Attributable mortality of vancomycin resistance in ampicillin-resistant Enterococcus faecium bacteremia in Denmark and the Netherlands: A matched cohort study.

OBJECTIVE: To study whether replacement of nosocomial ampicillin-resistant Enterococcus faecium (ARE) clones by vancomycin-resistant E. faecium (VRE), belonging to the same genetic lineages, increases mortality in patients with E. faecium bacteremia, and to evaluate whether any such increase is mediated by a delay in appropriate antibiotic therapy. DESIGN: Retrospective, matched-cohort study. SETTING: The study included 20 Dutch and Danish hospitals from 2009 to 2014. PATIENTS: Within the study period, 63 patients with VRE bacteremia (36 Dutch and 27 Danish) were identified and subsequently matched to 234 patients with ARE bacteremia (130 Dutch and 104 Danish) for hospital, ward, length of hospital stay prior to bacteremia, and age. For all patients, 30-day mortality after bacteremia onset was assessed. METHODS: The risk ratio (RR) reflecting the impact of vancomycin resistance on 30-day mortality was estimated using Cox regression with further analytic control for confounding factors. RESULTS: The 30-day mortality rates were 27% and 38% for ARE in the Netherlands and Denmark, respectively, and the 30-day mortality rates were 33% and 48% for VRE in these respective countries. The adjusted RR for 30-day mortality for VRE was 1.54 (95% confidence interval, 1.06-2.25). Although appropriate antibiotic therapy was initiated later for VRE than for ARE bacteremia, further analysis did not reveal mediation of the increased mortality risk. CONCLUSIONS: Compared to ARE bacteremia, VRE bacteremia was associated with higher 30-day mortality. One explanation for this association would be increased virulence of VRE, although both phenotypes belong to the same well-characterized core genomic lineage. Alternatively, it may be the result of unmeasured confounding.

The Value of 18F-FDG PET/CT in Diagnosis and During Follow-up in 273 Patients with Chronic Q Fever.

In 1%-5% of all acute Q fever infections, chronic Q fever develops, mostly manifesting as endocarditis, infected aneurysms, or infected vascular prostheses. In this study, we investigated the diagnostic value of 18F-FDG PET/CT in chronic Q fever at diagnosis and during follow-up. Methods: All adult Dutch patients suspected of chronic Q fever who were diagnosed since 2007 were retrospectively included until March 2015, when at least one 18F-FDG PET/CT scan was obtained. Clinical data and results from 18F-FDG PET/CT at diagnosis and during follow-up were collected. 18F-FDG PET/CT scans were prospectively reevaluated by 3 nuclear medicine physicians using a structured scoring system. Results: In total, 273 patients with possible, probable, or proven chronic Q fever were included. Of all 18F-FDG PET/CT scans performed at diagnosis, 13.5% led to a change in diagnosis. Q fever-related mortality rate in patients with and without vascular infection based on 18F-FDG PET/CT was 23.8% and 2.1%, respectively (P = 0.001). When 18F-FDG PET/CT was added as a major criterion to the modified Duke criteria, 17 patients (1.9-fold increase) had definite endocarditis. At diagnosis, 19.6% of 18F-FDG PET/CT scans led to treatment modification. During follow-up, 57.3% of 18F-FDG PET/CT scans resulted in treatment modification. Conclusion:18F-FDG PET/CT is a valuable technique in diagnosis of chronic Q fever and during follow-up, often leading to a change in diagnosis or treatment modification and providing important prognostic information on patient survival.

An electronic trigger tool to optimise intravenous to oral antibiotic switch: a controlled, interrupted time series study.

