Comparative evaluation of Panbio and SD Biosensor antigen rapid diagnostic tests for COVID-19 diagnosis.

The aim of our study was to evaluate the diagnostic performance of two antigen rapid diagnostic tests (Ag-RDTs) to diagnose severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We evaluated Panbio and SD-Biosensor Ag-RDTs. We employed 186 polymerase chain reaction (PCR) negative samples to evaluate the specificity and 170 PCR positive samples to assess the sensitivity. We evaluated their sensitivity according to Cycle threshold (C t ) values and days post onset of symptoms (d.p.o.). Tests were compared using the McNemar's test. Agreement was evaluated using the kappa score. Specificity was 100% for Panbio and 97.3% for SD-Biosensor. Sensitivity for samples with C t ≤ 20 was 100% for both assays and for samples with C t = 20-25 was 93.0% (Panbio) and 95.3% (SD-Biosensor) (p = 1.000). Sensitivity decreased for samples wit C t = 25-30 (Panbio: 41.3%, SD-Biosensor: 52.2%, p = 0.125) and samples with C t ≥ 30 (Panbio: 5.0%, SD-Biosensor: 17.5%, p = 0.063). Sensitivity within seven d.p.o. was 87.7% for Panbio and 90.4% for SD-Biosensor and notably decreased after seven d.p.o. Agreement with PCR was excellent for high viral load samples (C t ≤ 25): Panbio, 98.9%, kappa = 0.974; SD-Biosensor, 97.4%, kappa = 0.940. Agreement between Ag-RDTs was excellent (94.9%, kappa = 0.882). Panbio and SD-Biosensor Ag-RDTs showed excellent agreement and diagnostic performance results for samples with high viral loads (C t ≤ 25) or samples within seven d.p.o.

Comparative evaluation of six immunoassays for the detection of antibodies against SARS-CoV-2.

OBJECTIVES: Serologic techniques can serve as a complement to diagnose SARS-CoV-2 infection. The objective of our study was to compare the diagnostic performance of six immunoassays to detect antibodies against SARS-CoV-2: three lateral flow immunoassays (LFAs), one ELISA and two chemiluminescence assays (CLIAs). METHODS: We evaluated three LFAs (Alltest, One Step and SeroFlash), one ELISA (Dia.Pro) and two CLIAs (Elecsys and COV2T). To assess the specificity, 60 pre-pandemic sera were used. To evaluate the sensitivity, we used 80 serum samples from patients with positive PCR for SARS-CoV-2. Agreement between techniques was evaluated using the kappa score (k). RESULTS: All immunoassays showed a specificity of 100 % except for SeroFlash (96.7 %). Overall sensitivity was 61.3 %, 73.8 %, 67.5 %, 85.9 %, 88.0 % and 92.0 % for Alltest, One Step, SeroFlash, Dia.Pro, Elecsys and COV2T, respectively. Sensitivity increased throughout the first two weeks from the onset of symptoms, reaching sensitivities over 85 % from 14 days for all LFAs, being One Step the most sensitive (97.6 %), followed by SeroFlash (95.1 %). Dia.Pro, Elecsys and COV2T showed sensitivities over 97 % from 14 days, being 100 % for COV2T. One Step showed the best agreement results among LFAs, showing excellent agreement with Dia.Pro (agreement = 94.2 %, k = 0.884), COV2T (99.1 %, k = 0.981) and Elecsys (97.3 %, k = 0.943). Dia.Pro, COV2T and Elecsys also showed excellent agreement between them. CONCLUSIONS: One Step, Dia.Pro, Elecsys and COV2T obtained the best diagnostic performance results. All these techniques showed a specificity of 100 % and sensitivities over 97 % from 14 days after the onset of symptoms, as well as excellent levels of agreement.

Diagnostic performance of CerTest and Panbio antigen rapid diagnostic tests to diagnose SARS-CoV-2 infection.

