Jin Woo Jang

False-Positive Results for Rapid Diagnostic Tests for Malaria in Patients with Rheumatoid Factor

ABSTRACT Four different rapid diagnostic tests (RDTs) for malaria were evaluated by testing 82 healthy control patients, 89 Plasmodium vivax-infected patients, and 92 rheumatoid factor (RF)-positive nonmalaria patients. The false-positive rate ranged from 2.2% to 13% in RF-positive patients. High RF levels are associated with malaria RDT false positivity.

Evaluation and verification of the nanosphere Verigene RV+ assay for detection of influenza A/B and H1/H3 subtyping

With the emerging risks of drug‐resistant viruses and pandemic influenza, rapid and accurate detection of influenza viruses and determination of their subtypes is a crucial component of patient management. This study evaluated the performance of the Verigene respiratory virus plus nucleic acid (Verigene RV+) test for the detection of influenza A/B and subtype determination compared it with conventional molecular methods. Nasopharyngeal swabs were collected from 228 patients with influenza‐like illness (influenza A (n = 67), 2009‐H1N1 (n = 21), influenza B (n = 80), mixed A & B (n = 3), mixed RSV A and influenza (n = 3), and influenza‐negative (n = 54)). Patient samples were analyzed by Influenza A/B one‐step typing (Seegene, Seoul, Korea), Seeplex RV15 ACE Detection (Seegene), Nanosphere Verigene RV+ assay (Nanosphere, Northbrrook, IL) and virus culture. Out of 228 samples, 109 (47.8%) were positive by culture, and an additional 65 (28.5%) were positive by Seeplex RV15 ACE Detection, Influenza A/B one‐step typing or Nanosphere Verigene RV+ assay. In comparison tests with Seeplex RV15 ACE Detection RT‐PCR, the sensitivity of the Verigene RV+ kit for detection of the influenza A, 2009‐H1N1, influenza B, and mixed A & B was 97.1%, 100%, 100%, and 100%, respectively. The specificity of the Verigene RV+ was 100% for all types. The concordance between Verigene RV+ and Influenza A/B one‐step typing for H1, H3, H1/H3 mixed, and 2009‐H1N1 was 100% (26/26), 100% (35/35), 100% (4/4), and 100% (21/21), respectively. The Verigene RV+ assay showed acceptable sensitivity and specificity for detection and subtyping of influenza viruses compared with the conventional RT‐PCR method. J. Med. Virol. 87: 18–24, 2015.

Clinical performance evaluation of the BD Veritor System Flu A+B assay.

Early identification of influenza is important for optimal patient management and infection control. Rapid influenza antigen tests have been used routinely in clinical settings to confirm clinical suspicion, despite their low sensitivity. To improve sensitivity, various influenza point-of-care test reader systems have been developed. This study evaluated the clinical performance of a digital readout rapid influenza diagnostic test (RIDT), the BD Veritor™ System Flu A+B assay (BD). Nasopharyngeal swabs taken from 250 patients (influenza A positive, n=75; influenza B positive, n=75; and influenza negative, n=100) were analyzed using the BinaxNOW® Influenza A/B antigen kit (BN), SD Influenza Ag A/B kit (SD), BD, real-time reverse transcriptase polymerase chain reaction (RT-PCR), and an influenza virus culture. Compared to RT-PCR, the sensitivities of BN, SD, and BD were 56.0, 53.3, and 72.0%, respectively, for influenza A and 57.3, 65.3, and 69.3%, respectively, for influenza B. No false-positive results were noted with the three rapid antigen tests. For influenza A, the average RT-PCR threshold cycle (Ct) for specimens that tested positive using BD was higher than that for specimens that tested positive using BN and SD. BD is a sensitive and easy method for the early detection of influenza A and B.

Evaluation of the Simplexa Flu A/B and RSV test for the rapid detection of influenza viruses.

