- Rapid antigen diagnostic tests (Ag-RDTs) are the most widely used point-of-care tests for detecting SARS-CoV-2 infection. Since the accuracy may have altered by changes in SARS-CoV-2 epidemiology, indications for testing, sampling and testing procedures, and roll-out of COVID-19 vaccination, we evaluated the performance of three prevailing SARS-CoV-2 Ag-RDTs.
- In this cross-sectional study, we consecutively enrolled individuals aged >16 years presenting for SARS-CoV-2 testing at three Dutch public health service COVID-19 test sites. In the first phase, participants underwent either BD-Veritor System (Becton Dickinson), PanBio (Abbott), or SD-Biosensor (Roche Diagnostics) testing with routine sampling procedures. In a subsequent phase, participants underwent SD-Biosensor testing with a less invasive sampling method (combined oropharyngeal-nasal [OP-N] swab). Diagnostic accuracies were assessed against molecular testing.
- Six thousand nine hundred fifty-five of 7005 participants (99%) with results from both an Ag-RDT and a molecular reference test were analysed. SARS-CoV-2 prevalence and overall sensitivities were 13% (188/1441) and 69% (129/188, 95% CI 62-75) for BD-Veritor, 8% (173/2056) and 69% (119/173, 61-76) for PanBio, and 12% (215/1769) and 74% (160/215, 68-80) for SD-Biosensor with routine sampling and 10% (164/1689) and 75% (123/164, 68-81) for SD-Biosensor with OP-N sampling. In those symptomatic or asymptomatic at sampling, sensitivities were 72-83% and 54-56%, respectively. Above a viral load cut-off (≥5.2 log10 SARS-CoV-2 E-gene copies/mL), sensitivities were 86% (125/146, 79-91) for BD-Veritor, 89% (108/121, 82-94) for PanBio, and 88% (160/182, 82-92) for SD-Biosensor with routine sampling and 84% (118/141, 77-89) with OP-N sampling. Specificities were >99% for all tests in most analyses. Sixty-one per cent of false-negative Ag-RDT participants returned for testing within 14 days (median: 3 days, interquartile range 3) of whom 90% tested positive.
- Overall sensitivities of three SARS-CoV-2 Ag-RDTs were 69-75%, increasing to ≥86% above a viral load cut-off. The decreased sensitivity among asymptomatic participants and high positivity rate during follow-up in false-negative Ag-RDT participants emphasise the need for education of the public about the importance of re-testing after an initial negative Ag-RDT should symptoms develop. For SD-Biosensor, Rapid antigen test kit the diagnostic accuracy with OP-N and deep nasopharyngeal sampling was similar; adopting the more convenient sampling method might reduce the threshold for professional testing. COVID-19; Diagnostic accuracy; Rapid antigen tests; SARS-CoV-2.
Plasmodium falciparum pfhrp2 and pfhrp3 Gene Deletions from Persons with Symptomatic Malaria Infection in Ethiopia, Kenya, Madagascar, and Rwanda
- Histidine-rich protein 2 (HRP2)-based rapid diagnostic tests detect Plasmodium falciparum malaria and are used throughout sub-Saharan Africa. However, deletions in the pfhrp2 and related pfhrp3 (pfhrp2/3) genes threaten use of these tests. Therapeutic efficacy studies (TESs) enroll persons with symptomatic P. falciparum infection. We screened TES samples collected during 2016-2018 in Ethiopia, Kenya, Rwanda, and Madagascar for HRP2/3, pan-Plasmodium lactate dehydrogenase, and pan-Plasmodium aldolase antigen levels and selected samples with low levels of HRP2/3 for pfhrp2/3 genotyping.
- We observed deletion of pfhrp3 in samples from all countries except Kenya. Single-gene deletions in pfhrp2 were observed in 1.4% (95% CI 0.2%-4.8%) of Ethiopia samples and in 0.6% (95% CI 0.2%-1.6%) of Madagascar samples, and dual pfhrp2/3 deletions were noted in 2.0% (95% CI 0.4%-5.9%) of Ethiopia samples. Although this study was not powered for precise prevalence estimates, evaluating TES samples revealed a low prevalence of pfhrp2/3 deletions in most sites.
