1
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Crouch CF. Enzyme immunoassays for IgG and IgM antibodies to Toxoplasma gondii based on enhanced chemiluminescence. J Clin Pathol 1995; 48:652-7. [PMID: 7560174 PMCID: PMC502718 DOI: 10.1136/jcp.48.7.652] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
AIMS To evaluate the clinical performance of enzyme immunoassays for IgG and IgM antibodies to Toxoplasma gondii based on enhanced chemiluminescence. METHODS Classification of routine clinical samples from the originating laboratories was compared with that obtained using the chemiluminescence based assays. Resolution of discordant results was achieved by testing in alternative enzyme immunoassays (IgM) or by an independent laboratory using the dye test (IgG). RESULTS Compared with resolved data, the IgM assay was found to be highly specific (100%) with a cut off selected to give optimal performance with respect to both the early detection of specific IgM and the detection of persistent levels of specific IgM (sensitivity 98%). Compared with resolved data, the IgG assay was shown to have a sensitivity and a specificity of 99.4%. CONCLUSIONS The Amerlite Toxo IgM assay possesses high levels of sensitivity and specificity. Assay interference due to rheumatoid factor like substances is not a problem. The Amerlite Toxo IgG assay possesses good sensitivity and specificity, but is less sensitive for the detection of seroconversion than methods detecting both IgG and IgM.
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Affiliation(s)
- C F Crouch
- Kodak Clinical Diagnostics Ltd, Pollards Wood Laboratories, Chalfont, St Giles, Bucks
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2
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Salt A, Sutehall G, Sargaison M, Woodward C, Barnes ND, Calne RY, Wreghitt TG. Viral and toxoplasma gondii infections in children after liver transplantation. J Clin Pathol 1990; 43:63-7. [PMID: 2155947 PMCID: PMC502227 DOI: 10.1136/jcp.43.1.63] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The incidence and morbidity of viral and Toxoplasma gondii infections were studied in 40 children who underwent liver transplantation between December 1983 and February 1988. The incidence of primary and reactivated cytomegalovirus (CMV) infection was 19% and 47%, respectively; primary infection caused clinical disease in all five cases affected and was fatal in one. Primary Epstein-Barr virus (EBV) infection occurred in 10 (26%) recipients but caused only mild disease. No reactivated EBV infection was recorded and no lymphoproliferative disorders associated with EBV were found after a maximum of four years' follow up. Adenovirus infection occurred in seven (18%) patients; this was associated in one case with fatal pneumonia and fulminant hepatitis, but otherwise with only mild respiratory disease. Primary T gondii infection was detected in one patient who remained asymptomatic. Other viruses causing infection included herpes simplex, varicella zoster, and respiratory syncytial virus. Surveillance for these infections and the long term sequelae should be included in the follow up of all children who undergo transplantation.
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Affiliation(s)
- A Salt
- Public Health Laboratory, Addenbrooke's Hospital, Cambridge, England
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3
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Duffy KT, Wharton PJ, Johnson JD, New L, Holliman RE. Assessment of immunoglobulin-M immunosorbent agglutination assay (ISAGA) for detecting toxoplasma specific IgM. J Clin Pathol 1989; 42:1291-5. [PMID: 2613923 PMCID: PMC502063 DOI: 10.1136/jcp.42.12.1291] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
An immunoglobulin-M immunosorbent agglutination assay (ISAGA) was introduced to detect toxoplasma specific IgM. This assay incorporates mu chain capture and use of entire toxoplasma trophozoites as an antigen source. The performance of the ISAGA was compared with that of a double sandwich enzyme linked immunosorbent assay (DS-ELISA) currently used in the Public Health Laboratory Service Toxoplasma Reference Laboratories. The ISAGA was found to be more sensitive than DS-ELISA but there was no demonstrable difference in the specificity or reproducibility between the two assays. The ISAGA is suitable for the diagnosis of acute toxoplasmosis in immunocompetent patients and as a screening test for recent infection in pregnant women. The persistence of ISAGA reactivity, however, is such that additional serological assessment is required to define the risk of congenital infection.