OBJECTIVES: Antigen rapid diagnostic tests (Ag-RDT) have been developed as reliable tools to control the SARS-CoV-2 pandemic. The objective of our study was to evaluate the diagnostic performance of two Ag-RDTs. METHODS: We evaluated CerTest SARS-CoV-2 Ag One Step Card Test and Panbio COVID-19 Ag Rapid Test Device Ag-RDTs. We included 320 nasopharyngeal samples: 150 PCR negative samples to assess the specificity and 170 PCR positive samples to evaluate the sensitivity. We also evaluated their sensitivity according to cycle threshold (Ct) values and the time from the onset of symptoms. Tests were compared using the McNemar's test and agreement was evaluated using the kappa score (k). RESULTS: Both Ag-RDTs showed a specificity of 100 %. Overall sensitivity was 53.5 % for CerTest and 60.0 % for Panbio. For samples with Ct≤ 25, sensitivity was 94.0 % for CerTest and 96.4 % for Panbio (p = 0.500). Regarding samples with Ct>25, sensitivity was 14.0 % for CerTest and 24.4 % for Panbio (p = 0.004). Sensitivity for samples within the first 5 days after the onset of symptoms were 84.8 % for CerTest and 91.3 % for Panbio (p = 0.250) and notably decreased for samples taken after the fifth day. Both Ag-RDTs showed an excellent agreement between them (agreement = 96.7 %, k = 0.920). Agreement with PCR was also excellent for high viral load samples (Ct<25) for CerTest (98.0 %, k = 0.954) and Panbio (98.8 %, k = 0.973). CONCLUSIONS: CerTest SARS-CoV-2 and Panbio COVID-19 Ag showed excellent performance and agreement results for samples with high viral loads (Ct ≤ 25) or samples taken within the first 5 days after the onset of symptoms.

Panbio antigen rapid test is reliable to diagnose SARS-CoV-2 infection in the first 7 days after the onset of symptoms.

BACKGROUND: RT-qPCR is the current recommended laboratory method to diagnose SARS-CoV-2 acute infection, several factors such as requirement of special equipment, time consuming, high cost and skilled staff limit the use of these techniques. A more rapid and high-throughput method is essential. METHODS: We analyzed clinical data and nasopharyngeal samples, collected during September 2020, from patients attended at the emergency department of a secondary hospital and in two primary healthcare centers in Madrid. The performance of the Panbio™ COVID-19 AG Rapid Test Device for the detection of SARS-CoV-2 antigen was compared to RT-qPCR. RESULTS: 255 nasopharyngeal swabs, including 150 from the emergency department and 105 from primary helthcare centers, were tested. 184 patients were symptomatic (72.1 %). Amongst the 60 positive RT-qPCR samples, 40 were detected by the rapid antigen test, given an overall sensitivity of 73.3 %. All the samples detected positive with the rapid antigen test were also positive with RT-qPCR. The median cycle threshold was 23.28 (IQR 18.5-30.16). Patients with less than seven days onset of symptoms showed a higher viral load, and sensitivity for rapid antigen test (86.5 %), compared to those with more days (sensitivity of 53.8 %)(p < 0.004). CONCLUSIONS: The rapid antigen test evaluated in this study showed a high sensitivity and specificity in samples obtained during the first week of symptoms and with high viral loads. This assay seems to be an effective strategy for controlling the COVID-19 pandemic for the rapid identification and isolation of SARS-CoV-2 infected patients.

Study of susceptibility to antibiotics and molecular characterization of high virulence Staphylococcus aureus strains isolated from a rural hospital in Ethiopia.

We characterised 80 Staphylococcus aureus strains isolated from human patients with SSTIs at a rural hospital in Ethiopia. Susceptibility to antibiotic of all strains was tested. The MLST method was used to type and a phylogenetic analysis was conducted employing the sequences of 7 housekeeping genes. PCR amplification was used to investigate the presence of the following virulence genes in all strains: hla (α-haemolysin), tstH (toxic shock syndrome toxin), luk PV (Panton-Valentine leukocidin), fnbA (fibronectin binding protein A) and mecA (methicillin resistance). Most of the strains were resistant to penicillin and ampicillin, but only 3 strains were resistant to oxacillin, and 1 of them was a true MRSA. The MLST results showed a high diversity of sequence types (ST), 55% of which were new, and ST152 was the most prevalent. A phylogeny study showed that many of the new STs were phylogenetically related to other previously described STs, but bore little relationship to the only ST from Ethiopia described in the database. Virulence gene detection showed a high prevalence of strains encoding the hla, fnbA and pvl genes (98.77%, 96.3% and 72.84%, respectively), a low prevalence of the tst gene (13.58%) and a markedly low prevalence of MRSA (1.25%). S. aureus strains isolated from patients in a rural area in Ethiopia showed low levels of antibiotic resistance, except to penicillin. Moreover, this study reveals new STs in Eastern Africa that are phylogenetically related to other previously described STs, and confirm the high prevalence of the pvl gene and the low prevalence of MRSA on the continent.

