Prevalence of Coxiella burnetii in Hungary: screening of dairy cows, sheep, commercial milk samples, and ticks

Molecular and genotyping techniques in diagnosis of Coxiella burnetii: An overview

Although we live in the genomic era, the accessibility of the complete genome sequence of Coxiella burnetii, the etiological agent of Q fever, has increased knowledge in the field of genomic diversity of this agent However, it is still somewhat of a "question" microorganism. The epidemiology of Q fever is intricate due to its global distribution, repository and vector variety, as well as absence of surveys defining the dynamic interaction among these factors. Moreover, C. burnetii is a microbial agent that can be utilized as a bioterror weapon. Therefore, typing techniques used to recognize the strains can also be used to trace infections back to their source which is of great significance. In this paper, the latest and current typing techniques of C. burnetii spp. are reviewed illustrating their advantages and constraints. Recently developed multi locus VNTR analysis (MLVA) and single-nucleotide polymorphism (SNP) typing methods are promising in improving diagnostic capacity and enhancing the application of genotyping techniques for molecular epidemiologic surveys of the challenging pathogen. However, most of these studies did not differentiate between C. burnetii and Coxiella-like endosymbionts making it difficult to estimate the potential role that ticks play in the epidemiology of Q fever. Therefore, it is necessary to analyze the vector competence of different tick species to transmit C. burnetii. Knowledge of the vector and reservoir competence of ticks is important for taking adequate preventive measures to limit infection risks. The significant prevalence observed for the IS1111 gene underscores its substantial presence, while other genes display comparatively lower prevalence rates. Methodological variations, particularly between commercial and non-commercial kit-based methods, result in different prevalence outcomes. Variations in sample processing procedures also lead to significant differences in prevalence rates between mechanical and non-mechanical techniques.

Molecular identification of Coxiella burnetii in raw milk samples collected from farm animals in districts Kasur and Lahore of Punjab, Pakistan

Coxiella burnetii is the worldwide zoonotic infectious agent for Q fever in humans and animals. Farm animals are the main reservoirs of C. burnetii infection, which is mainly transmitted via tick bites. In humans, oral, percutaneous, and respiratory routes are the primary sources of infection transmission. The clinical signs vary from flu-like symptoms to endocarditis for humans' acute and chronic Q fever. While it is usually asymptomatic in livestock, abortion, stillbirth, infertility, mastitis, and endometritis are its clinical consequences. Infected farm animals shed C. burnetii in birth products, milk, feces, vaginal mucus, and urine. Milk is an important source of infection among foods of animal origin. This study aimed to determine the prevalence and molecular characterization of C. burnetii in milk samples of dairy animals from two districts in Punjab, Pakistan, as it has not been reported there so far. Using a convenience sampling approach, the current study included 304 individual milk samples from different herds of cattle, buffalo, goats, and sheep present on 39 farms in 11 villages in the districts of Kasur and Lahore. PCR targeting the IS1111 gene sequence was used for its detection. Coxiella burnetii DNA was present in 19 of the 304 (6.3%) samples. The distribution was 7.2% and 5.2% in districts Kasur and Lahore, respectively. The results showed the distribution in ruminants as 3.4% in buffalo, 5.6% in cattle, 6.7% in goats, and 10.6% in sheep. From the univariable analysis, the clinical signs of infection i.e. mastitis and abortion were analyzed for the prevalence of Coxiella burnetii. The obtained sequences were identical to the previously reported sequence of a local strain in district Lahore, Sahiwal and Attock. These findings demonstrated that the prevalence of C. burnetii in raw milk samples deserves more attention from the health care system and veterinary organizations in Kasur and Lahore of Punjab, Pakistan. Future studies should include different districts and human populations, especially professionals working with animals, to estimate the prevalence of C. burnetii.

Molecular prevalence of Coxiella burnetii in cheese samples: Systematic review and meta-analysis

BACKGROUND

Cheese is a popular dairy product consumed worldwide, and it has been implicated as a source of Coxiella burnetii infections.

OBJECTIVES

The present study aimed to describe the molecular prevalence and source analysis of C. burnetii in cheese samples.

METHODS

A systematic literature search was conducted using the Medline/PubMed, Science Direct, Web of Science, Scopus, and Google Scholar databases to identify studies reporting the molecular prevalence of C. burnetii in cheese samples. The pooled prevalence of C. burnetii in cheese samples was estimated using a random-effects model.

RESULTS

A meta-analysis was conducted using the mean and standard deviation values obtained from 13 original studies. The overall molecular prevalence of C. burnetii in cheese was estimated to be 25.2% (95% confidence interval [CI]: 13.1%-39.7%). The I2 value of 96.3% (CI95% 94.9-97.3) suggested high heterogeneity, with a τ2 of 0.642 (CI95% -0.141 to 0.881), and an χ2 statistic of 323.77 (p < 0.0001).

CONCLUSIONS

In conclusion, our meta-analysis provides a thorough assessment of the molecular prevalence and source analysis of C. burnetii in cheese samples.

A scoping review of the testing of bulk milk to detect infectious diseases of dairy cattle: Diseases caused by bacteria

