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Purpose: The current diagnostic methods for leptospirosis diagnosis are technically complex and expensive, with limited applicability to specialized laboratories. Furthermore, they lack diagnostic accuracy in the acute stage of the disease, which coincides with a period when antibiotics are highly effective. New simple and accurate tests are mandatory to decentralize and improve diagnosis. Here, we introduced a new lateral flow immunoassay (Lepto-LF) for human leptospirosis. Methods: We conducted a double-blinded assay using 104 serum samples from patients with confirmed or discarded diagnosis for leptospirosis. The diagnostic performance of Lepto-LF was estimated across different ranges of days from onset of symptoms (dpo), considering the diagnostic algorithm as reference standard. Additionally, it was compared with the screening methods enzyme-linked immunosorbent assay (IgM-ELISA) and the slide agglutination test using temperature-resistant antigen (SATR). Results: Lepto-LF exhibited perfect diagnostic performance with a Youden´s index J = 1 from 6 dpo in the acute phase. IgM-ELISA gave slightly lower accuracy with J = 0.91 and 95.5% of both sensitivity and specificity; while SATR showed a markedly inferior yield (J = 0.41, sensitivity = 95.5%, specificity = 45.5%). The performances remained consistent in the convalescence phase of the disease (> 10 dpo). Conclusion: Lepto-LF was found to be a reliable test for simple, rapid and early diagnosis of leptospirosis, resulting a promising tool for decentralizing leptospirosis diagnosis and enabling timely treatment of patients. In addition, Lepto-LF may be employed as confirmatory test, especially in remote areas and vulnerable contexts where the standard MAT is not available. [ABSTRACT FROM AUTHOR]

Introduction: In the fight against virus-caused pandemics like COVID-19, diagnostic tests based on RT-qPCR are essential, but they are sometimes limited by their dependence on expensive, specialized equipment and skilled personnel. Consequently, an alternative nucleic acid detection technique that overcomes these restrictions, called loop-mediated isothermal amplification following reverse transcription (RTLAMP), has been broadly investigated. Nevertheless, the developed RT-LAMP assays for SARS-CoV-2 detection still require laboratory devices and electrical power, limiting their widespread use as rapid home tests. This work developed a flexible RT-LAMP assay that gets beyond the drawbacks of the available isothermal LAMP-based SARS-CoV-2 detection, establishing a simple and effective at-home diagnostic tool for COVID-19. Methodology: A multiplex direct RT-LAMP assay, modified from the previously developed test was applied to simultaneously identify the two genes of SARS-CoV-2. We used a colorimetric readout, lyophilized reagents, and benchmarked an electro-free and micropipette-free method that enables sensitive and specific detection of SARS-CoV-2 in home settings. Results: Forty-one nasopharyngeal swab samples were tested using the developed home-testing RT-LAMP (HT-LAMP) assay, showing 100% agreement with the RT-qPCR results. Conclusions: This is the first electrically independent RT-LAMP assay successfully developed for SARS-CoV-2 detection in a home setting. Our HT-LAMP assay is thus an important development for diagnosing COVID-19 or any other infectious pandemic on a population scale. [ABSTRACT FROM AUTHOR]

Background: Respiratory infections pose a major public health threat. The predominant viruses causing viral respiratory infections are influenza A and B (Flu-A, Flu-B), coronaviruses, respiratory syncytial virus (RSV), and adenovirus. This study aims to investigate the proportion of these cases via rapid antigen tests and assess seasonal patterns. Methods: Clinical samples were collected from symptomatic adults presenting to the Emergency and Respiratory Medicine Departments of the University Hospital of Larissa (UHL), Greece from 16 October 2023 to 31 March 2024. Nasal specimens were antigen-tested for Flu-A/B, SARS-CoV-2, RSV, and adenovirus. Results: The total sample of specimens collected was 1434, of which 739 (51.5%) were female and 695 were male (48.5%). The mean age of participants was 57 ± 5.5 years. Among the positive results, we recorded a proportion of 40.18% and 11.40% for influenza A and B, respectively, followed by 35.79% for SARS-CoV-2, 10.70% for RSV, and 1.93% for adenovirus. Conclusions: In Greece, surveillance systems in infection control are underutilized. Rapid tests via multiple antigens can quickly identify viral infections, making them a valuable tool with financial benefits for health systems. Early detection of respiratory infections helps allocate resources efficiently, ensures adequate staff and facilities are available, and improves patient care through refined clinical management. [ABSTRACT FROM AUTHOR]

Feline parvovirus (FPV) is one of the most common causes of acute hemorrhagic enteritis, with high mortalities in kittens. As clinical diagnosis is often indecisive, the aim of our study was to evaluate the diagnostic accuracy of in-clinic rapid tests for the detection of FPV infection in cats. To this end, we contrasted the most reliable diagnostic technique--PCR--with the rapid diagnostic kit for FPV antigen. A total of 100 stool samples were collected from cats suspected of being infected with FPV. A vaccination history was reported for all sampled cats. Every sample underwent both PCR and the rapid diagnostic test, with the results being compared. Anorexia, bloody diarrhea, severe dehydration, hypothermia, and vomiting were the most common clinical findings significantly associated with parvovirus- infected cats. 35 out of 100 clinically ill cats were FPV positive (35%) using the rapid screening test, while 43 (43%) of the tested samples were PCR positive. Overall, the two tests found FPV infection in 32 cases and ruled it out in 54. The PCR technique confirmed the infection in 11 cases that their rapid testing were negative. Rapid antigen-based screening assays demonstrated sensitivity and specificity of 74.42% and 94.74%, respectively. In conclusion, a positive result certainly indicates FPV infection, while a negative result does not rule out parvoenteritis from the differential diagnosis, especially in cats exhibiting clinical symptoms. It is possible to anticipate increased sensitivity if the test is run right following sample collection. [ABSTRACT FROM AUTHOR]

Rapid tests allow outpatient, low cost, reliable, screening for chronic HIV infection. However, data regarding their sensitivity on primary infection remain scarce. The objective of this study was to assess sensitivity of nine HIV rapid tests for primary HIV-1 infection screening. Seventy-five serum samples from patients during HIV-1 primary infection were included. Primary infection was diagnosed by a positive 4th generation ELISA and HIV-1 RNA positivity confirmed by Western blot patterns associated with HIV-1 primary infection. Early seroconversion was defined as the absence of antibodies on HIV-1 Western blot associated with HIV-1 RNA and p24-antigen positivity. An identical sensitivity (95% CI) of 76.7% (65.2–84.2%) was observed for HIV 1/2 STAT-PAK® Assay (STAT-PAK), INSTI™ HIV-1/HIV-2 antibody Test (INSTI), SURE CHECK® HIV 1/2 (SURE CHECK) and MULTISURE HIV rapid test (MULTISURE) with visual reading. Sensitivity was 74.7% (63.8–83.1%) for MULTISURE (automatic reading), 77.0% (66.3–85.1%) for FIRST RESPONSE® Test VIH 1–2.O CARTE (FIRST RESPONSE), 83.8% (73.8–90.5%) for VIKIA HIV1/2® (VIKIA), 88.0% (78.7–93.6%) for Genie™ Fast HIV 1/2 (Genie Fast), 88.6% (79.0-94.1%) for Hexagon HIV (Hexagon), and 92.8% (83.6–96.3%) for Exacto® TEST HIV Pro (Exacto). However, rapid tests performed poorly for the early seroconversion subgroup (n = 14), with sensitivities ranging from 7% (1.3–31.5%) for STAT-PAK, INSTI, SURE CHECK, MULTISURE (automatic reading), to 29% (12–55%) for FIRST RESPONSE, 31% (13–58%) for VIKIA, 43% (21–67%) for Hexagon and 57.1% (32.6–78.6%) for Exacto and Genie Fast. Overall, despite significant discrepancies in sensitivity, HIV rapid tests should be used with caution in the context of a suspected primary infection. [ABSTRACT FROM AUTHOR]

The identification of the type of body fluid in crime scene evidence may be crucial, so that the efforts are high to reduce the complexity of these analyses and to minimize time and costs. Reliable immunochromatographic rapid tests for specific and sensitive identification of blood, saliva, urine and sperm secretions are already routinely used in forensic genetics. The recently introduced Seratec® PMB test is said to detect not only hemoglobin, but also differentiate menstrual blood from other secretions containing blood (cells) by detecting D-dimers. In our experimental set-up, menstrual blood could be reliably detected in mock forensic samples. Here, the result was independent of sample age and extraction buffer volume. It was also successfully demonstrated that all secretions without blood cells were negative for both, hemoglobin (P) and D-dimer (M). However, several blood cell–containing secretions/tissues comprising blood (injury), nasal blood, postmortem blood and wound crust also demonstrated positive results for D-dimer (M) and were therefore false positives. For blood (injury) and nasal blood, this result was reproduced for different extraction buffer volumes. The results of this study clearly demonstrate that the Seratec® PMB test is neither useful nor suitable for use in forensic genetics because of the great risk of false positive results which can lead to false conclusions, especially in sexual offense or violent acts. [ABSTRACT FROM AUTHOR]

