Molecular and serological prevalence of Coxiella burnetii in bovine dairy herds in southern Chile: A PCR and ELISA-based assessment of bulk tank milk samples.

Coxiella burnetii (C. burnetii) is a highly resilient zoonotic bacterium responsible for Q fever, a disease which occurs worldwide, with the exception of New Zealand. However, in Chile, the prevalence and impact of C. burnetii in cattle herds remain poorly understood due to limited research. This study aimed to assess the presence of C. burnetii in dairy cattle herds in southern Chile, using two diagnostic methods on bulk tank milk samples. The results of the study revealed a high prevalence of C. burnetii infection in the analyzed herds. Of the 271 milk tank samples tested, 76% (208/271, CI: 71.1-81.5) tested positive using ELISA, while 73% (200/271, CI: 68.0-78.8) tested positive using qPCR. These findings indicate a significant presence of C. burnetii in the cattle herds studied. Despite the high prevalence observed, no new Q fever outbreaks have been reported in the study area. This discrepancy highlights the need for further research to better understand the transmission dynamics, environmental factors, and livestock management practices associated with C. burnetii infection. These studies will contribute to the development of effective prevention and control strategies and promote public health regarding Q fever.

Epidemiological investigation and physician awareness regarding the diagnosis and management of Q fever in South Korea, 2011 to 2017.

BACKGROUND: In South Korea, the number of Q fever cases has rapidly increased since 2015. Therefore, this study aimed to characterize the epidemiological and clinical features of Q fever in South Korea between 2011 and 2017. METHODS/PRINCIPAL FINDINGS: We analyzed the epidemiological investigations and reviewed the medical records from all hospitals that had reported at least one case of Q fever from 2011 to 2017. We also conducted an online survey to investigate physicians' awareness regarding how to appropriately diagnose and manage Q fever. The nationwide incidence rate of Q fever was annually 0.07 cases per 100,000 persons. However, there has been a sharp increase in its incidence, reaching up to 0.19 cases per 100,000 persons in 2017. Q fever sporadically occurred across the country, with the highest incidences in Chungbuk (0.53 cases per 100,000 persons per year) and Chungnam (0.27 cases per 100,000 persons per year) areas. Patients with acute Q fever primarily presented with mild illnesses such as hepatitis (64.5%) and isolated febrile illness (24.0%), whereas those with chronic Q fever were likely to undergo surgery (41.2%) and had a high mortality rate (23.5%). Follow-up for 6 months after acute Q fever was performed by 24.0% of the physician respondents, and only 22.3% of them reported that clinical and serological evaluations were required after acute Q fever diagnosis. CONCLUSIONS: Q fever is becoming an endemic disease in the midwestern area of South Korea. Given the clinical severity and mortality of chronic Q fever, physicians should be made aware of appropriate diagnosis and management strategies for Q fever.

Cost-effectiveness of Screening Program for Chronic Q Fever, the Netherlands.

In the aftermath of a large Q fever (QF) epidemic in the Netherlands during 2007-2010, new chronic QF (CQF) patients continue to be detected. We developed a health-economic decision model to evaluate the cost-effectiveness of a 1-time screening program for CQF 7 years after the epidemic. The model was parameterized with spatial data on QF notifications for the Netherlands, prevalence data from targeted screening studies, and clinical data from the national QF database. The cost-effectiveness of screening varied substantially among subpopulations and geographic areas. Screening that focused on cardiovascular risk patients in areas with high QF incidence during the epidemic ranged from cost-saving to €31,373 per quality-adjusted life year gained, depending on the method to estimate the prevalence of CQF. The cost per quality-adjusted life year of mass screening of all older adults was €70,000 in the most optimistic scenario.

Assessment of Coxiella burnetii presence after tick bite in north-eastern Poland.

