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 2006–2012. 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

A Dutch nationwide evaluation of serological assays for detection of Borrelia antibodies in clinically well-defined patients

Numerous tests for the detection of antibodies against Borrelia burgdorferi are commercially available. Manufacturer-derived data invariably report a high sensitivity and specificity, but comparative studies demonstrate large differences in clinical practice, especially with regard to specificity. We retrospectively collected data from validation studies for B. burgdorferi antibody assays from 8 laboratories in the Netherlands. The total number of samples was 809. Samples were selected based on clinical and laboratory parameters. We included samples from patients with erythema migrans, acrodermatitis chronicum atrophicans, and neuroborreliosis; cross-reactivity controls; and healthy controls. Data are presented from 10 enzyme-linked immunosorbent assays and 5 immunoblots. For manifestations of B. burgdorferi infection with short disease duration, the positivity rate of the assays varied significantly. In patients with long disease duration, the positivity rate differed only marginally. In cross-reactivity controls, there was significant variation in the reactivity rate. The majority of false-positive reactions are of the IgM isotype. © 2015 Elsevier Inc.

Galactomannan detection for invasive aspergillosis in immunocompromised patients

Invasive aspergillosis is the most common life-threatening opportunistic invasive mycosis in immunocompromised patients. A test for invasive aspergillosis should neither be too invasive nor too great a burden for the already weakened patient. The serum galactomannan enzyme-linked immunosorbent assay (ELISA) seems to have the potential to meet both requirements. To obtain summary estimates of the diagnostic accuracy of galactomannan detection in serum for the diagnosis of invasive aspergillosis. We searched MEDLINE, EMBASE and Web of Science with both MeSH terms and text words for both aspergillosis and the sandwich ELISA. We checked the reference lists of included studies and review articles for additional studies. We conducted the searches in February 2014. We included cross-sectional studies, case-control designs and consecutive series of patients assessing the diagnostic accuracy of galactomannan detection for the diagnosis of invasive aspergillosis in patients with neutropenia or patients whose neutrophils are functionally compromised. The reference standard was composed of the criteria given by the European Organization for Research and Treatment of Cancer (EORTC) and the Mycoses Study Group (MSG). Two review authors independently assessed quality and extracted data. We carried out meta-analysis using the bivariate method. We investigated sources of heterogeneity by adding potential sources of heterogeneity to the model as covariates. We included 54 studies in the review (50 in the meta-analyses), containing 5660 patients, of whom 586 had proven or probable invasive aspergillosis. When using an optical density index (ODI) of 0.5 as a cut-off value, the sensitivity of the test was 82% (73% to 90%) and the specificity was 81% (72% to 90%). At a cut-off value of 1.0 ODI, the sensitivity was 72% (65% to 80%) and the specificity was 88% (84% to 92%). At a cut-off value of 1.5 ODI, the sensitivity was 61% (47% to 75%) and the specificity was 93% (89% to 97%). None of the potential sources of heterogeneity had a statistically significant effect on either sensitivity or specificity. If we used the test at a cut-off value of 0.5 ODI in a population of 100 patients with a disease prevalence of 9% (overall median prevalence), two patients who have invasive aspergillosis would be missed (sensitivity 82%, 18% false negatives), and 17 patients would be treated unnecessarily or referred unnecessarily for further testing (specificity 81%, 19% false negatives). If we used the test at a cut-off value of 1.5 in the same population, that would mean that four invasive aspergillosis patients would be missed (sensitivity 61%, 39% false negatives), and six patients would be treated or referred for further testing unnecessarily (specificity 93%, 7% false negatives). These numbers should, however, be interpreted with caution because the results were very heterogeneou

Limited humoral and cellular responses to Q fever vaccination in older adults with risk factors for chronic Q fever

Contains fulltext : 125612.pdf (publisher's version ) (Closed access)OBJECTIVES: In the Netherlands, people at risk for chronic Q fever were vaccinated against Coxiella burnetii with the inactivated whole cell vaccine Q-vax(R). We aimed to measure the immune responses to C. burnetii six and twelve months after vaccination in this relevant population. METHODS: In 260 vaccinees, antibody responses were assessed by immunofluorescence assay (IFA), complement fixation test and ELISA. The cellular immune responses were assessed by measuring C. burnetii-specific interferon (IFN)-gamma production in blood. Serological results of 200 individuals with past Q fever were used for comparison. RESULTS: At six months, 46% of vaccinees showed low IFA antibody titres and 67% had a positive IFN-gamma assay; At twelve months, both were 60%. In contrast, individuals with a past Q fever were seropositive in 99.5% at six and twelve months, with relatively higher IFA titres. Interestingly, vaccinees with positive IFN-gamma assay pre-vaccination, showed a higher seroconversion rate than IFN-gamma negative vaccinees: 74% vs. 41% (p < 0.001). CONCLUSIONS: The immune response after Q-vax(R) vaccination is lower and restricted to a smaller proportion than found after past Q fever and than previously described after vaccination, suggesting decreased vaccine immunogenicity in this high-risk population. A positive IFN-gamma assay before vaccination in seronegative vaccinees likely points to pre-existing immunity resulting in boosting by vaccination