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Affiliation(s)
- K T Duffy
- Public Health Laboratory Service, St George's Hospital, London
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4
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Holliman RE, Johnson J, Duffy K, New L. Discrepant toxoplasma latex agglutination test results. J Clin Pathol 1989; 42:200-3. [PMID: 2921361 PMCID: PMC1141827 DOI: 10.1136/jcp.42.2.200] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The analysis of 4450 toxoplasma serology results showed that 59 (1.3%) latex agglutination reactions were not confirmed in the dye test. These discrepant results were associated with an unspecified IgM antibody but not associated with kit batch variation, inactivation of sera, concurrent cytomegalovirus infection, or the presence of hepatitis B virus "e" antigen. The latex agglutination test is useful as a screen for toxoplasma infection but false positive reactions do occur. Patients at risk of severe toxoplasmosis should be investigated by additional tests.
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Affiliation(s)
- R E Holliman
- Laboratory Service Toxoplasma Reference Laboratory, St George's Hospital, London
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5
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Francis JM, Payne RA, Joynson DH. Rapid indirect enzyme linked immunosorbent assay (ELISA) for detecting antitoxoplasma IgG: comparison with dye test. J Clin Pathol 1988; 41:802-5. [PMID: 3261740 PMCID: PMC1141591 DOI: 10.1136/jcp.41.7.802] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A rapid and simple enzyme linked immunosorbent assay (ELISA) for the detection of specific IgG against Toxoplasma gondii was compared with the dye test on 533 serum samples. In general, results were comparable but not with sera that contained high concentrations of toxoplasma specific IgM or that had been heated at 56 degrees C. There were no false positive results with sera containing rheumatoid factor or anti-nuclear factor. It is concluded that if a dye test is not to be performed then the serum should be tested for both toxoplasma specific IgG and IgM to avoid misleading results. Heat inactivated serum should also not be tested in this type of specific IgG assay.
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Affiliation(s)
- J M Francis
- Public Health Laboratory, Singleton Hospital, Swansea
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6
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Nielsen KH, Wright PF, Kelly WA, Cherwonogrodzky JH. A review of enzyme immunoassay for detection of antibody to Brucella abortus in cattle. Vet Immunol Immunopathol 1988; 18:331-47. [PMID: 3137720 PMCID: PMC7133660 DOI: 10.1016/0165-2427(88)90160-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/1987] [Indexed: 01/04/2023]
Abstract
Enzyme immunoassay has gained wide acceptance for serological diagnosis of bovine brucellosis because of its ability to detect antibody of all isotypes unlike the conventional tests. The indirect enzyme immunoassay, however, presents several parameters that require careful analysis. These parameters include the choice of antigen and antiglobulin-enzyme conjugate reagents for use in the assay, dealing with the large amount of data the semi-automatic or automatic assay can generate and the inter- and intralaboratory standardization and quality control. This review considers the various methods described in the literature and, briefly, how some of the problems have been overcome or how they might be dealt with.
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Affiliation(s)
- K H Nielsen
- Agriculture Canada, Animal Diseases Research Institute, Nepean, Ont., Canada
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7
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Payne RA, Joynson DH, Wilsmore AJ. Enzyme-linked immunosorbent assays for the measurement of specific antibodies in experimentally induced ovine toxoplasmosis. Epidemiol Infect 1988; 100:205-12. [PMID: 3356219 PMCID: PMC2249225 DOI: 10.1017/s0950268800067339] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Tachyzoites of the RH strain of Toxoplasma gondii were inoculated intravenously into sheep following which serum samples were collected at approximately weekly intervals for 9 months. The sera were examined by the toxoplasma dye test and two enzyme-linked immunosorbent assays (ELISA) specifically developed for investigations of ovine toxoplasmosis. One was an antibody class capture assay for the detection of anti-toxoplasma specific IgM, the other an indirect assay which detected anti-toxoplasma IgG. Some of the sheep had antibodies to toxoplasma prior to inoculation but none had specific IgM. Sera collected 17 days after inoculation showed that all had raised specific antibody levels but the only sheep that produced specific antitoxoplasma IgM were those that were initially without any antibody. Specific IgM could be detected in all these particular sheep for at least 1 month after infection and up to 3 months in some. Specific IgG persisted at high levels for at least 3 months and could still be detected at moderate levels for at least 9 months. The ELISA methods described are simple to perform and could clearly distinguish between previous infection and this experimental infection with Toxoplasma gondii.