Development of a Test Card Based on Colloidal Gold Immunochromatographic Strips for Rapid Detection of Antibodies against Theileria equi and Babesia caballi
- Equine piroplasmosis (EP) is a serious problem in the horse industry, and controlling EP is critical for international horse trading. EP is caused by two apicomplexan protozoan parasites, Theileria equi and Babesia caballi. Rapid and accurate methods that are suitable for detecting these parasites in the field are crucial to control the infection and spread of EP.
- In this study, we developed a card to detect antibodies against T. equi and B. caballi based on two colloidal gold immunochromatographic strips according to the principle of the double-antigen sandwich. The proteins equi merozoite antigen 1 (EMA1) and rhoptry protein BC48 are commonly used as diagnostic antigens against T. equi and B. caballi, respectively.
- On the strip, the purified EMA1 or BC48 protein labeled with colloidal gold was used as the detector, and nitrocellulose membranes were coated with EMA1 or BC48 and the corresponding MAb as the test and control lines, respectively. The protocol takes 10 to 15 min and requires no specialized equipment or chemical reagents, and one test can detect two EP pathogens in one card.
- Specificity tests confirmed there was no cross-reactivity with sera positive for common equine pathogens. Using a commercial competitive enzyme-linked immunosorbent assay (cELISA) kit for comparison, 476 clinical samples were tested with the card.
- The coincidence rates were 96.43% and 97.90% for T. equi and B. caballi, respectively. The field trial feedback was uniformly positive, suggesting that this diagnostic tool may be useful for controlling the spread of T. equi and B. caballi.
- Equine piroplasmosis (EP), caused by Theileria equi and Babesia caballi, is an important tick-borne disease of equines that is prevalent in most parts of the world. EP is considered a reportable disease by the World Organization for Animal Health (OIE).
- The accurate diagnosis and differentiation of T. equi and B. caballi are very important for the prevention, control, and treatment of EP. Therefore, we developed a double-antigen sandwich colloidal gold immunochromatography assay (GICG) to detect T. equi and B. caballi.
- Two GICG strips were assembled side by side on one card for the detection of T. equi and B. caballi, and the two EP pathogens could be detected in one test. This method was simple, rapid, and specific for the detection of EP; therefore, compared to the previous methods, this method is more suitable for pathogen diagnosis in the field.
Direct Detection of Feline Coronavirus by Three Rapid Antigen Immunochromatographic Tests and by Real-Time PCR in Cat Shelters.
The aim of this study was the direct detection of feline coronavirus by real-time PCR and by three different rapid immunochromatographic (RIM) tests detecting antigens in faecal samples of shelter cats. Based on sensitivity and specificity calculated for each of the RIM tests, the utility of RIM tests was compared.
Seventy faecal samples originating from shelter cats housed in quarantine were examined. Out of 70 samples analyzed by real-time PCR, 44 (62.9%) were positive. Significantly more cats (p < 0.05) tested positive than negative. Neither age nor sex of the cats played a significant role (p > 0.05) in the shedding status of the virus. The sensitivity of the RIM tests was found to be at low (<35%; RIM tests A and C) to satisfactory level (>50%, RIM test B). The number of virus particles determined by real-time RT-PCR analysis did not significantly correlate with the results detected by any of the RIM tests (p > 0.05).