BACKGROUND: Timely switch from intravenous (iv) antibiotics to oral therapy is a key component of antimicrobial stewardship programs in order to improve patient safety, promote early discharge and reduce costs. We have introduced a time-efficient and easily implementable intervention that relies on a computerized trigger tool, which identifies patients who are candidates for an iv to oral antibiotic switch. METHODS: The intervention was introduced on all internal medicine wards in a teaching hospital. Patients were automatically identified by an electronic trigger tool when parenteral antibiotics were used for >48 h and clinical or pharmacological data did not preclude switch therapy. A weekly educational session was introduced to alert the physicians on the intervention wards. The intervention wards were compared with control wards, which included all other hospital wards. An interrupted time-series analysis was performed to compare the pre-intervention period with the post-intervention period using '% of i.v. prescriptions >72 h' and 'median duration of iv therapy per prescription' as outcomes. We performed a detailed prospective evaluation on a subset of 244 prescriptions to evaluate the efficacy and appropriateness of the intervention. RESULTS: The number of intravenous prescriptions longer than 72 h was reduced by 19% in the intervention group (n = 1519) (p < 0.01) and the median duration of iv antibiotics was reduced with 0.8 days (p = <0.05). Compared to the control group (n = 4366) the intervention was responsible for an additional decrease of 13% (p < 0.05) in prolonged prescriptions. The detailed prospective evaluation of a subgroup of patients showed that adherence to the electronic reminder was 72%. CONCLUSIONS: An electronic trigger tool combined with a weekly educational session was effective in reducing the duration of intravenous antimicrobial therapy.

Effectiveness of Long-term Doxycycline Treatment and Cognitive-Behavioral Therapy on Fatigue Severity in Patients with Q Fever Fatigue Syndrome (Qure Study): A Randomized Controlled Trial.

Background: Approximately 20% of patients with acute Q fever will develop chronic fatigue, referred to as Q fever fatigue syndrome (QFS). The objective of this randomized controlled clinical trial was to assess the efficacy of either long-term treatment with doxycycline or cognitive-behavioral therapy (CBT) in reducing fatigue severity in patients with QFS. Methods: Adult patients were included who met the QFS criteria according to the Dutch guideline: a new onset of severe fatigue lasting ≥6 months with significant disabilities, related to an acute Q fever infection, without other somatic or psychiatric comorbidity explaining the fatigue. Using block randomization, patients were randomized between oral study medication and CBT (2:1) for 24 weeks. Second, a double-blind randomization between doxycycline (200 mg/day, once daily) and placebo was performed in the medication group. Primary outcome was fatigue severity at end of treatment (EOT; week 26), assessed with the Checklist Individual Strength subscale Fatigue Severity. Results: Of 155 patients randomized, 154 were included in the intention-to-treat analysis (doxycycline, 52; placebo, 52; CBT, 50). At EOT, fatigue severity was similar between doxycycline (40.8 [95% confidence interval {CI}, 37.3-44.3]) and placebo (37.8 [95% CI, 34.3-41.2]; difference, doxycycline vs placebo, -3.0 [97.5% CI, -8.7 to 2.6]; P = .45). Fatigue severity was significantly lower after CBT (31.6 [95% CI, 28.0-35.1]) than after placebo (difference, CBT vs placebo, 6.2 [97.5% CI, .5-11.9]; P = .03). Conclusions: CBT is effective in reducing fatigue severity in QFS patients. Long-term treatment with doxycycline does not reduce fatigue severity in QFS patients compared to placebo. Clinical Trials Registration: NCT01318356.

First Complete Genome Sequence of the Dutch Veterinary Coxiella burnetii Strain NL3262, Originating from the Largest Global Q Fever Outbreak, and Draft Genome Sequence of Its Epidemiologically Linked Chronic Human Isolate NLhu3345937.

The largest global Q fever outbreak occurred in The Netherlands during 2007 to 2010. Goats and sheep were identified as the major sources of disease. Here, we report the first complete genome sequence of ITALIC! Coxiella burnetiigoat outbreak strain NL3262 and that of an epidemiologically linked chronic human strain, both having the outbreak-related ITALIC! CbNL01multilocus variable-number tandem-repeat analysis (MLVA) genotype.

Chronic Q fever diagnosis­ consensus guideline versus expert opinion

Chronic Q fever, caused by Coxiella burnetii, has high mortality and morbidity rates if left untreated. Controversy about the diagnosis of this complex disease has emerged recently. We applied the guideline from the Dutch Q Fever Consensus Group and a set of diagnostic criteria proposed by Didier Raoult to all 284 chronic Q fever patients included in the Dutch National Chronic Q Fever Database during 2006­2012. Of the patients who had proven cases of chronic Q fever by the Dutch guideline, 46 (30.5%)would not have received a diagnosis by the alternative criteria designed by Raoult, and 14 (4.9%) would have been considered to have possible chronic Q fever. Six patients with proven chronic Q fever died of related causes. Until results from future studies are available, by which current guidelines can be modified, we believe that the Dutch literature-based consensus guideline is more sensitive and easier to use in clinical practice.

