Estudio comparativo entre un test de antígeno y la prueba de la reacción en cadena de la polimerasa en tiempo real (RT-PCR) para el diagnóstico de infección por COVID-19 en pediatría / Comparative study between an antigen test and the reverse transcription-polymerase chain reaction (RT-PCR) test for the diagnosis of COVID-19 in pediatrics

Introducción. La pandemia por COVID-19 ha puesto de manifiesto la necesidad de pruebas diagnósticas rápidas. La prueba de referencia es la reacción en cadena de la polimerasa en tiempo real (RT-PCR). Requiere un equipo y personal capacitado, y su resultado puede llevar un tiempo de espera prolongado. El sistema BD Veritor® es el método rápido cromatográfico utilizado para la detección del antígeno del coronavirus de tipo 2 del síndrome respiratorio agudo grave, en individuos sintomáticos. El objetivo primario del siguiente trabajo es evaluar sensibilidad y especificidad del test de antígeno (TA) comparadas con la RT-PCR en población pediátrica. Población y métodos. Estudio prospectivo, de prueba diagnóstica. Se incluyó a todo menor de 17 años en los primeros 5 días de inicio de síntomas, que consultó desde julio de 2021 hasta febrero de 2022. Se calculó un mínimo de 300 muestras para lograr una precisión de ± 8,76 % y de ± 3,68 % para sensibilidad y especificidad respectivamente. Se analizaron en paralelo las muestras por ambas metodologías. Resultados. De 316 muestras pareadas, 33 fueron positivas por ambos métodos; 6 fueron positivas solo por RT-PCR. La especificidad del TA fue del 100 %; la sensibilidad, del 84,6 %, con un valor predictivo positivo y negativo del 100 % y del 98 % respectivamente. Conclusiones. El TA demostró ser útil en el diagnóstico de pacientes pediátricos con COVID-19 en los primeros 5 días de inicio de síntomas, aunque aquellos con TA negativo y alta sospecha clínica deberían confirmar su resultado con la RT-PCR.

Introduction. The COVID-19 pandemic has brought to light the need for rapid diagnostic tests. The gold standard test is reverse transcription-polymerase chain reaction (RT-PCR). RT-PCR requires equipment and trained personnel, and results may take a long waiting time. The BD Veritor® System is a rapid chromatographic method used for the detection of severe acute respiratory syndrome coronavirus 2 antigen in symptomatic individuals. The primary objective of this study is to assess the sensitivity and specificity of the antigen test (AT) compared to the RT-PCR in the pediatric population. Population and methods. Prospective study with a diagnostic test. All children younger than 17 years in the first 5 days of symptom onset, who consulted between July 2021 and February 2022, were included. A minimum of 300 specimens was estimated to achieve an accuracy of ±8.76% and ±3.68% for sensitivity and specificity, respectively. Specimens were analyzed in parallel using both methodologies. Results. Of 316 paired samples, 33 were positive by both methods; 6 were positive only by RT-PCR. The specificity of the AT was 100%; sensitivity was 84.6%, with a positive and negative predictive value of 100% and 98%, respectively. Conclusions. The AT proved to be useful in the diagnosis of pediatric patients with COVID-19 in the first 5 days of symptom onset, although those with a negative AT and high clinical suspicion should confirm their result with a RT-PCR.

Rapid antigen test as a tool for the identification of SARS-CoV-2 infection and its potential as a self-testing device