Testing of bulk milk (BM) samples is a convenient, cost-effective strategy that can easily be implemented as part of disease surveillance programs on dairy farms. Here, we performed a scoping review to summarize the literature reporting on the testing of BM samples to detect infectious diseases of dairy cattle caused by bacteria. We also provide a non-exhaustive, albeit significant, list of diagnostic tests that are marketed for BM samples, as well as a list of disease surveillance activities that included testing of BM samples. A literature search was carried out in 5 databases, yielding 8,829 records from which 474 were retained. Overall, 575 eligible bacterial pathogens were screened for using BM samples, ranging from 1 to 6 individual pathogens per study. Staphylococcus aureus, including methicillin-resistant Staph. aureus, were the most studied bacteria (n = 179 studies), followed by Streptococcus agalactiae (86), Mycobacterium avium ssp. paratuberculosis (79), Coxiella burnetii (79), and Mycoplasma spp. (67). Overall, culture-based protocols, ELISA, real-time PCR, and PCR were the most commonly adopted methodologies to screen BM samples. Sensitivity of BM testing for bovine paratuberculosis was generally low and varied greatly according to the ELISA cut-offs adopted and herd-level definition of disease. In general, protocols had low to moderate sensitivities (<50%), which increased for herds with high within-herd seroprevalence. Specificity of BM testing for paratuberculosis was generally high. With respect to mastitis pathogens, BM testing demonstrated high sensitivity and specificity for Strep. agalactiae, in general. However, we observed inconsistency among studies with respect to the sensitivity of BM culture to detect infected herds, which was notably higher if enrolled herds were heavily infected or had history of clinical disease. Among Salmonella spp. pathogens, Salmonella Dublin was the most frequently studied bacterium for which BM testing has been validated. Specificity of BM ELISA was high, ranging from 89.0 to 99.4. In contrast, sensitivity varied greatly among studies, ranging from 50.6% to 100%. Our findings support that one of most important factors affecting sensitivity of BM ELISA for Salmonella Dublin is whether nonlactating cattle are considered in the definition of herd infection status. In general, protocols analyzed in this review suffered from very low sensitivities, which hardly justifies their use as part of disease surveillance as single testing. Nevertheless, test sensitivity can be increased by the adoption of more inclusive definitions of disease-free herds. Further, low-sensitivity and high-specificity methods can be valuable tools for surveillance when used repeatedly over time.

Coxiella burnetii DNA in milk, milk products, and fermented dairy products

Introduction

Q fever in dairy cattle has been investigated in Latvia since 2012. In 2015, 10.7% of farms tested positive for the DNA of C. burnetii, its aetiological agent, in bulk tank milk. The presence of C. burnetii DNA and infectious bacteria in dairy products has been assessed in several countries, and because Latvian milk may contain them, parallel assessment in this country is recommended. Accordingly, the present study tested shop and farm retail dairy products from Latvia and included foreign products for comparison.

Material and Methods

Investigation was carried out of 187 samples of a diverse range of dairy products from 41 Latvian milk producers. Twenty-six comparable samples pooled from Estonia, France, Germany, Greece, Italy, Lithuania, the Netherlands, Poland and Spain were also included. The all-countries total number of fermented milk products was 160. Special attention was paid to products that could be more attractive to children because of their added chocolate, cacao, berry and fruit content. DNA was extracted and amplification of C. burnetii IS1111 was performed using a commercial PCR kit.

Results

Overall positivity was 60.56%. Domestic products were positive more often (60.96%) than foreign ones (57.69%). Only 26.67% of unpasteurised Latvian cow’s milk samples were positive whereas 76.47% of pasteurised equivalents and 63.13% of fermented milk products were. Sweetened and fruit-containing samples were 71.43% positive.

Conclusion

The shedding of C. burnetii via milk should be monitored and only milk from healthy animals allowed for sale for direct human consumption without pasteurisation. Raw milk quality and the effectiveness of industrial heat treatment and pasteurisation methods in Latvia and other countries should be carefully assessed to ensure adequate consumer health protection.

Serological survey of Coxiella burnetii infections in dairy cattle, sheep, goats and zoo animals in Hungary - Short communication

Q fever is a disease of high zoonotic potential, but interest in its causative agent is rather low although it causes some public health problems in Hungary. The prevalence of Q fever is highly variable by country. The main reservoirs of the disease are the same domestic ruminant species everywhere, but the epidemiological profile depends on the features of the specific reservoir. The aim of this large-scale study was to demonstrate the importance of Q fever in different species as a possible source for human infection in most regions of Hungary. A total of 851 serum samples from 44 dairy farms, 16 sheep flocks, 4 goat farms and 3 zoos located in different parts of Hungary were tested. The presence of antibodies to Coxiella burnetii was surveyed in dairy cattle (n = 547), goats (n = 71), sheep (n = 200) and zoo animals (n = 33). The animal species tested in Hungary showed different seroprevalence values of C. burnetii infection. Seropositivity by the enzyme-linked immunosorbent assay was found in 258 out of 547 (47.2%) cows and in 69 out of 271 (25.5%) small ruminants, among them in 47 out of 200 (23.5%) sheep and in 22 out of 71 (31.0%) goats. Antibodies to C. burnetii were not detected in zoo animals. Seropositivity was demonstrated in 44 out of 44 (100%) dairy cattle farms, with at least one serum sample found to be positive on each farm. The seropositivity rate of small ruminant farms was 55.0% (11 positive out of 20 tested), with 9 out of 16 (56.3%) sheep flocks and 2 out of 4 (50.0%) goat herds showing seropositivity.

Industrial Dairy Cattle Farms in Hungary Source of Coxiella burnetii Infection in Humans

Previous research has demonstrated a high prevalence of Coxiella burnetii in the bulk tank milk on large industrial dairy farms of the central and eastern European region. The aim of this survey was to estimate the prevalence of specific IgG antibodies to C. burnetii proving previous infection among dairy farm workers and to determine the possible risk factors. Serum samples from veterinarians, inseminators, animal caretakers, milking parlor workers, and herd managers working on dairy farms were tested for the presence of IgG to phase I and phase II of C. burnetii using an indirect microimmunofluorescence assay. Antibodies phase II to C. burnetii were detected in 59 out of 70 individuals tested (84.3%). All occupational groups are highly exposed to C. burnetii infection. Veterinarians, inseminators, and animal caretakers had 100% seropositivity rate of phase II, whereas the seropositivity rate found among herd managers and milking parlor workers was 71.4% and 47%, respectively. The findings of this survey suggest that the risk of C. burnetii infection is correlated with cattle density in the large dairy farms and also with occupational groups.

