Characteristics of pediatric patients with enterovirus meningitis and no cerebral fluid pleocytosis.

UNLABELLED: Human non-polio enterovirus (EV) is the most important cause of aseptic meningitis in children. Only a few studies report the lack of cerobrospinal fluid (CSF) pleocytosis in children with confirmed EV meningitis; however, the characteristics of these children have not been well defined. This paper describes the clinical and laboratory features of EV meningitis in children with no CSF pleocytosis. Clinical, laboratory, and virological data of Dutch patients <16 years diagnosed with EV meningitis, between 2003 and 2008, were analyzed retrospectively. Data of children with and without CSF pleocytosis were compared. A total of 149 children were infected with EV. Patients presented mainly with fever (n = 113), malaise (n = 43), abdominal pain (n = 47), and irritability (n = 61). Of the 60 patients with EV meningitis, 23 had no pleocytosis. Those who lacked CSF pleocytosis were younger [odds ratio (OR) 1.00; 95% confidence interval (CI) 1.000-1.002; p = 0.001], had experienced drowsiness more (OR 9.60; 95% CI 2.24-41.15; p = 0.002), had lower white blood cell counts (OR 0.73; 95% CI 0.61-0.89; p = 0.001), and had higher C-reactive protein (OR 1.13; 95% CI 1.03-1.23; p = 0.006) than those with pleocytosis. CONCLUSION: These findings show that EV meningitis occurs in the absence of CSF pleocytosis, particularly in young infants, meaning that EV meningitis in this age group cannot be solely excluded by the absence of CSF pleocytosis. They also confirm the importance of genome detection in the diagnosis of EV meningitis in young infants.

Identification by genotyping of a commercial antigen preparation as the source of a laboratory contamination with Coxiella burnetii and as an unexpected rich source of control DNA.

By performing genotyping, a laboratory contamination involving Q fever was traced back to the antigen preparation used in a commercially available complement fixation test. It was established that such antigen preparations contain relatively high loads of DNA/RNA, making them potential sources of contamination but also convenient preparations for control material.

Utility of real-time PCR for diagnosis of Legionnaires' disease in routine clinical practice.

The main aim of our study was to determine the added value of PCR for the diagnosis of Legionnaires' disease (LD) in routine clinical practice. The specimens were samples submitted for routine diagnosis of pneumonia from December 2002 to November 2005. Patients were evaluated if, in addition to PCR, the results of at least one of the following diagnostic tests were available: (i) culture for Legionella spp. on buffered charcoal yeast extract agar or (ii) detection of Legionella pneumophila antigen in urine specimens. Of the 151 evaluated patients, 37 (25%) fulfilled the European Working Group on Legionella Infections criteria for a confirmed case of LD (the "gold standard"). An estimated sensitivity, specificity, and overall percent agreement of 86% (32 of 37; 95% confidence interval [CI] = 72 to 95%), 95% (107 of 112; 95% CI = 90 to 98%), and 93% (139 of 149), respectively, were found for 16S rRNA-based PCR, and corresponding values of 92% (34 of 37; 95% CI = 78 to 98%), 98% (110 of 112; 95% CI = 93 to 100%), and 97% (144 of 149), respectively, were found for the mip gene-based PCR. A total of 35 patients were diagnosed by using the urinary antigen test, and 34 were diagnosed by the 16S rRNA-based PCR. With the mip gene PCR one more case of LD (n = 36; not significant) was detected. By combining urinary antigen test and the mip gene PCR, LD was diagnosed in an additional 4 (11%) patients versus the use of the urinary antigen test alone. The addition of a L. pneumophila-specific mip gene PCR to a urinary antigen test is useful in patients with suspected LD who produce sputum and might allow the early detection of a significant number of additional patients.

Evaluation of real-time PCR for the early detection of Legionella pneumophila DNA in serum samples.

Legionella pneumonia can be difficult to diagnose. Existing laboratory tests all have shortcomings, especially in the ability to diagnose Legionnaires' disease (LD) at an early stage of the disease in a specimen that is readily obtainable. The aim of this study was to assess the performance of PCR as a rapid diagnostic method and to compare the results of different PCR assays of serum samples from patients with LD. Samples included 151 serum samples from 68 patients with proven LD and 60 serum samples from 36 patients with respiratory tract infections other than Legionella. PCR assays were based on the 5S rRNA gene, 16S rRNA gene and the mip gene. The samples from patients with infections caused by pathogens other than Legionella all tested negative in PCR. Among the patients with proven LD 54.4 % (37/68) tested positive in 5S rRNA PCR, 52.9 % (36/68) in mip gene PCR and 30.9 % (21/68) in 16S rRNA PCR in the first available serum sample. The association between threshold cycle value in 5S PCR positive serum samples (n=49) and C-reactive protein value was determined, and showed a strong negative correlation (Pearson correlation coefficient r=-0.63, P<0.0001). In addition to existing tests for the diagnosis of LD, detection of Legionella DNA in serum could be a useful tool for early diagnosis of LD caused by any Legionella species and serogroup, and has the potential to provide a diagnosis in a time frame that could affect initial infection management.

