Investigation of a Q fever outbreak in a Scottish co-located slaughterhouse and cutting plant

MLVA and com1 genotyping of Coxiella burnetii in farmed ruminants in Great Britain

Coxiella burnetii, the causative agent of the zoonotic disease Q fever, has been shown to be endemic in Great Britain, but information on the prevailing genomic lineages or Genomic Groups (GGs) of Coxiella burnetii is limited. The aim of this study was to genotype C. burnetii isolates from infected farmed ruminants by Multiple Locus Variable Number Tandem Repeat Analysis (MLVA) and identify their associated Genomic Group. A total of 51 Coxiella-containing abortion samples from farmed ruminants (sheep, goats, and cattle), which were collected in Great Britain during 2013-2018, were included in the study, 34 of which returned a C. burnetii MLVA genotype. All bovine samples (n = 18), 5/7 of the ovine samples, and 3/9 of the caprine samples belonged to an MLVA cluster which we could link to the MST20 genotype of GG III, whereas 6/9 of the caprine samples and 2/7 of the ovine samples belonged to MLVA clusters which we could link to the MST33 or MST32 genotypes of GG II (7 vs 1 sample(s), respectively). We also noted that the Coxiella-specific com1 gene contained unique mutations that could genomotype isolates, i.e. assign them to a Genomic Group. In conclusion, both goats and sheep in Great Britain (from 2014 onward) were found to carry the same MLVA genotypes (MST33-like; GG II) that were linked to a human Q fever outbreak in the Netherlands. This knowledge in combination with the usage of genotyping/genomotyping methods should prove useful in future surveillance programs and in the management of outbreaks.

Prevalence and risk factors associated with Q fever infection in slaughterhouse workers in Fars province, Iran

OBJECTIVE

Q fever is a main occupational zoonotic disease. Slaughterhouse is one of the most remarkable ways of transmitting the infection from livestock to humans. This study aimed to survey the prevalence of Q fever in slaughterhouse workers in Fars province, Iran, for the first time.

METHODS

Ninety serum samples were collected from slaughterhouse workers and tested to detect Immunoglobulin G (IgG) against Coxiella burnetii using ELISA and indirect immunofluorescence assay (IFA). PCR was also applied to identify C. burnetii DNA in the blood samples.

RESULTS

Q fever seroprevalence was found at 26.7% in ELISA, showing recent infection. This result indicates that Q fever seroprevalence is relatively high in the Fars region. IFA showed a high seroprevalence of total IgG antibodies at 1:64 titer (73.3%) and relatively high IgG at 1:256 titer (40%) against C. burnetii. 2.2% of the workers were recognized as having probable acute Q fever. The IgG II prevalence at 1:64 and 1:256 titers was, respectively, 63.3% and 24.4% positive. The IgG I prevalence at 1:64 and 1:256 titers was also found 33.3% and 22.2% positive, respectively. Molecular prevalence of Q fever was also 8.9%. A significant relationship was found between IgG I seropositivity and longer work experience and employing other livestock-related jobs (animal husbandry and butchery) (P < 0.05).

CONCLUSIONS

As such, the high seroprevalence of Q fever among abattoir workers highlights the importance of further comprehensive epidemiological studies, occupational screening programs, and preventive measures for Q fever in high-risk groups. This also warns animal health care organizations about the risk of Q fever infection in livestock in this region.

Exposure of South African Abattoir Workers to Coxiella burnetii

Abattoir workers may contract Q fever by inhalation of Coxiella burnetii bacteria in aerosols generated by slaughtering livestock, or in contaminated dust. We estimated the seroprevalence of C. burnetii and examined the associated factors in a survey of South African abattoir workers. Coxiella burnetii seropositivity was determined by detection of IgG antibodies against C. burnetii phase II antigen. Logistic regression, adjusted for clustering and sampling fraction, was employed to analyze risk factors associated with C. burnetii seropositivity. Among 382 workers from 16 facilities, the overall seroprevalence was 33% (95% confidence interval (CI): 28–38%) and ranged from 8% to 62% at the facility level. Prolonged contact with carcasses or meat products (odds ratio (OR): 4.6, 95% CI: 1.51–14.41) and prior abattoir or butchery work experience (OR: 1.9, 95% CI: 1.13–3.17) were associated with C. burnetii seropositivity. In contrast, increasing age and livestock ownership were inversely associated. Precautions to protect abattoir personnel from Q fever are discussed.

