Publications by authors named "Alexander C A P Leenders"

17 Publications

  • Page 1 of 1

The clinical relevance of IgM and IgA anti-pneumococcal polysaccharide ELISA assays in patients with suspected antibody deficiency.

Clin Exp Immunol 2021 Aug 1;205(2):213-221. Epub 2021 Jun 1.

Department of Tranzo, Tilburg University, Tilburg, the Netherlands.

Unlike immunoglobulin (Ig)G pneumococcal polysaccharide (PnPS)-antibodies, PnPS IgA and IgM-antibodies are not routinely determined for the assessment of immunocompetence. It is not yet known whether an isolated inability to mount a normal IgM or IgA-PnPS response should be considered a relevant primary antibody deficiency (PAD). We studied the clinical relevance of anti-PnPS IgM and IgA-assays in patients with suspected primary immunodeficiency in a large teaching hospital in 's-Hertogenbosch, the Netherlands. Serotype-specific-PnPS IgG assays were performed; subsequently, 23-valent-PnPS IgG assays (anti-PnPS IgG assays), and later anti-PnPS IgA and IgM assays, were performed in archived material (240 patients; 304 samples). Eleven of 65 pre- and six of 10 post-immunization samples from good responders to PnPS serotype-specific IgG testing had decreased anti-PnPS IgA and/or IgM titres. Of these, three pre- and no post-immunization samples were from patients previously classified as 'no PAD'. Determination of anti-PnPS IgA and IgM in addition to anti-PnPS IgG did not reduce the need for serotype-specific PnPS IgG testing to assess immunocompetence [receiver operating characteristic (ROC) analysis of post-immunization samples: anti-PnPS IgA + IgG area under the curve (AUC) = 0.80, 95% confidence interval (CI) = 0.63-0.97; anti-PnPS IgM + IgG AUC 0.80, 95% CI = 0.62-0.98; anti-PnPS IgA + IgG + IgM AUC = 0.71, 95% CI = 0.51-0.91; anti-PnPS IgG AUC = 0.93, 95% CI = 0.85-1.00]. Our data show that patients classified as having an intact antibody response based on measurement of serotype-specific PnPS IgG can still display impaired anti-PnPS IgM and IgA responses, and that the additional measurement of anti-PnPS IgA and IgM could not reduce the need for serotype-specific IgG testing. Future studies are needed to investigate the clinical relevance of potential 'specific IgA or IgM antibody deficiency' in patients with recurrent airway infections in whom no PAD could be diagnosed according to the current definitions.
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http://dx.doi.org/10.1111/cei.13605DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8274160PMC
August 2021

Focusing on Good Responders to Pneumococcal Polysaccharide Vaccination in General Hospital Patients Suspected for Immunodeficiency. A Decision Tree Based on the 23-Valent Pneumococcal IgG Assay.

Front Immunol 2019 5;10:2496. Epub 2019 Nov 5.

Department of Tranzo, Tilburg University, Tilburg, Netherlands.

Recently, the 23-valent IgG-assay was suggested as screening assay to identify responders to pneumococcal polysaccharide (PnPS)-vaccination with the serotype-specific assay as a second-line test. However, in a low pre-test probability general hospital setting predicting responders could be more valuable to reduce the number of samples needing serotyping. Serotype-specific PnPS antibody-assays were performed for suspected immunodeficiency in two Dutch general hospitals (Jeroen Bosch Hospital, 's-Hertogenbosch; Elisabeth Tweesteden Hospital, Tilburg). 23-Valent PnPS antibody-assays were subsequently performed in archived material. Data were analyzed using receiver operating characteristic curves (AUC) and agreement indices (ICC). Sera of 284 patients (348 samples) were included; 23-valent IgG-titres and the corresponding sum of PnPS-serotype specific antibodies showed moderate correlation (ICC = 0.63). In 232 conjugated-pneumococcal-vaccine-naïve patients (270 samples), a random 23-valent IgG-titer could discriminate between samples with and without ≥7/11, ≥7/13, or ≥6/9 pneumococcal serotypes when both cut-off values 0.35 and 1.0 μg/ml were used (AUC 0.86 and 0.92, respectively). All patients with a pre-immunization-titer ≥38.2 μg/ml and/or post-immunization-titer ≥96.1 μg/ml and none with a post-immunization-titer ≤38.5 μg/ml exhibited a good response to PnPS vaccination. Using these breakpoints as screening test to predict responders, only 24% of patients would require further serotyping, as opposed to 68% if breakpoints to predict responders would have been used. In a low pre-test probability setting, the 23-valent IgG-assay proved to be a reliable screening test for good responders in conjugated-pneumococcal-vaccine-naïve patients, reducing the overall number of patient samples needing further serotyping, thus reducing overall costs of pneumococcal vaccination response assessment.
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http://dx.doi.org/10.3389/fimmu.2019.02496DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6848064PMC
November 2020

Acute Mono-Arthritis of the Knee: A Case Report of Infection with and Concomitant Pseudogout.

