Development of a new accurate lateral flow immunoassay for diagnosis of human leptospirosis.

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.

Comparison of SensPERT® Leishmania rapid test with two other immunochromatographic tests for the diagnosis of canine visceral leishmaniasis in Brazil.

Background and Aim: In urban environments, dogs serve as the primary reservoir for visceral leishmaniasis (VL). Rapidly diagnosing canine VL through tests enables early treatment and a favorable prognosis. This study aimed to assess the diagnostic performance of the SensPERT® Leishmania test kit (Dechra®), Alere® Leishmaniasis Ac test kit, and the rapid test dual path platform (TR-DPP®) Bio-Manguinhos in detecting VL. Materials and Methods: 30 serum samples from reactive VL dogs and 30 serum samples from healthy dogs were employed for assessing the sensitivity and specificity variation between SensPERT® Leishmania test kit, Alere® Leishmaniasis Ac test kit, and rapid test dual platform - TR-DPP®. Results: The SensPERT® Leishmania test outperformed Alere® and TR-DPP® in terms of sensitivity, specificity, positive and negative predictive values and demonstrated near-perfect concordance with Alere® and substantial concurrence with TR-DPP®. Conclusion: The SensPERT® Leishmania rapid test proved to be a promising test in the detection of VL in dogs.

Diagnostic performance of the bioline dengue duo rapid test on symptomatic patients assisted at Armed Forces Hospital (Hfa) in Brasília, Brazil.

Dengue necessitates accurate diagnosis. Rapid tests such as Bioline™ DENGUE DUO have gained traction, but validation in specific populations is essential. This study aimed to evaluate the performance of the Bioline™ test, alongside assessing the socio-epidemiological profile of symptomatic patients in a Brasília Military Hospital. The serum of 404 symptomatic patients was analyzed by the Bioline™ DENGUE DUO test, followed by Dengue virus detection and discrimination of the four serotypes by RT-qPCR. Accuracy was assessed using parameters including sensitivity (S), specificity (E), positive and negative predictive values (PPV and NPV), and positive (RV +) and negative (RV-) likelihood ratios. The NS1 component exhibited a sensitivity of 70.37%, a specificity of 97.30%, and an overall efficiency of 90.10% when compared to RT-qPCR as the gold standard. The IgM component demonstrated a sensitivity of 26.85%, a specificity of 89.53%, and an overall efficiency of 72.77% when compared to RT-qPCR as the gold standard. The IgG component demonstrated a sensitivity of 23.15%, a specificity of 68.92%, and an overall efficiency of 56.68% when compared to RT-qPCR as the gold standard. Several rapid tests are commercially available. However, considering variations across regions and demographic groups, it is important to question their accuracy in specific populations. Rapid tests are important screening tools, but they can have limitations for the certainty of diagnosis. Bioline™ DENGUE DUO displayed good specificity, but sensitivity was slightly below optimal levels. While helpful for confirming dengue, improvements are needed to effectively rule out the disease.

Leptospira interrogans insoluble fraction as a potential antigen source for lateral flow immunochromatography

BACKGROUND Leptospirosis is an emerging zoonosis that affects humans and animals. Immunochromatography rapid test is widely used for early diagnosis of leptospirosis, but with low sensitivity and specificity. OBJECTIVES To evaluate Leptospira interrogans insoluble fraction as a potential antigen source for lateral flow immunochromatography. METHODS Insoluble fraction derived from the crude bacterial extract was obtained by serial centrifugation. The polypeptide profile was determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Immune reactivity of this fraction was assessed by Western Blotting and lateral flow immunochromatography (LFI). It was tested 160 microagglutination test (MAT)-positive sera from patients in the acute phase, 100 MAT-negative sera from patients with acute febrile illness, and 45 patients with other infectious diseases. FINDINGS There was a predominance of low molecular mass-polypeptide bands, ranging from 2 to 37 kDa. The antibody reactivity of theses polypeptides was found to range from 13-50%, especially between 10 and 38 kDa. Among MAT-positive sera of patients with leptospirosis in the acute phase, 97% were also positive in LFI, indicating high sensitivity. Among MAT-negative sera, all were negative in LFI, indicating high specificity. Only 2% of cross-reactivity was detected. CONCLUSION The insoluble fraction can be a valuable antigen source for development of point-of-care diagnosis test for leptospirosis.