PURPOSE: The aim of the study is to assess anti-Coxiella burnetii antibodies presence in inhabitants of north-eastern Poland, to assess the risk of Q fever after tick bite and to assess the percentage of co-infection with other pathogens. METHODS: The serological study included 164 foresters and farmers with a history of tick bite. The molecular study included 540 patients, hospitalized because of various symptoms after tick bite. The control group consisted of 20 honorary blood donors. Anti-Coxiella burnetii antibodies titers were determined by Coxiella burnetii (Q fever) Phase 1 IgG ELISA (DRG International Inc. USA). PCR was performed to detect DNA of C. burnetii, Borrelia burgdorferi and Anaplasma phagocytophilum. RESULTS: Anti-C. burnetii IgG was detected in six foresters (7.3%). All foresters with the anti-C. burnetii IgG presence were positive toward anti-B. burgdorferi IgG and anti-TBE (tick-borne encephalitis). Anti-C. burnetii IgG was detected in five farmers (6%). Four farmers with anti-C. burnetii IgG presence were positive toward anti-B. burgdorferi IgG and two with anti-TBE. Among them one was co-infected with B. burgdorferi and TBEV. Correlations between anti-C. burnetii IgG and anti-B. burgdorferi IgG presence and between anti-C. burnetii IgG presence and symptoms of Lyme disease were observed. C. burnetii DNA was not detected in any of the 540 (0%) patients. CONCLUSIONS: C. burnetii is rarely transmitted by ticks, but we proved that it is present in the environment, so it may be a danger to humans. The most common co-occurrence after tick bite concerns C. burnetii and B. burgdorferi.

Seroprevalence of Bartonella spp., Coxiella burnetii, and Hantavirus among people who inject drugs in Rio de Janeiro, Brazil: a retrospective assessment of a biobank.

The increasing use of illicit drugs imposes a public health challenge worldwide. People who inject drugs (PWID) are more susceptible to health complications due to immunosuppression associated with drug use and non-hygienic self-administration of substances, contaminants, and liquids. PWID are subjected to increased risk of acquiring and transmitting different pathogens (frequently functioning as sentinel cases for (re)emerging pathogens), including those transmitted by arthropods and vertebrate reservoirs in unhealthy environments. A clear association between injection drug use and HIV, HBV, and HCV infections has been described; however, other infectious viral and bacterial agents have been seldomly assessed. In this study, we investigated the seroprevalence of Bartonella spp., Coxiella burnetii, and Hantavirus among 300 randomly selected PWIDs from Rio de Janeiro, as part of a multi-city cross-sectional study carried out in the 1990s. Point seroprevalences and respective 95% CIs are as follows: 9.3% for C. burnetii (95% CI: 6.0%-13.0%), 1.0% for Bartonella spp. (95% CI: 0.0%-3.0%), and 4.0% for Hantavirus (95% CI: 2.0%-7.0%). In addition to the blood-borne pathogens, the results of this study increase our knowledge on other transmissible infectious agents in PWID. The high seroprevalence of C. burnetii and Hantavirus found among PWID is intriguing and suggests the need to carry out prospective studies, including molecular analyses, to confirm these findings and allow a better understanding of the putative relevance of these zoonotic infectious agents among PWID.

To notify or not to notify: decision aid for policy makers on whether to make an infectious disease mandatorily notifiable.

Mandatory notification can be a useful tool to support infectious disease prevention and control. Guidelines are needed to help policymakers decide whether mandatory notification of an infectious disease is appropriate. We developed a decision aid, based on a range of criteria previously used in the Netherlands or in other regions to help decide whether to make a disease notifiable. Criteria were categorised as being effective, feasible and necessary with regard to the relevance of mandatory notification. Expert panels piloted the decision aid. Here we illustrate its use for three diseases (Vibrio vulnificus infection, chronic Q fever and dengue fever) for which mandatory notification was requested. For dengue fever, the expert panel advised mandatory notification; for V. vulnificus infection and chronic Q fever, the expert panel concluded that mandatory notification was not (yet) justified. Use of the decision aid led to a structured, transparent decision making process and a thorough assessment of the advantages and disadvantages of mandatory notification of these diseases. It also helped identify knowledge gaps that required further research before a decision could be made. We therefore recommend use of this aid for public health policy making.

Population Screening for Chronic Q-Fever Seven Years after a Major Outbreak.