J Bone Jt Infect 2016 1;1:65-67. Epub 2016 Oct 1.

Jeroen Bosch general hospital, 's-Hertogenbosch, The Netherlands.

is a rare pathogen for septic arthritis and is known for its subacute onset. We report a case of acute arthritis of the knee caused by and pseudogout. Initially, calcium pyrophosphate crystals were found in the knee, which were successfully treated with a steroid injection. Only anaerobic cultures became positive. A 16S rRNA PCR-analysis was necessary to identify as causative agent, a method which is never described before in similar cases. The infection was treated with clindamycin for 6 weeks. This is the third case report of a septic arthritis caused by and the second which also reports concomitant pseudogout.
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http://dx.doi.org/10.7150/jbji.16124DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5423566PMC
October 2016

Outbreak of NDM-1-Producing Klebsiella pneumoniae in a Dutch Hospital, with Interspecies Transfer of the Resistance Plasmid and Unexpected Occurrence in Unrelated Health Care Centers.

J Clin Microbiol 2017 08 17;55(8):2380-2390. Epub 2017 May 17.

Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, the Netherlands.

In the Netherlands, the number of cases of infection with New Delhi metallo-beta-lactamase (NDM)-positive is low. Here, we report an outbreak of NDM-1-producing infection in a Dutch hospital with interspecies transfer of the resistance plasmid and unexpected occurrence in other unrelated health care centers (HCCs). Next-generation sequencing was performed on 250 carbapenemase-producing isolates, including 42 NDM-positive isolates obtained from 29 persons at the outbreak site. Most outbreak isolates were ( = 26) and ( = 11), but 5 isolates comprising three other species were also cultured. The 26 isolates had sequence type 873 (ST873), as did 7 unrelated isolates originating from five geographically dispersed HCCs. The 33 ST873 isolates that clustered closely together using whole-genome multilocus sequence typing (wgMLST) carried the same plasmids and had limited differences in the resistome. The 11 outbreak isolates showed great variety in STs, did not cluster using wgMLST, and showed considerable diversity in resistome and plasmid profiles. The gene-carrying plasmid present in the ST873 isolates was found in all the other species cultured at the outbreak location and in a single isolate from another HCC. We describe a hospital outbreak with an NDM-1-producing strain from an unknown source that was also found in patients from five other Dutch HCCs in the same time frame without an epidemiological link. Interspecies transfer of the resistance plasmid was observed in other species isolated at the outbreak location and in another HCC.
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http://dx.doi.org/10.1128/JCM.00535-17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5527415PMC
August 2017

Prevention of Surgical Site Infections: Universal Decontamination Not for All, but for a Selection of Surgical Patients.

Clin Infect Dis 2016 06 5;62(11):1469-70. Epub 2016 Apr 5.

Regional Laboratory Medical Microbiology and Infection Prevention, Jeroen Bosch Hospital, Den Bosch, The Netherlands.

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http://dx.doi.org/10.1093/cid/ciw214DOI Listing
June 2016

Long-Term Serological Follow-Up of Acute Q-Fever Patients after a Large Epidemic.

PLoS One 2015 10;10(7):e0131848. Epub 2015 Jul 10.

Department of Medical Microbiology and Infection Control, Jeroen Bosch Hospital, 's-Hertogenbosch, the Netherlands; Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.

Background: Serological follow-up of acute Q-fever patients is important for detection of chronic infection but there is no consensus on its frequency and duration. The 2007-2009 Q-fever epidemic in the Netherlands allowed for long-term follow-up of a large cohort of acute Q-fever patients. The aim of this study was to validate the current follow-up strategy targeted to identify patients with chronic Q-fever.