Coxiella burnetii Shedding in Milk and Molecular Typing of Strains Infecting Dairy Cows in Greece

Ruminants are considered the commonest animal reservoir for human infection of Coxiella burnetii, the Q fever causative agent. Considering the recently described importance of human Q fever in Greece, we aimed at providing the first comprehensive direct evidence of C. burnetii in dairy cows in Greece, including the genetic characterization of strains. The 462 examined dairy farms represented all geographical areas of Greece. One bulk tank milk sample was collected from every farm and tested for the presence of C. burnetii. Molecular genotyping of strains, performed directly on samples, revealed the existence of two separate clades characterized by single nucleotide polymorphism (SNP) genotypes of type 1 and type 2. The two clades were clearly distinguished in multiple locus variable-number tandem repeat analysis (MLVA) by two discriminative loci: MS30 and MS28. Whereas MLVA profiles of SNP-type 2 clade were closely related to strains described in other European cattle populations, the MLVA profile observed within the SNP type 1 clade highlighted a peculiar genetic signature for Greece, related to genotypes found in sheep and goats in Europe. The shedding of C. burnetii bearing this genotype might have yet undefined human epidemiological consequences. Surveillance of the genetic distribution of C. burnetii from different sources is needed to fully understand the epidemiology of Q fever in Greece.

Identification of Coxiella burnetii in Raw Milk of Livestock Animal in Iran

Coxiella burnetii is the causative agent of Q fever in humans and animals. This study aimed to determine the frequency of C. burnetii in milk samples of dairy animals (goats, sheep, and cattle) in some selected regions in Iran, where there is no information about prevalence of C. burnetii. In this study, 162 individual milk samples were collected from 43 farms in three provinces (Tehran, Hamadan, and Mazandaran). Real-time PCR was used for the detection of IS1111a element of C. burnetii. In total, 23 of 162 samples (14.2%, 95% confidence interval (CI): 9.65–20.2%) were positive for C. burnetii by real-time PCR. C. burnetii was detected in 10.17% (95% CI: 4.74–20.46) of goat milk samples. In sheep milk samples, 18.6% (95% CI: 9.74–32.62) were positive, and C. burnetii was detected in 15% (95% CI: 8.1–26.11) of cattle milk samples. Molecular evidence of the presence of C. burnetii was seen in milk samples of dairy animals in all the studied regions. These findings demonstrated that C. burnetii infection, especially in raw milk samples, deserves more attention from the health care system and veterinary organization in Iran.

First isolation and molecular phylogenetic analysis of Coxiella burnetii in lactating cows

Q fever is an infectious disease of animals and humans, caused by globally distributed C. burnetii. In Iraq, there are no previous studies associated with the detection of the organism in cattle. An overall of 130 lactating cows were submitted to direct collection of milk samples. Initially, the samples of milk were tested using the molecular polymerase chain reaction (PCR) assay targeting three genes (16S rRNA, IS1111a transposase, and htpB). However, positive results (18.46%; 24/130) were detected only with the 16s rRNA gene. Concerning risk factors, the highest prevalence of C. burnetii was showed in the district of Badra (42.86%), whereas the lowest - in Al-Numaniyah and Al-Suwaira districts (P=0.025). There was no significant variation in positivity between the months of sampling period (P=0.082) and between age groups (P=0.076). Crossbred cows (20.69%) showed a higher positivity than local and pure breeds (P=0.043). Milk of positive samples (n=24) was used for cultivation of C. burnetii into specific pathogen free-embryonated chicken eggs (SPF-ECEs). After three passages into SPF-ECEs, contents of yolk sac were collected, subjected for DNA extraction, and re-tested by PCR assay using the primer of 16s rRNA gene only. Of 24 cultivated milk samples, 12.5% (3/24) were positive for C. burnetii. Finally, the positive local isolates were analysed phylogenetically and reported in NCBI-Genbank under the accession numbers of MN121700.1, MN121701.1, and MN121702.1. In conclusion, this is a unique study as it detected C. burnetii in Iraqi lactating cows, and confirmed that organism was shed actively through milk, suggesting that these animals can play a role as a reservoir for organism with potential risk for transmission of infection from these animals to humans as well as to other animal species.

Molecular prevalence of Coxiella burnetii in bulk-tank milk from bovine dairy herds: Systematic review and meta-analysis

Coxiella burnetii is an obligate intracellular zoonotic bacterium that causes Q fever. Ruminants, including cattle, are broadly known to be reservoirs for this bacterium. Since 2006, many research groups have evaluated the herd-level prevalence of C. burnetii in cattle by molecular techniques on composite milk samples. This study explored the global C. burnetii herd-level prevalence from studies done on bovine bulk-tank milk (BTM) samples using PCR-based analysis. Also, moderators were investigated to identify sources of heterogeneity. Databases (CAB Abstracts, Medline via Ovid, PubMed, Web of Science and Google Scholar) were searched for index articles on C. burnetii prevalence in BTM samples by PCR published between January-1973 and November-2018. Numerous studies (1054) were initially identified, from which seventeen original publications were included in the meta-analysis based on the pre-defined selection criteria. These studies comprised 4031 BTM samples from twelve countries. A random-effects model was used because of considerable heterogeneity (I² = 98%) to estimate the herd-level prevalence of C. burnetii as 37.0%(CI_95%25.2–49.5%). The average herd size appeared to account for a high level of the heterogeneity. No other moderators (geographic location, gross national income or notification criteria for Q fever) seemed to be determinant. This systematic evaluation demonstrated a high molecular prevalence of C. burnetii in BTM samples both in European and non-European countries, evidencing a widespread herd-level circulation of this agent in bovine dairy farms around the world. Meta-regression showed herd size as the most relevant moderator with the odds of a BTM sample testing positive doubling with every unit increase.

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First meta-analysis of the PCR-based prevalence of C. burnetii in bovine milk

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Results showed a high molecular prevalence of C. burnetii in bulk-tank milk samples.

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C. burnetii is widely distributed in dairy farms in Europe and the wider world.

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Current results reinforce the need for further investigations on this zoonosis.