Accu-Tell COVID-19 IgG/IgM Rapid Test |
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GEN-B352-20tests | Accu test | 20 tests |
Accu-Tell COVID-19 IgG/IgM Rapid Test |
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GEN-B352-40tests | Accu test | 40 tests |
COVID-19 IgG/IgM Rapid Test Kit |
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UNCOV-20 | UnScience | 20T/kit |
Panbio™ COVID-19 IgG/IgM Rapid Test |
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ICO-T402 | Abbott | 25 Tests/Kit |
Panbio™ COVID-19 Ag Rapid Test Device |
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41FK10 | Abbott | 25 Tests/Kit |
Panbio™ COVID-19 Ag Rapid Test Device (Nasal) |
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41FK11 | Abbott | 25 Tests/Kit |
SARS-CoV-2 Antigen Rapid Test Kit |
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CoV2Ag-1 | UnScience | 1T |
SARS-CoV-2 Antigen Rapid Test Kit |
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CoV2Ag-25 | UnScience | 25T/kit |
NOVATest Antigen Rapid Test Kit (For Single Use) (NOVA Test) |
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nCov-500-01 | Atlas Link Technology | 1T |
NOVATest Antigen Rapid Kit (NOVA Test) |
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nCov-500 | Atlas Link Technology | 20 Tests |
SARS-CoV-2 Rapid Antigen Test Nasal |
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9901-NCOV-03G | Roche Diagnostics | 25 Tests/Kit |
Human Streptococcus Pneumoniae (SP) Antigen Rapid Test Kit |
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abx092096-20tests | Abbexa | 20 tests |
Avian Influenza Virus Antigen Rapid Test Kit (Colloidal gold) |
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abx092015-40tests | Abbexa | 40 tests |
Coronavirus (SARS-Cov-2) Antigen Rapid Test Device (Saliva) |
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IOV87952 | INVBIO | 20T/kit |
Newcastle Disease Virus Antigen Rapid Test Kit (Colloidal gold) |
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abx092016-40tests | Abbexa | 40 tests |
Human Chlamydia Trachomatis Antigen Rapid Test Kit (Colloidal gold) |
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abx092049-20tests | Abbexa | 20 tests |
Avian Influenza H5 Virus Antigen Rapid Test Kit (Colloidal gold) |
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abx092014-40tests | Abbexa | 40 tests |
Avian Influenza H7 Virus Antigen Rapid Test Kit (Colloidal gold) |
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abx092017-40tests | Abbexa | 40 tests |
TruStrip RDT Anthrax Protective antigen 83 (PA83) Rapid Test cards, 25/pk |
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800-100-RDT-25 | Alpha Diagnostics | 1 pk |
2019-nCoV IgG/IgM Rapid Test Cassette (Whole Blood/Serum/Plasma) |
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GEN-402-25tests | All test | 25 tests |
TruStrip RDT Zaire Ebola Virus antigen (GP) rapid test (visual results in 2-10 mins), 10 cassettes/pk |
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AE-320805-RDT-10 | Alpha Diagnostics | 1 pk |
Melamine Rapid Test Kit |
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abx092011-50tests | Abbexa | 50 tests |
Brucella Antibody Rapid Test Kit |
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abx092069-40tests | Abbexa | 40 tests |
TruStrip RDT Canine distemper virus (hardpad disease) antigen rapid test card, results is 2-10 mins, 50 cards/pk |
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RV-501200-RDT | Alpha Diagnostics | 1 pk |
NOVATest IgG/IgM Antibody Rapid Test Kit (NOVA Test) |
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UNCOV-40 | Atlas Link Technology | 40 Tests |
Melamine (MEL) Rapid Test Kit |
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abx092057-50tests | Abbexa | 50 tests |
Quinolones (QNs) Rapid Test Kit |
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abx092065-40tests | Abbexa | 40 tests |
Salbutamol (SAL) Rapid Test Kit |
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abx092060-50tests | Abbexa | 50 tests |
Quinolones (QNs) Rapid Test Kit |
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abx092067-40tests | Abbexa | 40 tests |
Clenbuterol (CLE) Rapid Test Kit |
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abx092058-50tests | Abbexa | 50 tests |
Ractopamine (RAC) Rapid Test Kit |
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abx092059-50tests | Abbexa | 50 tests |
Tetracycline (TCs) Rapid Test Kit |
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abx092063-50tests | Abbexa | 50 tests |
Sulfonamides (Sas) Rapid Test Kit |
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abx092064-40tests | Abbexa | 40 tests |
Cow Brucella Antibody Rapid Test Kit |
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abx092071-40tests | Abbexa | 40 tests |
Goat Brucella Antibody Rapid Test Kit |
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abx092070-40tests | Abbexa | 40 tests |
Ciprofloxacin (CPFX) Rapid Test Kit |