Background: While Plasmodium falciparum and Plasmodium vivax cause the majority of malaria cases and deaths, infection by Plasmodium malariae and other Plasmodium species also causes morbidity and mortality. Current understanding of these infections is limited in part by existing point-of-care diagnostics that fail to differentiate them and have poor sensitivity for low-density infections. Accurate diagnosis currently requires molecular assays performed in well-resourced laboratories. This report describes the development of a P. malariae diagnostic assay that uses rapid, isothermal recombinase polymerase amplification (RPA) and lateral-flow-strip detection. Methods: Multiple combinations of custom RPA primers and probes were designed using publicly available P. malariae genomic sequences, and by modifying published primer sets. Based on manufacturer RPA reaction conditions (TwistDx nfo kit), an isothermal assay was optimized targeting the multicopy P. malariae 18S rRNA gene with 39 °C incubation and 30-min run time. RPA product was visualized using lateral strips (FAM-labeled, biotinylated amplicon detected by a sandwich immunoassay, visualized using gold nanoparticles). Analytical sensitivity was evaluated using 18S rRNA plasmid DNA, and clinical sensitivity determined using qPCR-confirmed samples collected from Tanzania, Ethiopia, and the Democratic Republic of the Congo. Results: Using 18S rRNA plasmid DNA, the assay demonstrates a detection limit of 10 copies/µL (~ 1.7 genome equivalents) and 100% analytical specificity. Testing in field samples showed 95% clinical sensitivity and 88% specificity compared to qPCR. Total assay time was less than 40 min. Conclusion: Combined with simplified DNA extraction methods, the assay has potential for future field-deployable, point-of-care use to detect P. malariae infection, which remains largely undiagnosed but a neglected cause of chronic malaria. The assay provides a rapid, simple readout on a lateral flow strip without the need for expensive laboratory equipment. [ABSTRACT FROM AUTHOR]

Compared to other infectious diseases, for which LFT development can take years, SARS-CoV-2 antigen LFTS were developed and deployed within months. LFTS for antigen detection were adopted on an unprecedented scale during the COVID-19 pandemic, but many of them lack the sensitivity especially for samples with low viral load. In our previous work, we developed an enhanced signal strip for detection of SARS CoV-2 SI antigens in saliva. Here we introduce some modification to improve the sensitivity, and specificity, and to lower the cost of the strip, by using biotin streptavidin (BS) system. In the modified BS strip, gold-streptavidin and biotinylated Nanobodies (Nbs) against S1 antigen were externally mixed with the tested samples (saliva or nasopharyngeal swab) before their application on the sample pad of the test strip containing angiotensin converting enzyme (ACE-2), as the capturing probe. The study included 320 individuals, with 180 being positively confirmed by RT-PCR and 140 confirmed negative, as well as, 45 health care workers, who were responsible for screening and handling of surgical cases in General Surgery Department and COVID clinic of TBRI. Our results proved that modified BS strip improved the overall sensitivity and specificity of S1antigen detection in saliva samples (95.21% and 99.29% respectively) compared to our previously developed enhanced LFTS (91.66% and 98.57% respectively). Also, the sensitivity of cases with Ct ≤ 30, Ct ≤ 35, and Ct ≤ 40 using the modified BS strip showed higher values (98.54%, 95.38%, and 88.89% respectively), compared to the corresponding results of our previously developed enhanced LFTS (95.86%, 92.31%, and 82.22% respectively). There were no cross-reactions with either Middle East respiratory syndrome corona virus MERS-CoV or SARS-CoV antigens. Furthermore, we found that the lower viral detection limit (LVD) of BS strip was obviously lower than our previous LVD limit of the enhanced LFTS (0.2 × 104 copies/ml vs. 0.4 × 104 copies/ml, respectively). Our developed BS strip showed that saliva samples gave better results than nasopharyngeal swabs of the same patients. The fact of using smaller amounts of Nbs, and ACE2, as well as the dispensing off of conjugate pad when applying BS strip modifications, justified the expected reduction in the costs of the strip. The implementation of BS strips on saliva samples of 45 health co-workers, who were tested 4 and 6 days after exposure to infection, showed an increase in the sensitivity, starting from the 4th day and reaching its highest level on the 6th day in both high risk and paramedic groups (90.9%, and 80.0%, respectively). This study provides evidence that employment of the modified BS system could increase the sensitivity of the strips, lower their cost, and render them an effective screening tool for early detection of the virus in saliva of suspected Covid-19 patients. [ABSTRACT FROM AUTHOR]

Food and fish adulteration is a major public concern worldwide. Apart from economic fraud, health issues are in the forefront mainly due to severe allergies. Sardines are one of the most vulnerable-to-adulteration fish species due to their high nutritional value. Adulteration comprises the substitution of one fish species with similar species of lower nutritional value and lower cost. The detection of adulteration, especially in processed fish products, is very challenging because the morphological characteristics of the tissues change, making identification by the naked eye very difficult. Therefore, new analytical methods and (bio)sensors that provide fast analysis with high specificity, especially between closely related fish species, are in high demand. DNA-based methods are considered as important analytical tools for food adulteration detection. In this context, we report the first DNA sensors for sardine species identification. The sensing principle involves species recognition, via short hybridization of PCR-amplified sequences with specific probes, capture in the test zone of the sensor, and detection by the naked eye using gold nanoparticles as reporters; thus, avoiding the need for expensive instruments. As low as 5% adulteration of Sardina pilchardus with Sardinella aurita was detected with high reproducibility in the processed mixtures simulating canned fish products. [ABSTRACT FROM AUTHOR]

Indonesia began deploying a COVID-19 vaccine in January 2021, prioritising vaccination for high-risk groups such as healthcare workers, the elderly and those with comorbidities, and ending with the general public due to limited vaccine availability. Our study aimed to evaluate antibody response in Indonesians who had received two doses of the vaccine vs. those who had not. The study design was a cohort study involving 46 unvaccinated people and 23 people who had received the second dose of the AstraZeneca vaccine in three months. Methods used for the qualitative and quantitative detection of IgG antibodies included rapid RI-GHA and ELISA tests. Findings showed that positive IgG antibodies qualitatively detected by the rapid RI-GHA test were significantly higher in those vaccinated (60.9%) than in unvaccinated people (26.1%). Using the ELISA assay, all vaccinated individuals qualitatively showed positive antibodies (cut-off ≥4.33 BAU/ml), and the average quantitative titer of anti-SARS-CoV-2 s-RBD IgG was significantly higher in vaccinated (157.06±238.68 BAU/ml) than in unvaccinated (51.90±87.60 BAU/ml) individuals. Some unvaccinated individuals with no history of infection were found to have anti-SARS-CoV-2 antibodies that may have been previously asymptomatic, although their mean antibody titers were certainly lower than those in the 2-dose group. Approximately 56% of vaccinated individuals had antibody titers above 60 BAU/ml as a cut-off for protective threshold, a significantly higher proportion than unvaccinated individuals. In conclusion, vaccination with two doses AstraZeneca increased anti-SARS-CoV-2 antibodies which resulted in enhanced immunity against symptomatic COVID-19. [ABSTRACT FROM AUTHOR]

Purpose: Due to its ability to disseminate worldwide and its multiple resistance trait, Acinetobacter baumannii is becoming a threat for public health worldwide. Cefiderocol (FDC) is a promising broad-spectrum cephalosporin recently approved for treating Gram-negative infection. The aim of this study was to develop a rapid test, namely the rapid FDC Acinetobacter baumannii NP test, for the detection of FDC susceptibility/resistance in A. baumannii since the current FDC susceptibility tests are rather time-consuming (at least 24 h). Materials and methods: The rapid test is based on the reduction of resazurin to resorufin product by bacterial viable cells, thus detecting bacterial growth in the presence of FDC (38.4 mg/L). A color change from blue (resazurin) to violet or pink (resorufin) represents visual detection of bacterial growth. 95 randomly selected A. baumannii isolates were used to evaluate the performance of the rapid FDC Acinetobacter baumannii NP test. Results: The test showed 95.5% (95% CI 78.2–99.2%) and 100.0% (95% CI 95.0–100.0%) of sensitivity and specificity, respectively. All the results were obtained within 4 h30–4 h45 incubation time at 35 °C ± 2 °C, saving virtually one day when compared with currently-used antimicrobial susceptibility tests. The test showed only a single very major error, an isolate with a MIC of 8 mg/L. Conclusions: The rapid FDC Acinetobacter baumannii NP test can be a valuable method which is easier and faster to interpret when compared with the gold standard broth microdilution method. The test showed remarkable performances; hence, it may be suitable for implementation in clinical microbiology routine laboratories. [ABSTRACT FROM AUTHOR]