Methods: A cohort of adult acute Q-fever patients, diagnosed between 2007 and 2009, for whom a twelve-month follow-up sample was available, was invited to complete a questionnaire and provide a blood sample, four years after the acute episode. Antibody profiles, determined by immunofluorescence assay in serum, were investigated with a special focus on high titres of IgG antibodies against phase I of Coxiella burnetii, as these are considered indicative for possible chronic Q-fever.

Results: Of the invited 1,907 patients fulfilling inclusion criteria, 1,289 (67.6%) were included in the analysis. At any time during the four-year follow-up period, 58 (4.5%) patients were classified as possible, probable, or proven chronic Q-fever according to the Dutch Q-fever Consensus Group criteria (which uses IgG phase I ≥1:1,024 to as serologic criterion for chronic Q-fever). Fifty-two (89.7%) of these were identified within the first year after the acute episode. Of the six patients that were detected for the first time at four-year follow-up, five had an IgG phase I titre of 1:512 at twelve months.

Conclusions: A twelve-month follow-up check after acute Q-fever is recommended as it adequately detects chronic Q-fever in patients without known risk factors. Additional serological and clinical follow-up is recommended for patients with IgG phase I ≥1:512, as they showed the highest risk to progress to chronic Q-fever.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0131848PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4498618PMC
April 2016

Pediatric acute Q fever mimics other common childhood illnesses.

PLoS One 2014 10;9(2):e88677. Epub 2014 Feb 10.

Department of Pediatrics, Jeroen Bosch Hospital's-Hertogenbosch, The Netherlands.

Knowledge of Q fever has increased over the last decades, but research has mainly focused on adults. Data in children are scarce, and current knowledge is mostly based on case reports. The aim of this study was to determine predictors for acute Q fever in children in the general population. We retrospectively studied all children tested for Coxiella burnetii by serology and/or PCR upon request of their general practitioner in the regional laboratory for Medical Microbiology of the Jeroen Bosch during the Q fever outbreak in the Netherlands between 2007 and 2011. A total of 1061 patients was analyzed. Influenza-like illness and respiratory tract infection were the most common presentations of acute Q fever, mimicking other common childhood illnesses. None of the reported symptoms was significantly related to a positive test outcome and therefore presenting signs or symptoms have no predictive value in diagnosing Q-fever in children. Only diagnostic tests are reliable. As the infection generally follows a mild and uncomplicated course, we question if the difficulty of recognizing pediatric Q fever is a problem worth solving.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0088677PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3919820PMC
October 2014

Epidemic Q fever in humans in the Netherlands.

Adv Exp Med Biol 2012 ;984:329-64

National Institute for Public Health and the Environment (RIVM), Centre for Infectious Disease Control (Clb), 1, Antonie van Leeuwenhoeklaan 9, 3720 BA, Bilthoven, The Netherlands.

In 2005, Q fever was diagnosed on two dairy goat farms and 2 years later it emerged in the human population in the south of the Netherlands. From 2007 to 2010, more than 4,000 human cases were notified with an annual seasonal peak. The outbreaks in humans were mainly restricted to the south of the country in an area with intensive dairy goat farming. In the most affected areas, up to 15% of the population may have been infected. The epidemic resulted in a serious burden of disease, with a hospitalisation rate of 20% of notified cases and is expected to result in more cases of chronic Q fever among risk groups in the coming years. The most important risk factor for human Q fever is living close (<5 km) to an infected dairy goat farm. Occupational exposure plays a much smaller role. In 2009 several veterinary control measures were implemented including mandatory vaccination of dairy goats and dairy sheep, improved hygiene measures, and culling of pregnant animals on infected farms. The introduction of these drastic veterinary measures has probably ended the Q fever outbreak, for which the Netherlands was ill-prepared.
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http://dx.doi.org/10.1007/978-94-007-4315-1_17DOI Listing
January 2013

Proximity to goat farms and Coxiella burnetii seroprevalence among pregnant women.

Emerg Infect Dis 2011 Dec;17(12):2360-3

National Institute for Public Health and the Environment, Bilthoven, the Netherlands.

During 2007-2009, we tested serum samples from 2,004 pregnant women living in an area of high Q fever incidence in the Netherlands. Results confirmed that presence of antibodies against Coxiella burnetii is related to proximity to infected dairy goat farms. Pregnant women and patients with certain cardiovascular conditions should avoid these farms.
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http://dx.doi.org/10.3201/eid1712.110738DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3311170PMC
December 2011

Follow-up of 686 patients with acute Q fever and detection of chronic infection.