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Affiliation(s)
- R A Payne
- Public Health Laboratory, Singleton Hospital, Swansea, Wales
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8
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Johnson AM, Gu QM, Roberts H. Antibody patterns in the serological diagnosis of acute lymphadenopathic toxoplasmosis. AUSTRALIAN AND NEW ZEALAND JOURNAL OF MEDICINE 1987; 17:430-4. [PMID: 3435321 DOI: 10.1111/j.1445-5994.1987.tb00082.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Sera from six patients at various stages of acute lymphadenopathic toxoplasmosis were tested using nine different types of test currently available for the serological diagnosis of the disease. A diagnosis was made on positive serology in three of the patients. The antibody patterns of two of these patients were studied over a period of six months and the third was studied over two months. A diagnosis was made on lymph node morphology in the other three cases. Two serum samples were tested from each of these patients. The results obtained suggest that a rationalisation of the types of test used should be encouraged and that an enzyme-linked immunosorbent assay (ELISA) for parasite-specific IgG and an antibody class capture ELISA for parasite-specific IgM are sufficient to confirm the diagnosis of acute lymphadenopathic toxoplasmosis.
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9
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Balfour AH, Harford JP, Goodall M. Use of monoclonal antibodies in an ELISA to detect IgM class antibodies specific for Toxoplasma gondii. J Clin Pathol 1987; 40:853-7. [PMID: 3654986 PMCID: PMC1141124 DOI: 10.1136/jcp.40.8.853] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Two monoclonal antibodies CH6 and C1E3 were used in an antibody class capture assay for the detection of IgM antibodies specific for Toxoplasma gondii. CH6 was used on the solid phase to capture human IgM. After a Toxoplasma gondii antigen had been added, specifically bound material was detected using C1E3 coupled to horseradish peroxidase. The assay was compared with an established system using polyclonal antisera at both the capture and antigen detection stages. A good correlation was found, with 97.3% (125 of 128) of sera giving the same classification in both assays. Three sera were positive only in the polyclonal system. No false positive results were found when 118 negative sera were examined. The two monoclonal antibodies provide a viable alternative to the use of polyclonal sera at the capture and antigen detection stages in the antibody class capture assay for the measurement of specific IgM against T gondii.
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Affiliation(s)
- A H Balfour
- Toxoplasma Unit, Regional Public Health Laboratory, Leeds
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10
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Wreghitt T, Hughes M, Calne R. A retrospective study of viral and Toxoplasma gondii infections in 54 liver transplant recipients in Cambridge. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/0888-0786(87)90028-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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11
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Payne RA, Joynson DH, Balfour AH, Harford JP, Fleck DG, Mythen M, Saunders RJ. Public Health Laboratory Service enzyme linked immunosorbent assay for detecting Toxoplasma specific IgM antibody. J Clin Pathol 1987; 40:276-81. [PMID: 3558860 PMCID: PMC1140898 DOI: 10.1136/jcp.40.3.276] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
An enzyme linked immunosorbent assay (ELISA) based on the antibody class capture method for the detection of specific IgM against Toxoplasma gondii, using the microtitre plate format, was developed. Antigen binding was detected using a monoclonal antibody, CIE3, conjugated to horseradish peroxidase. Prior mixing of the conjugate and antigen improved the stability of these reagents as well as removing an incubation stage from the assay. The incubation time of less than four hours permits a rapid throughput of specimens. Using the assay, a total of 163 sera were examined in a three centre study and good agreement was found. Results were expressed as arbitrary enzyme immunoassay units (EIUs) against a freeze dried standard. Throughout the study the standard serum showed a coefficient of variation less than 10% across the microtitre plate. By measuring IgM titres in patients having toxoplasmic lymphadenopathy with a known date of onset, IgM class antibodies were shown to peak at two months, persisting for about six months. In addition, a case of laboratory acquired toxoplasmosis was monitored. Sera shown to contain rheumatoid factor and antinuclear factor did not give false positive results. This rapid, robust, and simplified assay is used by the Public Health Laboratory Service Toxoplasma Reference Units and will provide a standard with which other assays can be compared.