Detection of allergens in foods, including soybean, is relevant for food labelling requirements. Moreover, allergen-specific methods may allow standardisation of allergens in food matrices for use in food challenges as allergy diagnostic approaches. Rapid methods are preferred for screening and along the manufacturing line. Previously, we demonstrated sensitive and specific detection of soybean DNA by combining loop-mediated isothermal amplification (LAMP) and lateral flow device (LFD)-like visualisation. However, lengthy DNA extraction and potential contamination of subsequent by previous LAMP reactions from unclosed LFD may impact its use as a rapid and robust method. Here, we developed a rapid protocol for DNA extraction. Moreover, we identified phenol red for distinct visualisation of positive reactions in permanently closed reaction tubes. The optimised method was validated using complex foods (boiled sausage, instant soup, and chocolate) with known amounts of soybean. Further, its applicability was shown in 12 processed retail foods. Results were verified by orthogonal qPCR. The enhanced LAMP method allowed detection at or below 10 mg soybean per kg processed food. The method provides rapid and easy-to-use screening without the need for detection equipment. Hence, it may serve to verify the presence of soybean ingredients and support a risk-based precautionary labelling of non-ingredient soybean in compound foods. Also, as determination of clinical reaction thresholds before and after allergen immunotherapy (AIT) is both inclusion and exclusion criterion for clinical trials and success parameter of AIT, the method may allow verification of calculable soybean content in provocation meals and thus a standardised administration for threshold determination before and after AIT. [ABSTRACT FROM AUTHOR]

The performance evaluation of new and old subgrades is critical for the quality and safety of reconstruction and extension projects. It is necessary to achieve rapid and easy performance testing. In this study, a Portable FallingWeight Deflectometer (PFWD) is chosen to rapid evaluate the performance of subgrade. First, a testing area, the reconstruction and expansion project of the Hefei to Dagudian section of the Shanghai-Shaanxi Expressway, is selected. Then, the PFWD modulus Ep of resilient tested by PFWD and the corresponding water content w and compacting degree K tested by the cutting ring method for old subgrade are obtained. And the correlation relationship between Ep and w and K is established. The performance of old subgrade can be rapid obtained by PFWD. Meanwhile, for the new subgrade, the correlation relationship between Ep and bending value L, w and K is established, and the performance can also be rapid tested by PFWD. Finally, a rapid evaluation method for the reconstruction and expansion of subgrade performance was proposed, which aims to provide technical support for ensuring construction quality and safety and provides a technical reference and a theoretical basis for the prediction of similar subgrade performance. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic has primarily been controlled by testing for SARS-CoV-2 infections. Despite vaccines, testing will remain crucial for surveillance and screening, allowing for the detection of new variants in a timely manner and to isolate the infected people to lower the danger of the disease spreading further. The research study attempts to found out the efficiency of Reverse-transcriptase polymerase chain reaction (RT-PCR) and Rapid antigen tests in symptomatic COVID-19 patients at tertiary care hospitals. The research was performed on 1000 patients, both In-patients and Out-patients, who presented with COVID-19 symptoms. SARS-COV-2 nucleocapsid protein antigen was detected qualitatively with rapid antigen test in human nasal specimens through the immuno-chromatographic assay. The rapid test results were compared with a molecular test RT-PCR in which FAM, HEX, and ROX were the indicator dyes for the RdRp gene, E gene, and the internal control (RNAse P), respectively. Nearly 322 cases were positive with both RT-PCR and rapid antigen test methods. Fifty-nine samples yielded negative results with the rapid antigen test and positive with PCR. Three samples were negative with RT-PCR and positive with the rapid antigen test. The findings from our study show that the common symptoms are fever 92.2% and cough 74.1% in the reported test population. But in confirmed cases of RT-PCR showed cough at 74.1% was more prevalent, followed by fever at 41.3%. Rapid antigen test showed a overall sensitivity and specificity of 85.3% and 99.5%. According to World Health Organization, rapid antigen detection tests meet the minimum performance requirements of ≥80% sensitivity and ≥97% specificity. Hence, the present study meets this criterion and may perhaps be a probable tool for point-of-care in hospital settings. [ABSTRACT FROM AUTHOR]

Self-administered HIV testing may be a promising strategy to improve testing in hard-to-reach young adults, provided they are aware of and willing to use oral HIV self-testing (HIVST). This study examined awareness of and willingness to use oral HIVST among 350 high-risk young adults, aged 18–22, living in Kenya's informal urban settlements. Bivariate and multivariate logistic regressions were used to examine differences in HIVST awareness and willingness by demographic and sexual risk factors. Findings showed that most participants were male (56%) and less than 20 years old (60%). Awareness of oral HIVST was low (19%). However, most participants (75%) were willing to use an oral HIV self-test in the future and ask their sex partner(s) to self-test before having sex (77%). Women (OR = 1.80, 95%CI:1.11, 2.92), older participants (aged 20+) (OR = 2.57, 95% CI:1.48, 4.46), and more educated participants (OR = 2.25, 95%CI:1.36, 3.70) were more willing to use HIVST as compared to men, teen-aged, and less educated participants, respectively. Young adults who reported recent engagement in high-risk sexual behaviors, such as unprotected sex, sex while high or drunk, or sex exchange, were significantly less likely to be willing to use an oral HIV self-test kit (OR = 0.34, 95%CI:0.13,0.86). Those with the highest monthly income (OR = 0.47, 95%CI: 0.25, 0.89) were also less willing to use HIVST. More community- and peer-based efforts are needed to highlight the range of benefits of HIVST (i.e., social, clinical, and structural) to appeal to various youth demographics, in addition to addressing concerns relating to HIVST. [ABSTRACT FROM AUTHOR]

Background & objectives: High transmissibility of the SARS-CoV-2 has significant implications on healthcare workers' safety, preservation, handling, transportation and disposal of the deceased bodies. The objective of this study was to detect SARS-CoV-2 antigen in nasopharyngeal samples and its implications in handling and care of COVID-19 deceased bodies. Methods: A study was conducted at a dedicated COVID-19 centre on deceased individuals from April to December 2020. Rapid antigen test (RAT) and reverse transcription (RT)-PCR was compared on all the SARS-CoV-2 positive cadavers recruited in the study. Results: A total of 115 deceased individuals were included in the study. Of these, 79 (68.7%) were male and 36 (31.3%) were female and majority were in the age group of 51-60 yr [31 (27%)]. SARS-CoV-2 antigen test was positive in 32 (27.8%) and negative in 83 (72.1%) individuals. The mean time interval between deaths to the sample collection was 13.2 h with interquartile range of eight to 20 h. Reverse transcription (RT)-PCR was used as the reference test and 24 (20.9%) cases were true positive; 93.6 per cent [95% confidence interval (CI) 88.8-98.4%] sensitivity, 45.2 per cent (95% CI 35.5-55%) specificity, 60.2 per cent (95% CI 50.6-69.8%) positive predictive value and 88.8 per cent (95% CI 82.7-95%) negative predictive value of antigen test was computed. Interpretation & conclusions: SARS-CoV-2 antigen test was positive beyond 19 h in COVID-19 deceased individuals. Antigen test was found to be highly sensitive in the deceased. Patients, suspected of having died due to COVID-19, can be screened by this method. As infectiousness of the virus in the deceased bodies cannot be directly concluded from either the antigen or RT-PCR test, yet possible transmission cannot be completely ruled out. Strict infection control measures need to be followed during the handling and clearance of COVID-19 cadavers. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the performance characteristics of a rapid antigen test developed to detect SARS-CoV-2 (COVID-19), influenza A virus (IAV), and influenza B virus (IBV) (flu) compared with those of the real-time reverse transcription-polymerase chain reaction (rRT-PCR) method. One hundred SARS-CoV-2, one hundred IAV, and twenty-four IBV patients whose diagnoses were confirmed by clinical and laboratory methods were included in the patient group. Seventy-six patients, who were negative for all respiratory tract viruses, were included as the control group. The Panbio™ COVID-19/Flu A&B Rapid Panel test kit was used in the assays. The sensitivity values of the kit were 97.5%, 97.9%, and 33.33% for SARS-CoV-2, IAV, and IBV, respectively, in samples with a viral load below 20 Ct values. The sensitivity values of the kit were 16.7%, 36.5%, and 11.11% for SARS-CoV-2, IAV, and IBV, respectively, in samples with a viral load above 20 Ct. The kit's specificity was 100%. In conclusion, this kit demonstrated high sensitivity to SARS-CoV-2 and IAV for viral loads below 20 Ct values, but the sensitivity values were not compatible with PCR positivity for lower viral loads over 20 Ct values. Rapid antigen tests may be preferred as a routine screening tool in communal environments, especially in symptomatic individuals, when diagnosing SARS-CoV-2, IAV, and IBV with high caution. [ABSTRACT FROM AUTHOR]