ABSTRACT Background: SARS-CoV-2 virus originated in Wuhan (China) in December (2019) and quickly spread worldwide. Antigen tests are rapid diagnostic tests (RDT) that produce results in 15-30 min and are an important tool for the scale-up of COVID-19 testing. COVID-19 diagnostic tests are authorized for self-testing at home in some countries, including Brazil. Widespread COVID-19 diagnostic testing is required to guide public health policies and control the speed of transmission and economic recovery. Methods: Patients with suspected COVID-19 were recruited at the Hospital da Baleia (Belo Horizonte, Brazil). The SARS-CoV-2 antigen-detecting rapid diagnostic tests were evaluated from June 2020 to June 2021 using saliva, nasal, and nasopharyngeal swab samples from 609 patients. Patient samples were simultaneously tested using a molecular assay (RT-qPCR). Sensitivity, specificity, accuracy, and positive and negative predictive values were determined using the statistical program, MedCalc, and GraphPad Prism 8.0. Results: The antigen-detecting rapid diagnostic tests displayed 98% specificity, 60% sensitivity, 96% positive predictive value, and moderate concordance with RT-qPCR. Substantial agreement was found between the two methods for patients tested < 7 days of symptom onset. Conclusions: Our findings support the use of Ag-RDT as a valuable and safe diagnostic method. Ag-RDT was also demonstrated to be an important triage tool for suspected COVID-19 patients in emergencies. Overall, Ag-RDT is an effective strategy for reducing the spread of SARS-CoV-2 and contributing to COVID-19 control.

Comparación del test de antígeno y la reacción en cadena de polimerasa para SARS-CoV-2 en niños menores de 12 años / Comparison of antigen test and polymerase chain reaction for SARS-CoV-2 in children younger than 12 years

Frenar la propagación de la enfermedad por el coronavirus 2019 (COVID-19, por su sigla en inglés) es fundamental, y se puede realizar mediante técnicas de detección rápidas y efectivas. El objetivo fue comparar la precisión diagnóstica de un test rápido de antígeno (TRAg,) con la reacción en cadena de polimerasa con retrotranscripción (RT-qPCR, por su sigla en inglés) y describir los umbrales de amplificación (Ct, por su sigla en inglés). Participaron niños de 1 mes a 11 años que tuvieran menos de 7 días de síntomas, sin resultado detectable en los últimos 90 días, e inmunocompetentes. Se incluyeron 1855 pacientes con una prevalencia de COVID-19 del 4,7 %. La sensibilidad global del TRAg fue del 60,2 % y su especificidad, del 99,8 %; en niños mayores de 5 años los valores fueron de 69,8 % y 99,8 %, respectivamente. Los valores de Ct de las muestras discordantes fueron más altos. En conclusión, la precisión diagnóstica muestra que TRAg tiene una especificidad similar a la RT-qPCR, pero una sensibilidad considerablemente menor, sobre todo en niños de menos de 5 años.

Stopping the spread of coronavirus disease 2019 (COVID-19) is critical and can be achieved through rapid and effective detection techniques. Our objective was to compare the diagnostic accuracy of rapid antigen tests (RAgT) and reverse transcription quantitative polymerase chain reaction (RT-qPCR) and to describe amplification cycle thresholds (Cts). Participants were children aged 1 month to 11 years with symptoms for less than 7 days, who did not have a detectable result in the past 90 days, and were immunocompetent. A total of 1855 patients were included; the prevalence of COVID-19 was 4.7%. For the RAgT, overall sensitivity was 60.2% and specificity, 99.8%; in children older than 5 years, values were 69.8% and 99.8%, respectively. Ct values for discordant samples were higher. To conclude, the diagnostic accuracy indicated that the specificity of RAgT is similar to that of RT-qPCR, but its sensitivity is notably lower,especially in children younger than 5 years.

Viral Load-based Evaluation of the Sensitivity of Antigen-based Rapid Detection Assay for SARS-CoV-2

Background: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has become a global public health problem. The real-time reverse transcription-polymerase chain reaction (RT-PCR) is the gold standard test for the detection of SARS-CoV-2. However, the assay requires hours to get the final results. Therefore, antigen-based rapid assays are being used extensively to reduce the time. We have evaluated the performance of the antigen-based rapid test for the detection of SARS-CoV-2 virus in comparison with RT-PCR. Materials and methods: Nasopharyngeal and throat swabs were collected from 366 suspected patients of COVID-19 visiting our institute and subjected to qualitative RT-PCR and antigen-based rapid assays to detect the presence of SARS-CoV-2 virus. The sensitivity and specificity of the antigen-based assay were calculated in comparison with RT-PCR. Results: Compared with RT-PCR, sensitivity and specificity of the antigen-based rapid assay were observed to be 70.5% and 98.6%, respectively, in comparison with RT-PCR. However, the sensitivity of antigen-based rapid assay varied significantly with decreasing viral load. The sensitivity of the rapid antigen assay was equivalent to RT-PCR (23/23, 100%) at a higher viral load (Ct value 15�). In contrast, the antigen assay could only detect 3/21 (14.28%) samples with Ct value >30. Conclusion: The antigen-based assay could assist in the rapid screening of a large population. However, the rapid antigen assay might not detect early stages of infection represented by low viral load. Therefore, the antigen-based assay could not replace RT-PCR testing. The study reiterates that all antigen-based negative tests should be confirmed by RT-PCR.