Alltest rapid lateral flow immunoassays is reliable in diagnosing SARS-CoV-2 infection from 14 days after symptom onset: A prospective single-center study.

OBJECTIVES: SARS-CoV-2 infection diagnosis is challenging in patients from 2 to 3 weeks after the onset of symptoms, due to the low positivity rate of the PCR. Serologic tests could be complementary to PCR in these situations. The aim of our study was to analyze the diagnostic performance of one serologic rapid test in COVID-19 patients. METHODS: We evaluated a lateral flow immunoassay (AllTest COVID-19 IgG/IgM) which detects IgG and IgM antibodies. We validated the serologic test using serum samples from 100 negative patients (group 1) and 90 patients with COVID-19 confirmed by PCR (group 2). Then, we prospectively evaluated the test in 61 patients with clinical diagnosis of pneumonia of unknown etiology that were negative for SARS-CoV-2 by PCR (group 3). RESULTS: All 100 patients from group 1 were negative for the serologic test (specificity = 100 %). Regarding group 2 (PCR-positive), the median time from their symptom onset until testing was 17 days. For these 90 group-2 patients, the test was positive for either IgM or IgG in 58 (overall sensitivity = 64.4 %), and in patients tested 14 days or more after the onset of symptoms, the sensitivity was 88.0 %. Regarding the 61 group-3 patients, median time after symptom onset was also 17 days, and the test was positive in 54 (88.5 % positivity). CONCLUSIONS: Our study shows that Alltest lateral flow immunoassay is reliable as a complement of PCR to diagnose SARS-CoV-2 infection after 14 days from the onset of symptoms and in patients with pneumonia and negative PCR for SARS-CoV-2.

Genotypic and Phenotypic Characteristics of Staphylococcus aureus Prosthetic Joint Infections: Insight on the Pathogenesis and Prognosis of a Multicenter Prospective Cohort.

BACKGROUND: Staphylococcus aureus is the leading cause of prosthetic joint infection (PJI). Beyond the antibiogram, little attention has been paid to the influence of deep microbiological characteristics on patient prognosis. Our aim was to investigate whether microbiological genotypic and phenotypic features have a significant influence on infection pathogenesis and patient outcome. METHODS: A prospective multicenter study was performed, including all S. aureus PJIs (2016-2017). Clinical data and phenotypic (agr functionality, ß-hemolysis, biofilm formation) and genotypic characteristics of the strains were collected. Biofilm susceptibility to antimicrobials was investigated (minimal biofilm eradication concentration [MBEC] assay). RESULTS: Eighty-eight patients (39.8% men, age 74.7 ±â€…14.1 years) were included. Forty-five had early postoperative infections (EPIs), 21 had chronic infections (CPIs), and 19 had hematogenous infections (HIs). Twenty (22.7%) were caused by methicillin-resistant S. aureus. High genotypic diversity was observed, including 16 clonal complexes (CCs), with CC5 being the most frequent (30.7%). agr activity was greater in EPI than CPI (55.6% vs 28.6%; P = .041). Strains causing EPI were phenotypically and genotypically similar, regardless of symptom duration. Treatment failure (36.5%) occurred less frequently among cases treated with implant removal. In cases treated with debridement and implant retention, there were fewer failures among those who received combination therapy with rifampin. No genotypic or phenotypic characteristics predicted failure, except vancomycin minimal inhibitory concentration ≥1.5 mg/L (23.1% failure vs 3.4%; P = .044). MBEC50 was >128 mg/L for all antibiotics tested and showed no association with prognosis. CONCLUSIONS: S. aureus with different genotypic backgrounds is capable of causing PJI, showing slight differences in clinical presentation and pathogenesis. No major microbiological characteristics were observed to influence the outcome, including MBEC.

Prevalence of anti-hantavirus antibodies in patients with hypertransaminemia in Madrid (Spain).