This prospective study aimed to evaluate the performance of the InstaView COVID-19 (coronavirus diseases 2019) Antigen Home Test (InstaView AHT) which detects severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens. In this test kit, surface-enhanced Raman spectroscopy was used, a stacking pad was inserted, and nasal swab and salivary swab samples were used simultaneously to improve performance. The clinical performance of the InstaView AHT was compared to that of RT-PCR using nasopharyngeal samples. The participants without any prior training were recruited and performed the sample collection, testing, and interpretation of the results by themselves. Of the 91 PCR-positive patients, 85 had positive InstaView AHT results. The sensitivity and specificity of the InstaView AHT were 93.4% (95% confidence interval [CI]: 86.2–97.5) and 99.4% (95% CI: 98.2–99.9). The sensitivity of the InstaView AHT was above 90% for all samples obtained from patients with Ct ≤ 20, 20 < Ct ≤ 25, and 25 < Ct ≤ 30 (100%, 95.1%, and 92.0%, respectively). The InstaView AHT can be used as an alternative to RT-PCR testing because of its relatively high sensitivity and specificity, especially when SARS-CoV-2 prevalence is high, and the availability of RT-PCR testing is limited. [ABSTRACT FROM AUTHOR]

Molecular and antigen point-of-care tests (POCTs) have augmented our ability to rapidly identify and manage SARS-CoV-2 infection. However, their clinical performance varies among individual studies. The evaluation of the performance of molecular and antigen-based POCTs in confirmed, suspected, or probable COVID-19 cases compared with that of laboratory-based RT-PCR in real-life settings. MEDLINE/PubMed, Scopus, Embase, Web of Science, Cochrane Library, Cochrane COVID-19 study register, and COVID-19 Living Evidence Database from the University of Bern. Peer-reviewed or preprint observational studies or randomized controlled trials that evaluated any type of commercially available antigen and/or molecular POCTs for SARS-CoV-2, including multiplex PCR panels, approved by the United States Food and Drug Administration, with Emergency Use Authorization, and/or marked with Conformitè Europëenne from European Commission/European Union. Close contacts and/or patients with symptomatic and/or asymptomatic confirmed, suspected, or probable COVID-19 infection of any age. Molecular and/or antigen-based SARS-CoV-2 POCTs. Laboratory-based SARS-CoV-2 RT-PCR. Eligible studies were subjected to quality-control and risk-of-bias assessment using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Summary sensitivities and specificities with their 95% CIs were estimated using a bivariate model. Subgroup analysis was performed when at least three studies informed the outcome. A total of 123 eligible publications (97 and 26 studies assessing antigen-based and molecular POCTs, respectively) were retrieved from 4674 initial records. The pooled sensitivity and specificity for 13 molecular-based POCTs were 92.8% (95% CI, 88.9–95.4%) and 97.6% (95% CI, 96.6–98.3%), respectively. The sensitivity of antigen-based POCTs pooled from 138 individual evaluations was considerably lower than that of molecular POCTs; the pooled sensitivity and specificity rates were 70.6% (95% CI, 67.2–73.8%) and 98.9% (95% CI, 98.5–99.2%), respectively. Further studies are needed to evaluate the performance of molecular and antigen-based POCTs in underrepresented patient subgroups and different respiratory samples. [ABSTRACT FROM AUTHOR]

SARS-CoV-2 is still threat for humanity and its detection is crucial. Although real time reverse transcriptase polymerase chain reaction is the most reliable method for detection of N protein genes, alternative methods for molecular detection are still needed. Thus, lateral flow assay models for 2019-nCoV_ N3 were developed for molecular detection. Briefly, gold nanoparticles were used as label and three sandwich models (1A, 1B, and 1.2) were designed. Prob concentrations on gold nanoparticles, types of sandwich model and membrane, limit of detection of target gene and buffer efficiency were studied. Model 1B has shown the best results with M170 membrane. Lower limit of detection was achieved by model 1.2 as 5 pM. All parameters have significant role for molecular detection of SARS-CoV-2 by lateral flow assays, and these results will be useful for nucleic acid based lateral flow assays for viral detection or multiple detection of mutated forms in various detection systems. • 2019-nCoV_ N3 was rapidly detected by developed LFA. • This is the first sandwich assay that shows the hybridization models of PCR products for the detection of 2019-nCoV_N by LFA. • Developed LFAs can be an alternative method to the conventional and real time PCR. • Designed LFAs can be adoptable to the molecular detection of SARS-CoV-2 mutants. [ABSTRACT FROM AUTHOR]

Due to the many technical limitations of molecular biology, the possibility to sustain enormous volumes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostic testing relies strongly on the use of antigen rapid diagnostic tests (Ag-RDTs). Besides a limited analytical sensitivity, the manually intensive test procedures needed for performing these tests, very often performed by unskilled personnel or by the patients themselves, may contribute to considerably impair their diagnostic accuracy. We provide here an updated overview on the leading preanalytical drawbacks that may impair SARS-CoV-2 Ag-RDT accuracy, and which encompass lower diagnostic sensitivity in certain age groups, in asymptomatic subjects and those with a longer time from symptoms onset, in vaccine recipients, in individuals not appropriately trained to their usage, in those recently using oral or nasal virucidal agents, in oropharyngeal swabs and saliva, as well as in circumstances when instructions provided by the manufacturers are unclear, incomplete or scarcely readable and intelligible. Acknowledging these important preanalytical limitations will lead the way to a better, more clinically efficient and even safer use of this important technology, which represents an extremely valuable resource for management of the ongoing pandemic. [ABSTRACT FROM AUTHOR]

Introduction: Rapid antigen tests have gained importance during the COVID-19 pandemic due to low prices and availability. The present study investigated the performance of the SARS-CoV-2 rapid diagnostic test in diagnosing patients with COVID-19 referred to the emergency department. Methods: In this diagnostic accuracy study, patients with suspected COVID-19 referred to Imam Hossein and Shohadaye Tajrish Hospitals, Tehran, Iran, were examined. All patients were subjected to a rapid corona test according to the manufacturer's guide and a chest computed tomography (CT) scan as the standard test. The screening characteristics of the rapid test compared to CT scan were calculated and reported. Results: 183 people with an average age of 46.83 ± 14.26 (range: 21-83) years entered the study. 141 suspected cases of COVID-19 (77%) had evidence of lung involvement in CT, and the rapid test was positive in 83 (45%) cases. Out of 83 patients who tested positive for COVID-19, all (100%) had positive chest CT findings. Out of the 100 patients who tested negative, 42 patients (42%) had negative chest CT findings, and 58 patients (58%) had positive CT scans. The sensitivity, specificity, and accuracy of the mentioned test were 58.86, 100.00, and 68.30 percent, respectively. Conclusion: Due to the relatively low sensitivity, the Rapid SARS-CoV-2 antigen test fails to screen for SARS-CoV-2 infection. However, it can be used to confirm the presence of the disease in symptomatic individuals and reduce virus transmission during the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

Hemoglobin is a biomarker of interest for the diagnosis and prognosis of various diseases such as anemia, sickle cell disease, and thalassemia. In this paper, we present a disposable device that has the potential of being used in a setting for accurately quantifying hemoglobin levels in whole blood based on colorimetric analysis using a smartphone camera. Our biosensor employs a disposable microfluidic chip which is made using medical-grade tapes and filter paper on a glass slide in conjunction with a custom-made PolyDimethylSiloaxane (PDMS) micropump for enhancing capillary flow. Once the blood flows through the device, the glass slide is imaged using a smartphone equipped with a custom 3D printed attachment. The attachment has a Light Emitting Diode (LED) that functions as an independent light source to reduce the noise caused by background illumination and external light sources. We then use the RGB values obtained from the image to quantify the hemoglobin levels. We demonstrated the capability of our device for quantifying hemoglobin in Bovine Hemoglobin Powder, Frozen Beef Blood, and human blood. We present a logarithmic model that specifies the relationship between the Red channel of the RGB values and Hemoglobin concentration. [ABSTRACT FROM AUTHOR]

Melon is one of the most consumed cucurbits and commercially significant cucurbits in the world. It is planted predominantly through seedlings, and seed quality is essential in this process. Among the rapid tests used in seed analysis, the pH testing of exudate has shown promise for several cultivated species. Thus, this study aimed to verify the viability of melon (Cucumis melo L.) seeds through the pH testing of exudate. For this, seeds of the hybrids Premier and Supreme (three lots each) were subjected to germination and vigor tests (first germination count, tetrazolium, accelerated aging, emergence speed index, and emergence). The pH testing of exudate was evaluated using phenolphthalein and sodium carbonate solutions. The results indicated the possibility of classifying the lots into three quality levels for both hybrids, similar to most tests used to assess initial quality. Therefore, the pH testing of exudate was effective in determining the viability of lots of melon seeds and can be conducted with a soaking period of 120 minutes at 25 or 30 °C. [ABSTRACT FROM AUTHOR]