Ophthalmology practice in COVID-19 pandemic: Performance of rapid antigen test versus real time-reverse transcription polymerase chain reaction in a tertiary eye care institute in South India

Purpose: To assess the rapid antigen test (RAT) against the gold standard reverse transcription?polymerase chain reaction (RT?PCR) to screen COVID?19 infection in asymptomatic patients undergoing ophthalmic procedures. Methods: This was a retrospective hospital?based study. Point?of?care (PoC) RAT was performed using nasopharyngeal swab, while RT?PCR for SARS?CoV?2 viral RNA was performed using both nasopharyngeal and throat swabs. Results: A total of 629 patients were tested for SARS?CoV?2 by using both RAT and RT?PCR. Only one patient had tested positive for SARS?CoV?2 with both RAT and RT?PCR, while two patients had tested positive with RT?PCR after an initial negative RAT. The positivity rate for RAT was 0.15% (1/629), and that for RT?PCR was 0.47%. Percent agreement or proportion of agreement observed between the two tests was 99.68%, while Cohen’s kappa coefficient value was 0.49. The sensitivity of RAT in comparison to RT?PCR was 33.33%, specificity was 100%, positive predictive value was 100%, and negative predictive value was 99.68%. Conclusion: The sensitivity and Cohen’s kappa coefficient in our study were low but that can be attributed to the overall low positivity rates with both RAT and RT?PCR. However, percent agreement observed between the two tests was very high. Therefore, we recommend initial screening of all the patients for COVID?19 symptoms followed by RAT before performing any ophthalmic surgical procedure to ensure the safety of the health care professionals as well as the patients.

Helicobacter Pylori Treatment Eradication in Egypt: Standard Clarithromycin-based Triple versus Quadruple Regimen Therapy

Absence of adequate treatment for Helicobacter pylori (H. pylori) infection leads to prolonged life time colonization which is responsible for complications. Antibiotics resistance is the main cause of eradication failure in H. pylori infection, thus our study aimed to evaluate the efficiency and tolerability of standard triple therapy vs. quadruple regimen therapy in H. pylori eradication in Egypt.

The importance of disease prevalence in clinical decision making: a real practice study on COVID-19 antigen test in Curacao

ABSTRACT The performance of a test can be suboptimal, but in appropriate setting such a test is still useful for clinical decision making. We investigated the role of Antigen Rapid Diagnostic Test (Ag-RDT) for clinical decision making in an Emergency Department (ED) in Curacao during peak of COVID-19 pandemic. Ag-RDT was performed in the naso- and oropharynxswabs from patients with respiratory insufficiency presented to the ED. Ag-RDT was performed in 153 patients, of which 64 (41.8%) showed positive results. Comparing Ag-RDT results with molecular tests, its sensitivity was 68.8% (95% CI 57.4 to 78.7), and specificity of 94.6% (95% CI 84.9 to 98.9). The positive and negative predictive value were 95.1% (95% CI 86.5 to 98.3) and 66.3 (95% CI 58.6 to 73.3), respectively. All patients with Ag-RDT positive test were admitted to the cohorted COVD-19 department of the hospital. By using Ag-RDT, 35.9% of rapid PCR tests (that are more costly and laborious to perform) could be avoided at cost of 5.8% patients with false positive result. In conclusion, in real practice, disease prevalence is as important as test's performance for clinical decision making. The conclusion may also be applicable for other diagnostic tests than COVID-19 diagnostic.