Evidence of exposure to C. burnetii among slaughterhouse workers in western Kenya

Q fever, caused by C. burnetii, has been reported in slaughterhouse workers worldwide. The most reported risk factor for seropositivity is the workers' role in the slaughterhouse. This study examined the seroprevalence and risk factors for antibodies to C. burnetii in slaughterhouse workers in western Kenya to fill a data gap relating to this emerging disease in East Africa.

Individuals were recruited from all consenting slaughterhouses in the study area between February and November 2012. Information was collected from participating workers regarding demographic data, animals slaughtered and role in the slaughterhouse. Sera samples were screened for antibodies to C. burnetii using a commercial ELISA and risk factors associated with seropositivity were identified using multi-level logistic regression analysis.

Slaughterhouse workers (n = 566) were recruited from 84 ruminant slaughterhouses in western Kenya. The seroprevalence of antibodies to C. burnetii was 37.1% (95% Confidence Interval (CI) 33.2–41.2%). The risk factors identified for C. burnetii seropositivity included: male workers compared to female workers, odds ratio (OR) 5.40 (95% CI 1.38–21.22); slaughtering cattle and small ruminants compared to those who only slaughtered cattle, OR 1.52 (95% CI 1.06–2.19). In addition, specific roles in the slaughterhouse were associated with increased odds of being seropositive, including cleaning the slaughterhouse, OR 3.98 (95% CI 1.39–11.43); cleaning the intestines, OR 3.24 (95% CI 1.36–7.73); and flaying the carcass OR 2.63 (95% CI 1.46–4.75) compared to being the slaughterman or foreman.

We identified that slaughterhouse workers have a higher seroprevalence of antibodies to C. burnetii compared to published values in the general population from the same area. Slaughterhouse workers therefore represent an occupational risk group in this East African setting. Workers with increased contact with the viscera and fluids are at higher risk for exposure to C. burnetii. Education of workers may reduce transmission, but an alternative approach may be to consider the benefits of vaccination in high-risk groups.

Global infectious disease risks associated with occupational exposure among non-healthcare workers: a systematic review of the literature

Objectives

Employees in non-healthcare occupations may be in several ways exposed to infectious agents. Improved knowledge about the risks is needed to identify opportunities to prevent work-related infectious diseases. The objective of the current study was to provide an updated overview of the published evidence on the exposure to pathogens among non-healthcare workers. Because of the recent SARS-CoV-2 outbreaks, we also aimed to gain more evidence about exposure to several respiratory tract pathogens.

Methods

Eligible studies were identified in MEDLINE, Embase and Cochrane between 2009 and 8 December 2020. The protocol was registered with International Prospective Register of Systematic Reviews (CRD42019107265). An additional quality assessment was applied according to the Equator network guidelines.

Results

The systematic literature search yielded 4620 papers of which 270 met the selection and quality criteria. Infectious disease risks were described in 37 occupational groups; 18 of them were not mentioned before. Armed forces (n=36 pathogens), livestock farm labourers (n=31), livestock/dairy producers (n=26), abattoir workers (n=22); animal carers and forestry workers (both n=16) seemed to have the highest risk. In total, 111 pathogen exposures were found. Many of these occupational groups (81.1%) were exposed to respiratory tract pathogens.

Conclusion

Many of these respiratory tract pathogens were readily transmitted where employees congregate (workplace risk factors), while worker risk factors seemed to be of increasing importance. By analysing existing knowledge of these risk factors, identifying new risks and susceptible risk groups, this review aimed to raise awareness of the issue and provide reliable information to establish more effective preventive measures.

