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PubMedDate not supplied

[Trichinosis outbreak in Purranque County, X Region, Chile. October-November, 1992].

An outbreak of trichinosis occurred in Purranque County, X Region, Chile, between october and november of 1992, which involved 36 persons. The incubation period, determined by the clinical picture and laboratory assays, fluctuated between 10 and 12 days. Myalgias (88.9%) and palpebral oedema (86.1%), were the most important symptoms, followed by fever (44.4%) and headache (33.3%). Eosinophils count ranged from two to 42% the first week, and this value raised to 55% the second week of the outbreak. Anti-Trichinella spiralis antibodies were determined by some serological tests such as: precipitin test (PT), bentonite flocculation test (BFT) and indirect hemagglutination test (IHAT) in sera from 28 patients at the beginning of the outbreak. PT was positive in 46.4% of the cases, followed by IHAT (21.4%) and BFT (3.6%). After 15 days, the three tests were performed in sera from 12 patients. At that time, the positivity was elevated in all of them: PT (100.0%), BFT (66.7%) and IHAT (91.7%). It is believed that the outbreak had its origin in infected pork meat that was consumed raw or insufficiently cooked without a previous veterinary inspection.

Adolescent↗
PubMedDate not supplied

[The indirect hemagglutination reaction in the diagnosis of trichinosis].

An indirect hemagglutination test (IHAT) for trichinosis using a Melcher's antigen was evaluated and compared with a precipitin test (PT) and a bentonite flocculation test (BFT). One hundred and forty eight serum samples from patients from the whole country confirmed or suspected to have trichinosis by clinical or epidemiological evidences were studied: 117 (79.1%) samples resulted positive by IHAT, 138 (93.2%) by PT and 65 (43.9%) by BFT. Sixty three serum samples from patients with strong clinical suspect of trichinosis presented the PT and the BFT positive and were compared with the IHAT for sensitivity study. IHAT was positive in 60 (95.2%) serum samples. In order to determine the specificity of IHAT 25 serum samples from healthy volunteers and 124 serum samples from individuals with other parasitoses, such as cysticercosis (48), hydatidosis (45) and fascioliasis (31) were studied. The specificity, using a titre > or = 1:16 as a possible diagnostic value was 96%. The use of IHAT with RP and BFT in the diagnosis of human trichinosis is discussed.

Complement Hemolytic Activity Assay↗
PubMed1975

Comparison of the counter-immunoelectrophoresis technique with the Reiter protein and three other serological tests as a first line test for syphilis.

The counter-immunoelectrophoresis technique with the Reiter protein (RP-CIE) was compared with two complement fixation tests (Kolmer and RPCF) and a flocculation test (VDRL) in sensitivity and specificity. Of the 1,927 consecutive attendants of a venereal disease clinic whose serum samples were used, 250 were considered to be syphilitic. The number of true-positive and false-positive reactions were: 121 and 4 (VDRL), 124 and 2 (Kolmer), 179 and 41 (RPCF), 166 and 16 (RP-CIE). The VDRL and the RPCF combined were more sensitive and less specific than the VDRL combined with the Kolmer. If the RPCF was replaced by the RP-CIE the sensitivity remained the same but the specificity was higher. The RP-CIE scored more positives than the RPCF in untreated cases of primary syphilis. The results argue for substitution of the RP-CIE for the Kolmer in the combination with the VDRL in the serodiagnosis for syphilis. Moreover, the RP-CIE presents the technical advantages of simplicity, speed of performance, and of not being hampered by the anticomplementary nature of the serum sample.

Antigens, Bacterial↗
PubMed1975

Anti-DNA Investigated the DNA bentonite flocculation technique.

The DNA bentonite flocculation test was used to investigate the presence of antibody to DNA. In most sera a prozone-like phenomenon was found, caused by a non-specific inhibition of serum. Anti-DNA was found with extreme frequency in patients with SLE, chronic liver disease, acute hepatitis, infectious mononucleosis, and blood donors over the age of 60, but was found rarely or not at all in patients with some other disease or blood donors under 60 years of age.

Adolescent↗
PubMed1993

An immunosensor for syphilis screening based on surface plasmon resonance.

In this paper the development of a surface plasmon resonance (SPR) immunosensor for syphilis screening is described. This immunosensor is based on the detection of antibodies in serum against the causative organism Treponema pallidum. In order to achieve selectivity a recombinant Treponema pallidum membrane protein A (TmpA) was used. This antigen can react with antibodies to T. pallidum, present in serum of syphilitic patients. Reproducible results have been obtained, using a 'sandwich SPR' method: binding of a sandwich antibody to the treponemal antibody after serum incubation was measured in real time while the binding was taking place. The SPR results obtained from ten blind-coded sera corresponded well with classical syphilis tests (Treponema pallidum haemagglutination assay (TPHA), fluorescent treponemal antibody-absorbed test (FTA-ABS), venereal diseases research laboratory flocculation test (VDRL) and TmpA-based enzyme-linked immunosorbent assay (TmpA-ELISA)). Preliminary experiments showed that direct measurement of serum (in the 'one step SPR') is not yet possible, probably as a result of non-uniformity of serum samples. The application of latex beads is considered to solve this problem.