Differentiation of Acute Q Fever from Other Infections in Patients Presenting to Hospitals, the Netherlands

Differentiating acute Q fever from infections caused by other pathogens is essential. We conducted a retrospective case-control study to evaluate differences in clinical signs, symptoms, and outcomes for 82 patients with acute Q fever and 52 control patients who had pneumonia, fever and lower respiratory tract symptoms, or fever and hepatitis, but had negative serologic results for Q fever. Patients with acute Q fever were younger and had higher C-reactive protein levels but lower leukocyte counts. However, a large overlap was found. In patients with an indication for prophylaxis, chronic Q fever did not develop after patients received prophylaxis but did develop in 50% of patients who did not receive prophylaxis. Differentiating acute Q fever from other respiratory infections, fever, or hepatitis is not possible without serologic testing or PCR. If risk factors for chronic Q fever are present, prophylactic treatment is advised.

Chronic Q fever in the Netherlands 5 years after the start of the Q fever epidemic: results from the Dutch chronic Q fever database.

Coxiella burnetii causes Q fever, a zoonosis, which has acute and chronic manifestations. From 2007 to 2010, the Netherlands experienced a large Q fever outbreak, which has offered a unique opportunity to analyze chronic Q fever cases. In an observational cohort study, baseline characteristics and clinical characteristics, as well as mortality, of patients with proven, probable, or possible chronic Q fever in the Netherlands, were analyzed. In total, 284 chronic Q fever patients were identified, of which 151 (53.7%) had proven, 64 (22.5%) probable, and 69 (24.3%) possible chronic Q fever. Among proven and probable chronic Q fever patients, vascular infection focus (56.7%) was more prevalent than endocarditis (34.9%). An acute Q fever episode was recalled by 27.0% of the patients. The all-cause mortality rate was 19.1%, while the chronic Q fever-related mortality rate was 13.0%, with mortality rates of 9.3% among endocarditis patients and 18% among patients with a vascular focus of infection. Increasing age (P=0.004 and 0.010), proven chronic Q fever (P=0.020 and 0.002), vascular chronic Q fever (P=0.024 and 0.005), acute presentation with chronic Q fever (P=0.002 and P<0.001), and surgical treatment of chronic Q fever (P=0.025 and P<0.001) were significantly associated with all-cause mortality and chronic Q fever-related mortality, respectively.

Localizing chronic Q fever: a challenging query.

BACKGROUND: Chronic Q fever usually presents as endocarditis or endovascular infection. We investigated whether 18F-FDG PET/CT and echocardiography were able to detect the localization of infection. Also, the utility of the modified Duke criteria was assessed. METHODS: Fifty-two patients, who had an IgG titre of ≥ 1024 against C. burnetii phase I ≥ 3 months after primary infection or a positive PCR ≥ 1 month after primary infection, were retrospectively included. Data on serology, the results of all imaging studies, possible risk factors for developing proven chronic Q fever and clinical outcome were recorded. RESULTS: According to the Dutch consensus on Q fever diagnostics, 18 patients had proven chronic Q fever, 14 probable chronic Q fever, and 20 possible chronic Q fever. Of the patients with proven chronic Q fever, 22% were diagnosed with endocarditis, 17% with an infected vascular prosthesis, and 39% with a mycotic aneurysm. 56% of patients with proven chronic Q fever did not recall an episode of acute Q fever. Ten out of 13 18F-FDG PET/CT-scans in patients with proven chronic Q fever localized the infection. TTE and TEE were helpful in only 6% and 50% of patients, respectively. CONCLUSIONS: If chronic Q fever is diagnosed, 18F-FDG PET/CT is a helpful imaging technique for localization of vascular infections due to chronic Q fever. Patients with proven chronic Q fever were diagnosed significantly more often with mycotic aneurysms than in previous case series. Definite endocarditis due to chronic Q fever was less frequently diagnosed in the current study. Chronic Q fever often occurs in patients without a known episode of acute Q fever, so clinical suspicion should remain high, especially in endemic regions.