Serological screening for Coxiella burnetii in the context of early pregnancy loss in dairy cows

Q fever is one of the commonest infectious diseases worldwide. A Coxiella burnetii prevalence of 97.6% has been found by ELISA and PCR tests of the bulk tank milk in dairy cattle farms of Hungary. The herd- and individual-level seroprevalence rates of C. burnetii in the examined dairy cows and farms have dramatically increased over the past ten years. Three high-producing industrial dairy farms were studied which had previously been found ELISA and PCR positive for C. burnetii by bulk tank milk testing. Coxiella burnetii was detected in 52% of the 321 cows tested by ELISA. Pregnancy loss was detected in 18% of the cows between days 29-35 and days 60-70 of gestation. The study found a higher seropositivity rate (80.5%) in the cows that had lost their pregnancy and a seropositivity of 94.4% in the first-bred cows that had lost their pregnancy at an early stage. The ELISA-positive pregnant and aborted cows were further investigated by the complement fixation test (CFT). In dairy herds an average of 66.6% individual seropositivity was detected by the CFT (Phase II) in previously ELISA-positive animals that had lost their pregnancy and 64.5% in the pregnant animals. A higher (Phase I) seropositivity rate (50.0%) was found in the cows with pregnancy loss than in the pregnant animals (38.5%). The high prevalence of C. burnetii in dairy farms is a major risk factor related to pregnancy loss.

Molecular Investigation of the Status of Ticks on Infected Cattle for Coxiella burnetii in India

PURPOSE

In Indian subcontinent, the epidemiological studies on the status of ticks in the transmission of Coxiella burnetii have not been explored comprehensively. The objective of the present study was to investigate the status of ticks for C. burnetii among coxiellosis positive cattle.

METHODS

The present study was carried out in three locations of the northern states of India. A total of 1648 tick samples were collected from the tick infested cattle (n = 146) that were tested positive for coxiellosis by indirect serum-ELISA assay and/or the trans-PCR assay. The tick samples were screened using the trans-PCR assay targeting species-specific IS1111 transposase gene of C. burnetii. The sequencing of PCR products was planned to differentiate C. burnetii and Coxiella-like bacteria (CLB).

RESULTS

The collected ticks were identified as Rhipicephalus microplus (n = 1049), Hyalomma anatolicum (n = 416), and Hyalomma spp. (n = 183). On molecular investigation, none of the collected tick samples were found to be positive for the IS1111 gene.

CONCLUSION

The findings of the present study ruled out the involvement of ticks in circulation of the pathogen within the cattle population that were screened. However, extensive epidemiological studies are needed to conclusively rule out or establish the role of ticks as a competent vector for C. burnetii transmission in cattle and other hosts.

Detection of Coxiella burnetii antibodies in sheep and cattle on a veterinary campus in St. Kitts: Implications for one health in the Caribbean region

Coxiella burnetii is a ubiquitous zoonotic bacterium reported worldwide that causes Q-fever. Infections result in profound economic losses to livestock producers by causing abortions and low birth weights. Current information about the disease in the Caribbean region is scarce. With multiple small islands and territories, it is often considered that the bacterium is absent or circulates at a low prevalence. Our study aimed to determine whether sheep and cattle housed at a veterinary campus in St Kitts had previous exposure to C. burnetii. Blood samples were taken from cattle (n = 63; 72% of the herd) and sheep (n = 133; 71% of the flock). Antibodies to C. burnetii were detected by a commercial indirect enzyme-linked immunosorbent assay (IDvet® ELISA) test. The seroprevalence was estimated at 26.3% (95% CI: 19.1–34.7%) in sheep and 0% (95% CI: 0–5.7%) in cattle. Sheep importation to St. Kitts is very rare, thus, these results suggest that C. burnetii is present on the island. The seronegativity of all the cattle highlights the absence of the bacterium on the veterinary campus. The high seroprevalence in sheep, however, has potentially important implications for animal health and public health as well as for wildlife conservation. Further investigation about animal seroprevalence and human exposure are warranted in St. Kitts and in the Caribbean region.

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Seroprevalence in sheep from a veterinary university was 26.3%

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No cattle from the university were seropositive

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Risk for human and animal health is likely to be important in St. Kitts

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There is a need to investigate the prevalence of Coxiella burnetii in Caribbean region

Prevalence of C. burnetii DNA in sheep and goats milk in the northwest of Iran

Q fever is a common zoonotic disease with worldwide distribution. The causative agent of Q fever is Coxiella burnetii, a gram-negative and polymorphic rod bacterium. Sheep and goats are the primary reservoirs of this disease, although a variety of animal species can be infected. The main route of Q fever transmission from animals to humans is the inhalation of contaminated aerosols with C. burnetii. The bacterium is excreted in milk of infected animals and therefore; the consumption of unpasteurized milk and dairy products might be a route of coxiella burnetii transmission from animals to humans. The present study was conducted to determine the prevalence of C. burnetii in milk samples collected from sheep and goats in west Azerbaijan province, Iran. During 2018, a total number of 420 milk samples were collected from sheep (n = 210) and goats (n = 210) of different regions of the province. All milk samples were subjected to DNA extraction and examined by a highly and specific nested-PCR method. The results showed that 51 (12.1%) (95% CI: 9.3%-15.6%) examined samples [sheep; n = 16 (7.6%) and goat; n = 35 (16.6%)] were positive for C. burnetii. The prevalence of C. burnetii in goat milk samples was significantly higher than sheep milk samples (P < 0.05). The shedding of C. burnetii in milk was significantly higher in summer (25%) (P < 0.05, 95% CI: 17.7%-34%) than the other seasons. It was concluded that sheep and goat populations in west Azerbaijan play an important role in the epidemiology of Q fever.

Prevalence of Coxiella burnetii in Central and Eastern European dairy herds

The aim of the present study was to assess the prevalence of Coxiella burnetii in dairy herds in Central and Eastern European countries based on ELISA and PCR tests. A total of 370 bulk tank milk samples were collected in 2019 originating from Croatia (n = 13), Czech Republic (n = 138), Hungary (n = 126), Serbia (n = 24), Slovakia (n = 53) and Slovenia (n = 16). Prevalence of C. burnetii differed according to the country of origin with Croatia showing 100.00%, the Czech Republic 98.55%, Hungary 97.61%, Serbia 70.83%, Slovakia 90.56% and Slovenia showing 62.50% average percentages of the positive herds. C. burnetii specific ELISA showed 100.00% positivity in all examined countries if herds consisted of equal or above 250 milking cows. The growing number of farms managing large number of animals, where cattle density is high correlates with the increasing prevalence of C. burnetii in the region.