INTRODUCTION: From 2007 through 2010, the Netherlands experienced a large Q-fever epidemic, with 4,107 notifications. The most serious complication of Q-fever is chronic Q-fever. METHOD: In 2014, we contacted all 2,161 adult inhabitants of the first village in the Netherlands affected by the Q-fever epidemic and offered to test for antibodies against Coxiella burnetii using immunofluorescence assay (IFA) to screen for chronic infections and assess whether large-scale population screening elsewhere is warranted. RESULTS: Of the 1,517 participants, 33.8% were IFA-positive. Six IFA-positive participants had an IgG phase I titer ≥1:512. Two of these six participants were previously diagnosed with chronic Q-fever. Chronic infection was diagnosed in one of the other four participants after clinical examination. CONCLUSIONS: Seven years after the initial outbreak, seroprevalence remains high, but the yield of screening the general population for chronic Q-fever is low. A policy of screening known high-risk groups for chronic Q-fever in outbreak areas directly following an outbreak might be more efficient than population screening. A cost-effectiveness analysis should also be performed before initiating a population screening program for chronic Q-fever.

Recent advances in the study of Q fever epidemiology, diagnosis and management.

Q fever is a worldwide zoonotic infection with an epidemiological pattern consisting of sporadic cases, endemic situations and outbreaks of unsuspected magnitude, as occurred in Holland. This event highlighted the fact that the term "chronic Q fever" is misleading and should be avoided. Here, we review recent advances in the understanding and management of this disease. There have been clonal outbreaks of confirmed "geotypes," such as the outbreaks in French Guiana, where a very high incidence was restricted to one city, with a specific clinical expression, an unusual serological response and a putative common reservoir. The advent of positron emission tomography has improved the diagnosis of endocarditis, vascular and osteoarticular infections. Molecular tests, including fluorescent in situ hybridization, may be included in the diagnostic strategy using the new criteria for endocarditis, vascular and osteoarticular infections. Q fever during pregnancy is challenging because pregnant women are less symptomatic, but infection is associated with a poor fetal outcome, including malformations that are preventable by antibiotics. Male patients over 40 years old with a valvulopathy are at the highest risk for progression to endocarditis. Antibiotic prophylaxis prevents endocarditis in 100% of at-risk patients. Finally, IgG anticardiolipin antibodies, part of the auto-immune response during acute Q fever, were recently added to the risk factors for endocarditis, due to their ability to promote acute valvular lesions and endocarditis.

Clinician assessment for Coxiella burnetii infection in hospitalized patients with potentially compatible illnesses during Q fever outbreaks and following a health alert, Montana, 2011.

BACKGROUND: 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. METHODS: 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. RESULTS: A total of 103 patients were included in the analysis. Clinicians assessed<1% 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. CONCLUSION: 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.

Investigations concerning the prevalence of Coxiella burnetii and Chlamydia abortus in sheep in correlation with management systems and abortion rate in Lower Saxony in 2004.

The intracellular bacteria Coxiella (C) burnetii and Chlamydia (Chl) abortus induce abortion in sheep and also affect humans. While Chl. abortus only infrequently infects humans, C burnetii is the aetiological agent of numerous Q fever outbreaks during the last decades. There is only limited knowledge about the prevalence of both pathogens in sheep, although sheep are involved in almost all Q fever outbreaks in Germany. The aim of our study was to investigate the prevalence of both pathogens in flocks located in Lower Saxony, Germany, in correlation to the management form and abortion rate. Serum samples of 1714 sheep from 95 flocks located in Lower Saxony were investigated by ELISA. 2.7% of these samples were positive, 1.3% showed inconclusive results in the C. burnetii-ELISA. Elevated intra-flock seroprevalences were only detected in three migrating flocks. Chlamydia-specific antibodies could be detected in 15.1% serum samples of mainly shepherded and migrating flocks. In one of these flocks with a high intra-flock seroprevalence for C burnetii (27%) and Chlamydia (44.9%), C burnetii was detected in 21.6% of the placenta samples of normal births and in 12.5% of the colostrum samples by PCR. Aborted fetuses and the corresponding placentas were negative in C burnetii-PCR, but in most of them and also in many other placenta samples Chl. abortus could be detected by PCR and DNA microarray. This survey shows a low overall prevalence of C. burnetii in sheep in Lower Saxony in the year 2004. However, three migrating flocks with a high intra-flock prevalence are localized in the southern parts of Lower Saxony. Spreading of C burnetii could occur, because of the large radius of grazing of all three flocks.

Self-reported sick leave and long-term health symptoms of Q-fever patients.