Genotyping of Coxiella burnetii from domestic ruminants in northern Spain.

BACKGROUND: Information on the genotypic diversity of Coxiella burnetii isolates from infected domestic ruminants in Spain is limited. The aim of this study was to identify the C. burnetii genotypes infecting livestock in Northern Spain and compare them to other European genotypes. A commercial real-time PCR targeting the IS1111a insertion element was used to detect the presence of C. burnetii DNA in domestic ruminants from Spain. Genotypes were determined by a 6-loci Multiple Locus Variable number tandem repeat analysis (MLVA) panel and Multispacer Sequence Typing (MST). RESULTS: A total of 45 samples from 4 goat herds (placentas, N = 4), 12 dairy cattle herds (vaginal mucus, individual milk, bulk tank milk, aerosols, N = 20) and 5 sheep flocks (placenta, vaginal swabs, faeces, air samples, dust, N = 21) were included in the study. Samples from goats and sheep were obtained from herds which had suffered abortions suspected to be caused by C. burnetii, whereas cattle samples were obtained from animals with reproductive problems compatible with C. burnetii infection, or consisted of bulk tank milk (BTM) samples from a Q fever surveillance programme. C. burnetii genotypes identified in ruminants from Spain were compared to those detected in other countries. Three MLVA genotypes were found in 4 goat farms, 7 MLVA genotypes were identified in 12 cattle herds and 4 MLVA genotypes were identified in 5 sheep flocks. Clustering of the MLVA genotypes using the minimum spanning tree method showed a high degree of genetic similarity between most MLVA genotypes. Overall 11 different MLVA genotypes were obtained corresponding to 4 different MST genotypes: MST genotype 13, identified in goat, sheep and cattle from Spain; MST genotype 18, only identified in goats; and, MST genotypes 8 and 20, identified in small ruminants and cattle, respectively. All these genotypes had been previously identified in animal and human clinical samples from several European countries, but some of the MLVA genotypes are described here for the first time. CONCLUSIONS: Genotyping revealed a substantial genetic diversity among domestic ruminants from Northern Spain.

Genotypic diversity of clinical Coxiella burnetii isolates from Portugal based on MST and MLVA typing.

The temporal and spatial diversity of Coxiella burnetii genotypes associated with human and animal disease in Portugal was analysed using a 6-locus multiple-locus variable-number tandem repeat analysis (MLVA) and a 10-locus multi-spacer sequence typing (MST) panel. Fifteen cultured C. burnetii isolates from 13 Q fever patients and a stillborn goat and 6 additional PCR-positive ruminant tissue samples obtained during 2006-2011 were included in this study. Seven MLVA genotypes (types S-Y) were obtained, including 4 new MLVA types (U, V, W, and X), all corresponding to 3 MST profiles (types 4, 8, and 13) previously reported from France and Spain. MLVA types U-Y, all belonging to MST type 4, were found in acute Q fever patients from the districts of Évora, Faro, Lisbon, and Setúbal. Different MLVA types were associated with goats from Castelo Branco district (S) and chronic Q fever patients from both Castelo Branco and Lisboa districts (S and T), matching with MST types 13 and 8, respectively. In conclusion, a genotypic diversity of C. burnetii consistent with a non-outbreak situation was identified. The involvement of different genotypes in acute and chronic Q fever was found, linking one of the chronic genotypes to goats from the eastern region of the country.

Genotyping reveals the presence of a predominant genotype of Coxiella burnetii in consumer milk products.

Real-time PCR shows the widespread presence of Coxiella burnetii DNA in a broad range of commercially available milk and milk products. MLVA genotyping shows that this is the result of the presence of a predominant C. burnetii genotype in the dairy cattle population.

Microbiological challenges in the diagnosis of chronic Q fever.