Epizootiology of canine distemper in naturally infected dogs in Goiânia, Brazil / Epizootiologia da cinomose em cães naturalmente infectados em Goiânia, Brasil

Although the epizootiological profile of canine distemper in Goiânia is unknown, there is clinical evidence for a high incidence of canine distemper virus (CDV) infection among dogs. Therefore, this study determined the epizootiological characteristics of canine distemper in naturally infected dogs. Data of 46 dogs that tested positive for the CDV based on immunochromatography or reverse transcription-polymerase chain reaction were collected. Data on the sex, breed, age, and vaccination status were obtained from these dogs, and extraneural and neural sign analyses were performed. Although, the infected dogs belonged to both sexes, different breeds, and different age groups, a greater proportion of cases were seen in adults (1-6 years), undefined breeds, and unvaccinated dogs. Among the CDV-positive dogs, 10.87% had been vaccinated. In addition, 4.35% showed neural signs, 8.69% showed extraneural signs, and 86.96% showed both. High lethality was observed, with viral antigen and/or DNA detected in 82.61% dead dogs. Only 8.70% of the total CDV-infected dogs remained alive at the time of their assessment.

Embora o perfil epizootiológico da cinomose canina em Goiânia seja desconhecido, há evidencia clínica para alta incidência da infecção pelo vírus da cinomose (CDV) nos cães. Este estudo objetivou determinar as características epizootiológicas da cinomose em cães naturalmente infectados. Dados de 46 cães positivos por imunocromatografia ou reação em cadeia da polimerase via transcriptase reversa para o CDV foram coletados. Dados sobre sexo, raça, idade, estado vacinal foram obtidos desses cães, e os sinais extraneurais e neurais foram analisados. Animais de ambos os sexos, diferentes raças e idades foram acometidos. A maior proporção de casos foi vista em adultos (de um a seis anos), sem raça definida e não vacinados. Dentre os cães positivos, 10,87% haviam sido vacinados. Em adição, 4,35% apresentaram sinais neurais, 8,69% sinais extraneurais e 86,96% mostraram ambos. Alta letalidade foi observada, com o antígeno viral e/ou DNA identificado em 82,61% dos cães que foram a óbito. Apenas 8,7% dos cães infectados permaneceram vivos até o momento da avaliação.

Detecting KPC-2 and NDM-1 Coexpression in Klebsiella pneumoniae Complex from Human and Animal Hosts in South America.

Reports of Gram-negative bacteria harboring multiple carbapenemase genes have increased in South America, leading to an urgent need for appropriate microbiological diagnosis. We evaluated phenotypic methods for detecting Klebsiella pneumoniae carbapenemase 2 (KPC-2) and New Delhi metallo-ß-lactamase-1 (NDM-1) coexpression in members of the K. pneumoniae complex (i.e., K. pneumoniae, K. quasipneumoniae, and K. variicola) isolated from human and animal hosts, based on inhibition of ceftazidime-avibactam (CZA) and aztreonam (ATM) by dipicolinic acid (DPA), EDTA, or avibactam (AVI). While the presence of blaKPC-2 and blaNDM-1 genes was confirmed by whole-genome sequencing, PCR, and/or GeneXpert, coexpression was successfully detected based on the following: (i) a ≥5-mm increase in the zone diameter of ATM (30 µg) disks plus AVI (4 or 20 µg) and ≥4-mm and ≥10-mm increases in the zone diameters for "CZA 50" (30 µg ceftazidime [CAZ] and 20 µg AVI) and "CZA 14" (10 µg CAZ and 4 µg AVI) disks, respectively, when we added DPA (1 mg/disk) or EDTA (5 mM) in a combined disk test (CDT); (ii) a positive ghost zone (synergism) between ATM (30 µg) and CZA 50 disks and between CZA 50 and DPA (1 mg) disks, using the double-disk synergy test (DDST) at a disk-disk distance of 2.5 cm; (iii) ≥3-fold MIC reductions of ATM and CZA in the presence of AVI (4 µg/mL), DPA (500 µg/mL), or EDTA (320 µg/mL); and (iv) immunochromatography. Although our results demonstrated that inhibition by AVI, DPA, and EDTA may provide simple and inexpensive methods for the presumptive detection of coexpression of KPC-2 and NDM-1 in members of the K. pneumoniae complex, additional studies are necessary to confirm the accuracy of these methodologies by testing other Gram-negative bacterial species and other KPC and NDM variants coexpressed by WHO critical priority pathogens detected worldwide. IMPORTANCE Alerts regarding the emergence and increase of combinations of carbapenemases in Enterobacterales in Latin America and the Caribbean have recently been issued by PAHO and WHO, emphasizing the importance of appropriate microbiological diagnosis and the effective and articulated implementation of infection prevention and control programs. In this study, we evaluated methods based on inhibition of ceftazidime (CAZ), ceftazidime-avibactam (CZA), and aztreonam (ATM) by dipicolinic acid (DPA), EDTA, and avibactam (AVI) inhibitors for the identification of KPC-2- and NDM-1-coexpression in members of the K. pneumoniae complex recovered from human and animal hosts. Our results demonstrate that inhibition by AVI, DPA, and EDTA may provide simple and inexpensive methods for the presumptive detection of coexpression of KPC-2 and NDM-1 in members of the K. pneumoniae complex.