The hantaviruses are involved in a number of clinical syndromes of different severity and prognosis. Hantaviruses are widely distributed around the world, but the spectrum of illnesses they cause outside recognized endemic areas is unclear. A retrospective analysis was performed to detect anti-hantavirus antibodies in the serum of patients with hypertransaminemia of unknown etiology and in that of healthy members of the general population of Madrid (Spain). Antibodies were detected by indirect immunofluorescence and enzyme immunoassay; positive results were confirmed by Western blotting. Of the 182 patients with hypertransaminemia, 11 (6%) were positive for anti-hantavirus IgG antibodies; Western blotting using recombinant Puumala virus N antigen showed one of these patients to have hantavirus-specific IgM antibodies. Among the 146 healthy subjects from the general population, 3 (2%) were positive for anti-hantavirus IgG antibodies. These results show that anti-hantavirus antibodies are more commonly detected in patients with hypertransaminemia than in healthy people.

Nonfatal pulmonary Trichoderma viride infection in an adult patient with acute myeloid leukemia: report of one case and review of the literature.

Trichoderma species have been recognized to be pathogenic in immunosuppressed hosts with increasing frequency. Trichoderma species are responsible for continuous ambulatory peritoneal dialysis associated peritonitis and infections in immunocompromised patients with a hematologic malignancy or solid organ transplantation. Trichoderma longibrachiatum is the most common species involved in these infections. We report the first case of nonfatal pulmonary infection caused by Trichoderma viride in leukemia patient. It had a successful answer to new antifungal agents as voriconazole and caspofungin. Trichoderma viride was isolated from pulmonary aspirate culture from a 54-year-old female who had received chemotherapy for acute myeloid leukemia. The minimal inhibitory concentrations for the organism were the following: amphotericin B (0.25 microg/mL) and voriconazole (2 microg/mL). Initially, she was treated unsuccessful with liposomal amphotericin B and voriconazole and caspofungin were added later. The patient is alive. We report one case along review of the literature.

[Usefulness of Hybrid Capture II detection of high-risk human papillomavirus in women with abnormal pap-smears of the uterine cervix]. / Utilidad de la detección del virus del papiloma humano de alto riesgo mediante Hybrid Capture II en mujeres con citologías anormales del cuello uterino.

INTRODUCTION: The objectives of the study were to investigate the usefulness of high-risk human papillomavirus (HR-HPV) detection in women with abnormal pap-smears as an adjunct to screening by cervical cytology, and to determine the viral load distribution according to the histological grade of the lesions. METHODS: A total of 75 women were referred for cytological study of atypical cells of unknown origin (ASCUS), low-grade squamous intraepithelial lesions (LG-SIL) or high-grade squamous intraepithelial lesions (HG-SIL). All patients underwent colposcopy, histological study and HR-HPV detection using the Hybrid Capture II test. RESULTS: In the pap-smear studies, HR-HPV was detected in 31.2% of women with ASCUS and 65.7% with LG-SIL. Histological examination showed HR-HPV in 46.4% of women without lesions, 69.5% of those with LG-SIL and 75% with HG-SIL. Negative predictive values for HG-SIL in women with cytological diagnoses of ASCUS and LG-SIL were 81.8% and 92.3%, respectively. Percentages of infection with high viral load significantly increased in accordance with the histological grade. CONCLUSIONS: The Hybrid Capture II test can be useful for the management of women with cytological evidence of ASCUS because of the low prevalence of HR-HPV infection and the high negative predictive value for HG-SIL. The usefulness in women with a cytological diagnosis of LG-SIL is limited due to the high prevalence of HR-HPV infection. High viral load can be a risk factor for the development of premalignant cervical lesions.

Shewanella alga bacteremia and associated cellulitis in a patient with multiple myeloma.

Shewanella alga is a gram-negative bacillus found in all types of water as well as in a variety of tainted food. It has rarely been associated with human disease, either in healthy or in immunocompromised patients. We report a 66-year-old man with a multiple myeloma who developed a cellulitis in both forearms in the course of a Shewanella bacteremia. He had a renal insufficiency and was moderately neutropenic after chemotherapy (vincristine, adriamycin, dexamethasone). Outcome was good after treatment with ceftazidime-amikacin despite all the risk factors. Shewanella isolation may be clinically significant. Haematological patients constitute a group of risk as increasingly aggressive chemotherapy regimens are used. Clinical outcome is not necessarily bad.