Rapid Whole Blood Test Research Articles

Performance evaluation of a rapid whole-blood immunoassay for the detection of IgG antibodies against Helicobacter pylori in daily clinical practice.

BackgroundA growing number of rapid Helicobacter pylori antibody tests are commercially available now, however, some of these tests are often used without sufficient evaluation. The aim of this study was to evaluate the performance of a commercially available rapid whole-blood immunoassay (gabControl®H. pylori; gabmed GmbH, Köln, Germany), for the qualitative detection of IgG antibodies against H. pylori with the 13C-urea breath test (13C-UBT) serving as a reference method.MethodsA total of 108 consecutive outpatients, who were referred for 13C-UBT by general practitioners and specialists, were also tested for H. pylori infection by the gabControl®H. pylori immunoassay. The clinical performance of this rapid whole-blood test was evaluated by determining the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) compared to the 13C-UBT. The agreement between the two tests was calculated using Cohen’s Kappa (κ) with 95 % confidence intervals (CI).ResultsThe agreement between the gabControl®H. pylori assay and the 13C-UBT was 0.62 [95 % confidence intervals (CIs) 0.47–0.76; P < 0.001]. With the 13C-UBT serving as the non-invasive gold standard method of H. pylori diagnosis, the gabControl®H. pylori assay demonstrated a sensitivity and specificity of 91.4 and 76.7 %, respectively, with a PPV of 65.3 % and a NPV of 94.9 %. Seventeen (15.7 %) individuals with a positive H. pylori anamnesis showed a negative 13C-UBT and were typed positive by the gabControl®H. pylori assay. Of these, 13 (76.5 %) and 3 individuals (17.6 %) had completed one and two eradication therapies, respectively.ConclusionsThe gabControl®H. pylori immunoassay is a rapid and easy to use first line screening tool for H. pylori IgG antibody detection in daily clinical practice. However, this assay should not be used for confirmation of the successful H. pylori eradication after antibiotic treatment.

Are Participants in a Street-Based HIV Testing Program Able to Perform Their Own Rapid Test and Interpret the Results?

ObjectiveAvailability of over-the-counter rapid HIV tests could improve access to testing those reluctant or unable to use current services. We aimed to evaluate the feasibility of HIV self-testing using a finger-stick whole-blood rapid test (Determine™ HIV Combo) to detect both antigen and antibody.MethodsBefore being tested, 313 participants in a street-based testing program were given adapted instructions and a test kit, and performed the self-test without supervision. These participants, together with another 207 who performed supervised self-testing, received additional instructions on how to interpret the test results shown in six colour photos and filled out a questionnaire. Logistic regression and generalized estimating equations (GEE) were used in the statistical analysis.ResultsAbout 8.0% (95%CI:4.8%–11.2%) obtained an invalid self-test. An invalid result was inversely associated with male participants who had sex with men (OR = 0.3;95%CI:0.1–1.0). Of the 3111 photos interpreted,4.9% (95%CI:4.1–5.7) were incorrect. Only 1.1% (95%CI:0.3–1.8) of the positive results were interpreted as negative. Age 30 or older (OR = 2.1; 95%CI:1.2–3.7), having been born in Latin America (OR = 1.6; 95%CI:1.1–2.2),and not having university education (OR = 2.1;95%CI:1.2–3.7) were associated with misinterpreting test results in the GEE. Participant's perceptions of both their proficiency when conducting the test and interpretation were related with actual outcomes. Most participants (83.9%) were more motivated than before to use the self-test in the future, and 51.7% would pay >10 Euros for the test if it was sold in pharmacies.ConclusionsThis is the first study showing that blood-based self-testing with current technology is feasible in HIV-negative participants demanding the test and without prior training or supervision. Bearing in mind that it was conducted under difficult weather conditions and using a complex kit, over-the-counter tests could be a feasible option to complement current diagnostic strategies. More studies are needed to accommodate technology, minimise interpretation mistakes and provide on-line support.

Supervised blood-based self-sample collection and rapid test performance: a valuable alternative to the use of saliva by HIV testing programmes with no medical or nursing staff

ObjectivesSome saliva-based HIV testing programmes have resulted in an unacceptable percentage of false positives. Many countries require blood-based testing programmes to have doctors/nurses. The authors evaluate whether, after brief training...