Clin Infect Dis 2011 Jun;52(12):1431-6

Epidemiology and Surveillance Unit, Center for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, The Netherlands.

Background: Recent outbreaks in the Netherlands allowed for laboratory follow-up of a large series of patients with acute Q fever and for evaluation of test algorithms to detect chronic Q fever, a condition with considerable morbidity and mortality.

Methods: For 686 patients with acute Q fever, IgG antibodies to Coxiella burnetii were determined using an immunofluorescence assay at 3, 6, and 12 months of follow-up. Polymerase chain reaction (PCR) was performed after 12 months and on earlier serum samples with an IgG phase I antibody titer ≥ 1:1024.

Results: In 43% of patients, the IgG phase II antibody titers remained high (≥ 1:1024) at 3, 6, and 12 months of follow-up. Three months after acute Q fever, 14% of the patients had an IgG phase I titer ≥ 1:1024, which became negative later in 81%. IgG phase I antibody titers were rarely higher than phase II titers. Eleven cases of chronic Q fever were identified on the basis of serological profile, PCR results, and clinical presentation. Six of these patients were known to have clinical risk factors at the time of acute Q fever. In a comparison of various serological algorithms, IgG phase I titer ≥ 1:1024 at 6 months had the most favorable sensitivity and positive predictive value for the detection of chronic Q fever.

Conclusions: The wide variation of serological and PCR results during the follow-up of acute Q fever implies that the diagnosis of chronic Q fever, necessitating long-term antibiotic treatment, must be based primarily on clinical grounds. Different serological follow-up strategies are needed for patients with and without known risk factors for chronic Q fever.
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http://dx.doi.org/10.1093/cid/cir234DOI Listing
June 2011

Foam sclerotherapy: investigating the need for sterile air.

Dermatol Surg 2011 Aug 25;37(8):1119-24. Epub 2011 May 25.

Department of Dermatology, DermaPark, Uden, The Netherlands.

Background: Sclerotherapy with foam is becoming increasingly popular for the treatment of varicose veins. There is no consensus on the necessity of sterile air or other gases to produce foam.

Objectives: To evaluate the potential risk of bacterial inoculation of polidocanol (POL) foam using room air and the antimicrobial properties of polidocanol.

Materials And Methods: The amount of airborne microorganisms was quantitatively measured. Four bacterial strains were tested for susceptibility to polidocanol: Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Streptococcus pyogenes.

Results: Air measurements varied as a result of air movement and the number of people in the room. Although the risk of introducing one colony-formin unit can be calculated as less than 1 in 330, the clinical relevance is still to be determined. No inhibition of bacterial growth was achieved with POL in of any of the tested strains.

Conclusions: Foam sclerotherapy with POL prepared in a standard treatment room is a safe procedure without the risk of introducing a severe bacterial complication. The use of sterile air, nitrogen, or carbon dioxide is unnecessary and will make foam sclerotherapy with POL more elaborate and more expensive to use.
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http://dx.doi.org/10.1111/j.1524-4725.2011.02044.xDOI Listing
August 2011

Evaluation of a diagnostic algorithm for acute Q fever in an outbreak setting.

Clin Vaccine Immunol 2011 Jun 20;18(6):963-8. Epub 2011 Apr 20.

Department of Medical Microbiology and Infection Control, Jeroen Bosch Hospital, 5200 ME 's-Hertogenbosch, Netherlands.

In the peak of the 2009 Q fever outbreak in the Netherlands, we introduced a diagnostic algorithm for acute Q fever with an enzyme-linked immunosorbent assay for immunoglobulin M antibodies to Coxiella burnetii phase II antigens (MII screen) as an initial step. Subsequently, an immunofluorescence assay or PCR was performed depending on the MII screen outcome, date of onset of disease, and inpatient or outpatient setting. The impact of MII screen on the number of immunofluorescence assays performed and the contribution of PCR to diagnosis were retrospectively evaluated in 825 patients referred in a 17-day period. Acute Q fever was diagnosed in 256 patients. The introduction of MII screen reduced the number of immunofluorescence assays performed by more than 80%. In 103 patients, PCR analysis contributed to the diagnosis of acute Q fever. Q fever diagnostics were hampered by the fact that for a high number of patients the date of onset of disease was not provided and the requested follow-up serum samples were not received.
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http://dx.doi.org/10.1128/CVI.00009-11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3122604PMC
June 2011

[Chronic Q fever during pregnancy].