Virus de la leucemia e inmunodeficiencia felina: un estudio retrospectivo en clínicas veterinarias particulares en Bogotá y Chía (Colombia), 2015-2019 / Leukemia viruses and feline immunodeficiency: a retrospective study in private veterinary clinics in Bogotá and Chía (Colombia), 2015-2019

Resumen Los virus de inmunodeficiencia y leucemia felina representan un problema de gran envergadura para los felinos domésticos debido a la multiplicidad de sintomatologías que manifiestan. El objetivo del presente estudio fue establecer, retrospectivamente, la prevalencia en la presentación de ViLeF y VIF en pacientes de seis clínicas de pequeños animales en Bogotá y Chía, en relación con factores como su edad, raza y género. Se realizó un estudio transversal y retrospectivo, mediante la recopilación de datos de 1.014 historias clínicas de pacientes felinos que ingresaron a seis clínicas de la ciudad de Bogotá y Chía, para determinar la prevalencia de VIF y ViLeF y la asociación de estas con factores como edad, género y raza, entre 2015 y 2019, a través de la prueba OR. La detección de los virus se realizó mediante una prueba rápida basada en inmunocromatografía. La mayor prevalencia para cada enfermedad por año fue: 12,3% para VIF en 2012 y 18% para ViLeF en 2019. Los machos presentaron mayores seroprevalencias para ambas enfermedades durante la mayoría los años evaluados. Factores como raza (criolla: VIF: 1,85; ViLeF: 2,01), género (macho: VIF: 1,53 OR; ViLeF: 1,64) y edad (> 7 años: VIF: 3,82; ViLeF: 3,21) se relacionaron positivamente con la presentación de ambas enfermedades en la población felina evaluada.

Abstract Immunodeficiency virus and feline leukemia virus represent major problems for domestic felines due to the multiplicity of symptoms they manifest. The objective of the present study was to establish, retrospectively, the prevalence in the presentation of FeLV and FIV in patients from six small animal clinics in Bogota and Chia, related to factors such as age, race, and gender. A cross-sectional and retrospective study was carried out, collecting data from 1.014 clinical records of feline patients who were admitted to six clinics in the city of Bogota and Chia, to determine the prevalence of FIV and FeLV and their association with factors such as age, gender, and race, between 2015 and 2019 through the OR test. The detection of the viruses was carried out through a rapid test based on immunochromatography. The highest prevalence for each disease per year was 12,3% for FIV in 2012 and 18% for FeLV in 2019. Males presented higher seroprevalences for both diseases during most of the years evaluated. Factors such as race (Creole: FIV: 1,85; FeLV: 2,01), gender (male: FIV: 1.53 OR, FeLV: 1,64), and age (> 7 years: FIV: 3.82; FeLV: 3.21) were positively related to the presentation of both diseases in the feline population evaluated.