Diagnosis of chronic Q fever is difficult. PCR and culture lack sensitivity; hence, diagnosis relies mainly on serologic tests using an immunofluorescence assay (IFA). Optimal phase I IgG cutoff titers are debated but are estimated to be between 1:800 and 1:1,600. In patients with proven, probable, or possible chronic Q fever, we studied phase I IgG antibody titers at the time of positive blood PCR, at diagnosis, and at peak levels during chronic Q fever. We evaluated 200 patients, of whom 93 (46.5%) had proven, 51 (25.5%) had probable, and 56 (28.0%) had possible chronic Q fever. Sixty-five percent of proven cases had positive Coxiella burnetii PCR results for blood, which was associated with high phase I IgG. Median phase I IgG titers at diagnosis and peak titers in patients with proven chronic Q fever were significantly higher than those for patients with probable and possible chronic Q fever. The positive predictive values for proven chronic Q fever, compared to possible chronic Q fever, at titers 1:1,024, 1:2,048, 1:4,096, and ≥1:8,192 were 62.2%, 66.7%, 76.5%, and ≥86.2%, respectively. However, sensitivity dropped to <60% when cutoff titers of ≥1:8,192 were used. Although our study demonstrated a strong association between high phase I IgG titers and proven chronic Q fever, increasing the current diagnostic phase I IgG cutoff to >1:1,024 is not recommended due to increased false-negative findings (sensitivity < 60%) and the high morbidity and mortality of untreated chronic Q fever. Our study emphasizes that serologic results are not diagnostic on their own but should always be interpreted in combination with clinical parameters.

Genotypic diversity of Coxiella burnetii in the 2007-2010 Q fever outbreak episodes in The Netherlands.

The genotypic diversity of Coxiella burnetii in clinical samples obtained from the Dutch Q fever outbreak episodes of 2007-2010 was determined by using a 6-locus variable-number tandem repeat analysis panel. The results are consistent with the introduction of one founder genotype that is gradually diversifying over time while spreading throughout The Netherlands.

Molecular epidemiology of Coxiella burnetii from ruminants in Q fever outbreak, the Netherlands.

Q fever is a zoonosis caused by the bacterium Coxiella burnetii. One of the largest reported outbreaks of Q fever in humans occurred in the Netherlands starting in 2007; epidemiologic investigations identified small ruminants as the source. To determine the genetic background of C. burnetii in domestic ruminants responsible for the human Q fever outbreak, we genotyped 126 C. burnetii-positive samples from ruminants by using a 10-loci multilocus variable-number tandem-repeat analyses panel and compared them with internationally known genotypes. One unique genotype predominated in dairy goat herds and 1 sheep herd in the human Q fever outbreak area in the south of the Netherlands. On the basis of 4 loci, this genotype is similar to a human genotype from the Netherlands. This finding strengthens the probability that this genotype of C. burnetii is responsible for the human Q fever epidemic in the Netherlands.

Contamination of commercial PCR master mix with DNA from Coxiella burnetii.

Contamination of an in-house diagnostic real-time PCR for Q fever was traced back to a commercially obtained PCR Master Mix. It was established that this Master Mix contained DNA from Coxiella burnetii, probably as a result of the use of compounds of animal origin such as bovine serum albumin.

Interlaboratory evaluation of different extraction and real-time PCR methods for detection of Coxiella burnetii DNA in serum.

In the Netherlands, there is an ongoing and unparalleled outbreak of Q fever. Rapid and reliable methods to identify patients infected with Coxiella burnetii, the causative agent of Q fever, are urgently needed. We evaluated the performance of different DNA extraction methods and real-time PCR assays that are in use in seven diagnostic or reference laboratories in the Netherlands. A low degree of variation in the sensitivities of most of the developed real-time PCR assays was observed. However, PCR assays amplifying short DNA fragments yielded better results than those producing large DNA fragments. With regard to DNA extraction, the automated MagNA Pure Compact system and the manual QIAamp DNA mini kit consistently yielded better results than either the MagNA Pure LC system and NucliSens EasyMag (both automated) or the High Pure viral nucleic acid kit (manual). The present study shows that multiple combinations of DNA extraction kits and real-time PCR assays offer equivalent solutions to detect C. burnetii DNA in serum samples from patients suspected to have Q fever.