Performance evaluation of standard™ Q Covid-19 Ag saliva test in detection of Covid-19 among patients in tertiary hospital

@#Newer diagnostic tests for COVI D-19 such as antigen tests are being used for rapid identification of cases. Compared to reverse transcriptase polymerase chain reaction (RT-PCR), these tests offer simpler collection and processing. This study aims to determine the accuracy of a SARS-CoV-2 antigen-detecting rapid diagnostic test (Ag-ROT) using saliva compared to nasopharyngeal and oropharyngeal swab (NPS/OPS) RT- PCR among patients tested in the Emergency Room at Makati Medical Center. Patients who underwent NPS/OPS RT-PCR and who consented to participate in the study were asked to submit salivary sample to be analyzed using the Standard™ Q Covid-19 Ag Saliva Test kit. A total of 366 samples were collected . The overall accuracy was 81 .69% with a sensitivity of 63.58% and a specificity of 97.93%. Subgroup analyses as to processing time, number of days from symptom onset, and presence or absence of symptoms had no effect the overall accuracy. The Standard™ Q Covid-19 Ag Saliva Test kit was able to satisfy the ~97% specificity recommended by the WHO for SARS-CoV-2 Ag-RDTs but did not meet the minimum performance requirements of ~80% sensitivity. A positive test results can help in the initiation of early treatment and isolation of cases, but a negative test should still be confirmed by NPS/OPS RT-PCR test.

Effects of Rapid Influenza Antigen Test on Antimicrobial Management of Pediatric Patients with Influenza-Like Illness in the Emergency Room

Background@#Influenza is a commonly encountered respiratory tract infection and diagnosis remains to be a challenge. Use of a rapid antigen test may influence decisions on treatment in the emergency room (ER). @*Objectives@#This research aims to determine the effects of rapid influenza antigen test (RIAT) on antimicrobial management of influenza-like illness (ILI) in the ER, determine the clinical profile of pediatric patients with ILI and look into the relationship between RIAT result, symptomatology, and immunization status. @*Methods@#This is a cross-sectional study which involved review of charts of 195 pediatric patients with ILI who underwent RIAT (KlintecTM) through a nasopharyngeal swab in the ER of a tertiary hospital from September 2019 to February 2020. Chi-square, Fischer exact test and likelihood ratio were used for data analysis. @*Results@#Most pediatric patients were 7–12 years old males. Majority presented with fever, cough, and colds and underwent RIAT at 2–4 days from onset of illness. About 73.33% of study participants did not receive their yearly influenza vaccine and 70.7% of patients with positive RIAT had no influenza vaccine. There is a lower percentage of vaccinated children who developed cough (86.5% vs. 89.5%) and colds (80.8% vs. 83.2%) when compared with unvaccinated children. RIAT result significantly affected management in terms of antimicrobial prescribing to patients with ILI. @*Conclusion@# Influenza presents with non-specific symptoms and vaccination remains a major preventive measure against the disease. The result of RIAT facilitates targeted treatment for influenza and decreases unnecessary antibacterial use, but this should be done with careful thought and interpretation.

Adaptación a la realidad de Latinoamérica de la Guía Clínica NASPGHAN/ESPGHAN 2016 sobre Diagnóstico, Prevención y Tratamiento de Infección por Helicobacter pylori en Pediatría / Adaptation to the reality of Latin America of the NASPGHAN/ESPGHAN 2016 Guidelines on the Diagnosis, Prevention and Treatment of Helicobacter pylori Infection in Pediatrics