Ned Tijdschr Geneeskd 2011 ;155:A2781

Universitair Medisch Centrum Groningen, afd. Obstetrie en Gynaecologie, Groningen, the Netherlands.

A 42-year-old woman visited the pulmonologist for follow-up after a pneumonia. In retrospect the pneumonia appeared to be a manifestation of an acute Q fever infection. A few weeks later the patient was found to be unexpectedly pregnant. At the normal serological follow-up six months after the primary infection chronic Q fever infection was diagnosed. Doxycycline and hydroxychloroquine are contraindicated in pregnancy and the patient was found to be allergic to co-trimoxazole. Therefore treatment with erythromycin was chosen on empirical grounds. The patient had many symptoms during pregnancy. After 38 weeks and 2 days amenorrhea labour was induced on maternal indication. Finally a healthy boy of 3850 grams was born by caesarean section. In view of the increased risk of chronic Q fever infection during pregnancy we advise intensified serological monitoring of patients with acute Q fever who subsequently become pregnant.
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August 2011

Antibodies against Coxiella burnetii and pregnancy outcome during the 2007-2008 Q fever outbreaks in The Netherlands.

BMC Infect Dis 2011 Feb 11;11:44. Epub 2011 Feb 11.

Centre for Infectious Disease Control, National Institute for Public Health and the Environment, PO Box 1, 3720 BA Bilthoven, The Netherlands.

Background: Q fever has become a major public health problem in The Netherlands. Infection with Coxiella burnetii (Q fever) during pregnancy has resulted in adverse pregnancy outcome in the majority of reported cases. Therefore, we aimed to quantify this risk by examining the earliest periods corresponding to the epidemic in The Netherlands.

Methods: Serum samples that had been collected from the area of highest incidence by an existing national prenatal screening programme and data from the Netherlands Perinatal Registry (PRN) on diagnosis and outcome were used. We performed indirect immunofluorescence assay to detect the presence of IgM and IgG antibodies against C. burnetii in the samples. The serological results were analyzed to determine statistical association with recorded pregnancy outcome.

Results: Evaluation of serological results for 1174 women in the PRN indicated that the presence of IgM and IgG antibodies against phase II of C. burnetii was not significantly associated with preterm delivery, low birth weight, or several other outcome measures.

Conclusion: The present population-based study showed no evidence of adverse pregnancy outcome among women who had antibodies to C. burnetii during early pregnancy.
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http://dx.doi.org/10.1186/1471-2334-11-44DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3042933PMC
February 2011

Cost-effectiveness of a screening strategy for Q fever among pregnant women in risk areas: a clustered randomized controlled trial.

BMC Womens Health 2010 Nov 1;10:32. Epub 2010 Nov 1.

University of Groningen, University Centre for Pharmacy, PharmacoEpidemiology & PharmacoEconomics, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands.

Background: In The Netherlands the largest human Q fever outbreak ever reported in the literature is currently ongoing with more than 2300 notified cases in 2009. Pregnant women are particularly at risk as Q fever during pregnancy may cause maternal and obstetric complications. Since the majority of infected pregnant women are asymptomatic, a screening strategy might be of great value to reduce Q fever related complications. We designed a trial to assess the (cost-)effectiveness of a screening program for Q fever in pregnant women living in risks areas in The Netherlands.

Methods/design: We will conduct a clustered randomized controlled trial in which primary care midwife centres in Q fever risk areas are randomized to recruit pregnant women for either the control group or the intervention group. In both groups a blood sample is taken around 20 weeks postmenstrual age. In the intervention group, this sample is immediately analyzed by indirect immunofluorescence assay for detection of IgG and IgM antibodies using a sensitive cut-off level of 1:32. In case of an active Q fever infection, antibiotic treatment is recommended and serological follow up is performed. In the control group, serum is frozen for analysis after delivery. The primary endpoint is a maternal (chronic Q fever or reactivation) or obstetric complication (low birth weight, preterm delivery or fetal death) in Q fever positive women. Secondary aims pertain to the course of infection in pregnant women, diagnostic accuracy of laboratory tests used for screening, histo-pathological abnormalities of the placenta of Q fever positive women, side effects of therapy, and costs. The analysis will be according to the intention-to-screen principle, and cost-effectiveness analysis will be performed by comparing the direct and indirect costs between the intervention and control group.