Recently, various molecular systems have been introduced for the detection of influenza viruses. Among these, the Simplexa Flu A/B and respiratory syncytial virus (RSV) test can provide results in approximately 2 hr. Nasopharyngeal swabs from 241 patients (influenza A, n = 81; influenza B, n = 80; influenza A and influenza B mixed, n = 1; influenza A and RSV A mixed, n = 2; and influenza and RSV negative, n = 77) were analyzed using the Simplexa Flu A/B and RSV test, a conventional reverse‐transcription polymerase chain reaction (RT‐PCR) assay, and a real‐time RT‐PCR assay. Compared to conventional RT‐PCR, the Simplexa test had respective sensitivities and specificities of 100% and 100% for influenza A and 100% and 99.4% for influenza B with extracted RNA samples, and 91.7% and 99.4% for influenza A, and 97.5% and 98.1% for influenza B with unprocessed patient specimens. All RSV A specimens were successfully detected by the Simplexa test using both extracted RNA samples and unprocessed patient specimens. The real‐time RT‐PCR assay had respective sensitivities and specificities of 96.4% and 99.4% for influenza A, and 98.8% and 99.4% for influenza B. The Simplexa test was effective at detecting influenza viruses from extracted RNA samples as well as from unprocessed patient specimens. The assay was not only simple and rapid for influenza detection, but the performance was also comparable to that of other conventional molecular methods. J. Med. Virol. 85:2160–2164, 2013.

Clinical Performance Evaluation of the Sofia RSV FIA Rapid Antigen Test for Diagnosis of Respiratory Syncytial Virus Infection

ABSTRACT A recently introduced Sofia respiratory syncytial virus (RSV) fluorescent immunoassay (FIA) was evaluated against the BinaxNOW RSV card and the SD Bioline RSV test using 348 respiratory samples. The Sofia, BinaxNOW, and SD Bioline kits showed sensitivities of 66%, 65%, and 64%, respectively, for detecting RSV-A, and 71%, 63%, and 65% for detecting RSV-B, respectively.

GENEDIA Multi Influenza Ag Rapid Test for detection and H1, H3, and H5 subtyping of influenza viruses.

BACKGROUND Rapid identification and subtype determination of influenza virus is important in managing infected patients. Rapid influenza diagnostic tests (RIDTs) are widely used in this manner, but most can only detect influenza A and B viruses without subtyping. A new RIDT, GENEDIA Multi Influenza Ag Rapid Test (GENEDIA), was developed for detection of influenza A and B viruses and also subtyping of influenza A to H1, H3, H5 which has not been possible with other RIDTs. OBJECTIVES Assess the performance of GENEDIA. STUDY DESIGN Nasopharyngeal swabs were collected from 274 clinically suspected patients (influenza A/H1N1/2009 (n=50), influenza A/H3 (n=50), influenza B (n=73) and influenza-negative (n=101)) and analyzed with the real-time RT-PCR, GENEDIA, SD Bioline Influenza Ag, and Alere BinaxNow Influenza A&B Card. Also, 46 fecal specimens (H5N2 (n=3), H5N3 (n=3)) of spot-billed duck were analyzed with RT-PCR and GENEDIA. RESULTS Compared to real-time RT-PCR, the sensitivities of GENEDIA, SD Bioline Influenza Ag, and Alere BinaxNow Influenza A&B Card were 73.0%, 57.0%, 58.0% for influenza A, respectively, and 68.5%, 65.8%, 57.5% for influenza B, respectively. Specifically, the sensitivity of GENEDIA was 70.0% for influenza A/H1N1/2009 and 76.0% for influenza A/H3. From the avian influenza samples, GENEDIA detected all six H5 subtype without any cross-reactions. CONCLUSION The GENEDIA Multi Influenza Ag Rapid Test was sensitive in detecting influenza viruses compared with other commercial RIDTs and also useful for rapid subtype determination of influenza A.

Flow Cytometric Enumeration of Parasitemia in Cultures of Plasmodium falciparum Stained with SYBR Green I and CD235A

A flow cytometric (FACS) detection method for Plasmodium falciparum cultures (P. falciparum) was developed using SYBR Green I and CD235A and compared against the Giemsa stained microscopic examination. The cultured P. falciparum were spiked into red blood cells (RBCs) to yield parasitemia, ranging from 0.01% to 22.0%. FACS analysis demonstrated a clear separation between P. falciparum infected and uninfected RBCs. The measured percentage of parasitemia by FACS revealed higher precision (CV of 2.2–37.2%) with the sensitivity of 0.01% parasitemia than Giemsa stained microscopic examination (CV of 7.2–66.0%). High correlation of measured parasitaemia (r = 0.98, P < 0.05) was observed between FACS and Giemsa stained microscopic analyses. The higher levels of parasitaemia detection were observed in all ranges by FACS in comparison to Giemsa stained microscopic analysis. The currently reported FACS method using SYBR Green I and CD235A is potentially useful for measuring parasitemia in treating patients.