Prevalence and correlates of HIV, syphilis, and hepatitis knowledge among intrapartum patients and health care providers in Kabul, Afghanistan

Little is known about blood-borne infection awareness and knowledge among obstetric populations and health care providers in Afghanistan. HIV and hepatitis B awareness and knowledge are described among 4452 intrapartum patients completing an interviewer-administered questionnaire and whole-blood rapid testing and 123 obstetric care providers completing a questionnaire between June 2006 and September 2006. Participants were enrolled from three Kabul public maternity hospitals. Most participants were aware of HIV (50.8% of patients and 95.9% of providers) and hepatitis (72.1% of patients and 91.1% of providers). Correct transmission knowledge (defined as naming three correct routes and no incorrect routes) was lower for both groups (HIV: 19.4% for patients and 59.7% for providers; hepatitis B: 1.90% for patients and 33.9% for providers). Correct HIV transmission knowledge among providers was independently associated with level of education (AOR=1.75, 95% CI: 1.20–2.55). While HIV and hepatitis B awareness is common, correct and comprehensive knowledge is not. Continuing education for providers and health communications strategies should address identified knowledge gaps.

Application of microagglutination test for detection of antibodies to &lt;i&gt;Salmonella gallinarum&lt;/i&gt; in commercial layer chickens&lt;BR&gt;&lt;BR&gt;Application du test de microagglutination pour la detection des anticorps a &lt;i&gt;Salmonella gallinarum&lt;/i&gt; chez les pondeuses commerciales

In this study a microagglutination test (MAT) was developed, evaluated and compared with a rapid whole-blood agglutination test (RWBAT) for detection of Salmonella gallinarum antibodies in commercial layer chickens in Morogoro, Tanzania. The results showed that at Kigurunyembe farm, 16 (32%) of chicken tested were RWBAT positive while 30 (60%) were MAT positive among the 50 sera tested. Results from Kilakala farm revealed 10 (20%) sera that were RWBAT positive whereas 5 (10%) were positive for MAT among the 50 sera tested. On both farms, S. gallinarum was isolated from 21 chickens. The sensitivities, specificities, positive and negative predictive values for MAT were 57, 71, 34 and 86%, respectively, and 67, 85, 54 and 82 %, respectively for RWBAT. Although MAT was slightly less sensitive and less specific than RWBAT, it revealed a higher true seroprevalence (35%) of fowl typhoid than RWBAT (26%). When the test is optimized it may be preferred because it uses less time, space and antigen while permitting more objective evaluation of antibody titers. Higher growth and seroprevalence of S. gallinarum was observed in Rhode Island Red than Black Australop chickens. Keywords : chickens, microagglutination test, Salmonella gallinarum , seroprevalence, whole blood agglutination test Bulletin of Animal Health and Production in Africa Vol. 54(2) 2006: 124-130

Epidemiological Investigation, Cleanup, and Eradication of Pullorum Disease in Adult Chickens and Ducks in Two Small-Farm Flocks

Pullorum disease causing acute septicemia and mortality in adult brown chickens was diagnosed in a small-farm chicken flock in Iowa. Also, Salmonella Pullorum was isolated from the intestine of one of four rats trapped on this index farm. Tracing movements of spent hens from the index farm resulted in identification of a second infected flock on a contact farm. Poultry on the contact farm were tested with the stained-antigen, rapid whole-blood test, and two ducks and one chicken gave positive reactions. Reactors were necropsied and cultures of appropriate tissues resulted in isolation of Salmonella Pullorum from one duck and the chicken. Pulsed-field gel electrophoresis banding patterns of Salmonella Pullorum isolates from chickens on the index and contact farms, the duck, and the rat demonstrated that all isolates were genetically very similar. Both flocks were quarantined and depopulated and a detailed flock cleanup plan was created for both farms. After extensive cleaning and disinfection procedures were completed on the index farm, environmental monitoring and bioassays of trapped mice were conducted. Negative cultures of environmental swabs and trapped mice and negative blood tests of all birds conducted 4 mo after placement of a new flock on the index farm demonstrated that cleaning and disinfection methods used in this outbreak had successfully eliminated Salmonella Pullorum organisms from this farm.

P2265 Reliability of diagnosing myocardial injury by rapid bedside whole-blood quantitative cardiac troponin-T test in patients with coronary artery disease

P2265 Reliability of diagnosing myocardial injury by rapid bedside whole-blood quantitative cardiac troponin-T test in patients with coronary artery disease

Evaluation of Pyloriset Screen, a rapid whole-blood diagnostic test for Helicobacter pylori infection.