Discussion: With this study we aim to provide insight into the balance of risks of undetected and detected Q fever during pregnancy.

Trial Registration: ClinicalTrials.gov, protocol record NL30340.042.09.
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http://dx.doi.org/10.1186/1472-6874-10-32DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2987891PMC
November 2010

Real-time PCR with serum samples is indispensable for early diagnosis of acute Q fever.

Clin Vaccine Immunol 2010 Feb 23;17(2):286-90. Epub 2009 Dec 23.

Jeroen Bosch Hospital, Department of Medical Microbiology and Infection Control, P.O. Box 90153, 5200 ME 's-Hertogenbosch, The Netherlands.

The world's largest Q fever outbreak is ongoing in The Netherlands with around 3,000 confirmed cases since the first half of 2007. Increased awareness has resulted in early referral of patients for diagnostics. An important drawback to serological diagnosis of acute Q fever is the lag phase in antibody response. Therefore, we evaluated the performance of a real-time PCR for detection of Coxiella burnetii DNA using serum samples from patients with acute Q fever. PCR, targeting IS1111, was retrospectively performed on acute-phase and follow-up convalescent-phase serum samples from 65 patients with acute Q fever as diagnosed by immunofluorescence assay. The results obtained by PCR were related to disease stage as defined by subsequent appearance of phase II IgM, phase II IgG, phase I IgM, and phase I IgG (IgM-II, IgG-II, IgM-I, and IgG-I, respectively) antibodies and time since onset of disease. In addition, we analyzed seronegative acute-phase serum samples from patients with inconclusive Q fever serology, because no convalescent-phase serum samples were available. PCR was scored positive in 49/50 (98%) seronegative sera, 9/10 (90%) sera with isolated IgM-II antibodies, 3/13 (23%) sera with IgM-II/IgG-II antibodies, 2/41 (5%) sera with IgM-II/IgG-II/IgM-I antibodies, 0/15 (0%) sera with IgM-II/IgG-II/IgM-I/IgG-I antibodies, and 0/1 (0%) serum sample with IgM-II/IgG-II/IgG-I antibodies. The latest time point after onset of disease in which C. burnetii DNA could be detected was at day 17. In patients with inconclusive Q fever serology, PCR was positive in 5/50 (10%) cases. We conclude that real-time PCR with serum samples is indispensable for early diagnosis of acute Q fever. C. burnetii DNA becomes undetectable in serum as the serological response develops.
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http://dx.doi.org/10.1128/CVI.00454-09DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2815520PMC
February 2010

Markers of infection in inpatients and outpatients with acute Q-fever.

Clin Chem Lab Med 2009 ;47(11):1407-9

Laboratory for Clinical Chemistry and Haematology, Jeroen Bosch Hospital, 's-Hertogenbosch, The Netherlands.

Background: Query-fever (Q-fever) is a zoonotic infection caused by the intracellular Gram-negative coccobacillus Coxiella burnetii. A large ongoing outbreak of Q-fever has been reported in the Netherlands. We studied various markers of infection in inpatients (hospitalised) and outpatients (treated by a general physician) with acute Q-fever in relation to disease severity.

Methods: Leukocyte counts, C-reactive protein (CRP) and procalcitonin (PCT) concentrations were measured in 25 inpatients and 40 outpatients upon presentation with acute Q-fever. Chest X-rays, if available, were analysed and confusion, urea, respiratory rate, blood pressure-age 65 (CURB-65) scores, indicating severity of pneumonia, were calculated.

Results: CRP was the only marker that significantly differentiated between inpatients and outpatients. It was increased in all patients from both groups. Leukocyte counts and PCT concentrations did not differ between inpatients and outpatients. Overall, only 13/65 patients had an increased leukocyte count and only 11/65 patients presented with PCT concentrations indicative of possible bacterial respiratory tract infection. Infiltrative changes on the chest X-ray were observed in the majority of patients. CURB-65 score was 0+/-1 (mean+/-SD).

Conclusions: Acute Q-fever, a relatively mild pneumonia with low CURB-65 scores, specifically induces a response in CRP, while PCT concentrations and leukocytes are within the normal range or increased only marginally.
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http://dx.doi.org/10.1515/CCLM.2009.307DOI Listing
February 2010
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