Combined Use of Malaria Antigen and Antibody Enzyme-Linked Immunosorbent Assay for Blood Screening of Plasmodium vivax in the Republic of Korea

Objective: To evaluate the clinical sensitivity and specificity of the newly developed Genedia malaria antigen enzyme-linked immunosorbent assay (ELISA) test and to evaluate the diagnostic efficiency of the combined use of the Genedia malaria antigen and antibody ELISA tests to detect Plasmodium vivax in blood samples. Materials and Methods: In all, 1,070 samples were analyzed: 300 P. vivax-infected patients, 41 samples from posttreatment patients upon follow-up and 729 healthy volunteers. The Genedia malaria antigen ELISA test and the Genedia malaria antibody ELISA 2.0 test were evaluated and compared to polymerase chain reaction and microscopy. Results: The Genedia malaria antigen ELISA test had a clinical sensitivity of 94.7% (284/300) and a clinical specificity of 99.3% (724/729). The Genedia malaria antibody ELISA 2.0 test had a clinical sensitivity of 94.0% (282/300) and a clinical specificity of 98.4% (717/729). The Genedia malaria antigen ELISA test was able to detect 13 confirmed P. vivax cases without antibodies against P. vivax, whereas the Genedia malaria antibody ELISA 2.0 test detected 11 confirmed P. vivax cases nonreactive to the Genedia malaria antigen ELISA test, and 25 cases from 41 follow-up samples nonreactive in the Genedia malaria antigen ELISA test. The combined Genedia malaria antigen and antibody ELISA 2.0 tests had a clinical sensitivity of 98.3% (295/300) and a clinical specificity of 97.9% (714/729). Conclusion: The combination of antigen and antibody ELISAs improved the diagnostic sensitivity in P. vivax-confirmed cases in the Republic of Korea.

Evaluation of Novel Multiplex Antibody Kit for Human Immunodeficiency Virus 1/2 and Hepatitis C Virus Using Sol-Gel Based Microarray

Background. Microarrays enable high-throughput screening (HTS) of disease-related molecules, including important signaling proteins/peptides and small molecules that are in low abundance. In this study, we developed a multiplex blood bank screening platform, referred to as the Hi3-1 assay, for simultaneous detection of human immunodeficiency virus 1/2 (HIV 1/2) and hepatitis C virus (HCV). Methods. The Hi3-1 assay was tested using four panels (Panel 1, n = 4,581 patient samples; Panel 2, n = 15 seroconversion samples; Panel 3, n = 4 performance samples; and Panel 4, n = 251 purchased positive control samples), and the results were collected by the Department of Laboratory Medicine, Korea University Medical College, Republic of Korea. The present study compares the sensitivity of the multiplex detection platform for both HIV and HCV using a sol-gel based microarray, which was based on a reference test (Architect HIV Ag/Ab Combo and Architect anti-HCV assays), in Korean patients. Results. The sensitivity of the multiplex detection platform for both HIV and HCV was 100%, and the specificity was 99.96% for HIV and 99.76% for HCV, which is equivalent to that of the reference test. Conclusion. We have successfully applied a novel screening technology to multiplex HIV and HCV diagnoses in a blood bank screening test.

Corrigendum to “GENEDIA multi influenza Ag rapid test for detection and H1, H3, and H5 subtyping of influenza viruses” [J. Clin. Virol. 73 (2015) 42–46]

Corrigendum to “GENEDIA multi influenza Ag rapid test for detection and H1, H3, and H5 subtyping of influenza viruses” [J. Clin. Virol. 73 (2015) 42–46] Jin Woo Jang, Sun-Young Ko, Mun Sub Byoun, Haan Woo Sung, Chae Seung Lima, a Department of Laboratory Medicine, College of Medicine Korea University, Seoul, Republic of Korea b Department of Veterinary Microbiology, College of Veterinary Medicine, Kangwon National University, Chuncheon, Republic of Korea