Antibodies, Bacterial↗
PubMed1982

Interpreting serologic tests for syphilis.

Since syphilis is most often diagnosed by serologic studies, the correct interpretation of these tests is critical. Serologic tests are classified as nontreponemal of treponemal, according to the antigen employed. Flocculation tests are generally used for routine screening because of their simplicity. The treponemal procedures are more specific, but false-positive results may still occur. Results vary with the procedure, stage of disease and treatment. Significant difficulties remain with the serologic diagnosis of neurosyphilis and congenital syphilis.

Complement Fixation Tests↗
PubMed1984

Interlaboratory comparison of the toluidine red unheated serum test antigen preparation.

The toluidine red unheated serum test (TRUST) antigen, a macroscopic flocculation test antigen developed by Pettit et al. (J. Clin. Microbiol. 18:1141-1145, 1983) by modifying the color-coded antigen of Kasatiya and Lambert (Appl. Microbiol. 28:317-318, 1974), was compared with the Venereal Disease Research Laboratory (VDRL) slide and rapid plasma reagin (RPR) 18-mm circle card tests for sensitivity, specificity, and reproducibility. Two lots of TRUST antigen were prepared by two laboratories in the Centers for Disease Control. Both laboratories performed the TRUST and VDRL slide test on serum samples from 1,102 patients attending the DeKalb County, Georgia, Sexually Transmitted Disease Clinic. In addition, one laboratory performed the RPR card test. Reactive sera were quantitated in the three nontreponemal tests and confirmed with the fluorescent treponemal antibody absorption test. The sensitivity in untreated syphilis for all nontreponemal tests involved was 98.4%. The specificity for these tests was 98.6%. The qualitative reproducibility among the four lots of TRUST antigen, VDRL slide, and RPR card tests was 98.2%. Only 20 sera showed discrepant results. Intralaboratory reproducibility of the two TRUST antigens was 100% for one laboratory and 99.6% for the other. Interlaboratory reproducibility for the four lots of TRUST and the VDRL slide test was 99%. Quantitative agreement +/- 1 dilution between the TRUST and RPR card test was 92.3%, and quantitative agreement +/- 1 dilution for the TRUST and RPR card test versus the VDRL slide test averaged 50%. The TRUST appeared to be comparable to the RPR card test in all parameters compared.

Antigens, Bacterial↗
PubMed1962

The nature of flurescent antibody reactions in infections and artificial immunizations with Schistosoma mansoni.

This paper describes studies in which Schistosoma mansoni eggs, miracidia, cercariae, schistosomula and adults were fixed with formol and stained with antibodies labelled with fluorescein isothiocyanate. The cuticle of the cercariae, cuticle of the schistosomula and ciliated epithelium of the miracidia were consistently and specifically reactive with labelled immune serum. In cercariae fixed with acetic acid and subsequently treated with immune serum followed by exposure to labelled antispecies globulin, the post-acetabular glands and ducts assumed a bright fluorescent stain. Absorption of sera that were reactive in the fluorescent antibody test and the cercarial slide flocculation test with antigen used in the latter removed the antibody reactive in both tests.The reproducibility of results with the indirect fluorescent antibody technique, employing different pools of cercariae and various lots of labelled antiglobulins, compared favourably with that in other serological procedures employing whole organisms. A correlation between the early appearance of fluorescent antibodies and the size of the cercarial inoculum was observed in Rhesus monkeys and albino mice. Fluorescent antibodies were detected much earlier in animals which are naturally resistant to S. mansoni infection. No fluorescent antibodies were detected in sera from infected St. Kitts and West African green monkeys, which are very susceptible to the disease.Schistosomula recovered from tissues gave identical results in the FA test to those obtained with the free-living cercariae and miracidia.

Animals↗
PubMed1972

Crystalline cholera toxin and toxoid.

The exo-enterotoxin of Vibrio cholerae has been obtained in crystalline form. A solution of the crystalline protein was equal in potency to the parent pure toxin in both choleragenicity and skin reactivity. Crystals of the natural toxoid, choleragenoid, resemble those of the toxin in appearance. A solution of crystalline choleragenoid was equivalent to the parent preparation in the flocculation test.

Animals↗
PubMed1976

Radiological cervical arthritis in populations.