Resumen: Introducción: Las últimas guías clínicas conjuntas de NASPGHAN y ESPGHAN en relación a la infección por H. pylori publicadas el año 2016, contienen 20 afirmaciones que han sido cuestionadas en la práctica respecto a su aplicabilidad en Latinoamérica (LA); en particular en relación a la preven ción del cáncer gástrico. Métodos: Se realizó un análisis crítico de la literatura, con especial énfasis en datos de LA y se estableció el nivel de evidencia y nivel de recomendación de las afirmaciones mas controversiales de las Guías Conjuntas. Se realizaron 2 rondas de votación de acuerdo a la técnica Delfi de consenso y se utilizó escala de Likert (de 0 a 4) para establecer el "grado de acuerdo" entre un grupo de expertos de SLAGHNP. Resultados: Existen pocos estudios en relación a diagnóstico, efectividad de tratamiento y susceptibilidad a antibióticos de H. pylori en pacientes pediátricos de LA. En base a estos estudios, extrapolaciones de estudios de adultos y la experiencia clínica del panel de expertos participantes, se realizan las siguientes recomendaciones. Recomendamos la toma de biopsias para test rápido de ureasa e histología (y muestras para cultivo o técnicas moleculares, cuando estén disponibles) durante la endoscopia digestiva alta sólo si en caso de confirmar la infección por H. pylori, se indicará tratamiento de erradicación. Recomendamos que centros regionales seleccio nados realicen estudios de sensibilidad/resistencia antimicrobiana para H. pylori y así actúen como centros de referencia para toda LA. En caso de falla de erradicación de H. pylori con tratamiento de primera línea, recomendamos tratamiento empírico con terapia cuádruple con inhibidor de bomba de protones, amoxicilina, metronidazol y bismuto por 14 días. En caso de falla de erradicación con el esquema de segunda línea, se recomienda indicar un tratamiento individualizado considerando la edad del paciente, el esquema indicado previamente y la sensibilidad antibiótica de la cepa, lo que implica realizar una nueva endoscopía con extracción de muestra para cultivo y antibiograma o es tudio molecular de resistencia. En niños sintomáticos referidos a endoscopía que tengan antecedente de familiar de primer o segundo grado con cáncer gástrico, se recomienda considerar la búsqueda de H. pylori mediante técnica directa durante la endoscopia (y erradicarlo cuando es detectado). Con clusiones: La evidencia apoya mayoritariamente los conceptos generales de las Guías NASPGHAN/ ESPGHAN 2016, pero es necesario adaptarlas a la realidad de LA, con énfasis en el desarrollo de centros regionales para el estudio de sensibilidad a antibióticos y mejorar la correcta selección del tratamiento de erradicación. En niños sintomáticos con antecedente familiar de primer o segundo grado de cáncer gástrico, se debe considerar la búsqueda y erradicación de H. pylori.

Abstract: Introduction: The latest joint H. pylori NASPGHAN and ESPGHAN clinical guidelines published in 2016, contain 20 statements that have been questioned in practice regarding their applicability in Latin America (LA); in particular in relation to gastric cancer prevention. Methods: We conduc ted a critical analysis of the literature, with special emphasis on LA data and established the level of evidence and level of recommendation of the most controversial claims in the Joint Guidelines. Two rounds of voting were conducted according to the Delphi consensus technique and a Likert scale (from 0 to 4) was used to establish the "degree of agreement" among a panel of SLAGHNP ex perts. Results: There are few studies regarding diagnosis, treatment effectiveness and susceptibility to antibiotics of H. pylori in pediatric patients of LA. Based on these studies, extrapolations from adult studies, and the clinical experience of the participating expert panel, the following recom mendations are made. We recommend taking biopsies for rapid urease and histology testing (and samples for culture or molecular techniques, when available) during upper endoscopy only if in case of confirmed H. pylori infection, eradication treatment will be indicated. We recommend that selected regional centers conduct antimicrobial sensitivity/resistance studies for H. pylori and thus act as reference centers for all LA. In case of failure to eradicate H. pylori with first-line treatment, we recommend empirical treatment with quadruple therapy with proton pump inhibitor, amoxi cillin, metronidazole, and bismuth for 14 days. In case of eradication failure with the second line scheme, it is recommended to indicate an individualized treatment considering the age of the pa tient, the previously indicated scheme and the antibiotic sensitivity of the strain, which implies performing a new endoscopy with sample extraction for culture and antibiogram or molecular resistance study. In symptomatic children referred to endoscopy who have a history of first or se cond degree family members with gastric cancer, it is recommended to consider the search for H. pylori by direct technique during endoscopy (and eradicate it when detected). Conclusions: The evidence supports most of the general concepts of the NASPGHAN/ESPGHAN 2016 Guidelines, but it is necessary to adapt them to the reality of LA, with emphasis on the development of regional centers for the study of antibiotic sensitivity and to improve the correct selection of the eradication treatment. In symptomatic children with a family history of first or second degree gastric cancer, the search for and eradication of H. pylori should be considered.