Frecuencia de la leucemia felina (ViLeF) en un refugio municipal de Rionegro, Colombia, durante 2020 / Frequency of Feline Leukemia (FeLV): Municipal Shelter Rionegro, Colombia 2020

RESUMEN La leucemia viral felina (ViLeF) es una enfermedad retroviral letal, de una elevada prevalência en Colombia, que afecta a felinos de diferentes edades y sexos. El objetivo de esta investigación fue determinar la frecuencia por serodiagnóstico de ViLeF en felinos del centro integral de bienestar animal Ceiba, ubicado en Rionegro, Antioquia (Colombia), en 2020. Para ello, se realizó un estudio descriptivo longitudinal de serofrecuencia de ViLeF desde enero hasta diciembre de 2020. Fueron muestreados 92 gatos, a los cuales se les efectuó una prueba p27 por inmunoensayo comercial Elisa (Idexx©, Snap Combo Plus®, Maine, EE. UU.). La frecuencia de felinos positivos fue 30/92 (32,60%) y el mes de mayo fue el de mayor frecuencia (9,78%). Los machos positivos fueron 17/92 (18,47%) y las hembras 13/92 (14,13%). La edad promedio de seropositividad fue 2,14 años. La frecuencia de ViLeF en 2020 para Ceiba, Rionegro (Colombia) es de 32,60%, un valor elevado con respecto a descripciones en otros albergues para felinos. ViLeF es una enfermedad que está siendo reportada con mayor frecuencia en Colombia, debido a que las medidas de prevención no se están adoptando rutinariamente.

ABSTRACT Feline viral leukemia (ViLeF) is a lethal retroviral disease with a high prevalence in Colombia that affects felines of different ages and sexes. The purpose of this investigation was to determine the frequency by serodiagnosis of ViLeF in felines of the integral center of animal welfare Ceiba, located in Rionegro, Antioquia (Colombia), during 2020. For that, a longitudinal descriptive study of ViLeF serofrequency from were made January to December 2020. 92 cats were sampled, which were tested for p27 by commercial Elisa immunoassay (Idexx©, Snap Combo Plus®, Maine, USA). The frequency of positive felines was 30/92 (32,60%). May was the month with the highest frequency (9,78%). The positivity frequency for males was 17/92 (18,47%) and the frequency for females 13/92 (14,13%). The main age of seropositivity was 2,14 years. The frequency of ViLeF in 2020 for Ceiba, Rionegro (Colombia) is 32,60%. This is a high value in comparison to descriptions in other shelters for felines. ViLeF, in Colombia, is a disease that has been reported with more frequency because prevention measures are not being adopted routinely.

Development of a novel glycoprotein-based immunochromatographic test for the rapid serodiagnosis of bovine brucellosis.

AIMS: Bovine brucellosis is a worldwide zoonotic disease that causes important economic losses and public health concerns. Because control of the disease depends on vaccination, serodiagnosis and isolation of the infected animals, affordable, rapid and accurate point of care (POC) tests are needed. METHODS AND RESULTS: We developed and evaluated a novel glycoprotein-based immunochromatographic test for the detection of IgG antibodies against the O-polysaccharide of Brucella in bovine serum samples. Brucella GlycoStrip combines the power of immunochromatographic and bacterial glycoengineering technologies for the diagnosis of bovine brucellosis. The analysis of positive and negative reference samples indicated that the test has a diagnostic sensitivity and specificity of 96.9% (95% CI: 92.7%-100.0%) and 100%, respectively. CONCLUSIONS: Due to the recombinant glycoprotein-based antigen OAg-AcrA, which consists of the O-side chain of Brucella smooth lipopolysaccharide (sLPS) covalently linked to the carrier protein AcrA, the test is highly accurate, allows the differentiation of infected animals from those vaccinated with a rough strain or with a single dose of a smooth strain and fulfil the minimum diagnostic requirements established by the national and international regulations. SIGNIFICANCE AND IMPACT OF STUDY: This strip test could provide a rapid (10 min) and accurate diagnosis of bovine brucellosis in the field contributing to the control of the disease.

Comparative assessment of immunochromatography and ELISA diagnostic tests for HBsAg detection in PCR-confirmed HBV infection.