Molecular Detection of Rickettsia Spp. and Coxiella Burnetii in Cattle, Water Buffalo, and Rhipicephalus (Boophilus) Microplus Ticks in Luzon Island of the Philippines

Rickettsia and Coxiella burnetii are zoonotic, tick-borne pathogens that can cause febrile illnesses with or without other symptoms in humans, but may cause subclinical infections in animals. There are only a few reports on the occurrence of these pathogens in cattle and water buffalo in Southeast Asia, including the Philippines. In this study, molecular detection of Rickettsia and C. burnetii in the blood and in the Rhipicephalus (Boophilus) microplus ticks of cattle and water buffalo from five provinces in Luzon Island of the Philippines was done. A total of 620 blood samples of cattle and water buffalo and 206 tick samples were collected and subjected to DNA extraction. After successful amplification of control genes, nested PCR was performed to detect gltA of Rickettsia and com1 of C. burnetii. No samples were positive for Rickettsia, while 10 (cattle = 7, water buffaloes = 3), or 1.6% of blood, and five, or 1.8% of tick samples, were C. burnetii-positive. Sequence analysis of the positive amplicons showed 99-100% similarity to reported C. burnetii isolates. This molecular evidence on the occurrence of C. burnetii in Philippine ruminants and cattle ticks and its zoonotic nature should prompt further investigation and surveillance to facilitate its effective control.

The prevalence of Coxiella burnetii in ticks and animals in Slovenia

BACKGROUND

The obligate intracellular bacterium Coxiella burnetii causes globally distributed zoonotic Q fever. Ruminant livestock are common reservoirs of C. burnetii. Coxiella burnetii are shed in large numbers in the waste of infected animals and are transmitted by inhalation of contaminated aerosols. This study was conducted to evaluate the prevalence of C. burnetii infection in domestic animals and ticks in areas of Slovenia associated with a history of Q fever outbreaks.

RESULTS

A total of 701 ticks were collected and identified from vegetation, domestic animals and wild animals. C. burnetii DNA was detected in 17 out of 701 (2.4%) ticks. No C. burnetii DNA was found in male ticks. Ticks that tested positive in the PCR-based assay were most commonly sampled from wild deer (5.09%), followed by ticks collected from domestic animals (1.16%) and ticks collected by flagging vegetation (0.79%). Additionally, 150 animal blood samples were investigated for the presence of C. burnetii-specific antibodies and pathogen DNA. The presence of pathogen DNA was confirmed in 14 out of 150 (9.3%) blood samples, while specific antibodies were detected in sera from 60 out of 150 (40.4%) animals.

CONCLUSIONS

Our results indicate that ticks, although not the primary source of the bacteria, are infected with C. burnetii and may represent a potential source of infection for humans and animals. Ticks collected from animals were most likely found to harbor C. burnetii DNA, and the infection was not lost during molting. The persistence and distribution of pathogens in cattle and sheep indicates that C. burnetii is constantly present in Slovenia.

Prevalence of Coxiella burnetii in milk collected from buffalo (water buffalo) and cattle dairy farms in Northwest of Iran

The present study was conducted to determine the prevalence of C. burnetii in raw milk samples collected from water buffalos and cattle in Northwest of Iran (West Azerbaijan Province). A total number of 840 milk samples were randomly collected from buffalos and cattle belonged to three different geographical regions in west Azerbaijan (the map is necessary). The milk samples were collected seasonally during 2018 and the age of animals were recorded. All the milk samples were subjected to DNA extraction. Nested-PCR was used to detect C. burnetii based on the transposable gene IS1111. The results showed that 16.9% (95% CI: 14.5%-19.6%) of the examined milk samples (19.3% buffalo and 14.6% cattle samples) were positive for C. burnetii. There was a significant difference in C. burnetii shedding in milk between different age groups in cattle but not in buffalos (p value <0.05). The shedding of C. burnetii in milk was highly prevalent in summer (31.1%) (p < 0.05, 95% CI: 26.1%-38.4%). There were significant regional and seasonal variations in the prevalence of C. burnetii in the examined milk samples. It was concluded that buffalo population in west Azerbaijan should be considered as an important factor in the epidemiology of Q fever and consequently in public health.

Occurrence and risk factors of Coxiella burnetii in domestic ruminants in Lebanon

Coxiella burnetii causes diseases in humans (Q fever) and animals, domestic ruminants playing a major role in the epidemiology of the infection. Information on C. burnetii infection in Lebanon is scanty. In order to assess the prevalence of C. burnetii infection in ruminants, a cross-sectional study was undertaken in 2014. A total of 1633 sera from ruminants (865 cattle, 384 sheep and 384 goats) from 429 farms (173 cattle, 128 sheep and 128 goats), in seven provinces of Lebanon were randomly selected and assayed for the presence of antibodies. 39.86% of farms (95% CI: 35.23-44.56) resulted positive. The seroprevalence was 30.63% in Cattle-farms, 46.88% in sheep-farms and 45.31% in goat-farms. Milk samples collected from 282 seropositive animals (86 cows, 93 sheep and 103 goats) from 171 positive farms were tested by a high sensitive Real-Time PCR targeted to the IS1111 transposon of C. burnetii. The overall prevalence in farms was estimated to be 14.04%. Cattle-, sheep- and goat farm prevalence rates were 15.09%, 10% and 17.24%, respectively. The findings of the study show that C. burnetii prevalence in Lebanese domestic ruminants is related to animal species and farming practices. Indeed, the mixed herds with sheep (p < 0.01), the presence of common lambing/kidding areas (p < 0.001) in farms where the use of disinfectants was not a routine practice (p < 0.05) were identified as important risk factors. The results of the study provide baseline information for setting up herd management and public health measures for the prevention and control of Q fever in Lebanon.

