Value of Serological Testing for Diagnosis of Legionellosis in Outbreak Patients

Rojas, Almudena; Navarro, María Dolores; Fornés, Francisca E.; Serra, Estefanía; Simarro, Encarnación; Rojas, José; Ruiz, J.

doi:10.1128/jcm.43.8.4022-4025.2005

Cited by 16 publications

(33 citation statements)

References 26 publications

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“…However, IgM may be present later in some confirmed cases, limiting the usefulness of the assay for early diagnosis in all patients. In a study by Rojas et al, serum antibody detection (Vircell) and urine antigen detection techniques (Binax Now) were compared in samples from 116 patients epidemiologically characterized as belonging to a legionellosis outbreak (11). ELISA for IgM, ELISA for IgG plus IgM, antigenuria detection, and IFA for IgM were able to diagnose 72.3%, 60.5%, 53.3%, and 51.4% of patients, respectively.…”

Section: Discussionmentioning

confidence: 99%

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Evaluation of Vircell Enzyme-Linked Immunosorbent Assay and Indirect Immunofluorescence Assay for Detection of Antibodies against Legionella pneumophila

Diederen

Kluytmans

Peeters

2006

Clin Vaccine Immunol

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We evaluated the abilities of the Vircell immunoglobulin G (IgG) and IgM indirect immunofluorescence assay (IFA) for Legionella pneumophila serogroup 1, the IgM and IgG enzyme-linked immunosorbent assay (ELISA) for Legionella pneumophila serogroup 1, and the IgM-plus-IgG ELISA for Legionella pneumophila serogroups 1 to 6 to diagnose Legionnaires' disease (LD) in a well-described sample of patients with and without LD. Also, we determined the agreements, sensitivities, and specificities of the different Vircell assays in comparison to a validated ELISA (Serion classic ELISA The genus Legionella of the family Legionellaceae includes more than 45 species of fastidious gram-negative bacilli, 20 of which have been reported to infect humans. Bacteria of the family Legionellaceae are ubiquitous in both natural and manmade aqueous environments, and inhalation or aspiration of contaminated water can cause Legionnaires' disease (LD), a severe pneumonia. Legionellae can also cause subclinical infection and extrapulmonary inflammation (5). Legionella pneumophila causes 91% of all reported cases of LD, with serogroup 1 being the most predominant serogroup, causing approximately 80% of all culture-confirmed cases (10).Of the various antibody detection methods that are available to detect Legionella infection, indirect immunofluorescence assays (IFA) and enzyme-linked immunosorbent assays (ELISA) are the most commonly used methodologies (1,3,8). A fourfold or greater increase in the titer of antibody is considered diagnostic. An ELISA is generally preferred over IFA testing because it is less subjective, is thought to be more sensitive than IFA testing, and has the potential for automated performance (1,7,14). The availability of commercial ELISA and IFA kits has resulted in the increasing use of these products, despite the fact that few studies determining their sensitivity and specificity are available.The aim of our study was to evaluate commercial ELISA and IFA (Vircell, S.L., Santa Fé, Granada, Spain) for the detection of antibodies against L. pneumophila. MATERIALS AND METHODSClinical samples. Serum samples were collected between 1999 and 2004 and stored at Ϫ20°C until processing was performed. We included 129 serum samples of 65 patients with proven LD (cases). A proven case of LD was defined as a patient who suffered from symptoms of pneumonia, had radiological signs of infiltration, and showed laboratory evidence of infection with L. pneumophila. Laboratory evidence included one or more of the following criteria: isolation of L. pneumophila from a respiratory sample; a positive urinary antigen test (Binax Now Legionella urinary antigen test; Binax Inc.); a positive PCR result on respiratory tract samples using a 16S rRNA assay (12); a single high titer in immunoglobulin M (IgM) and/or IgG; and/or seroconversion to positive IgM and/or IgG antibodies to L. pneumophila (L. pneumophila antibodies of serogroups 1 to 7) in paired acute-phase and convalescent-phase sera using a commercial enzyme-linked immunosorbent assay (S...

