scholarly journals Evaluation of Commonly Used Serological Tests for Detection of Coxiella burnetii Antibodies in Well-Defined Acute and Follow-Up Sera

2012 ◽  
Vol 19 (7) ◽  
pp. 1110-1115 ◽  
Author(s):  
M. C. A. Wegdam-Blans ◽  
C. C. H. Wielders ◽  
J. Meekelenkamp ◽  
J. M. Korbeeck ◽  
T. Herremans ◽  
...  

ABSTRACTIn this study, we comparedCoxiella burnetiiIgG phase I, IgG phase II, and IgM phase II detection among a commercially available enzyme-linked immunosorbent assay (ELISA) (Virion/Serion), an indirect fluorescent antibody test (IFAT) (Focus Diagnostics), and a complement fixation test (CFT) (Virion/Serion). For this, we used a unique collection of acute- and convalescent-phase sera from 126 patients with acute Q fever diagnosed by positiveCoxiella burnetiiPCR of blood. We were able to establish a reliable date of onset of disease, since DNA is detectable within 2 weeks after the start of symptoms. In acute samples, att= 0, IFAT demonstrated IgM phase II antibodies in significantly more sera than did ELISA (31.8% versus 19.7%), although the portion of solitary IgM phase II was equal for IFAT and for ELISA (18.2% and 16.7%, respectively). Twelve months after the diagnosis of acute Q fever, 83.5% and 62.2% of the sera were still positive for IgM phase II with IFAT and ELISA, respectively. At 12 months IFAT IgG phase II showed the slowest decline. Therefore, definitive serological evidence of acute Q fever cannot be based on a single serum sample in areas of epidemicity and should involve measurement of both IgM and IgG antibodies in paired serum. Based on IgG phase II antibody detection in paired samples (at 0 and 3 months) from 62 patients, IFAT confirmed more cases than ELISA and CFT, but the differences were not statically significant (100% for IFAT, 95.2% for ELISA, and 96.8% for CFT). This study demonstrated that the three serological tests are equally effective in diagnosing acute Q fever within 3 months of start of symptoms. In follow-up sera, more IgG antibodies were detected by IFAT than by ELISA or CFT, making IFAT more suitable for prevaccination screening programs.

2012 ◽  
Vol 19 (10) ◽  
pp. 1661-1666 ◽  
Author(s):  
C. C. H. Wielders ◽  
L. M. Kampschreur ◽  
P. M. Schneeberger ◽  
M. M. Jager ◽  
A. I. M. Hoepelman ◽  
...  

ABSTRACTLittle is known about the effect of timing of antibiotic treatment on development of IgG antibodies following acute Q fever. We studied IgG antibody responses in symptomatic patients diagnosed either before or during development of the serologic response toCoxiella burnetii. Between 15 and 31 May 2009, 186 patients presented with acute Q fever, of which 181 were included in this retrospective study: 91 early-diagnosed (ED) acute Q fever patients, defined as negative IgM phase II enzyme-linked immunosorbent assay (ELISA) and positive PCR, and 90 late-diagnosed (LD) acute Q fever patients, defined as positive/dubious IgM phase II ELISA and positive immunofluorescence assay (IFA). Follow-up serology at 3, 6, and 12 months was performed using IFA (IgG phase I and II). High IgG antibody titers were defined as IgG phase II titers of ≥1:1,024 together with IgG phase I titers of ≥1:256. At 12 months, 28.6% of ED patients and 19.5% of LD patients had high IgG antibody titers (P= 0.17). No statistically significant differences were found in frequencies of IgG phase I and IgG phase II antibody titers at all follow-up appointments for adequately and inadequately treated patients overall, as well as for ED and LD patients analyzed separately. Additionally, no significant difference was found in frequencies of high antibody titers and between early (treatment started within 7 days after seeking medical attention) and late timing of treatment. This study indicates that early diagnosis and antibiotic treatment of acute Q fever do not prohibit development of the IgG antibody response.