Molecular prevalence of Coxiella burnetii in milk in Iran: a systematic review and meta-analysis

Q fever is a major zoonotic disease in the world. The aim of this meta-analysis was to estimate the prevalence of Coxiella burnetii in animal milk in Iran. We systematically reviewed the literature to identify eligible studies from January 2008 to June 2016 in English or Farsi (Persian) databases. We extracted the molecular prevalence of C. burnetii in milk from cows, goats, sheep, and camels in Iran. The total prevalence of C. burnetii in cow milk was 15.09% (95% CI 11.08-19.10) by PCR methods. The highest and lowest prevalence of Q fever agent were seen in the East Azerbaijan (25.55%) and Khorasan-Razavi (4.22%) provinces, respectively. The molecular prevalence of C. burnetii in goat milk was 7.80% (95% CI 3.54-12.07%). The provinces of Qom (0%) and Lorestan (44.71%) had the lowest and the highest frequency of C. burnetii infection in goat's milk, respectively. Total prevalence of C. burnetii in sheep milk was 3.79% (95% CI 0.72-6.87%). The highest frequency of C. burnetii in sheep milk was detected in the Khorasan-Razavi province (34.78%). The frequency of C. burnetii in camel milk was 1.43%. High infection of C. burnetii in milk is an important health problem in Iran, amplified by the traditional preparations of dairy products.

High prevalence and risk factors of Coxiella burnetii in milk of dairy animals with a history of abortion in Iran

Coxiella burnetii is causative agent of Q fever, which is a public health problem in most countries. The aim of this study was to study the prevalence rate of C. burnetii in raw milk of dairy animals in Iran with previous history of abortion. In this survey, milk samples were collected from different dairy animals with history of abortion from Qom province (center of Iran). Samples were tested by Nested PCR and Real-time PCR for detection of IS1111 gene of C. burnetii. In total, 34.92% (44 of 126) milk samples were positive for C. burnetii. Prevalence of C. burnetii in cattle, sheep and goat milk was 33.33%, 35.71% and 35.71%, respectively. Age was a significant risk factor for shedding of C. burnetii in cattle (P = 0.02) and goat (P = 0.05). Shedding of C. burnetii was high prevalence in milk of dairy animals with history of abortion in Iran. The high prevalence of this bacterium in milk (especially in animals with history of abortion) indicates that Excreted by milk as a potential source to spread of infection in the environment.

Assessing bat droppings and predatory bird pellets for vector-borne bacteria: molecular evidence of bat-associated Neorickettsia sp. in Europe

In Europe, several species of bats, owls and kestrels exemplify highly urbanised, flying vertebrates, which may get close to humans or domestic animals. Bat droppings and bird pellets may have epidemiological, as well as diagnostic significance from the point of view of pathogens. In this work 221 bat faecal and 118 bird pellet samples were screened for a broad range of vector-borne bacteria using PCR-based methods. Rickettsia DNA was detected in 13 bat faecal DNA extracts, including the sequence of a rickettsial insect endosymbiont, a novel Rickettsia genotype and Rickettsia helvetica. Faecal samples of the pond bat (Myotis dasycneme) were positive for a Neorickettsia sp. and for haemoplasmas of the haemofelis group. In addition, two bird pellets (collected from a Long-eared Owl, Asio otus, and from a Common Kestrel, Falco tinnunculus) contained the DNA of a Rickettsia sp. and Anaplasma phagocytophilum, respectively. In both of these bird pellets the bones of Microtus arvalis were identified. All samples were negative for Borrelia burgdorferi s.l., Francisella tularensis, Coxiella burnetii and Chlamydiales. In conclusion, bats were shown to pass rickettsia and haemoplasma DNA in their faeces. Molecular evidence is provided for the presence of Neorickettsia sp. in bat faeces in Europe. In the evaluated regions bat faeces and owl/kestrel pellets do not appear to pose epidemiological risk from the point of view of F. tularensis, C. burnetii and Chlamydiales. Testing of bird pellets may provide an alternative approach to trapping for assessing the local occurrence of vector-borne bacteria in small mammals.

Prevalence and Risk Factors of Coxiella burnetii Antibodies in Bulk Milk from Cattle, Sheep, and Goats in Jordan

This large-scale cross-sectional study was conducted to determine the prevalence, geographical distribution, and risk factors for the presence of antibodies against Coxiella burnetii in bulk tank milk derived from dairy cattle, sheep, and goats in Jordan. Bulk milk samples were collected from 78 dairy cattle, 48 sheep, and 23 goat farms from various places in Jordan according to the density of these animal species in each region of the country. The samples were tested for C. burnetii antibodies using the CHEKIT Q-Fever Antibody ELISA kit. A standardized questionnaire was also used to collect data from each farm to identify and rank the risk factors for the presence of C. burnetii antibodies. The results revealed that 62.9% (95% confidence interval: 55.1 to 70.0%) of the tested ruminant farms were positive for C. burnetii antibodies. Positive results were obtained from 70.9% (60.6 to 79.5%) of dairy cattle farms, 52.1% (38.3 to 65.5%) of sheep farms, and 56.0% (37.1 to 73.3%) of goat farms. Six factors were associated with the presence of these antibodies on cattle farms, and five factors were associated with these antibodies on sheep and goat farms (chi-square test). The multivariate logistic regression model revealed that large dairy cattle farms, farms that add new animals to the herd, farms that infrequently clean the feeders, and farms in particular areas are 28.6, 19.9, 8.0, and 6.4 times more likely, respectively, to have animals with C. burnetii antibodies. Sheep and goat farms that mix their animals with those from other farms, graze more than 5 km, and infrequently sanitize the feeders were 8.0, 0.06, and 13.6 times more likely, respectively, to have animals with C. burnetii antibodies. These data reveal the widespread exposure of Jordanian ruminants to C. burnetii and suggest a high risk for public health.

Detection and risk factors of Coxiella burnetii infection in dairy cattle based on bulk tank milk samples in center of Iran

Infection with Coxiella burnetii has a worldwide distribution in ruminants and is associated with abortions and reproductive problems in this group of animals. This study aimed to determine the prevalence of C. burnetii DNA in bulk tank milk (BTM) of dairy cattle herds and to identify the risk factors of infection. This cross-sectional study was conducted in spring 2015. A total of 163 BTM samples from 74 commercial and 89 traditional dairy cattle herds in Isfahan, Iran was tested for the IS1111 transposon of C. burnetii by real-time polymerase chain reaction (PCR). A checklist containing general information of the herds was filled for each farm. Data were analyzed using univariate tests (chi square and t-tests) and multivariable binary logistic regression analysis. Bacterial DNA was detected in 8.6% of the samples (95% CI: 4.2- 12.9). In univariate analysis, the prevalence rate was higher in traditional herds than in commercial herds (n=12; 13.5% vs. n=2; 2.7%; P=0.01). The prevalence rate was inversely associated with the size and infection control score of the herd. In multivariable binary logistic regression, however, only herd size was found to be related with the infection rate, i.e. herds with ≥80 cattle were less likely to be infected (OR: 0.07; 95% CI: 0.01- 0.77; P=0.03). The only identified risk factor for this infection was the herd size. In fact, smaller herds (size <80) were more likely to be infected.