Risk factors for acute respiratory tract infections in general practitioner patients in The Netherlands: a case-control study.

BACKGROUND: Acute respiratory tract infections (ARTI) are an important public health problem. Improved identification of risk factors might enable targeted intervention. Therefore we carried out a case-control study with the aim of identifying environmental risk factors for ARTI consultations in the Dutch general population. METHODS: A subset of patients visiting their GP in the period of 2000-2003 with an ARTI (cases) and age-matched controls (visiting for other complaints) were included in a case-control study. They were asked to complete a questionnaire about potential risk factors. Conditional logistic regression was used to calculate odds ratio's (OR) and 95% confidence intervals (CI) to estimate the independent effect of potential risk factors. RESULTS: A total of 493 matched pairs of case and control subjects were enrolled. Exposure to persons with respiratory complaints, both inside and outside the household, was found to be an independent risk factor for visiting a GP with an ARTI (respectively ORadj = 1.9 and ORadj = 3.7). Participants exposed to dampness or mould at home (ORadj=0.5) were significantly less likely to visit their GP. In accordance with the general risk of consultations for ARTI, participants with a laboratory-confirmed ARTI who were exposed to persons with respiratory complaints outside the household were also significantly more likely to visit their GP (ORadj=2.5). CONCLUSION: This study confirmed that heterogeneity in the general population as well as in pathogens causing ARTI makes it complicated to detect associations between potential risk factors and respiratory infections. Whereas it may be difficult to intervene on the risk posed by exposure to persons with respiratory complaints, transmission of ARTI in the general population might be reduced by improved hygienic conditions.

Molecular evidence for the ubiquitous presence of Legionella species in Dutch tap water installations.

Our aim was to investigate the occurrence and identity of Legionella spp. in Dutch tap water installations using culture, real-time PCR and sequence analysis. The PCR assays used were a 16S rRNA gene based PCR with both a Legionella species specific probe and a L. pneumophila specific probe and a L. pneumophila-specific PCR based on the sequence of the mip gene. A total of 357 water samples from 250 locations in The Netherlands was investigated. The detection rates of Legionella spp. were 2,2% (8 of 357) by culture, and 87,1% (311 of 357) by PCR. The majority of samples was found to contain Legionella species other than L. pneumophila. These comprised of Legionella Like Amoebal Pathogens (LLAPs), L. busanensis, L. worsliensis and others. Fourteen (3,9%) samples were positive for L. pneumophila by either culture, 16S rRNA based PCR and/or mip based PCR. It is apparent from this study that Legionella spp. DNA is ubiquitous in Dutch potable water samples. Our findings further suggest that LLAPs and viable but nonculturable (VBNC) Legionella represent a large proportion of the population in man-made environments.

Transient paresis associated with cat-scratch disease: case report and literature review of vertebral osteomyelitis caused by Bartonella henselae.

Cat-scratch disease (CSD) rarely presents as vertebral osteomyelitis. We describe a case with paresis of the arm with total recovery after antibiotic and neurosurgical therapy. We reviewed 20 other cases of CSD vertebral osteomyelitis in the literature. This diagnosis should be considered in patients with systemic symptoms, back pain, and cat contact. The prognosis is generally good.

Sensitivity of three serum antibody tests in a large outbreak of Legionnaires' disease in the Netherlands.