The prevalence of cervical rheumatoid arthritis and its relationship to rheumatoid serum factors and erosive arthritis in peripheral joints has been studied in radiographs of the cervical spine and of the hands and feet drawn from 12 population samples. The changes were graded in accordance with the Atlas of Standard Radiographs of Arthritis. Rheumatoid arthritis of the cervical spine (grades 2-4) was observed in 4.1% of males and 4.7% of females aged 15 and over. Prevalence was greatest in those born before 1900, 15% of whom were affected. There was a significant association with the sheep cell agglutination test but not with the bentonite flocculation test, though the latter correlated well with erosive arthritis in the joints of the hands and feet. Arthritis of the cervical spine showed a significant correlation with both seropositive and seronegative erosive arthritis in the peripheral joints. A significantly higher prevalence of cervical arthritis than expected was noted in two population samples, one in Germany and the other in West Africa, though in neither was there a high prevalence of peripheral arthritis. The German population had relatively high antistreptolysin titres. A low prevalence of cervical arthritis was noted in populations in Czechoslovakia and in Arizona. 'Congenital' block vertebra had a prevalence of 0.9% in persons born before 1935, but none was observed in those born since. The figures suggest that environmental influences predisposing to cervical arthritis and block vertebra have changed in the last 40 years.

Adolescent↗
PubMed1962

Human trichinosis: studies on eleven cases affecting two families in Nova Scotia.

A two-family outbreak of 11 cases of trichinosis with one fatality has been described. Efforts were made to obtain an early assessment of the severity of parasitization on the basis of initial clinical appearance, serial electrocardiograms, changes in eosinophil count, serum protein analyses and SGOT levels. The diagnoses were confirmed by muscle biopsy and by Suessenguth-Kline flocculation tests on serum. Factors portending a severe illness included: (a) rapid decline in total eosinophil count, (b) very low levels of serum albumin, (c) elevation of alpha(1)- and alpha(2)-fractions of serum proteins. A review of current serological methods available for the diagnosis of trichinosis has been presented and emphasis has been placed on the importance of interpreting laboratory tests in conjunction with clinical signs and symptoms. The severity and duration of illness in these cases have shown the importance of enforcing present public health regulations designed to prevent this illness being acquired by humans through consumption of infected pork.

Adrenocorticotropic Hormone↗
PubMed1980

Quantitative determination of rheumatoid factor by an enzyme-labeled immunoassay.

The presence and quantity of rheumatoid factor (RF) in human serum were determined by an indirect enzyme-linked immunoabsorbent assay (ELISA). A human rheumatoid factor control serum, standardized against the WHO reference rheumatoid arthritis serum preparation, was used to derive a standard curve in each assay. The results of unknowns were estimated from the standard curve and reported in International Units (IU) per milliliter (ml). The ELISA assay was compared with the bentonite flocculation test. The overall coefficient of correlation between the two assays was 87%; it was 93.3% for patients with rheumatoid arthritis but only 67.5% for patients with undiagnosed conditions. The error of the ELISA assay (coefficient of variation) was generally less than 10% at both high and low concentrations of rheumatoid factor. The quantitative reproducible nature of the assay allows the detection of small variations of rheumatoid factor level and could be useful in the serial evaluation of patients.

Animals↗
PubMed1990

Antiphospholipid antibodies in syphilis.

1. An enzyme-linked immunosorbent assay was used to determine the phospholipid specificity of antibodies present in sera from 35 syphilis patients. 2. Based on the cross-reaction obtained against a mixture of cardiolipin, phosphatidylcholine and cholesterol that is standard for flocculation tests according to the Venereal Disease Research Laboratory (CECON, São Paulo, Brazil), all 35 patients tested positive for antibodies of the IgG class whereas 13 (37%) also had IgM antibodies for the same mixture of lipids. IgG antibodies to cardiolipin were demonstrated in 2 patients (6%) and IgM antibodies in 5 (15%). Significant levels of IgG anti-phosphatidylcholine were detected in 3 patients (9%) and IgM antibodies in 4 (11%). IgG anti-phosphatidylethanolamine antibodies were found in 1 patient (3%) and IgM antibodies in 3 (9%). Antibody binding to cardiolipin plus cholesterol or cardiolipin plus phosphatidylcholine was as effective as when the standard mixture of all 3 lipids was used. 3. A comparison with serum from systemic lupus erythematosus patients and inhibition studies using liposomes of cardiolipin or the mixture of 3 lipids suggests that there are at least 3 groups of anticardiolipin antibodies.

Antibodies, Anti-Idiotypic↗
PubMed1961

Evaluation of some laboratory procedures in diagnosing infections with Schistosoma mansoni.

THIS PAPER REPORTS ON A COMPARATIVE EVALUATION CARRIED OUT IN PUERTO RICO ON THE FOLLOWING PROCEDURES USED IN DIAGNOSING BILHARZIASIS: recovery of S. mansoni ova from stools; serological tests (complement-fixation tests with adult worm and cercarial antigens, slide flocculation test with cercarial antigens, cercarial agglutination test, and circumoval precipitin test) and intradermal tests with adult worm, cercarial and egg antigens.Stool examinations revealed infections in only 74% of 485 patients hospitalized for bilharziasis, but most of the serological and intradermal tests gave results which, when corrected for false negative reactions, suggested infections in 89%-94% of patients. Cercarial agglutination results were discounted because of weak reactions and low specificity; the intradermal test with egg antigen lacked specificity.From the results of their comparative studies, the authors suggest particular uses for the various serological and stool tests, but consider that the intradermal tests do not appear to have a definable role in the diagnosis or detection of bilharziasis.

Adult↗