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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.

Occurrence and Genotyping of Coxiella burnetii in Ixodid Ticks in Oromia, Ethiopia

This study was conducted from September 2011 to March 2014 to address the occurrence and genotypes of Coxiella burnetii using molecular methods in ticks collected from domestic animals in Ethiopia. Ticks were tested for C. burnetii by quantitative real-time polymerase chain reaction (qPCR) targeting two different genes followed by multispacer sequence typing (MST). An overall prevalence of 6.4% (54/842) of C. burnetii was recorded. C. burnetii was detected in 28.6% (14/49) of Amblyomma gemma, 25% (31/124) of Rhipicephalus pulchellus, 7.1% (1/14) of Hyalomma marginatum rufipes, 3.2% (2/62) of Am. variegatum, 3.1% (4/128) of Am. cohaerens, 1.6% (1/63) of Rh. praetextatus, and 0.6% (1/153) of Rhipicephalus (Boophilus) decoloratus. Significantly higher overall frequencies of C. burnetii DNA were observed in Am. gemma and Rh. pulchellus than in other tick species (Mantel-Haenszel [MH], P < 0.0001). The overall frequency of C. burnetii was significantly higher (MH, P < 0.0001) in ticks from southeastern districts (Arero, Moyale, and Yabelo) than that from other districts. This study demonstrated the presence of C. burnetii genotype MST 18 in ticks in southeastern districts and genotype MST 20 in ticks in central districts. This study highlights the importance of ticks in the epidemiology of C. burnetii in Ethiopia.

Emergence of Coxiella burnetii in ruminants on Reunion Island? Prevalence and risk factors

Q fever is a widespread zoonosis that is caused by Coxiella burnetii (C. burnetii), and ruminants are identified as the main sources of human infections. Some human cases have been described, but very limited information was available about Q fever in ruminants on Reunion Island, a tropical island in the Indian Ocean. A cross-sectional study was undertaken from March 2011 to August 2012 to assess the Q fever prevalence and to identify the major risk factors of C. burnetii infection in ruminants. A total of 516 ruminants (245 cattle, 137 sheep and 134 goats) belonging to 71 farms and localized in different ecosystems of the island were randomly selected. Samples of blood, vaginal mucus and milk were concomitantly collected from females, and a questionnaire was submitted to the farmers. Ticks from positively detected farms were also collected. The overall seropositivity was 11.8% in cattle, 1.4% in sheep and 13.4% in goats. C. burnetii DNA was detected by PCR in 0.81%, 4.4% and 20.1% in cow, sheep and goat vaginal swabs, respectively. C. burnetii shedding in milk was observed in 1% of cows, 0% in sheep and 4.7% in goats. None of the ticks were detected to be positive for C. burnetii. C. burnetii infection increased when the farm was exposed to prevailing winds and when there were no specific precautions for a visitor before entering the farm, and they decreased when a proper quarantine was set up for any introduction of a new ruminant and when the animals returned to the farm at night. MLVA genotyping confirmed the role of these risk factors in infection.

Q fever is a disease that could be transmitted from animals (cattle, sheep and goats) to humans and caused by a bacterium called Coxiella burnetii (C. burnetii). Some human cases exhibiting characteristic clinical signs of that disease have been detected on Reunion Island, a tropical island in the Indian Ocean, but to date, we did not know if these animals could be seen as potential sources of the disease. Thus, a study was undertaken from March 2011 to August 2012 to detect the presence of that bacterium in these animals and to understand how they could get infected themselves. A total of 516 ruminants (245 cattle, 137 sheep and 134 goats) belonging to 71 farms and localized in different environments of the island were selected. Samples of blood, vaginal mucus and milk were concomitantly collected from females, and a questionnaire was submitted to the farmers. Ticks from positively detected farms were also collected. We observed 11.8% of cattle, 1.4% of sheep and 13.4% of goats had already been in contact with the bacterium. Coxiella burnetii was also directly detected in some vaginal and milk samples. None of the ticks were detected to be positive for C. burnetii. We found that the ruminants could be infected when their farm was exposed to prevailing winds because the bacterium can be transported by the wind, and when there were no specific precautions for visitors before entering the farm, because they could act as mechanical carriers of Coxiella. Conversely, keeping new animals under surveillance for some days to detect any signs of the disease before they enter the farm or keeping the animals in the barn at night limit the risk of infection.

Q fever epidemic in Hungary, April to July 2013

We investigated a Q fever outbreak with human patients showing high fever, respiratory tract symptoms, headache and retrosternal pain in southern Hungary in the spring and summer of 2013. Seventy human cases were confirmed by analysing their serum and blood samples with micro-immunofluorescence test and real-time PCR. The source of infection was a merino sheep flock of 450 ewes, in which 44.6% (25/56) seropositivity was detected by enzyme-linked immunosorbent assay. Coxiella burnetii DNA was detected by real-time PCR in the milk of four of 20 individuals and in two thirds (41/65) of the manure samples. The multispacer sequence typing examination of C. burnetii DNA revealed sequence type 18 in one human sample and two manure samples from the sheep flock. The multilocus variable-number tandem repeat analysis pattern of the sheep and human strains were also almost identical, 4/5-9-3-3-0-5 (Ms23-Ms24-Ms27-Ms28-Ms33-Ms34). It is hypothesised that dried manure and maternal fluid contaminated with C. burnetii was dispersed by the wind from the sheep farm towards the local inhabitants. The manure was eliminated in June and the farm was disinfected in July. The outbreak ended at the end of July 2013.