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abx092066-50tests | Abbexa | 50 tests |
Pig Parvovirus Antibody Rapid Test Kit |
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abx092074-50tests | Abbexa | 50 tests |
Procalcitonin rapid test (Colloidal Gold) |
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abx095264-80Units | Abbexa | 80 Units |
Chlamydia Rapid Test Device (Swab/Urine) |
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173-8537306 | Abbott | 20 Tests/Kit |
Aflatoxin Rapid Test Kit (Colloidal gold) |
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abx092054-50tests | Abbexa | 50 tests |
Dynamiker Monkeypox Virus Ag Rapid Test |
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DNK-2114-1 | Dynamiker Biotechnology | 20 tests |
Salbutamol Rapid Test Kit (Colloidal gold) |
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abx092043-50tests | Abbexa | 50 tests |
Quinolones Rapid Test Kit (Colloidal gold) |
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abx092046-50tests | Abbexa | 50 tests |
Clenbuterol Rapid Test Kit (Colloidal gold) |
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abx092040-50tests | Abbexa | 50 tests |
Ractopamine Rapid Test Kit (Colloidal gold) |
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abx092042-50tests | Abbexa | 50 tests |
Zearalenone Rapid Test Kit (Colloidal gold) |
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abx092051-50tests | Abbexa | 50 tests |
Zearalenone Rapid Test Kit (Colloidal gold) |
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abx092056-50tests | Abbexa | 50 tests |
Sulfonamides Rapid Test Kit (Colloidal gold) |
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abx092047-50tests | Abbexa | 50 tests |
Tetracycline Rapid Test Kit (Colloidal gold) |
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abx092048-50tests | Abbexa | 50 tests |
Fetal Fibronectin rapid test (Colloidal Gold) |
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abx095261-80Units | Abbexa | 80 Units |
Deoxynivalenol Rapid Test Kit (Colloidal gold) |
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abx092052-50tests | Abbexa | 50 tests |
Deoxynivalenol Rapid Test Kit (Colloidal gold) |
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abx092053-50tests | Abbexa | 50 tests |
Chloramphenicol Rapid Test Kit (Colloidal gold) |
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abx092045-50tests | Abbexa | 50 tests |
Human Echovirus (ECHO) IgM Rapid Test Kit |
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abx092093-20tests | Abbexa | 20 tests |
Human Toxoplasma (TOX) IgG Rapid Test Kit |
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abx092098-20tests | Abbexa | 20 tests |
Cattle and Goat Hydatid Antibody Rapid Test Kit |
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abx092072-40tests | Abbexa | 40 tests |
Aflatoxin B1 Rapid Test Kit (Colloidal gold) |
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abx092055-50tests | Abbexa | 50 tests |
Aflatoxin B1 Rapid Test Kit (Colloidal gold) |
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abx092050-50tests | Abbexa | 50 tests |
GENLISA™ Human SARS-CoV-2 (Covid-19) Spike Protein Antigen Quantitative ELISA |
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KBVH015-10 | Krishgen | 12 × 8 wells |
TruStrip RDT Testosterone Rapid Test cards, 10/pk |
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1880-RDT-10 | Alpha Diagnostics | 1 pk |
Avian Influenza H5N1 Virus Antibody Rapid Test Kit |
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abx092075-40tests | Abbexa | 40 tests |
Human Treponema Pallidum (TP) Antibody Rapid Test Kit |
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abx092101-20tests | Abbexa | 20 tests |
Malachite Green Rapid Test Kit (Colloidal gold) |
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abx092041-10tests | Abbexa | 10 tests |
Rabies Virus Antibodies Rapid Test Kit (Colloidal gold) |
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abx092033-40tests | Abbexa | 40 tests |
Human Rubella Virus (RV) IgG Rapid Test Kit |
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abx092097-20tests | Abbexa | 20 tests |
Human Rabies Virus (HRV) IgG Rapid Test Kit |
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abx092100-20tests | Abbexa | 20 tests |
Human Hantavirus (HV) IgM / IgG Rapid Test Kit |
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abx092094-20tests | Abbexa | 20 tests |
Human Hepatitis A Virus IgG Rapid Test Kit |
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abx092012-25tests | Abbexa | 25 tests |
Influenza Rapid Test Control Pack (3 X 1.5mL) |
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KZMC033 | Zeptometrix | 3 X 1.5mL |
Rotavirus Rapid Test Control Pack (2 X 1.5mL) |
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KZMC036 | Zeptometrix | 2 X 1.5mL |
The results of this study indicate that the use of rapid antigen RIM tests in routine screening of FCoV shedding status in shelter cats is limited due to the occurrence of a high number of false negative results.