HCV point of care screening in people tested for SARS-CoV-2 in a social-housing neighbourhood of Milan, Italy Keywords: awareness; COVID-19; diagnosis; elimination strategy; hepatitis C; rapid test EN awareness COVID-19 diagnosis elimination strategy hepatitis C rapid test 251 255 5 01/04/23 20230101 NES 230101 Key points In our study, we assessed the antibody positivity for hepatitis C using point-of-care-testing in subjects undergoing COVID-19 screening in the San Siro social-housing neighbourhood of Milan which is characterized by a multi-ethnical population and low socio-economic status. Milestones to reach hepatitis C virus (HCV) elimination in Italy: from free-of-charge screening to regional roadmaps for an HCV-free nation. [Extracted from the article]

Background: Covert hepatic encephalopathy (CHE) adversely affects the clinical outcomes of patients with cirrhosis but remains largely undiagnosed and untreated. Although the Stroop test is a useful method for CHE detection, a faster, simpler, and more accurate test is required to diagnose CHE. This prospective study aimed to develop a new shortened Stroop test that can detect CHE and predict overt hepatic encephalopathy (OHE) in Japanese patients with cirrhosis. Methods: Patients who underwent neuropsychological tests (NPT) and the Stroop test between November 2018 and December 2021 were enrolled and followed until OHE occurrence or March 2022. The discriminative ability of various run combinations in the off and on states to detect CHE was evaluated using the area under the receiver-operating characteristic curve (AUC) and compared with that of the total Stroop test time. Results: Among the 227 eligible patients, the On1–2Time cutoff value of 44.4 s had a comparable discriminative ability with the total Stroop test time to detect CHE, with an AUC of 0.791, a sensitivity of 0.827, and a specificity of 0.685. During a median follow-up period of 16 months, 37 patients developed OHE. On1–2Time ≥ 44.4 s (hazard ratio [HR], 3.93; 95% confidence interval [CI] 1.36–11.36) and serum albumin levels (HR, 0.28; 95% CI 0.11–0.67) were independently associated with OHE occurrence. Conclusions: The shortened Stroop test (On1–2Time) is equivalent to the total Stroop test not only for identifying CHE but also for estimating the risk of progression to OHE. [ABSTRACT FROM AUTHOR]

Introduction: Hepatitis B Virus (HBV) causes most frequent chronic liver disease of infectious origin in human beings worldwide, with more than 600,000 deaths caused by end-stage liver disease complications per year. The most used test for identifying acute HBV infections and carriers is the detection of HBsAg. Immunochromatography assays have been suggested for routine use in clinical microbiology laboratories for the detection of HBsAg since they are easy to use, affordable, don't need specialised equipment, and are straightforward to run. Compared to commercially available HEPA card kit for the detection of the same markers, Enzyme Linked Immunosorbent Assay (ELISA) was shown to be more sensitive for the detection of HBsAg. This study is first of its kind in District Doda, Jammu and Kashmir, India. Aim: To know the burden of HBV in a tertiary Care Hospital, Government Medical College, Doda using HEPA card kit and ELISA method. Materials and Methods: The present hospital-based crosssectional study was carried out in the Department of Microbiology, Government Medical College and Hospital, Doda Jammu and Kashmir, India during the period from January 2020 to December 2020. The study comprised blood samples from all age groups referred by clinical departments for testing HBsAg. Tests were performed using an immunochromatographic technique (Hepa Card Diagnostic enterprises) for the qualitative detection of HBsAg, and results were interpreted in accordance with the manufacturer's guidelines. The collected data was analysed in microsoft excel sheet using Chi-square test to know the burden of HBV infection. Results: Among total number of 5,448 samples tested, 50 (0.92%) were positive for HBsAg which comes under low epidemicity (<2%) as per World Health Organisation (WHO) guidelines. The number of positive females and males were 30 (0.84%) and 20 (1.07%), respectively. Females were predominate over males and majority of the positive patients (N=29) were younger than 40 years though prevalance (2.1%) was higher in age group above 40 years. All samples which shows positive by rapid test were also shown positive by ELISA test. Conclusion: Overall prevalence of HBV was 0.92% which comes under low epidemicity (<2%) as per WHO guidelines. It can be an alternate option for community based studies and also helps to improve the public health and to prevent the spreading of disease in the local population. [ABSTRACT FROM AUTHOR]

Since the onset of the coronavirus disease 2019 (COVID‐19) pandemic, preventive social paradigms and vaccine development have undergone serious renovations, which drastically reduced the viral spread and increased collective immunity. Although the technological advancements in diagnostic systems for severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) detection are groundbreaking, the lack of sensitive, robust, and consumer‐end point‐of‐care (POC) devices with smartphone connectivity are conspicuously felt. Despite its revolutionary impact on biotechnology and molecular diagnostics, the reverse transcription polymerase chain reaction technique as the gold standard in COVID‐19 diagnosis is not suitable for rapid testing. Today's POC tests are dominated by the lateral flow assay technique, with inadequate sensitivity and lack of internet connectivity. Herein, the biosensing advancements in Internet of Things (IoT)‐integrated electroanalytical tools as superior POC devices for SARS‐CoV‐2 detection will be demonstrated. Meanwhile, the impeding factors pivotal for the successful deployment of such novel bioanalytical devices, including the incongruous standards, redundant guidelines, and the limitations of IoT modules will be discussed. [ABSTRACT FROM AUTHOR]

The spread of the SARS‐CoV‐2 virus produces a new disease termed COVID‐19, the underlying physiological mechanisms of which are still being understood. Characteristic of the infection is the compromising of taste and smell. There is a persistent need to discriminate the dysfunctions and correlation between taste and smell, which are probably epiphenomena of other concealed conditions. Anosmic and ageusic long‐term COVID‐19 patients were re‐evaluated after 1 year using a Volabolomic approach with an e‐nose recording system coupled with olfactometric and gustometric tests. Here a range of sensory arrangements was found, from normal taste and smell to complete losses. The following patterns of olfactory threshold (OT)‐taste threshold‐olfactory uni‐ and cross‐modal perception were found anosmia‐severe hypogeusia‐anosmia; hyposmia‐hypogeusia‐severe hyposmia; normosmia‐ageusia‐hyposmia; severe hyposmia ‐normogeusia‐normosmia. There is a strong correlation between OT and olfactory uni‐ and cross‐modal perception, a moderate correlation between olfactory and taste threshold and no correlation between OT and taste threshold. In conclusion, this study provides evidence for the feasibility of testing the chemical senses to directly objectify function in order to discriminate taste from olfactory impairment. Furthermore, it allows to hypothesize a long‐term effect of the virus due to neuroinvasion through, probably, the olfactory system with injury in the related multisensory areas of taste and smell. [ABSTRACT FROM AUTHOR]

Bolts are important connectors on the transmission tower. Due to the long-term influence of external conditions during the operation of the transmission tower, the bolts gradually loosen and the rigidity of the transmission tower decreases, which seriously affects the normal operation of the transmission tower. Aiming at the complete loosening fault of the transmission tower bolt, a fast detection method for towers bolt complete loosening based on the vibration characteristics was proposed. Firstly, before and after the bolt was completely loosened, the vibration signals of the iron tower were measured by the pulse excitation method. The vibration signals of the tower component where the excitation point was located, and that of the tower component which was connected by bolt were obtained respectively. Then, the autocorrelation-variational mode decomposition (VMD) method was used to process the vibration signals, and the spectrograms of vibration signals were obtained. The following conclusions were drawn by comparing the spectrograms: when the bolts are tightened, each tower component is connected to each other as a whole, resulting in free vibration under pulse excitation, and a peak value appears at its natural frequency. When the bolt is completely loosened, the tower component where the excitation point is located is free to vibrate, and still has a peak value at its natural frequency, while the other tower component is subjected to the vibration of the tower component at the excitation point, which causes its vibration properties to change, and the forced vibration component increases. The vibration spectrums of the tower componentsare relatively close. The variation spectrograms between the two tower components connected by bolts can be used as the judgment basis for whether the bolts are completely loosening, and provides a new offline detection method for the tower partial loose bolt. [ABSTRACT FROM AUTHOR]