In 1999, an outbreak involving 188 patients with Legionnaires' disease (LD) occurred at a flower show in the Netherlands. This large outbreak provided the opportunity to evaluate serum antibody tests to assay anti-Legionella pneumophila, since limited data are available on the sensitivity of these tests. The sensitivities of an indirect serotype 1-6 immunofluorescence antibody test (IFAT), a rapid micro-agglutination test (RMAT) IgM serotype 1 antibody assay, and an ELISA to detect IgM and IgG serotype 1-7 antibodies, were evaluated using serum samples from LD patients related to the 1999 outbreak. Sensitivity was calculated using positive culture and/or a positive urinary antigen test as the gold standard in outbreak-related patients with radiographically confirmed pneumonia who fulfilled the epidemiological criteria. The IFAT, RMAT and ELISA showed sensitivities of 61, 44 and 64%, respectively. The sensitivity of the three tests combined was 67%. In epidemic situations, however, high standing titres may be included in the laboratory evidence of LD cases. In the study population, high standing titres were found in 16% of cases. If the presence of high standing antibody titres was added to the criteria of a positive test, the sensitivities of IFAT, RMAT and ELISA were 86, 48 and 75%, respectively. The sensitivity was 91% for all tests combined. The higher sensitivity for the combined use of tests is offset by a reduction in specificity to 97.6%. The results of this study indicate that using a combination of serologic tests in pneumonia patients suspected to have LD does not substantially improve sensitivity. The results suggest that in the microbiological diagnosis of LD, both IFAT and ELISA are reasonably sensitive assays. In an epidemic situation, both tests are highly sensitive, the IFAT more so than the ELISA.

Detection and quantification of Legionella pneumophila DNA in serum: case reports and review of the literature.

Legionella pneumonia can be difficult to diagnose. Existing laboratory tests all have shortcomings, especially the ability to diagnose all Legionella spp. at an early stage. Detection of Legionella DNA in serum can be a valuable tool for the diagnosis of Legionnaires' disease (LD). This report describes two patients with LD diagnosed by PCR using serum samples. In addition, quantification of L. pneumophila DNA using real-time PCR during the course of illness was carried out. The results obtained mirrored both the clinical condition and C-reactive protein values during the course of the illness. Quantification of Legionella DNA in serum using real-time PCR could be a valuable tool to monitor the effects of antimicrobial therapy in patients with LD.

Treatment with clarithromycin prior to coronary artery bypass graft surgery does not prevent subsequent cardiac events.

BACKGROUND: Recently, it has been suggested that Chlamydia pneumoniae possibly plays a possible role in the pathogenesis of atherosclerosis. We investigated whether treatment with clarithromycin prior to coronary artery bypass graft (CABG) surgery would prevent subsequent cardiovascular events and mortality. METHODS: Patients who were scheduled for CABG surgery were randomly assigned to receive either clarithromycin or placebo until the day of surgery in a double-blind trial. During the 2 years of follow-up, mortality and cardiovascular events were assessed. RESULTS: Follow-up at 2 years was achieved for 473 patients. The mean duration of treatment was 16 days. Patient characteristics at baseline were well balanced between the 2 treatment groups. Mortality was equal in the 2 groups: 10 (4.2%) of 238 patients in the clarithromycin group and 9 (3.8%) of 235 patients in the placebo group (relative risk, 1.10; 95% CI, 0.42-2.89; P=1.0). Also, there were no significant differences in the proportion of patients who experienced cardiovascular events during the follow-up period: 20 (8.4%) of 238 patients in the clarithromycin group and 19 (8.1%) of 235 patients in the placebo group (relative risk, 1.04; 95% CI, 0.55-1.98; P=1.0). The overall rate of such events was 58 (12.3%) of 473 patients. CONCLUSIONS: Treatment with clarithromycin in patients scheduled for CABG surgery did not reduce the subsequent occurrence of cardiovascular events or mortality during a 2-year follow-up period.

Comparison of three Legionella urinary antigen assays during an outbreak of legionellosis in Belgium.

During an outbreak of legionellosis in Belgium, urine samples of 32 legionellosis patients were tested with three Legionella urinary antigen assays: the Biotest enzyme immunoassay (EIA) kit, the Binax EIA kit and the Binax NOW Immunochromatographic Test kit. The three tests were concomitantly compared. The test sensitivities on the first urine samples were 65.6 % for the Biotest EIA, 50.0 % for the Binax EIA and 56.3 % for the Binax NOW. Testing of a second urine sample increased the sensitivities to 71.9 %, 59.4 % and 65.6 %, respectively. The differences were not statistically significant. In outbreak settings, testing second samples from patients presenting with symptoms but initially testing negative and/or concentrating urine samples for testing might be valuable additions to the urinary antigen test to increase the sensitivities of the tests.

Encephalopathy associated with influenza A.