2012 ◽  
Vol 140 (11) ◽  
pp. 1950-1954 ◽  
Author(s):  
C. F. H. RAVEN ◽  
J. L. A. HAUTVAST ◽  
T. HERREMANS ◽  
A. C. A. P. LEENDERS ◽  
P. M. SCHNEEBERGER

SUMMARYWe investigated the positive predictive value (PPV) of a solitary positive immunoglobulin M (IgM) phase II response for the serodiagnosis of acute Q fever detected with either an indirect immunofluorescence assay (IFA) or an enzyme-linked immunosorbent assay (ELISA). Initial and follow-up sera from patients suspected of acute Q fever were included if initially only IgM phase II tested positive with IFA in 2008 (n=92), or ELISA in 2009 (n=85). A seroconversion for Q fever was defined as an initial sample being IgG phase II negative but positive in the follow-up sample. The PPV of an initial isolated IgM phase II result detected by IFA or ELISA was 65% and 51%, respectively, and therefore appeared not to adequately predict acute Q fever. For this reason it cannot be used as a diagnostic criterion nor should it be included in public health notification without confirmation with other markers or a follow-up serum sample.


Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1075
Author(s):  
Salvatore Ledda ◽  
Cinzia Santucciu ◽  
Valentina Chisu ◽  
Giovanna Masala

Q fever is a zoonosis caused by Coxiella burnetii, a Gram-negative pathogen with a complex life cycle and a high impact on public and animal health all over the world. The symptoms are indistinguishable from those belonging to other diseases, and the disease could be symptomless. For these reasons, reliable laboratory tests are essential for an accurate diagnosis. The aim of this study was to validate a novel enzyme-linked immunosorbent assay (ELISA) test, named the Chorus Q Fever Phase II IgG and IgM Kit (DIESSE, Diagnostica Senese S.p.A), which is performed by an instrument named Chorus, a new device in medical diagnostics. This diagnostic test is employed for the detection of antibodies against C. burnetii Phase II antigens in acute disease. Our validation protocol was performed according to the Italian Accreditation Body (ACCREDIA) (Regulation UNI CEI EN ISO/IEC 17025:2018 and 17043:2010), OIE (World Organization for Animal Health), and Statement for Reporting Studies of Diagnostic Accuracy (STARD). Operator performance was evaluated along with the analytical specificity and sensitivity (ASp and ASe) and diagnostic accuracy of the kit, with parameters such as diagnostic specificity and sensitivity (DSp and DSe) and positive and negative predictive values (PPV and NPV), in addition to the repeatability. According to the evaluated parameters, the diagnostic ELISA test was shown to be suitable for validation and commercialization as a screening method in human sera and a valid support for clinical diagnostics.


2017 ◽  
Vol 55 (12) ◽  
pp. 3444-3453 ◽  
Author(s):  
Virginia Balouz ◽  
Luciano J. Melli ◽  
Romina Volcovich ◽  
Guillermo Moscatelli ◽  
Samanta Moroni ◽  
...  

ABSTRACTChagas disease is caused by the protozoan parasiteTrypanosoma cruzi. Assessment of parasitological cure upon treatment with available drugs relies on achieving consistent negative results in conventional parasitological and serological tests, which may take years to assess. Here, we evaluated the use of a recombinantT. cruziantigen termed trypomastigote small surface antigen (TSSA) as an early serological marker of drug efficacy inT. cruzi-infected children. A cohort of 78 pediatric patients born toT. cruzi-infected mothers was included in this study. Only 39 of the children were infected withT. cruzi, and they were immediately treated with trypanocidal drugs. Serological responses against TSSA were evaluated in infected and noninfected populations during the follow-up period using an in-house enzyme-linked immunosorbent assay (ELISA) and compared to conventional serological methods. Anti-TSSA antibody titers decreased significantly faster than anti-whole parasite antibodies detected by conventional serology both inT. cruzi-infected patients undergoing effective treatment and in those not infected. The differential kinetics allowed a significant reduction in the required follow-up periods to evaluate therapeutic responses or to rule out maternal-fetal transmission. Finally, we present the case of a congenitally infected patient with an atypical course in whom TSSA provided an early marker forT. cruziinfection. In conclusion, we showed that TSSA was efficacious both for rapid assessment of treatment efficiency and for early negative diagnosis in infants at risk of congenitalT. cruziinfection. Based upon these findings we propose the inclusion of TSSA for refining the posttherapeutic cure criterion and other diagnostic needs in pediatric Chagas disease.