• Visby COVID-19 test correctly identified 96.7% positive and 98.6% negative samples. • Sensitivity of the method is as low as or lower than 500 copies/mL. • A result of invalid was observed with 2.0% of specimens. • Visby COVID-19 test is well-suited to address rapid SARS-CoV-2 testing needs. Rapid and widespread diagnostic testing is critical to providing timely patient care and reducing transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Recently, the Visby Medical COVID-19 point of care (POC) test was granted emergency use authorization (EUA) for qualitative detection of SARS-CoV-2 nucleic acid at the point of care. We evaluated its performance characteristics using residual specimens (n = 100) collected from Mayo Clinic patients using nasopharyngeal (NP) swabs and placed in viral transport media (VTM). The same specimen was tested using both the laboratory reference method (RT-qPCR) and Visby test. The reference methods utilized included a laboratory developed test with EUA (Mayo Clinic Laboratories, Rochester, MN) using the TaqMan assay on a Roche Light Cycler 480 or a commercially available EUA platform (cobas® SARS-CoV-2; Roche Diagnostics, Indianapolis, IN). Positive, negative, and overall percent agreement between the Visby COVID-19 test and the reference method were calculated. Additionally, the limit of detection (LoD) claimed by the manufacturer (1112 copies/mL) was verified with serial dilutions of heat inactivated virus. The Visby COVID-19 test correctly identified 29/30 positive samples and 69/70 negative samples, resulting in an overall concordance of 98.0%, positive percent agreement of 96.7%, and negative percent agreement of 98.6%. The abbreviated LoD experiment showed that the analytical sensitivity of the method is as low as or lower than 500 copies/mL. Our study demonstrated that Visby COVID-19 is well-suited to address rapid SARS-CoV-2 testing needs. It has high concordance with central laboratory-based RT-qPCR methods, a low rate of invalid results, and superior analytical sensitivity to some other EUA POC devices. [ABSTRACT FROM AUTHOR]

Globally, cases of COVID-19 in children (0-17 years) tend to be lower than adults, but the number of confirmed cases of children continues to increase. Based on data obtained from IDAI, the number of COVID-19 cases in children in Indonesia is the highest in Asia. In December 2020, there were 35,506 suspected cases of COVID-19 in children in Indonesia, with a total death toll of 522, and a CFR of 1.4. In the case of COVID-19, the child population shows non-specific signs and symptoms, so proper diagnosis and treatment of COVID-19 is needed. Based on the explanation above, to assess the clinical picture of pediatric patients infected with COVID-19, the researcher wanted to see the characteristics of the clinical manifestations of pediatric patients with COVID-19. The method used is descriptive observational, meaning that the object is observed only once. Variable measurements were carried out at the time of data assessment. The age of the most Covid-19 patients in children is 0-5 years of age with the most gender being male. The most common clinical manifestation of Covid-19 patients in children is fever. Severe symptoms were found in the 0-5 year age group and the 12-17 year age group and were found in the normal and underweight nutritional status groups. [ABSTRACT FROM AUTHOR]

Objectives. To assess the diagnostic performance of the SD dengue DUO rapid test (Inyecta) for the detection of NS1, IgM and IgG in comparison to the ELISA test. Materials and methods. This is a diagnostic test evaluation that included 286 serum samples from patients with symptomatology attributable to dengue from endemic areas of Peru. The samples were analyzed by ELISA and the SD dengue DUO rapid test (Inyecta) for IgM, NS1 and IgG at the Instituto de Investigación Nutricional in Lima. Results. The sensitivity of the rapid test was 68.0% for NS1 and IgM, and 86.0% for IgG, improving to 75.0% and 81.0% for NS1 and IgM, respectively, during the first three days. The specificity for all three analytes was greater than 87.0%. The concordance of the results, measured by the Kappa coefficient for the three analytes, was good and no cross-reaction with other arboviruses was found. Conclusions. The SD dengue DUO rapid test allows detection of NS1, IgM and IgG with adequate sensitivity and specificity. Sensitivity for IgM and NS1 increases when detected during the first three days of symptoms. Therefore, we recommend its implementation in primary care centers for early and timely diagnosis. [ABSTRACT FROM AUTHOR]

Background: The use of point-of-care tests (POCTs) has been a central strategy to cope with the COVID-19 pandemic. Yet, evidence on the application and consequences of POCTs within medical settings is rare. Purpose: To assess and understand patient perspectives on molecular point-of-care SARS-CoV-2 testing conducted in primary care. Methods: We conducted a cross-sectional survey study among patients who were tested with a molecular SARS-CoV-2 rapid test (ID NOWTM COVID-19 rapid test, Abbott) in 13 primary care practices in the state of Thuringia (Germany) from February to April 2021. The following aspects were covered in the questionnaire through rating scales and open text formats: test characteristics, trust in test result, consequences of immediate result, cost amount willing to pay and expectations in the future. Open text answers were categorized; quantitative data were analyzed using descriptive statistics and a Mann–Whitney U-test to reveal differences in cost contribution depending on the test result. Results: A total of 215 patients from nine family practices and one pediatric practice participated. The immediate availability of the test result was important to the majority of patients (94.3%). 95.7% of patients trusted in their test result. Personal consequences of the immediate test result referred to pandemic measures, certainty of action and reassurance. For further tests, patients were willing to pay between 0€ and 100€ (interquartile range = 10– 25€) for the molecular SARS-CoV-2 POCT, regardless of the test result. Expectations of being offered the test again in case of renewed cold symptoms were reported by 96.2%. Conclusion: Patients highly appreciated molecular SARS-CoV-2 rapid testing conducted in primary care practices. The immediate availability of the test result led to adjustments in patients' behavior and emotional wellbeing. However, potentially challenging for the implementation of POCTs in primary care practices may be the reimbursement of test costs and patients' expectations in future situation. [ABSTRACT FROM AUTHOR]

Rapid milk tests for the indirect diagnosis of brucellosis are limited and generally not preferred due to insufficient diagnostic performances and inappropriate handling process. In this study, a rapid immunofiltration assay known as Non-Enzymatic Immunofiltration Assay (NERIFA) was evaluated based on diagnostic performances and applicability for the detection of anti-Brucella antibodies in bovine milk samples as milk NERIFA (mNERIFA). For this purpose, wheys, that were obtained from rennin precipitated milk constituted with reference sera, were used as test material. Besides, an enzyme-linked immunosorbent assay (ELISA) was also developed for the evaluation of mNERIFA. After approval, the ELISA was evaluated as important (P<0.001) by Receiver Operating Procedures (ROC) analysis based on the diagnostic index (J) score specified as the Youden index (J: 0.963) and the Area Under the Curve (AUC) value (0.996), its results compared with mNERIFA by kappa statistical analysis. ELISA's comparison with mNERIFA based on diagnostic performances indicated that ELISA's performance was in perfect agreement with mNERIFA (κ=0.97) and the agreement was 0.97% (0.92-0.99%) with CI 95%. In the optimization process of mNERIFA, it was found that there was no significant difference between the individual and pooled whey samples (P>0.05), and a pool of 5 samples can be used instead of individual testing. In this study, it was concluded that mNERIFA may be recommended as a rapid test for anti-Brucella antibody detection in bovine milk samples based on the diagnostic performances, applicability, and pooling capacity. [ABSTRACT FROM AUTHOR]

• Establishment of a rapid FISH method with a turn around time of less than one hour. • FISH hybridization time was reduced to 10 min using Vysis IntelliFISH buffer. • Allowed the combined same day reporting of morphology and FISH results. • There was no detrimental effect on the quality or accuracy of the FISH results. • Enabled clinicians to have rapid access to targeted therapies. This study evaluated a rapid fluorescence in-situ hybridization (FISH) method with a novel 10 min hybridization time to identify the presence of recurrent gene re-arrangements in patients with Haematological malignancies (HMs). A method comparison experimental approach was used to compare this rapid method to the standard method. Hybridization results using the rapid method were comparable to standard methods in terms of result, signal strength and hybridization quality. This rapid FISH turn around time (TAT) was 1 h and enabled same day reporting of genetic and morphology results for a prompt diagnosis and timely access to targeted therapies. [ABSTRACT FROM AUTHOR]

[Display omitted] • A Dip-Type colorimetric paper-based sensor array with three organic dyes. • Discrimination of original bottled mineral waters from tap waters. • A discriminant model with an accuracy of > 95 % based on the analysis of 85 water samples. • A simple sensing device based on optical tongue concept with long-term stability and high reproducibility. Mineral water is a natural water that originated from an underground water table, a well, or a natural spring which is considered microbiologically intact. The revenue from the bottled mineral water industry will be USD 342.40 billion in 2023, and it is expected to grow at a compound annual growth rate (CAGR) of 5.24 %. Consequently, the discrimination of original bottled mineral water from tap water is an important issue that requires designing sensors for simple and portable identification of these two types of water. In this work, we have developed a Dip-Type colorimetric paper-based sensor array with three organic dyes (Bromothymol Blue, Bromophenol Blue, and Methyl Red) followed by chemometrics' pattern recognition methods (PCA and LDA) for discrimination of original bottled mineral waters from tap waters based on differences in ion variety and ion quantity. Forty brands of mineral water and twenty-six Tap water samples from different regions of Shiraz and other Iranian cities were analyzed by this sensor array. Moreover, these experiments were performed in two consecutive years to check the versatility of the sensor with seasonal changes in waters. This sensor array was able to discriminate these two water types from each other with an accuracy of > 95 % based on the analysis of 85 water samples. [ABSTRACT FROM AUTHOR]

