetii infection. However, our study clearly proves that there was no increased risk for people working in an obstetric department.

Seroprevalence and associated risk factors of Coxiella burnetii (Q fever) in goats and sheep in northern Jordan.

This cross-sectional study aimed to study animal, farm, and within-farm seroprevalence of C. burnetii and to identify associated risk factors in goat and sheep farm in northern Jordan. Questionnaire was developed to collect information about risk factors and farms management practices. Blood samples from 730, ≥ 1-year-old females (goat n = 250; sheep n = 480) were randomly collected from 20 goat herds and 40 sheep flocks. IDEXX ELISA Kit was used to detect C. burnetii antibodies. The overall goat and sheep seroprevalence level was 32.5% (237/730) and was significantly higher in goats (43.3%, 108/250; 95% CI 37-49.6) than sheep (27%, 129/480; 95% CI 29.1-36.2) (χ2 test, p ≤ 0.001). Eighty percent (16/20) of goat herds and 60% (24/40) of sheep flocks had at least one seropositive animal (p ≥ 0.05). The average within goat herds and sheep flock seroprevalence were 36.4% (ranged: 0-91%) and 23.4% (ranged: 0-82%), respectively. Multivariate logistic regression model revealed that seroprevalence increased 1.79 times in goat herds compared with sheep flocks, 3.2 times more in farms containing ≥ 100 animals, and 1.7 times higher in farms with their animals that were ≥ 2 years of age than in farms with their animals that are < 2 years of age. In addition, seroprevalence significantly increased 1.52 times in farms loaning bucks or rams during breeding season and 1.63 times in farms containing cats on premises (p ≤ 0.05). Farm biosecurity measures are essential to prevent introduction and minimize transmission of C. burnetii infection to humans and animals.

Comparison of Different Commercially Available Enzyme-Linked Immunosorbent Assays with Immunofluorescence Test for Detection of Phase II IgG and IgM Antibodies to Coxiella burnetii.

Several commercially available enzyme-linked immunosorbent assays (ELISAs) for the detection of phase II IgG or IgM antibodies against Coxiella burnetii were compared. In addition, an indirect immunofluorescence test was used as a confirmation test. In all, 70 serum samples for IgG and 43 serum samples for IgM were tested. The ELISAs showed large differences in sensitivity and specificity, which led to a partially high ratio of false-negative determinations. The most convincing test was PanBio from Abbott, which unfortunately can only test IgG but not IgM.

Prevalence of serum antibodies to Coxiella burnetii in Alaska Native Persons from the Pribilof Islands.

BACKGROUND: Q fever is a febrile illness caused by infection with the bacterium Coxiella burnetii. It is most often transmitted by inhalation of the bacteria after it is shed by infected livestock. Recent studies have found very high C. burnetii infection rates among marine mammals, but it is not known if shedding by marine mammals creates a risk of Q fever among humans. To better understand infection of humans with exposure to marine mammals, the prevalence of antibodies against C. burnetii in serum samples taken from Alaskan Native persons residing on the Pribilof Islands was evaluated. The Pribilof Islands support large populations of northern fur seals infected with C. burnetii that may increase the risk of exposure for island residents. METHODS: Serum testing for IgG antibodies against C. burnetii (phase I and phase II) was performed, and demographic data were analysed utilizing banked serum specimens drawn from island residents from 1980 to 2000. RESULTS: The overall seroprevalence rate was 11.6% (95% CI = 9.3%-14.4%; 72/621). This is higher than the previously reported 3.1% (95% CI = 2.1%-4.3%) seroprevalence for the U.S. CONCLUSIONS: These results suggest that Alaskan Native persons may be at higher risk for exposure to C. burnetii than the general US. population, possibly due to proximity to large populations of infected marine mammals.

Seroprevalence of Coxiella burnetii in dairy cattle from Sicily.

Q fever is a widespread zoonotic disease caused by Coxiella burnetii, an obligate intracellular bacterium with a wide range of hosts. The aim of this study was to estimate the seroprevalence of C. burnetii infection in cattle in Sicilian farms. A total of 4,661 serum samples, from cattle belonging to 198 Sicilian farms, were examined by ELISA test and 246 resulted positive. The average seroprevalence at the farm level was 38.8% (77/198) (95% CI), while at the animal level it was 5.28% (246/4,661) (95% CI). The present study highlights the need for continuous monitoring of C. burnetii spread as it represents a serious risk for human health.

Q fever in Bulgaria: Laboratory and epidemiological findings on human cases and outbreaks, 2011 to 2017.

BackgroundQ fever is a zoonosis, included in category B of particularly dangerous infectious agents and as such merits careful surveillance and regular updating of the information about its distribution.AimThis observational retrospective study aimed to provide an overview of Q fever incidence in Bulgaria in the period 2011 to 2017.MethodsAggregated surveillance data from Bulgaria's mandatory surveillance system, laboratory data on individual samples received at the National Reference Laboratory Rickettsiae and Cell Cultures and outbreak reports sent by the regional health authorities to the National Centre of Infectious and Parasitic Diseases, were used in this analysis. Cases were described by year, region, age group and most commonly identified risk behaviours.ResultsA total of 139 confirmed cases were reported in the study period (average annual incidence: 0.27 cases/100,000 inhabitants). No seasonality or trend in reported cases was observed. Cases were mostly sporadic, with two small outbreaks in 2017. Identified risk behaviours among cases were occupational exposure and consumption of milk and dairy products, although exposure data were incomplete. The male/female ratio was 1.4. The identification and resolution of the two rural outbreaks in 2017 with a total of 18 cases involved good practices: active case finding and collaboration between public health and veterinary authorities.ConclusionBetween 2011 and 2017, Bulgaria retained low Q fever incidence, mostly sporadic cases and two small outbreaks. Occupational exposure and consumption of milk and dairy products were the most often reported likely exposures among cases. The outbreak investigations demonstrate the application of good control practices.