BACKGROUND: In The Netherlands, 1168 Q-fever patients were notified in 2007 and 2008. Patients and general practitioners (GPs) regularly reported persisting symptoms after acute Q-fever, especially fatigue and long periods of sick leave, to the public health authorities. International studies on smaller Q-fever outbreaks demonstrate that symptoms may persist years after acute illness. Data for the Dutch outbreaks were unavailable. The aim of this study is to quantify sick leave after acute Q-fever and long-term symptoms. METHODS: Our study targeted 898 acute Q-fever patients, notified in 2007 and 2008 residing in the Province Noord-Brabant. Patients from the 2008 cohort were mailed a questionnaire at 12 months and those of the 2007 cohort at 12-26 months after onset of illness. Patients reported underlying illness, Q-fever-related symptoms and sick leave. RESULTS: The response rate was 64%. Forty percent of the working patients reported long-term (>1 month) sick leave. Pre-existent heart disease odds ratio (OR) 4.50; confidence interval (CI) 1.27-16.09), hospitalization in the acute phase (OR 3.99; 95% CI 2.15-7.43) and smoking (OR 1.69; 95% CI 1.01-2.84) were significant predictors for long-term absence. Of the patients who resumed work, 9% were-at the time of completing the questionnaire-still unable to function at pre-infection levels due to fatigue or concentration problems. Of the respondents, 40% reported persisting physical symptoms at the time of follow-up. Fatigue (20%) was most frequently reported. Daily activities were affected in 30% of cases. CONCLUSIONS: Q-fever poses a serious persisting long-term burden on patients and society.

Applicability of evidence-based practice in public health: risk assessment on Q fever under an ongoing outbreak.

With reference to the Q fever outbreak in the Netherlands in 2009-10, we tested if an evidence-based approach, comparable to the methodology used in clinical medicine, was appropriate for giving public health advice under time constrains. According to the principles of evidence-based methodologies, articles were retrieved from bibliographic databases and categorised by type and size, outcome, strengths and limitations. The risk assessment was conducted in two months and involved six staff members. We retrieved and read 559 abstracts and selected approximately 150 full text articles. The most striking finding was the lack of sound scientific evidence behind standard treatment regimes for Q fever in pregnancy. Difficulties in applying existing evidence rating systems and in expressing uncertainties were identified as problems during the process. By systematically assessing the evidence on several questions about Q fever, we were able to draw new conclusions and specify earlier statements. We found it difficult to grade the mostly observational studies with the known evidence-based grading systems. There is need to develop new methods for grading evidence from different sources in the field of public health. We conclude that an evidence-based approach is feasible for providing a risk assessment within two to three months.

Preventing Q fever endocarditis: a review of cardiac assessment in hospitalised Q fever patients.

INTRODUCTION: Acute Q fever is an important zoonotic disease in some parts of rural Australia. Q Fever can lead to chronic disease such as endocarditis, this complication occurring more commonly in patients with underlying heart valve pathology or an impaired immune system. Untreated Q fever endocarditis has a high mortality rate, but even with appropriate therapy, 10% of patients will die. Cardiac assessment can identify patients at risk. The aim of this review was to examine recorded cardiac assessment of hospitalised Q fever patients within the regional area of Hunter New England (HNE), New South Wales (NSW). METHODS: Medical records of patients with Q fever admitted to hospitals in HNE during the period 2005-2009 were identified through the NSW Notifiable Diseases Database and the NSW Inpatient Statistics Collection. A standardised medical record review tool was used to undertake the review. RESULTS: Eighty-nine records were reviewed. Over 50% of patients were admitted to a district hospital staffed by local GPs. Cardiac assessment was not routinely documented and for 91% there was no record of a cardiac history being taken. Approximately 25% had no record of a cardiac physical examination and only 6 cases had a record of a complete cardiac examination. CONCLUSION: Q Fever remains an important disease in some parts of rural Australia. Q Fever endocarditis is a serious sequel to acute Q fever and underlying heart valve pathology. Due to its indolent progression and poor outcome when diagnosis is delayed, a thorough cardiac assessment of all patients with suspected or confirmed Q fever is important. The level of documentation of cardiac assessment for Q fever patients is of concern because it may indicate cardiac assessments were not performed. General practitioners, especially in rural and regional areas, are encouraged to conduct cardiac assessments for all patients with acute Q fever to identify patients at risk of developing Q fever endocarditis.