Coxiella burnetii in the environment: A systematic review and critical appraisal of sampling methods

Q fever is a zoonotic disease caused by the intracellular bacterium, Coxiella burnetii. Its primary mode of transmission is by inhalation of aerosols originating from infected animals and contaminated environments. The organism has a very low infective dose, can persist in the environment for long periods of time and large outbreaks fuelled by windborne spread have been previously reported. Detection of C. burnetii in the environment is therefore important during human and animal outbreak investigations and for the control and prevention of Q fever. This study aimed to systematically review and critically appraise the published literature on sampling methods used to detect C. burnetii from different environmental samples. A search of four electronic databases with subsequent hand searching identified 47 eligible articles published since 1935. These articles described sampling of dust, air, soil and liquids in attempts to detect C. burnetii during 19 Q fever outbreaks and in 28 endemic settings. Environmental positivity was most commonly associated with ruminant livestock populations. Evidence describing spatio-temporal characteristics and associated geographical dispersion gradients was limited. The most commonly tested sample type was dust which also yielded the highest bacterial loads of >10⁸ bacteria/cloth. The MD8 (Sartorius) air sampler was used widely for air sampling. Soil was the only sample type for which a validated laboratory protocol was established specifically for C. burnetii. Each environmental sample type has its advantages and limitations which are discussed in detail and a simplified framework to guide decisions around environmental sampling for C. burnetii is provided. In any type of environmental sampling, it is recommended to use standardized and validated methods and to match the most ideal sampling strategy and timing with the research context. These conditions are essential to be considered when designing future Q fever management plans that involve environmental sampling for C. burnetii.

Coxiella burnetii Antibody Prevalence and Risk Factors of Infection in the Human Population of Estonia

Q fever is an emerging health problem in both humans and animals. To estimate the prevalence of Coxiella burnetii (C. burnetii) antibodies in the Estonian population, we analyzed plasma samples from 1000 individuals representing the general population and 556 individual serum samples from five population groups potentially at a higher risk (veterinary professionals, dairy cattle, beef cattle, and small ruminant stockbreeders and hunters). Additionally, 118 dairy cow bulk tank milk samples were analyzed to establish the infection status of the dairy cattle herds and the participating dairy cattle keepers. Questionnaires were used to find the potential risk factors of exposure. The effects of different variables were evaluated using binary logistic regression analysis and mixed-effects logistic analysis. The prevalence in veterinary professionals (9.62%; p = 0.003) and dairy cattle farmers (7.73%; p = 0.047) was significantly higher than in the general population (3.9%). Contact with production animals in veterinary practice and being a dairy stockbreeder in C. burnetii positive farms were risk factors for testing C. burnetii seropositive (p = 0.038 and p = 0.019, respectively). Results suggest that C. burnetii is present in Estonia and the increased risk of infection in humans is associated with farm animal contact.

Epidemiological scenario of Q fever hospitalized patients in the Spanish Health System: What's new

OBJECTIVES

The objective of this study was to assess the epidemiology and burden of Q fever (QF) in Spain.

METHODS

We designed a retrospective descriptive study using the minimum basic data set in patients admitted to hospitals of the National Health System between 1998 and 2015 with a diagnosis of Q fever (ICD-9: 083.0.).

RESULTS

We found 4214 hospitalized patients with a mean age (±SD) of 50.9±19.3 years. The male/female ratio was 3:1. The incidence rate was between 0.41 and 0.65 cases per 100,000 person-years over the 18-year period. The highest incidence of cases was from March to August (p=0.024). 21.1% patients had pneumonia, 17.5% had liver disease, and only 3.2% had endocarditis. The average hospital stay was 13.8 days (±12.8). A total of 117 (2.8%) patients died. The total mean cost of QF is approximately €154,232,779 (€36,600±139,422 per patient).

CONCLUSIONS

QF is an important zoonosis in Spain with a stable incidence rate and high cost for hospitalization. Older patients have a more severe clinical picture and higher mortality, which can be decreased with early clinical suspicion.

Extensive genome analysis of Coxiella burnetii reveals limited evolution within genomic groups

BACKGROUND

Coxiella burnetii is a zoonotic pathogen that resides in wild and domesticated animals across the globe and causes a febrile illness, Q fever, in humans. An improved understanding of the genetic diversity of C. burnetii is essential for the development of diagnostics, vaccines and therapeutics, but genotyping data is lacking from many parts of the world. Sporadic outbreaks of Q fever have occurred in the United Kingdom, but the local genetic make-up of C. burnetii has not been studied in detail.