• Optical biosensors were critically reviewed, including ECL, SERS-based, and SPR-based biosensors. • Lateral flow immunoassays (LFIA) as point-of-care (POC) rapid tests were discussed. • Amperometric and label-free electrochemical biosensors developed for anti-CCP were analyzed. • The clinical significance of these biosensors and their advantages and disadvantages were demonstrated. • Various signal amplification systems with their peptide sequences and modifiers were revealed. Biosensors are unique analytical tools for the detection of biomarkers. Of these, autoantibodies against citrullinated proteins (ACPA) are useful for the differential diagnosis of rheumatoid arthritis (RA). The autoantibodies may be detected by immunoassay technology using synthetic cyclic citrullinated peptides (CCP), ie, anti-CCP. Recently, several biosensors have been developed for anti-CCP using CCP and mutated citrullinated vimentin (MCV) as recognition elements. In this review we highlight all currently available ACPA biosensor technology including those based on fluorescence, chemiluminescence, electrochemiluminescence (ECL), surface-enhanced Raman scattering (SERS)-based, surface plasmon resonance (SPR), lateral flow immunoassays (LFIA), and electrochemical. We explore various peptides as recognition elements, electrode modifiers and signal amplification systems thus providing new opportunities for next-generation biosensor design in RA. [ABSTRACT FROM AUTHOR]

Already at the very beginning of the COVID-19 pandemic, an extensive PCR and antigen testing strategy was considered necessary and subsequently also proved successful in order to limit the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections on international and national levels. However, equally important will be the continuous monitoring of the seroprevalence status of populations from defined regions to detect—in a timely manner—any recurrence of infections or an eventual decline in antibody levels of vaccinated individuals, especially in the emerging post-pandemic situation. The aim of this study was to estimate the prevalence of SARS-CoV-2-specific immunoglobulin G antibodies in the federal state of Upper Austria (Austria) during the period of December 2020 until April 2021. To achieve this goal, we have analyzed anonymized data on the immune status of self-referral volunteers that have been determined at local pharmacies through a low-entry-barrier point-of-care analysis approach. The seroprevalence values for immunoglobulin type G antibodies against SARS-CoV-2 antigens obtained by rapid diagnostic testing on peripheral blood from volunteers reflect the current population-based estimates reported in the literature as well as the positivity rates detected by PCR-screening analyses. In conclusion, broad-based monitoring of IgG antibodies by means of a point-of-care testing network represents a valuable tool to assess the current immune situation within regionally defined populations. [ABSTRACT FROM AUTHOR]

• The self–rapid antigen detection tests (RADTs) had sensitivities of 65.7 % and 62.1% and specificities of 100%. • Self-RADT sensitivities appeared higher among symptomatic participants. • Two of every 3 participants preferred the self-RADT over the polymerase chain reaction test. One strategy for reducing spread of COVID-19 is to contain the infection with broad screening, isolating infected individuals, and tracing contacts. This strategy requires widely available, reliable SARS-CoV-2 testing. To increase testing, rapid antigen detection tests (RADTs) were developed for self-sampling, self-testing, and self-interpretation. This study examined diagnostic performance, user acceptability, and safety of nasal self-RADTs compared with polymerase chain reaction (PCR) testing. Self-RADT kits were distributed at a public COVID-19 test center in Aarhus, Denmark or delivered to participants. Participants reported test results and test preferences. During enrollment, participants reported occurrence and duration of symptoms consistent with COVID-19. Sensitivity and specificity of self-RADT, relative to oropharyngeal PCR testing, were calculated. Among 827 participants, 102 showed positive PCR test results. Sensitivities of the self-RADTs were 65.7% (95% confidence interval [CI]: 49.2–79.2; DNA Diagnostic) and 62.1% (95% CI: 50.1–72.9; Hangzhou), and specificities were 100% (95% CI: 99.0–100; DNA Diagnostic) and 100% (95% CI: 98.9–100; Hangzhou). The sensitivities of both self-RADTs appeared higher in symptomatic participants than in asymptomatic participants. Two of every 3 participants preferred self-RADT over PCR test. Self-performed RADTs were reliable, user-acceptable, and safe among laypeople as a supplement to professionally collected oropharyngeal PCR testing. [ABSTRACT FROM AUTHOR]

Introduction: Nowadays, with the start of the vaccination campaign is very important to assess the extent of exposure of the population and identifying rapid, sensitive and accurate test to quickly identify new cases of SARS-CoV-2. The rapid test, cheap and easy to perform, is therefore very useful in developing countries, where the vaccination campaign has not yet reached adequate coverage. Methodology: We compared the VivaDiag COVID-19 IgM/IgG Rapid Test (VivaCheck Biotech Co., Ltd) with the Roche Elecsys Anti-SARSCoV-2 (Roche Diagnostics, Rotkreuz, Switzerland) to recognize past infections and to compare VivaDiag COVID-19 IgM/IgG Rapid Test (VivaCheck Biotech Co., Ltd) with Abbott Real Time PCR SARS-CoV-2 assay to recognize infection during its acute phase so that it’s possible to evaluate the use of commercially available assays in clinical practice. Results: Of the 1,100 patients tested with serological and rapid test, 1,085 were negative both to serological and rapid test, 4 patients were positive at rapid (2 for IgM and 2 for IgG) but negative serological test, 11 patients were positive at serological test but negative to rapid. Of the 300 tested with oropharyngeal swab and rapid test, 294 were negative both to swab and rapid test, 2 positives both to swab and rapid test, 3 positives at swab but negative at rapid test, 1 negative at swab but positive at rapid test. Conclusions: the combined use of these tests according to the specific needs of users, allows a reliable identification of infected patients in the acute phase, distinguishing them from subjects with an antibody response from a previous infection. [ABSTRACT FROM AUTHOR]

Avian influenza (AI) is a disease of birds caused by type A strain of influenza virus. Only type A influenza viruses are known to cause natural infection in birds. This study investigated the presence of avian influenza viruses in pigeons, local chickens, and ducks in randomly selected three Local Government Areas of Enugu North Agricultural Zone of Enugu State, Nigeria, from December 2016 to May 2017. A total of three hundred cloacal swabs were collected from pigeons, local chickens and ducks in Igbo-Eze North, Igbo-Eze South and Nsukka Local Government Areas respectively. The samples were moved to the laboratory in cold chain for laboratory analysis within an hour of collection. The cloacal swab samples were analyzed for AI using rapid antigen detection kit (X/pect H5N1 kit by Thermo Fisher Scientific Remel Inc. Lenexa, KS, USA), the spot and serial dilution haemagglutination (HA) methods. Of the one hundred samples from pigeons tested, 2% and 7% tested positive in rapid antigen detection and spot HA tests, respectively, while none of the samples from local chickens and ducks tested positive in the two tests. The detection of positive samples from pigeon in the two tests is an indication that pigeon is a potential threat to public health in the area because pigeons serve as a reservoir of H5N1 which is zoonotic. [ABSTRACT FROM AUTHOR]

Cholera is an acute diarrheal disease caused by Vibrio cholerae O1 or O139. Cholera rapid diagnostic tests (RDTs) are widely used to screen for cholera cases. However, their accuracy has not been systematically reviewed. To evaluate the diagnostic accuracy of cholera RDTs. Systematic review and meta-analysis. Medline, EMBASE and Web of science through to November 2020; references of included studies and a technical guidance on cholera RDTs. This review is registered with PROSPERO (CRD42021233124). Cross-sectional studies comparing the performance of cholera RDTs either to stool culture or PCR. Individuals with clinically suspected cholera. Two authors independently extracted data and assessed the quality using Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) criteria. Eighteen studies were included in the systematic review of which 17 were used for meta-analysis. Crystal VC was the most frequently used RDT (13 studies), followed by Cholkit and Institut Pasteur cholera dipstick (three studies each), SD Bioline (two studies), Artron (one study) and Smart (one study). Using direct testing (n = 12 627 specimens), the bivariate random-effects model yielded a pooled sensitivity and specificity of 91% (95% CI 87%–94%) and 80% (95% CI 74%–84%), respectively. However, through alkaline peptone water (APW) enrichment (n = 3403 specimens), the pooled sensitivity and specificity were 89% (95% CI 79%–95%) and 98% (95% CI 95%–99%), respectively. Cholera RDTs, especially when enriched with APW, have moderate sensitivity and specificity. Although less useful for clinical management, the current generation of RDTs have clear utility for surveillance efforts if used in a principled manner. Enrichment of stool specimens in APW before using cholera RDTs reduces the possibility of obtaining false-positive results, despite the few cholera cases that go undetected. It is noteworthy that APW-enriched cholera RDTs are not necessarily rapid tests, and are not listed in the Global Task Force on Cholera Control/WHO target product profile. [Display omitted] [ABSTRACT FROM AUTHOR]