Evaluating Diagnostic Tests for Helicobacter pylori Infection Without a Reference Standard: Use of Latent Class Analysis

Evaluation of diagnostic tests requires reference standards, which are often unavailable. Latent class analysis (LCA) can be used to evaluate diagnostic tests without reference standards, using a combination of observed and estimated results. Conditionally independent diagnostic tests for Helicobacter pylori infection are required. We used LCA to construct a reference standard and evaluate the capability of non-invasive tests (stool antigen test and serum antibody test) to diagnose H. pylori infection compared with the conventional method, where histology is the reference standard. A total of 96 healthy subjects with endoscopy histology results were enrolled from January to July 2016. Sensitivity and specificity were determined for the LCA approach (i.e., using a combination of three tests as the reference standard) and the conventional method. When LCA was used, sensitivity and specificity were 83.8% and 99.4% for histology, 80.0% and 81.9% for the stool antigen test, and 63.6% and 89.3% for the serum antibody test, respectively. When the conventional method was used, sensitivity and specificity were 75.8% and 71.1% for the stool antigen test and 77.7% and 60.7% for the serum antibody test, respectively. LCA can be applied to evaluate diagnostic tests that lack a reference standard.

Standardizing Diagnosis of Helicobacter pylori Infection to Improve Diagnostic Accuracy / 胃肠病学

Eradication of Helicobacter pylori (Hp) is important for the prevention and treatment of chronic gastritis, peptic ulcer and gastric cancer. The Chinese consensus on the management of Hp infection has taken "confirmed Hp infection" as an indication for eradication. The World Gastroenterology Organisation global guideline states the "test-and-treat strategy" for Hp infection. Accurate diagnosis of Hp infection is a prerequisite for standardized eradication. There are many methods to diagnose Hp infection. Each has its advantages and disadvantages. Different methods are suitable for different diseases and patients, and each method has strict requirements for reagents, equipment, testers and patients. Therefore, increasing the awareness of physicians and testers about the standardized diagnosis of Hp infection is essential to improve the diagnostic accuracy.

Recommendations of Test of Prostate-specific Antigen along with Histopathological Examination for the Prostate Lesions

Introduction: Prostate disease is an important growing health problem, presenting a challenge to urologists, radiologists, and pathologists. Objectives: The aim of the study is to correlate prostatic-specific antigen test with histopathological examination in prostatic lesions and to recommend combine approach for management of the patients of prostatic lesions. Materials and Methods:This was a prospective study conducted at the department of pathology in a tertiary care center over 6 months. Data were collected from histopathology record department. The 2002 WHO classification was used to diagnose and classify prostate tumors. Gleason’s grading system was used for the cases of adenocarcinoma. Results: In our study, a total of 119 cases of prostatic lesions were noticed. The lesions diagnosed were benign prostatic hyperplasia (79% of cases), adenocarcinoma (6% of cases), prostatic intraepithelial neoplasia (4% of cases), stromal nodules of hyperplasia (4% of cases), and atypical adenomatous hyperplasia (4% of cases). A total of 3% of cases were inadequate. Majority of prostatic lesions were belonging to the 6th decade followed by the 7th decade. All cases of adenocarcinoma were belonging to the 6th decade. The test of prostatic-specific antigen was higher (more than 10 ng) in cases of adenocarcinoma. Conclusions: The study is conducted to see that combine approach of prostate-specific antigen and histopathological examination is useful for its recommendation, for better management of prostatic lesions in tertiary care center.

Two cases of cholera O1 in South Batinah, Oman, April 2019: lessons learned / 한국역학회지

Cholera represents an ongoing threat to many low-income and middle-income countries, but some cases of cholera even occur in high-income countries. Therefore, to prevent or combat cholera outbreaks, it is necessary to maintain the capacity to rapidly detect cholera cases, implement infection control measures, and improve general hygiene in terms of the environment, water, and food. The 2 cases, 1 imported and 1 secondary, described herein are broadly indicative of areas that require improvement. These cases were missed at the primary health care stage, which should be the first detection point even for unusual diseases such as cholera, and the absence of strict infection control practices at the primary care level is believed to contribute to secondary cases of infection. This report also encourages countries to ensure that rapid diagnostic stool tests are available to enable quick detection, as well as to provide information to people travelling to areas where cholera is endemic.