Author(s):  
Ayse Kilic ◽  
Hakan Kalender

Q fever is a zoonotic disease that occurs worldwide and is caused by the obligate intracellular bacterium Coxiella burnetii. Infected animals are usually asymptomatic, but infection can cause abortion and stillbirth in ruminants. The main purpose of this study was to evaluate prevalance of Coxiella burnetii infection in aborted and nonaborted sheep serum samples in Eastern Anatolia region by using enzyme-linked immunosorbent assay (ELISA). The determine of prevalance in sheep flocks from four provinces (Elazig, Malatya, Tunceli, Bitlis) and tested for anti-C.burnetii antibody detection, by means of Chekit Q fever Elisa kit. 350 serum samples obtained from flocks belonging aborted sheep showed that a total of 56 (16%) were detected seropositivity, whereas 171 serum samples obtained from nonaborted sheep flocks in 13 of the 171 (7.60%) for C.burnetii in seropositivity were observed. Coxiellosis should be considered an important cause of sheep with abortion history and nonaborted in Elazig and neighboring provinces.


2017 ◽  
Vol 5 (38) ◽  
Author(s):  
Paul A. Beare ◽  
Brendan M. Jeffrey ◽  
Craig A. Martens ◽  
Robert A. Heinzen

ABSTRACT In the current study, we determined the draft genome sequences of three Coxiella burnetii human disease isolates. The Coxiella burnetii Turkey (RSA315) and Dyer (RSA345) strains were isolated from acute Q fever patients, while the Ko (Q229) strain was isolated from a Q fever endocarditis patient.


2011 ◽  
Vol 18 (6) ◽  
pp. 963-968 ◽  
Author(s):  
Mischa M. Jager ◽  
Gezina Weers-Pothoff ◽  
Mirjam H. A. Hermans ◽  
Jamie C. E. Meekelenkamp ◽  
Jeroen J. A. Schellekens ◽  
...  

ABSTRACTIn 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 toCoxiella burnetiiphase 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.


2014 ◽  
Vol 21 (3) ◽  
pp. 354-359 ◽  
Author(s):  
Murugesan Kanagavel ◽  
Santhanam Shanmughapriya ◽  
Kumarasamy Anbarasu ◽  
Kalimuthusamy Natarajaseenivasan

ABSTRACTLeptospirosis is a reemerging infectious disease that is underdiagnosed and under-recognized due to low-sensitivity and cumbersome serological tests. Rapid reliable alternative tests are needed for early diagnosis of the disease. Considering the importance of the pathogenesis-associated leptospiral LigA protein expressedin vivo, we have evaluated its application in the diagnosis of the acute form of leptospirosis. The C-terminal coding sequence ofligA(ligA-C) was cloned into pET15b and expressed inEscherichia coli. Furthermore, the B-cell-specific epitopes were predicted and were synthesized as peptides for evaluation along with recombinant LigA-C. Epitope 1 (VVIENTPGK), with a VaxiJen score of 1.3782, and epitope 2 (TALSVGSSK), with a score of 1.2767, were utilized. A total of 140 serum samples collected from leptospirosis cases during the acute stage of the disease and 138 serum samples collected from normal healthy controls were utilized for evaluation. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the recombinant LigA-C-specific IgM enzyme-linked immunosorbent assay (ELISA) and were found to be 92.1%, 97.7%, 92.8%, and 97.5%, respectively. Epitopes 1 and 2 used in the study showed 5.1 to 5.8% increased sensitivity over recombinant LigA-C in single and combination assays for IgM antibody detection. These findings suggest that these peptides may be potential candidates for the early diagnosis of leptospirosis.


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