Helicobacter pylori infection can be detected by several invasive tests based on gastroscopy and by noninvasive methods such as serologic assays. Noninvasive tests can be used not only in addition to invasive tests but also by themselves to screen for H. pylori infection in patients who are not in urgent need of endoscopy. Lately, rapid qualitative serologic tests have been developed. In the present study, the accuracy of a novel rapid whole-blood test, Pyloriset Screen, detecting immunoglobulin G (IgG) and IgA antibodies against H. pylori was evaluated. A total of 207 consecutive adult outpatients referred for upper endoscopy were enrolled. Gastric biopsy specimens were taken from the antrum and corpus for histologic examination and rapid urease testing. Cultures were available for 113 patients. Serum samples collected from all patients were tested for H. pylori antibodies by two enzyme immunoassays (EIAs) (Pyloriset EIA and an in-house EIA), a rapid latex agglutination test (Pyloriset Dry), and Pyloriset Screen. Patients were considered H. pylori positive if helicobacters were seen on histologic examination (77 patients) or, if in combination with histologically verified (although helicobacter-negative) gastritis, their IgG antibody titers were elevated in the two EIAs (five patients). The Pyloriset Screen test had a sensitivity of 95%, a specificity of 94%, a positive predictive value of 91%, and a negative predictive value of 97%. Among 63 patients under the age of 45 years, the Pyloriset Screen test did not miss a single H. pylori diagnosis, and only 1 patient had a false-positive result. Pyloriset Screen could be used reliably to screen for H. pylori infection.

Salmonella enteritidis in commercial layer farms in New York state; environmental survey results and significance of available monitoring tests.

Seven hundred fifty-one environmental samples were collected from 76 chicken layer houses in a voluntary Salmonella enteritidis (SE) survey study carried out in New York state between January 15 and April 8, 1991. SE was recovered from both houses on 1 farm. Sampling of manure pits and mice in hen houses was useful for SE screening. Phage types of SE from the environment, birds, and mice were identical. The rapid whole-blood test was unreliable, and culture of cloacal swabs was inadequate for detection of SE carriers. Culture of organs from chickens did not correlate well with results of environmental samples.

Serological response of chickens to Salmonella thompson and Salmonella pullorum infections

Chickens were experimentally infected with Salmonella thompson (serogroup C, paratyphoid) and Salmonella pullorum (serogroup D). Five serological methods and one cultural method were used in detecting the infections. The microantiglobulin test was superior to all other methods for detection of paratyphoid (S. THOMPSON) infection and was followed in efficacy by the microagglutination test, rapid serum plate test, cloacal swab culture, macroscopic tube agglutination test, and rapid whole-blood test, in that order. Birds infected with S. pullorum showed much higher agglutinin titers than the birds infected with paratyphoid. The microagglutination and microantiglobulin tests were not significantly different for detection of pullorum infection and were followed in efficacy by the rapid serum plate, macroscopic tube agglutination, rapid whole-blood, and cloacal swab culture tests, in that order. The cloacal swab culture test was totally inadequate for the detection of pullorum infection.

Chick rearing: VIII. The preparation of a sensitive and diagnostic stained antigen for the rapid whole-blood test for bacillary white diarrhoea of chicks

A method is presented for the preparation of a sensitive and diagnostic stained antigen for the detection of fowls suspected of infection by the organisms found in epidemic bacillary white diarrhoea (pullorum disease).Evidence is presented that an antigen prepared from organisms grown in a medium which provides for the peculiar growth requirements of the anaerobic organism associated with anaerogenic pullorum, is more sensitive than antigens prepared from organisms grown on media which lack these peculiar growth factors.A stained antigen has been prepared which is agglutinated by pullorum antisera in 15 sec. at 4°C. and in 6 sec. a t 15°C. and which is not agglutinated by normal sera in 5 min.The author wishes to thank the Directors of Messrs J. Bibby and Sons, Ltd., for permission to publish these papers.In particular he would thank Mr J. Pye Bibby for his keen interest in the investigations and for his loyal support throughout.In addition he wishes to thank Miss Margaret Davies for her assistance in the bacteriological investigations, and Miss Margaret Shafto for laboratory work and the compilation of relevant data.

Pullorum Testing of Turkeys

INTRODUCTIONPULLORUM disease appears to be spreading rapidly through the turkey population of the country and the testing program is becoming more important each year. This paper is a report on some investigations conducted by the Bacteriology Department and may be of interest to others.The work consisted in comparing various methods of testing and the use of different antigens. All the commercial antigens used were designed for testing chickens. The antigens prepared by us for use in the tube test were from pullorum cultures isolated from turkeys. A number of tests were made, both with the whole blood and rapid serum methods, and the results compared with those obtained by the tube method, which was considered as standard. In addition, postmortem examinations and bacteriological studies were made on 187 adult birds collected from several sources.Hinshaw et al. (1940) concluded that the stained antigen rapid whole-blood test was approximately .

Diseases

Use of the Rapid Whole-Blood Test for Pullorum Disease. H. Bunyea. U.S. Dept. Agric. Misc. Pub., 349, 1939.A practical account with explicit information concerning the qualifications of a pullorum testing agent, including the details of technique and equipment necessary for the work.

Comparison of Repeated Rapid Whole-Blood, Rapid Serum, and Tube Agglutination Tests for the Diagnosis of S. Pullorum Disease

Comparison of Repeated Rapid Whole-Blood, Rapid Serum, and Tube Agglutination Tests for the Diagnosis of S. Pullorum Disease