Two cases of cholera O1 in South Batinah, Oman, April 2019: lessons learned / 한국역학회지

Cholera represents an ongoing threat to many low-income and middle-income countries, but some cases of cholera even occur in high-income countries. Therefore, to prevent or combat cholera outbreaks, it is necessary to maintain the capacity to rapidly detect cholera cases, implement infection control measures, and improve general hygiene in terms of the environment, water, and food. The 2 cases, 1 imported and 1 secondary, described herein are broadly indicative of areas that require improvement. These cases were missed at the primary health care stage, which should be the first detection point even for unusual diseases such as cholera, and the absence of strict infection control practices at the primary care level is believed to contribute to secondary cases of infection. This report also encourages countries to ensure that rapid diagnostic stool tests are available to enable quick detection, as well as to provide information to people travelling to areas where cholera is endemic.

Fatal Cryptococcus gattii meningitis with negative cryptococcal antigen test in a HIV-non-infected patient

Cryptococcus gattii predominantly causes central nervous system and pulmonary infection in both immunocompromised and immunocompetent patients with substantial morbidity. We report a case of rapidly fatal meningitis by C. gattii in an HIV–non-infected man with CD4 lymphopenia who tested negative for cryptococcal antigen. This case may serve as an alert to its wider occurrence and less explored risk factors.

Clinical evaluation of a rapid diagnostic test kit for detection of canine coronavirus / 대한수의학회지

Canine coronavirus is a single-stranded RNA virus that causes enteritis in dogs of any age. Coronaviral enteritis is seldom definitively diagnosed, since it is usually much less severe than many other types of enteritis and is self-limiting. Conventional diagnostics for the canine coronaviral enteritis such as polymerase chain reaction (PCR), virus isolation, and electron microscopic examination are inappropriate for small animal clinics due to the complicated experimental processes involved. Therefore, a commercially available lateral flow test kit based on chromatographic immunoassay techniques was tested to evaluate its performance as a first-line diagnostic test kit that could be used in clinics. The coronavirus antigen test kit detected canine coronavirus-infected dogs with 93.1% sensitivity and 97.5% specificity. The detection limit of the test kit was between 1.97 × 10⁴/mL and 9.85 × 10³/mL for samples with a 2-fold serial dilution from 1.25 × 10⁶ TCID₅₀ (TCID₅₀, 50% tissue culture infectious dose). Additionally, the test kit had no cross-reactivity with canine parvovirus, distemper virus, or Escherichia coli. Overall, the commercially available test kit showed good diagnostic performance in a clinical setting, with results similar to those from PCR, confirming their potential for convenient and accurate use in small animal clinics.

Application of a stool antigen test to evaluate the burden of Helicobacter pylori infection in dyspepsia patients.

Helicobacter pylori (HP) is causally associated with peptic ulcer disease and gastric carcinoma. Determination of the prevalence of HP infection in dyspepsia patients’ in particular geographical area is imperative for the appropriate management of dyspepsia. HP antigen detection in stool is a noninvasive diagnostic test of HP infection. This prospective study was conducted to find out the prevalence of HP infection based on stool antigen testing in dyspeptic patients who had also undergone upper gastrointestinal (GI) endoscopy. This study highlights the high prevalence of HP infection in dyspeptic Indian patients, particularly males, and emphasizes the growing importance of the bacterium causing infection among children. We also found HP stool antigen testing to be superior to upper GI endoscopy for detecting HP infection. Hence, we recommend initial testing for HP stool antigen in dyspeptic patients before initiating treatment and before carrying out any invasive procedure such as endoscopy.