Genotyping of Coxiella burnetii from domestic ruminants and human in Hungary: indication of various genotypes

BACKGROUND

Information about the genotypic characteristic of Coxiella burnetii from Hungary is lacking. The aim of this study is to describe the genetic diversity of C. burnetii in Hungary and compare genotypes with those found elsewhere. A total of 12 samples: (cattle, n = 6, sheep, n = 5 and human, n = 1) collected from across Hungary were studied by a 10-loci multispacer sequence typing (MST) and 6-loci multiple-locus variable-number of tandem repeat analysis (MLVA). Phylogenetic relationships among MST genotypes show how these Hungarian samples are related to others collected around the world.

RESULTS

Three MST genotypes were identified: sequence type (ST) 20 has also been identified in ruminants from other European countries and the USA, ST28 was previously identified in Kazakhstan, and the proposed ST37 is novel. All MST genotypes yielded different MLVA genotypes and three different MLVA genotypes were identified within ST20 samples alone. Two novel MLVA types 0-9-5-5-6-2 (AG) and 0-8-4-5-6-2 (AF) (Ms23-Ms24-Ms27-Ms28-Ms33-Ms34) were defined in the ovine materials correlated with ST28 and ST37. Samples from different parts of the phylogenetic tree were associated with different hosts, suggesting host-specific adaptations.

CONCLUSIONS

Even with the limited number of samples analysed, this study revealed high genetic diversity among C. burnetii in Hungary. Understanding the background genetic diversity will be essential in identifying and controlling outbreaks.

High prevalence and two dominant host-specific genotypes of Coxiella burnetii in U.S. milk

Background

Coxiella burnetii causes Q fever in humans and Coxiellosis in animals; symptoms range from general malaise to fever, pneumonia, endocarditis and death. Livestock are a significant source of human infection as they shed C. burnetii cells in birth tissues, milk, urine and feces. Although prevalence of C. burnetii is high, few Q fever cases are reported in the U.S. and we have a limited understanding of their connectedness due to difficulties in genotyping. Here, we develop canonical SNP genotyping assays to evaluate spatial and temporal relationships among C. burnetii environmental samples and compare them across studies. Given the genotypic diversity of historical collections, we hypothesized that the current enzootic of Coxiellosis is caused by multiple circulating genotypes. We collected A) 23 milk samples from a single bovine herd, B) 134 commercial bovine and caprine milk samples from across the U.S., and C) 400 bovine and caprine samples from six milk processing plants over three years.

Results

We detected C. burnetii DNA in 96% of samples with no variance over time. We genotyped 88.5% of positive samples; bovine milk contained only a single genotype (ST20) and caprine milk was dominated by a second type (mostly ST8).

Conclusions

The high prevalence and lack of genotypic diversity is consistent with a model of rapid spread and persistence. The segregation of genotypes between host species is indicative of species-specific adaptations or dissemination barriers and may offer insights into the relative lack of human cases and characterizing genotypes.

Prevalence and molecular typing of Coxiella burnetii in bulk tank milk in Belgian dairy goats, 2009-2013

Q fever, a worldwide zoonosis, is an arousing public health concern in many countries since the recent Dutch outbreak. An emerging C. burnetii clone, genotype CbNL01, was identified as responsible for the Dutch human Q fever cluster cases. Since 2009, Q fever surveillance in the goat industry was implemented by the Belgian authorities. The herd prevalence (December 2009-March 2013) ranged between 6.3 and 12.1%. Genotypic analysis highlighted the molecular diversity of the Belgian strains from goats and identified an emerging CbNL01-like genotype. This follow-up allowed the description of shedding profiles in positive farms which was either continuous (type I) and associated to the CbNL01-like genotype; or intermittent (type II) and linked to other genotypes. Despite the circulation of a CbNL01-like strain, the number of notified Belgian human cases was very low. The mandatory vaccination (in June 2011) on positive dairy goat farms in Belgium, contributed to a decrease in shedding.

Non-pet dogs as sentinels and potential synanthropic reservoirs of tick-borne and zoonotic bacteria

Blood samples were collected from 100 shepherd dogs, 12 hunting dogs and 14 stray dogs (apparently healthy) in southern Hungary to screen for the presence of emerging tick-borne pathogens. Based on real-time PCR results, 14 dogs (11%) had single or dual haemoplasma infection, and a same number of samples were positive for Anaplasma phagocytophilum. In one sample Coxiella burnetii was molecularly identified, and 20.3% of dogs seroconverted to the Q fever agent. Rickettsaemia (sensu stricto) was also detected in one animal. This is the first molecular evidence of autochthonous infection of dogs with the above pathogens in Hungary. The relatively high prevalence of haemoplasma and anaplasma infection among non-pet dogs is suggestive of a prolonged carrier status and bacteraemia of these animals rendering them epidemiologically significant as potential reservoirs and sentinels for tick-borne infections.

Synanthropic birds associated with high prevalence of tick-borne rickettsiae and with the first detection of Rickettsia aeschlimannii in Hungary

The aim of this study was to analyze synanthropic birds as risk factors for introducing ticks and tick-borne pathogens into human settlements, with an emphasis on rickettsiae. Altogether 184 subadult ticks were found on 5846 birds. Tick infestation was most prevalent during the spring. In this sample group the majority of ticks were molecularly identified as Ixodes ricinus, and three individuals collected from the European robin as Hyalomma marginatum marginatum. The latter is the first molecularly confirmed occurrence of this species in Hungary. Rickettsia aeschlimannii was detected in H. marginatum, also for the first time in Hungary, and in ticks from an urbanized bird species north of the Mediterranean countries. The overall prevalence range of rickettsiae (including R. helvetica and R. monacensis) in ticks of synanthropic birds was 29-40%, exceeding that in questing ticks of relevant species reported earlier. Additionally, in specimens of I. ricinus, the presence of Borrelia burgdorferi sensu lato (s.l.), Anaplasma phagocytophilum, and a new Francisella-like genotype was also verified. Thus, it can be concluded that birds with urban or periurban habitats pose a high risk as tick carriers and reservoirs of zoonotic agents, especially of rickettsiae.