RESULTS

Here, we report whole genome data for nine C. burnetii sequences obtained in the UK. All four genomes of C. burnetii from cattle, as well as one sheep sample, belonged to Multi-spacer sequence type (MST) 20, whereas the goat samples were MST33 (three genomes) and MST32 (one genome), two genotypes that have not been described to be present in the UK to date. We established the phylogenetic relationship between the UK genomes and 67 publically available genomes based on single nucleotide polymorphisms (SNPs) in the core genome, which confirmed tight clustering of strains within genomic groups, but also indicated that sub-groups exist within those groups. Variation is mainly achieved through SNPs, many of which are non-synonymous, thereby confirming that evolution of C. burnetii is based on modification of existing genes. Finally, we discovered genomic-group specific genome content, which supports a model of clonal expansion of previously established genotypes, with large scale dissemination of some of these genotypes across continents being observed.

CONCLUSIONS

The genetic make-up of C. burnetii in the UK is similar to the one in neighboring European countries. As a species, C. burnetii has been considered a clonal pathogen with low genetic diversity at the nucleotide level. Here, we present evidence for significant variation at the protein level between isolates of different genomic groups, which mainly affects secreted and membrane-associated proteins. Our results thereby increase our understanding of the global genetic diversity of C. burnetii and provide new insights into the evolution of this emerging zoonotic pathogen.

Hepatitis in slaughterhouse workers

Slaughterhouse workers (SHW) are at increased risk of hepatitis which can occur due to different organisms and should be investigated for viral, bacterial, and parasitic organisms. Slaughter house personnel including butchers are at a higher risk of infections from cuts and blood-letting, with the possible risk of the transmission of blood-borne pathogens to their colleagues. The objective of this review is to evaluate the common etiologies of hepatitis in SHW which will assist in the assessment of these patients presenting with transaminitis. Types of Microorganisms causing hepatitis with their reservoirs, routes of transmission, laboratory diagnosis, clinical features, treatment options and preventive strategies are included in this review. Proper investigation and awareness is of utmost importance as it causes significant financial constraints derived from workers health cost and from livestock production losses when the disease is confirmed. The work up is essential because infected workers might be a source of infections to other colleagues, family and the consumers.

Seroprevlance of Coxiella burnetii among abattoir and slaughterhouse workers: A meta-analysis

Q fever caused by the gram negative bacteria, Coxiella burnetii, is an occupational hazard for those who live and work in rural settings and those who are in contact with animals, especially abattoir and slaughterhouse workers. Australia is the only country to register a vaccine to prevent Q fever (Q-vax®, Seqirus, Australia) that is used in high risk populations. Seroprevalence studies conducted to determine the burden of Q fever (C. burnetii infection) in different settings have demonstrated high levels of heterogeneity with estimates of the percent positive ranging from 30% to 70%. There is a need for a more systematic evaluation of the findings of these studies in order to provide summary estimates of the seroprevalence in different settings. We searched for published articles using PubMed, MEDLINE-EMBASE, and Scopus databases using search terms obtained from an initial review of published reports of recent Q fever outbreaks. Data on the seroprevalence of C. burnetii infection (Q fever) was extracted from the selected studies and a random effects meta-analysis was performed with stratification by outbreak status, year, country and serological techniques used. Results were visualised with a forest plot with 95% CI and measures of heterogeneity (I 2) for the random effects model. A total of 19 articles that met the search criteria were included. The reported seroprevalence rate ranged from 4.7% to 91.7% among abattoir and slaughterhouse workers. No inter-group heterogeneity was observed (p = 0.956), supporting the pooling of all studies into one pooled measure. The pooled estimate of seropositivity for C. burnetii infection in people working in abattoirs and slaughterhouses was 26% (95% CI: 18-35%) regardless of the evidence of an "outbreak", the time of year or country. Seropositivity for C burnetii was independent of a person's age and years of occupational experience. Within abattoirs and slaughterhouses, slaughtering of cattle, sheep and goats are the most important risk factors associated with seropositivity and for those who showed over symptoms upon infection. We recommend that vaccination programmes are directed towards people employed in the meat processing industry to mitigate the significant health and economic impacts of Q fever.