A Meta-analysis of the diagnostic accuracy of Streptocuccus pneumoniae urinary antigen test for adult ;community acquired Streptocuccus pneumoniae pneumoniae / 中华危重病急救医学

Objective To evaluate the diagnostic accuracy of Streptocuccus pneumoniae urinary antigen test (SpUAT) in patients with community acquired Streptocuccus pneumoniae pneumoniae (SPP). Methods The clinical studies relating SpUAT diagnostic accuracy for community acquired Streptocuccus pneumoniae infection were searched via computer and manual screening of Chinese databases including China National Knowledge Internet (CNKI), China Biology Medicine disc, China Technical Journal Full-text Database, and Wanfang Database as well as English databases such as PubMed, EBSCO, Elsevier Science, Ovid Technologies, and Springer. Data were extracted according to appropriate inclusion and exclusion criteria and analyzed with Meta-disc 1.4 and Stata 12.0 software. Pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio as well as diagnostic odds ratio (DOR) were calculated, and summary receiver operating characteristic curve (SROC) was plotted and area under SROC (AUC) was calculated to analyze the diagnostic accuracy of SpUAT for adult community acquired SPP. Results A total of 15 studies enrolling 6 866 patients were included, all of which with a quality assessment of diagnostic accuracy studies (QUADAS) score not lower than 10, indicating a high study quality. Random effect model was applied owing to non-threshold effect associated heterogeneity. It was shown by Meta analysis that compared with routine pathogen diagnosis (hemoculture, sputum smears, sputum culture and trachea and bronchus attractive culture), the pooled sensitivity, pooled specificity, pooled positive likelihood ratio, and pooled negative likelihood ratio was 73% [95% confidence interval (95%CI) = 71%-76%,] 91% (95%CI = 90%-92%), 6.97 (95%CI = 4.13-11.77), and 0.30 (95%CI = 0.26-0.34), respectively, pooled DOR was 24.34 (95%CI = 13.14-45.11), and AUC of SROC was 0.8051±0.0362. It was indicated by heterogeneity test that experiment design (prospective or retrospective), sample sizes (lower than 200 or higher than or equal to 200), reference test (fewer than 3 or more than or equal to 3 test methods), or literature language (Hispanic or non-Hispanic) had no effect on study heterogeneity, indicating certain other unknown factors may be involved. Funnel plot suggested that 15 involved studies uniformly distributed along the two sides of regression line, indicating no publication bias. Conclusions The use of SpUAT for the diagnosis of adult community acquired SPP has a moderate sensitivity and high specificity. Although the overall accuracy of SpUAT diagnosis is relatively high, there is significant heterogeneity among the studies, so more high-quality studies are needed.

Clinical Manifestations of Group A Streptococcal Pharyngitis and Comparison of Usefulness of Two Rapid Streptococcal Antigen Tests

BACKGROUND: Throat culture is the golden standard for diagnosis of group A streptococcal (GAS) pharyngitis. However, because it is a time-consuming procedure, antibiotics are often empirically administrated. Rapid antigen tests (RATs) can detect bacterial infections within 15 minutes, thus helping to reduce unnecessary administration of antibiotics. METHODS: In total, 108 patients, between 3 and 17 yr of age, who visited our hospital from August 2011 to July 2012, were tested for suspected acute pharyngitis with two RATs––SD Bioline Strep A (SD, Korea) and BinaxNOW Strep A (Binax, Inc., USA)––as well as throat culture. We compared the sensitivity, specificity, and consistency of the two RATs and assessed the clinical manifestations of GAS pharyngitis. RESULTS: Of the 108 patients, 15 were confirmed to have GAS pharyngitis by throat culture. The SD test showed a sensitivity of 93.3% and a specificity of 97.8%; the positive and negative predictive values were 87.5% and 98.9%, respectively. The Binax test showed a sensitivity of 86.7% and a specificity of 100%; the positive and negative predictive values were 100% and 97.9%, respectively. The Kappa values for conformity degree were high, 0.887 and 0.918 in the SD and the Binax tests, respectively (P=0.00). Clinical manifestation assessment of GAS pharyngitis indicated that scarlatiniform rash and strawberry tongue were significantly associated signs (P<0.05). CONCLUSIONS: GAS pharyngitis diagnosis based on clinical manifestations alone has practical limitations. The two RATs are useful as substitutes for throat culture and their frequent use in clinical settings is advisable.