Background & objective: Leptospirosis is a zoonotic disease associated with potentially fatal consequences and a grossly underreported disease in Uttar Pradesh. However, only a few studies are available which report the prevalence of leptospirosis in this State. Hence, this study was undertaken to know the status of the disease in central and eastern Uttar Pradesh. Methods: A total of 143 serum and urine samples were collected from patients with acute febrile illness from July 2017 to March 2019. All the serum samples were tested for Leptospira by rapid IgM antibody card and IgM ELISA and urine samples were tested by real-time polymerase chain reaction (RT-PCR) to detect Leptospira DNA. All positive and 10 per cent negative sera from ELISA and RT-PCR (all rapid test positive were also ELISA positive) were sent to the ICMR-Regional Medical Research Centre, Port Blair for microscopic agglutination test (MAT). Results: Thirty eight (26.6%) out of 143 samples were positive for leptospirosis either by ELISA or RT-PCR. Positive results were eight (6%) by Rapid card, 32 (22%) by IgM ELISA, 10 (7%) by MAT, 10 (7%) by RT-PCR. In MAT, the most common serovar was Lai followed by Hebdomadis, Bangkinang and Pomona. Interpretation & conclusions: Leptospirosis was found to be one of the important causes for acute febrile illness in the central and eastern parts of Uttar Pradesh. The results of the present study suggest that it is necessary to increase diagnostic facility and awareness in clinicians for the screening of leptospirosis in acutely febrile patients to decrease morbidity and mortality associated with this disease. [ABSTRACT FROM AUTHOR]

This study gives an overview of the performance and accuracy of devices used for the fast measurement of β-hydroxybutyrate (BHBA) in blood for the on-farm indication of subclinical ketosis. Data were collected on ten dairy farms. In each farm, blood samples were taken from ten cows on four test days (2, 4, 9 and 11), resulting in 400 samples. The reference method was the BHBA concentration in blood serum (BHBALAB). Four different devices that measure BHBA in whole blood were tested. The thresholds applied for identifying subclinical ketosis were ≥1.0, ≥1.2 and ≥1.4 mmol/L in blood serum. The BHBALAB was assigned in three classes: low--≤0.9 mmol/L; high-->0.9 mmol/L; and total--all values unclassified. Due to initial negative effects on the health and performance of cows with BHBA levels ≥0.9 mmol/L, this cut-off was chosen. The Passing--Bablok regression revealed different constant as well as absolute biases for each device in the aforementioned classes. The area under the receiver operating characteristics curve indicated highly accurate results, with 94-97% accuracy levels. As an overall conclusion, the performance of the devices was good and supports their use by farmers for the detection of subclinical ketotic cows in their herds. [ABSTRACT FROM AUTHOR]

OBJECTIVE Vancomycin is often empirically used in the management of head and neck infections (HNIs) in children. The objective of this study was to determine the utility of Staphylococcus aureus (SA) nasal PCR to facilitate de-escalation of vancomycin for pediatric HNIs. METHODS This was a single-center, retrospective cohort study of pediatric patients who received empiric intravenous vancomycin for a diagnosis of HNIs between January 2010 and December 2019. Subjects were excluded if they met any of the following: confirmed/suspected coinfection of another site, dialysis, immunocompromised status, admission to the NICU, alternative diagnosis that did not require antibiotics, or readmission for HNIs within 30 days of previous admission. The primary outcome was time to de-escalation of vancomycin. Total duration of antibiotics, treatment failure, hospital length of stay (LOS), and incidence of acute kidney injury (AKI) were also assessed. RESULTS Of the 575 patients identified, 124 patients received an SA nasal PCR. The median time to deescalation was 39.5 hours in those patients compared with 53.7 hours in patients who did not have a SA nasal PCR (p = 0.002). No difference was noted in total duration of all methicillin-resistant Staphylococcus aureus antibiotics, hospital LOS, treatment failure, and AKI. CONCLUSIONS In a large cohort of pediatric patients with HNIs, those who underwent testing with an SA nasal PCR spent less time receiving intravenous vancomycin, although their LOS was not significantly reduced. Further investigation is needed to better define the role of SA nasal PCRs in determining antibiotic therapy for HNIs. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to evaluate the application of the rapid influenza antigen test and the contribution of the test result to patient management in febrile infants aged 29-90 days. Methods: The medical records of febrile infants without a focus who presented during influenza seasons from 2017-2019 were analyzed retrospectively. The study was carried out in the Department of Pediatric Emergency, Dr. Sami Ulus Maternity and Children's Training and Research Hospital. The demographic characteristics, clinical and laboratory findings, and management of the patients were examined. The patients were divided into two groups as 'with' and 'without' testing based on whether a rapid influenza antigen test was performed or not. Test results were categorized as positive or negative. Serious bacterial infection (SBI) risk and patient management were evaluated according to test results. Results: A total of 173 patients (110 males/63 females) were evaluated. The influenza test was performed in 94 (54.3%) patients, and 31.9% were positive. SBI was present in 8.7% of all patients. The mean values of white blood cell (WBC), absolute neutrophil, platelet count, C-reactive protein (CRP) and, lumbar puncture, hospitalization, and initiation of antibiotic therapy were significantly lower in the positive group compared to the negative and without testing groups (P < 0.05). Conclusion: This study showed that using the influenza test in the emergency department in young febrile infants significantly reduced the use of antibiotics, hospitalization and the implementation of invasive procedures such as lumbar puncture, and the risk of SBI was not increased. [ABSTRACT FROM AUTHOR]

Objective: An irreversible process begins when a systemic infection causes sepsis. Therefore, rapid identification of the agent bacteria in sepsis and its antibiotic resistance is crucially important. In this study, it was aimed to investigate the efficiency of rapid genotype test in detecting sepsis agent Gram positive bacteria and important antibiotic resistance. Methods: 2132 blood culture samples sent to the laboratory were examined with an automatic blood culture system (BACTEC, BD, USA) between 2018-2019. Blood culture bottles sent to the laboratory were Growing bacteria was identificated by VİTEK (bioMérieux, France) automated bacteria identification / antibiotic susceptibility system. In addition, bacterial species and mecA, vanA, vanB, vanC1, vanC2 / C3 genes in blood cultures with Gram positive bacterial growth were also determined by the "Genotype® BC Gram-positive (Hain Lifesience, Germany)" test. Results: 72 patients with gram-positive bacteria growth in two or more blood culture bottles were included in the study. In 44 of the samples (61%) the same bacterial species were detected with conventional method (bacteria culture) and BC Gram positive test. In 28 of the samples (39%) differences were detected between results of methods regarding bacterial species name or vancomycin/methicillin resistance rate. Although single agent was isolated with culture method in all of the samples, multiple agents were detected in eight samples with rapid genotype test. Also, it was found that in mecA positive samples, ciprofloxacin resistance was higher than mecA negative ones. Conclusions: In the study, it was observed that BC Gram positive test could correctly identify sepsis agent bacteria and their resistance genes within 4-5 hours. [ABSTRACT FROM AUTHOR]

• ∙ Development of an immunochromatographic test for serodiagnosis of human trichinellosis. • ∙ Using Trichinella spiralis larval somatic antigen. • ∙ Valuable for a rapid, uncomplicated point-of-care testing tool. • ∙ A sensitive and specific tool for screening and detection of infection. • ∙ Useful in laboratories where sophisticated equipment is lacking. Objective: Trichinellosis is a globally distributed food-borne parasitic disease. Initially, diagnosis is usually made based on clinical signs, symptoms, and history of eating raw or undercooked meat. In the present study, an immunochromatographic test (ICT) kit was developed to diagnose trichinellosis by detecting IgG antibodies in sera of infected humans. Methods: Somatic extract from Trichinella spiralis larvae was used as the antigen for the ICT kit development. Diagnostic efficacy was evaluated using human serum samples from proven trichinellosis patients, healthy persons, and those with other parasitic infections. Results: The diagnostic sensitivity, specificity, positive and negative predictive values and accuracy of the ICT kit were 100.0% (95%; CI 88.8 to 100.0%), 92.5% (95% CI; 86.9 to 96.2%), 73.8% (95% CI; 58.0 to 86.1%), 100.0% (95% CI; 97.3 to 100.0%) and 93.8% (95% CI; 89.2 to 96.9%), respectively. Conclusions: This ICT diagnostic kit can be used as a testing tool for human trichinellosis. This test should permit rapid detection of infection to enable prompt anthelminthic treatment. It can also be used for retrospective diagnoses and field surveys based at laboratories where sophisticated equipment is lacking. [ABSTRACT FROM AUTHOR]

This study aims to identify the clinical characteristics for diagnosing streptococcal pharyngitis. The correlation between eighteen clinical manifestations and rapid antigen detection test results was analyzed. Among 205 patients, five clinical manifestations, pharyngeal hemorrhage (odds ratio [OR] = 11.85), palatal hemorrhage (OR = 9.32), tonsillar swelling (OR = 4.37), rash (OR = 3.02), and enlarged cervical nodes (OR = 1.91), were significantly correlated with group A Streptococcus (GAS) pharyngitis. Traditional indicators such as fever, pharyngeal redness, acute onset, headache, rhinorrhea, cough, tonsillar exudate, and cervical tenderness were not statistically related to GAS pharyngitis. Therefore, physicians should be cautious in using these traditional indicators. [ABSTRACT FROM AUTHOR]