Willingness of veterinarians in Australia to recommend Q fever vaccination in veterinary personnel: Implications for workplace health and safety compliance

Q fever vaccine uptake among veterinary nurses in Australia is low, suggesting veterinarians are not recommending the vaccination to veterinary personnel. This study aimed to determine the willingness of veterinarians to recommend Q fever vaccination to veterinary personnel and to identify factors influencing Q fever vaccine uptake by veterinary nurses in Australia. An online cross sectional survey targeted veterinarians and veterinary nurses in Australia in 2014. Responses were analysed using multivariable logistic regression. Factors significantly (p<0.05) associated with a willingness to recommend the vaccination, expressed by 35% (95% CI 31-38%) of veterinarians (n = 828), were (1) being very concerned for colleagues regarding Coxiella burnetii (OR 4.73), (2) disagreeing the vaccine is harmful (OR 3.80), (3) high Q fever knowledge (OR 2.27), (4) working within small animal practice (OR 1.67), (5) disagreeing the vaccine is expensive (OR 1.55), and (6) age, with veterinarians under 39 years most likely to recommend vaccination. Of the veterinary nursing cohort who reported a known Q fever vaccination status (n = 688), 29% (95% CI 26-33%) had sought vaccination. This was significantly (p<0.05) associated with (1) agreeing the vaccine is important (OR 8.34), (2) moderate/high Q fever knowledge (OR 5.51), (3) working in Queensland (OR 4.00), (4) working within livestock/mixed animal practice (OR 3.24), (5) disagreeing the vaccine is expensive (OR 1.86), (6) strong reliance on work culture for biosecurity information (OR 2.5), (7) perceiving personal exposure to Coxiella burnetii to be at least low/moderate (OR 2.14), and (8) both agreeing the vaccine is safe and working within a corporate practice structure (OR 4.28). The study identified the need for veterinarians to take greater responsibility for workplace health and safety promotion, and calls for better education of veterinary personnel to raise awareness of the potential for occupational exposure to C. burnetii and improve the perception of the Q fever vaccine as being important, safe and cost-effective.

Seroreactivity to Q Fever Among Slaughterhouse Workers in South Korea

Objectives

Q fever is a zoonotic disease that occurs worldwide; however, little is known about its prevalence in South Korea. We attempted to determine the prevalence of Q fever seroreactivity among Korean slaughterhouse workers and the risk factors for seroreactivity according to the type of work.

Methods

The study was conducted among 1503 workers at a total of 73 slaughterhouses and 62 residual-product disposal plants. During the study period, sites were visited and surveys were administered to employees involved in slaughterhouse work, and serological tests were performed on blood samples by indirect immunofluorescence assays. Serological samples were grouped by job classification into those of slaughter workers, residual-product handlers, inspectors and inspection assistants, and grading testers and testing assistants. Employee risk factors were analyzed according to the type of work.

Results

Out of 1481 study subjects who provided a blood sample, 151 (10.2%) showed reactive antibodies. When these results were analyzed in accordance with the type of work, the result of slaughter workers (11.3%) was similar to the result of residual-product handlers (11.4%), and the result of inspectors and assistants (5.3%) was similar to the result of grading testers and assistants (5.4%). Among those who answered in the affirmative to the survey question, “Has there been frequent contact between cattle blood and your mouth while working?” the proportions were 13.4 and 4.6%, respectively, and this was identified as a risk factor that significantly varied between job categories among slaughterhouse workers.

Conclusions

This study found a Q fever seroreactivity rate of 10.2% for slaughterhouse workers, who are known to be a high-risk population. Contact with cattle blood around the mouth while working was the differential risk factor between job categories among slaughterhouse workers.

The Epidemiology of Q Fever in England and Wales 2000-2015

Between 2000 and 2015, 904 cases of acute Q fever were reported in England and Wales. The case dataset had a male to female ratio of 2.5:1, and a median age of 45 years. Two outbreaks were recognised during this time period, and the incidence of sporadic cases was highest across the southwest of England, and Wales. There are limitations in the surveillance system for Q fever, including possible geographical differences in reporting and limited epidemiological data collection. The surveillance system needs to be strengthened in order to improve the quality and completeness of the epidemiological dataset. The authors conclude with recommendations on how to achieve this.