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12
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Tomasi JP, Schlit AF, Stadtsbaeder S. Rapid double-sandwich enzyme-linked immunosorbent assay for detection of human immunoglobulin M anti-Toxoplasma gondii antibodies. J Clin Microbiol 1986; 24:849-50. [PMID: 3533987 PMCID: PMC269041 DOI: 10.1128/jcm.24.5.849-850.1986] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The double-sandwich enzyme-linked immunosorbent assay has been compared with the indirect fluorescence assay for the detection of immunoglobulin M antibodies against Toxoplasma gondii in humans. Incubation times have been shortened, permitting the test to be completed within 2 h. The double-sandwich enzyme-linked immunosorbent assay is confirmed to be more sensitive and more specific than the immunofluorescence assay.
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13
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Wreghitt TG, Gray JJ, Balfour AH. Problems with serological diagnosis of Toxoplasma gondii infections in heart transplant recipients. J Clin Pathol 1986; 39:1135-9. [PMID: 3023454 PMCID: PMC500237 DOI: 10.1136/jcp.39.10.1135] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Of the first 128 patients to receive either heart or heart and lung transplants at Papworth Hospital, four developed Toxoplasma gondii infections acquired from the donor heart and two died. Six patients had passively acquired T gondii antibody as a result of blood transfusions around the time of transplantation. Eight patients developed antibodies against T gondii, which were detectable by changes in the latex agglutination test titres but not by those of the dye test. These false positive latex agglutination reactions occurred simultaneously with cytomegalovirus infection and were associated with the IgM serum fraction in the patients' sera. These reactions were not associated with cytomegalovirus specific IgM, Paul-Bunnell antibody, nor detectable rheumatoid factor. These findings emphasise the need for T gondii dye test confirmation of latex agglutination test titre rises in heart transplant recipients.
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14
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Johnson AM, Roberts H, McDonald PJ, Rothe J. Detection of Toxoplasma-specific IgM in cord blood sera by antibody-class capture enzyme-linked immunosorbent assay. Pathology 1985; 17:586-9. [PMID: 3912711 DOI: 10.3109/00313028509084757] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
An antibody class capture (ACC) enzyme-linked immunosorbent assay (ELISA) utilizing an F(ab)2 conjugate was established and its specificity and reproducibility were determined. The test was further validated by comparing its results with those obtained by 2 overseas reference laboratories which used the indirect immunofluorescence antibody test (IIFT) for Toxoplasma-specific IgM. It was found that the F(ab)2ACC-ELISA was not affected by the presence of rheumatoid and antinuclear factor in serum, that it was reproducible (coefficients of variation less than 10.0%), and that it compared well with tests currently used overseas. ELISA was then used to test for the presence of Toxoplasma-specific IgM in cord blood sera. The results obtained to date are consistent with the hypothesis that the prevalence of congenital toxoplasmosis in the population of Adelaide is less than 1/2,000.