We report a 3-year-old boy with influenza A virus-associated encephalopathy. The diagnosis was based on clinical findings, magnetic resonance imaging, repeated isolation of influenza A virus from nasopharyngeal aspirate and seroconversion between acute and convalescent sera. The clinical picture was characterized by fever and aphasia followed by seizures and a rapid deterioriation of consciousness 2 days later. This patient illustrates that influenza A-associated encephalopathy with severe neurological deficit can occur with atypical distribution of brain lesions during the course of the illness, while initial brain MRI and laboratory findings of cerebrospinal fluid are normal, including reverse transcription polymerase chain reaction.

Profiling of humoral response to influenza A(H1N1)pdm09 infection and vaccination measured by a protein microarray in persons with and without history of seasonal vaccination.

BACKGROUND: The influence of prior seasonal influenza vaccination on the antibody response produced by natural infection or vaccination is not well understood. METHODS: We compared the profiles of antibody responses of 32 naturally infected subjects and 98 subjects vaccinated with a 2009 influenza A(H1N1) monovalent MF59-adjuvanted vaccine (Focetria, Novartis), with and without a history of seasonal influenza vaccination. Antibodies were measured by hemagglutination inhibition (HI) assay for influenza A(H1N1)pdm09 and by protein microarray (PA) using the HA1 subunit for seven recent and historic H1, H2 and H3 influenza viruses, and three avian influenza viruses. Serum samples for the infection group were taken at the moment of collection of the diagnostic sample, 10 days and 30 days after onset of influenza symptoms. For the vaccination group, samples were drawn at baseline, 3 weeks after the first vaccination and 5 weeks after the second vaccination. RESULTS: We showed that subjects with a history of seasonal vaccination generally exhibited higher baseline titers for the various HA1 antigens than subjects without a seasonal vaccination history. Infection and pandemic influenza vaccination responses in persons with a history of seasonal vaccination were skewed towards historic antigens. CONCLUSIONS: Seasonal vaccination is of significant influence on the antibody response to subsequent infection and vaccination, and further research is needed to understand the effect of annual vaccination on protective immunity.

A clinical evaluation of statin pleiotropy: statins selectively and dose-dependently reduce vascular inflammation.

Statins are thought to reduce vascular inflammation through lipid independent mechanisms. Evaluation of such an effect in atherosclerotic disease is complicated by simultaneous effects on lipid metabolism. Abdominal aortic aneurysms (AAA) are part of the atherosclerotic spectrum of diseases. Unlike atherosclerotic occlusive disease, AAA is not lipid driven, thus allowing direct evaluation of putative anti-inflammatory effects. The anti-inflammatory potency of increasing doses (0, 20 or 40 mg/day) simvastatin or atorvastatin was evaluated in 63 patients that were at least 6 weeks on statin therapy and who underwent open AAA repair. A comprehensive analysis using immunohistochemistry, mRNA and protein analyses was applied on aortic wall samples collected during surgery. The effect of statins on AAA growth was analyzed in a separate prospective study in incorporating 142 patients. Both statins equally effectively and dose-dependently reduced aortic wall expression of NFκB regulated mediators (i.e. IL-6 (P<0.001) and MCP-1 (P<0.001)); shifted macrophage polarization towards a M2 phenotype (P<0.0003); selectively reduced macrophage-related markers such as cathepsin K and S (P<0.009 and 0.0027 respectively), and ALOX5 (P<0.0009), and reduced vascular wall NFκB activity (40 mg/day group, P<0.016). No effect was found on other cell types. Evaluation of the clinical efficacy of statins to reduce AAA progression did not indicate an effect of statins on aneurysm growth (P<0.337). Hence, in the context of AAA the clinical relevance of statins pleiotropy appears minimal.

Comparison of the performance of IFA, CFA, and ELISA assays for the serodiagnosis of acute Q fever by quality assessment.

The indirect immunofluorescence assay (IFA) is considered the reference method for diagnosing Q fever, but serology is also performed by complement fixation assay (CFA) or enzyme-linked immunosorbent assay (ELISA). However, comparability between these assays is not clear, and therefore a quality assessment was performed. A total of 25 serum samples from negative controls, Q fever patients, and a serial diluted high-positive sample were analyzed in 10 Dutch laboratories. Six laboratories performed CFA, 5 performed IFA, and 5 performed ELISAs. Three international reference laboratories from Australia, France, and the USA also participated in this study. Qualitative values between laboratories using the same methods were within close range, and all 3 methods correctly identified acute Q fever patients. The IFA, ELISA, and CFA are all suitable serodiagnostic assays to diagnose acute Q fever, but the IFA remains an important tool in the follow-up of patients and in identifying patients at risk for developing chronic Q fever.