[Not Available]

Q fever is a zoonosis of worldwide distribution with the exception of New Zealand. It is caused by an intracellular bacterium, Coxiella burnetii. The disease often goes underdiagnosed because the main manifestation of its acute form is a general self-limiting flu-like syndrome. The Dutch epidemics renewed attention to this disease, which was less considered before. This review summarizes the description of C. burnetii (taxonomy, intracellular cycle, and genome) and Q fever disease (description, diagnosis, epidemiology, and pathogenesis). Finally, vaccination in humans and animals is also considered.

Q Fever Outbreak among Workers at a Waste-Sorting Plant

An outbreak of Q fever occurred in February-April 2014 among workers at a waste-sorting plant in Bilbao (Spain). The outbreak affected 58.5% of investigated employees, 47.2% as confirmed cases (PCR and/or serology) and 11.3% as probable cases (symptoms without laboratory confirmation). Only employees who had no-access to the waste processing areas of the plant were not affected and incidence of infection was significantly higher among workers not using respiratory protection masks. Detection by qPCR of Coxiella burnetii in dust collected from surfaces of the plant facilities confirmed exposure of workers inside the plant. Animal remains sporadically detected among the residues received for waste-sorting were the most probable source of infection. After cleaning and disinfection, all environmental samples tested negative. Personal protection measures were reinforced and made compulsory for the staff and actions were taken to raise farmers' awareness of the biological risk of discharging animal carcasses as urban waste.

Timeliness of epidemiological outbreak investigations in peer-reviewed European publications, January 2003 to August 2013

Binary file ES_Abstracts_Final_ECDC.txt matches

[Biosafety of working in cold storage units: from the profit margin to the safety margin]

The cold storage unit and meat production industry has made Brazil one of the leading suppliers and exporters of products of animal origin. The rapid expansion of the market has led to a rise in competitiveness from a capitalist standpoint, and in this respect corporate profit often leads to the need to adapt human actions to new functions in order to reduce costs and maximize production. These routine activities involve repetitive work, multi-tasking, long hours and operating machines with the use of sharp cutting tools, which is why the work is conducted wearing protective gear. Among the main hazards present, biological risks are the most important due to direct exposure to internal organs, blood, fecal matter, urine and placental or fetal fluids from slaughtered animals that may be infected with pathogens of zoonotic origin. This paper discusses the risks to which slaughterhouse-cold storage unit professionals are exposed, conducting a thorough bibliographical review of the literature that takes into consideration the conceptual framework of Biosafety, which contributes to improve the safety and health conditions of these workers.

Assessing the long-term health impact of Q-fever in the Netherlands: a prospective cohort study started in 2007 on the largest documented Q-fever outbreak to date

Background

Between 2007 and 2011, the Netherlands experienced the largest documented Q-fever outbreak to date with a total of 4108 notified acute Q-fever patients. Previous studies have indicated that Q-fever patients may suffer from long-lasting health effects, such as fatigue and reduced quality of life. Our study aims to determine the long-term health impact of Q-fever. It will also compare the health status of Q-fever patients with three reference groups: 1) healthy controls, 2) patients with Legionnaires’ disease and 3) persons with a Q-fever infection but a-specific symptoms.

Methods/design

Two groups of Q-fever patients were included in a prospective cohort study. In the first group the onset of illness was in 2007–2008 and participation was at 12 and 48 months. In the second group the onset of illness was in 2010–2011 and participation was at 6 time intervals, from 3 to 24 months. The reference groups were included at only one time interval. The subjective health status, fatigue status and quality of life of patients will be assessed using two validated quality of life questionnaires.

Discussion

This study is the largest prospective cohort study to date that focuses on the effects of acute Q-fever. It will determine the long-term (up to 4 years) health impact of Q-fever on patients and compare this to three different reference groups so that we can present a comprehensive assessment of disease progression over time.