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Section: Discussionmentioning

confidence: 99%

“…Samples were tested for L. pneumophila serogroup 1 IgM and IgG antibodies by an IFA according to the manufacturer's instructions (11). IgG titers of Ն1:64 or IgM titers of Ն1:96 as well as seroconversion (fourfold rise in titer) were considered positive.…”

Section: Methodsmentioning

confidence: 99%

Evaluation of Vircell Enzyme-Linked Immunosorbent Assay and Indirect Immunofluorescence Assay for Detection of Antibodies against Legionella pneumophila

Diederen

Kluytmans

Peeters

2006

Clin Vaccine Immunol

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“…tezza delle richieste di esami di laboratorio (14,15). Da parte sua, il laboratorio presenta un ampio arsenale di test, diretti e indiretti, differenti per efficienza e significato diagnostico, talvolta difficilmente interpretabile dal clinico (1,5).…”

Section: Discussionunclassified

“…La diagnosi di legionellosi è un rompicapo per il clinico a causa di una serie di fattori negativi, a partire dalla non specificità dei sintomi, dalla qualità dei test di laboratorio e, non ultimo, dal pregiudizio di considerare l'infezione come "esotica"(14). Viceversa, Legionella pneumophila è uno dei più comuni agenti eziologici di polmonite, responsabile del 1-5% delle infezioni comunitarie e del 5-10% di quelle nosocomiali (1,5,14,15). Il quadro clinico non specifico dell'infezione contribuisce ad un approccio diagnostico spesso intuitivo, che ha ricadute negative sull'appropria- …”

Section: Introduzioneunclassified

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Combined use of two rapid test in Legionella pneumophila infections

Ciarrocchi¹,

D'Anzeo²,

Cimarelli³

et al. 2009

Microbiol Med

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INTRODUZIONELa legionellosi o Malattia dei Legionari è una severa forma di polmonite causata da Legionella pneumophila, clinicamente indistinguibile da altre forme infettive polmonari. Dal punto di vista epidemiologico, Legionella pneumophila sierotipo1 è responsabile del 91% dei casi di legionellosi in USA (13) e del 95% dei casi in Europa (1,14,15). Per contro, in Australia e Nuova Zelanda Legionella longbeachae è l'agente eziologico nel 50% dei casi (16). La malattia si presenta con esordio brusco, febbre elevata, tosse non produttiva e insufficienza respiratoria, a cui si possono accompagnare stato confusionale con iposodiemia, vomito, diarrea, artromialgie. L'esame Rx rivela uno o più infiltrati essudativi localizzati in diverse aree polmonari (3). La diagnosi di legionellosi è un rompicapo per il clinico a causa di una serie di fattori negativi, a partire dalla non specificità dei sintomi, dalla qualità dei test di laboratorio e, non ultimo, dal pregiudizio di considerare l'infezione come "esotica"(14). Viceversa, Legionella pneumophila è uno dei più comuni agenti eziologici di polmonite, responsabile del 1-5% delle infezioni comunitarie e del 5-10% di quelle nosocomiali (1,5,14,15). Il quadro clinico non specifico dell'infezione contribuisce ad un approccio diagnostico spesso intuitivo, che ha ricadute negative sull'appropria- Uso combinato di due test rapidi nelle infezioni da Legionella pneumophila SUMMARYLegionella pneumophila serogroup 1 (LPSg1) is the prevalent cause of legionellosis in many geographical areas of the world. LPSg1 infection may presents a severe pulmonary disease whose clinical picture is undistinguishable from that of other pneumotropic agents. In addition, a low clinical suspicion and some limitations in diagnostic tests (overall the lack of a "gold standard") make a correct diagnosis of legionnaires' disease easy to be missed. To provide a rapid and suitable diagnosis in patients with clinical signs and symptoms resembling legionnaires' disease, specific antibodies (IgM and IgG) against LPSg1 were detected in 25 sera collected from 22 male and female subjects using a rapid ELISA test (Legionella Chorus). Results were compared with those obtaiened by a standard ELISA (Legionella Vircel), which was set as the reference. In addition, a total of 16 urine specimen from individual patients were furtherly assessed for LPSg1 antigen by a rapid immunochromatographic test (BinaxNOW Legionella). In a control group of 104 healthy subjects, IgM and IgG Legionella Chorus specificity values were 99%.Agreement of IgM and IgG values with those obtained by the Legionella Vircel test were 98% and 95.5%, respectively. In patients with confirmed legionnaires' disease, IgM agreement between the above reported tests was 88%; IgM Legionella Chorus sensitivity was 88%. LPSg1 urine antigen was positive in 12 out of 16 examined specimen.Among these, 9 showed IgM positive sera. Conversely, 4 patients with IgM positive sera were negative upon urinary antigen. Although antigen detection remains the method of c...

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