Spread of Q fever within dairy cattle herds: key parameters inferred using a Bayesian approach.

Q fever is a worldwide zoonosis caused by Coxiella burnetii. Although ruminants are recognized as the most important source of human infection, no previous studies have focused on assessing the characteristics of the bacterial spread within a cattle herd and no epidemic model has been proposed in this context. We assess the key epidemiological parameters from field data in a Bayesian framework that takes into account the available knowledge, missing data and the uncertainty of the observation process owing to the imperfection of diagnostic tests. We propose an original individual-based Markovian model in discrete time describing the evolution of the infection for each animal. Markov chain Monte Carlo methodology is used to estimate parameters of interest from data consisting of individual health states of 217 cows of five chronically infected dairy herds sampled every week for a four-week period. Outputs are the posterior distributions of the probabilities of transition between health states and of the environmental bacterial load. Our findings show that some herds are characterized by a very low infection risk while others have a mild infection risk and a non-negligible intermittent shedding probability. Moreover, the antibody status seems to be a key point in the bacterial spread (shedders with antibodies shed for a longer period of time than shedders without antibodies). In addition to the biological insights, these estimates also provide information for calibrating simulation models to assess control strategies for C. burnetii infection.

Australia's national Q fever vaccination program.

A nationally funded Q fever vaccination program was introduced in Australia in 2002. The evaluation of this unique program included measures of program uptake, safety, and notification and hospitalisation rates for Q fever pre- and post-program implementation. Program uptake ranged from close to 100% amongst abattoir workers to 43% in farmers. The most commonly reported adverse event was injection site reaction. Q fever notification rates declined by over 50% between 2002 and 2006, particularly in young adult males, consistent with the profile of the abattoir workforce. Hospitalisation data showed similar trends. Available evidence suggests a significant impact of Australia's Q fever vaccination program; such a program merits consideration in other countries with a comparable Q fever disease burden.

Assessment tools in support of epidemiological investigation of airborne dispersion of pathogens.

Human health threats posed by airborne pathogens are difficult to handle for healthcare responders due to the fact that the contaminated area is not immediately recognizable. By means of wind dispersion modeling, it is possible to estimate the extent and geographical position of hazardous areas and health impact. Contemporary modeling tools can run on standard PCs, with short processing time and with easy-to-use interfaces. This enables health professionals without modeling experience to assess consequences of dispersion incidents, for example, from accidental releases from industries, shedding of pathogens from infectious animals or humans, as well as intentional releases caused by terrorist activity. Dispersion assessments can provide response managers with a chance to get on top of events. In the absence of modeling, reliable estimates of hazard areas may not be available until no earlier than the appearance of the first cases or after time-consuming sampling and laboratory analysis. In this article, the authors describe the concept of using wind dispersion assessments in epidemiological field investigations of naturally occurring disease outbreaks, as well as for bioterror scenarios. They describe the specifications of user friendly and real-time functional wind dispersion modeling systems that can serve as decision support tools during outbreak investigations and outline some of the currently available software packages.

An economic evaluation of increased uptake in Q fever vaccination among meat and agricultural industry workers following implementation of the National Q Fever Management Program.

INTRODUCTION: Q fever is a serious but vaccine-preventable infectious disease that predominantly affects those working in the meat and agricultural industries. In October 2000, the Commonwealth Government introduced the National Q Fever Management Program. This economic evaluation assesses the cost-effectiveness and cost-utility of improved vaccine uptake among meat and agricultural industry workers. METHODS: Separate analyses were conducted for meat and agricultural industry workers. Clinical and epidemiological data used to create the models were obtained from published sources. Markov modelling was used to estimate the impact of Q fever vaccination uptake on the direct costs and outcomes of Q fever over a 20-year period. RESULTS: Increasing vaccine uptake from 65% to 100% among meat industry workers results in an incremental cost per life year gained of $20,002, and a cost per QALY of $6,294. Increasing vaccine uptake from zero to 20% among agricultural industry workers results in an incremental cost per life year gained of $24,950, and a cost per QALY of $7,984. Including some indirect costs in the form of Workcover payments results in cost savings for both industry groups. CONCLUSION: The results of this evaluation indicate that public health strategies to enhance the uptake of Q fever vaccine among high-risk workers potentially provides excellent value for the money invested.