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15
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Payne RA, Francis JM, Kwantes W. Comparison of a latex agglutination test with other serological tests for the measurement of antibodies to Toxoplasma gondii. J Clin Pathol 1984; 37:1293-7. [PMID: 6501590 PMCID: PMC499001 DOI: 10.1136/jcp.37.11.1293] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
One hundred sera from 49 patients with glandular toxoplasmosis were examined by a latex agglutination test, the dye test, an indirect haemagglutination test, and a double antibody sandwich enzyme linked immunosorbent assay (ELISA) for antitoxoplasma IgM. The results support previous findings that the dye test, indirect haemagglutination test, and latex agglutination test measure different antibodies to Toxoplasma gondii. In early glandular toxoplasmosis, when specific IgM was detected, the titres of both the latex agglutination test and the indirect haemagglutination test were lower than the dye test. Repeat specimens from 11 of the patients showed four cases in which the latex agglutination test titres never exceeded 1/256, whereas both the dye test and the indirect haemagglutination test showed significant titres and specific IgM was detected in every case. We conclude that the latex agglutination test should not be used as a substitute for the dye test in the serological diagnosis of glandular toxoplasmosis. All sera giving a positive latex agglutination test result should be referred for further tests. A combination of the dye test and double antibody sandwich ELISA gives the most reliable serological diagnosis of early glandular toxoplasmosis.
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17
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Hall SM. Congenital toxoplasmosis in England, Wales, and Northern Ireland: some epidemiological problems. BRITISH MEDICAL JOURNAL 1983; 287:453-5. [PMID: 6411171 PMCID: PMC1548718 DOI: 10.1136/bmj.287.6390.453] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
It has been suggested that congenital toxoplasmosis could be prevented by antenatal serological screening, followed by treatment or by termination of pregnancy if infection occurs. The only study of the incidence of congenital toxoplasmosis in England, Wales, and Northern Ireland took place more than 10 years ago. To obtain more recent figures laboratory reports of cases occurring from 1975 to 1980 were analysed. A total of 91 cases were reported over the six years. By criteria established to classify these infections only 34 were congenital, 20 were acquired postnatally, and 37 were unclassifiable. The mean annual number of cases of congenital toxoplasmosis was considerably smaller than that found in other recent studies. The condition could be underdiagnosed or rates of placental transmission could be lower in Britain than in other countries. Variation in reporting criteria of the laboratories made the data difficult to interpret. Improved diagnosis of congenital toxoplasmosis would not only clarify the epidemiology but would also help clinicians in management of suspected cases. Further antenatal surveys are necessary to assess the role of screening in the prevention of congenital toxoplasmosis.
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18
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Wielaard F, van Gruijthuijsen H, Duermeyer W, Joss AW, Skinner L, Williams H, van Elven EH. Diagnosis of acute toxoplasmosis by an enzyme immunoassay for specific immunoglobulin m antibodies. J Clin Microbiol 1983; 17:981-7. [PMID: 6874915 PMCID: PMC272787 DOI: 10.1128/jcm.17.6.981-987.1983] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
A recently developed enzyme-linked immunosorbent assay for detection of immunoglobulin M (IgM) class antibodies to Toxoplasma gondii was evaluated with respect to specificity and sensitivity. By using an antibody capture principle and F(ab')2 conjugates, interference of rheumatoid factors was absent. No cross-reactions with anti-toxoplasma IgG occurred, and no interference with antinuclear antibodies was found. A large-scale study with about 1,500 clinical specimens revealed a 100% specificity. By testing 79 sera from patients with acute-phase acquired toxoplasmosis, sensitivity was found to be 97%. In routine clinical practice, the IgM-enzyme-linked immunosorbent assay proved to be a more sensitive tool for diagnosis than the immunofluorescent-antibody test. The course of IgM-enzyme-linked immunosorbent assay antibodies in acute patients was studied; IgM reached peak levels within 1 month after onset of illness, and could be demonstrated up to an average of 8 months after onset.
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