INTRODUCTION AND AIMS: Viral hepatitis, which appears most frequently at birth or during childhood, is a disease whose transmission routes include tears, bile, sexual fluids, sweat, milk, urine, feces, and saliva. The aim of the present study was to analyze the specificity of the immunochromatographic and ELISA diagnostic tests for hepatitis B surface antigen and compare them with PCR testing. MATERIALS AND METHODS: The study sample was made up of 140 men and 60 women referred to the Urmia Medical University hospital to undergo PCR testing for HBV diagnosis. The ELISA test was performed using the Pioneer Medicine Company kit (Tehran, Iran). RESULTS: The results of the HBs-Ag rapid test and the ELISA test were compared with the PCR test. The HBs-Ag rapid test had 97% sensitivity and 91% specificity, whereas the ELISA test had 78% sensitivity and 76% specificity. DISCUSSION AND CONCLUSION: According to our results, the immunochromatographic test was accurate for diagnosing HBs-Ag in blood and the ELISA test had acceptable sensitivity and specificity, compared with PCR testing.

Laboratory diagnosis of leprosy: Two staining methods from bacilloscopy and rapid ml flow test.

Background: The diagnosis of leprosy is based on the characteristic signs and symptoms of the disease, subsidized by laboratory tests. When positive, the bacilloscopy closes the diagnosis for leprosy. Phenolic glycolipid-I, or PGL-I, is a molecule in the bacillus cell wall that confers a greater immune response. The ML Flow test is an immunochromatographic test for the detection of anti-PGL-I IgM in human blood or serum. Methods: A prospective study with data collection and biological materials in patients with suspected leprosy from August 2020 to May 2021. For microscopy, intradermal smears were stained with Auramine O, and after reading under a fluorescence microscope, reviewed by Ziehl-Neelsen. The ML flow test was performed according to the Bührer-Sékula protocol. To assess the agreement between the methods, the Kappa index was estimated. Results: Of the 94 suspected leprosy patients, 31 (32.9%) were diagnosed with leprosy. There was moderate agreement between the results of the ML Flow and Auramine O tests (Kappa = 0.58) and substantial agreement between the ML Flow and Ziehl-Neelsen microscopy (Kappa = 0.72). In paucibacillary cases, serology was positive in 100% of patients. Conclusions: This study concluded that the Ziehl-Neelsen technique remains the best option for standard leprosy staining, and the ML flow test is more positive among the three techniques evaluated and can be an effective tool in the early diagnosis of leprosy cases.

Antigenemia temprana de Cryptococcus en pacientes asintomáticos VIH positivos en Barranquilla, Colombia / Cryptococcus early antigenemia in HIV positive asymptomatic patients in Barranquilla, Colombia

Resumen La criptococosis meníngea presenta alta mortalidad mundial, especialmente en población VIH/sida. La OMS recomienda detectar el antígeno capsular de Crypto coccus como estrategia para un diagnóstico temprano y poder minimizar complicaciones. Objetivo: realizar antigenemia temprana de Cryptococcus mediante in munocromatografía/ensayo de flujo lateral en pacientes asintomáticos VIH+. Material y método: estudio descriptivo observacional; entre julio-2016 y mayo-2019 se procesaron mediante ensayo de flujo lateral, muestras de suero de 169 pacientes asintomáticos VIH+, con CD4 ≤120 cel/μL en Barranquilla, Colombia. Ante resultado positivo, se indicó profilaxis con fluconazol; se hizo seguimiento a todos los casos. Resultados: la antigenemia fue positiva en cinco pacientes (2,96%); uno falleció, cuatro recibieron profilaxis y la prueba se negativizó en dos. Los pacientes con resultado negativo inicial no desarrollaron durante el estudio sinto matología compatible con esta micosis. Discusión: el ensayo de flujo lateral de Cryptococcus está recomendado para el diagnóstico temprano de la criptococosis en población VIH/sida. Conclusión: detectar tempranamente el antígeno circulante de Cryptococcus mediante ensayo de flujo lateral en pacientes asintomáticos VIH+, permitió instaurar profilaxis oportuna, hacer seguimiento y control para reducir la mortalidad asociada con la criptococosis meníngea.

Abstract Meningeal cryptococcosis presents high levels of global mortality, especially in the HIV/AIDS population. The WHO recommends detecting the capsular antigen as an important strategy for early diagnosis and be able to minimize complications. Objective: Perform early cryptococcal antigenemia by immunochromatographic/ lateral flow assay in asymptomatic HIV+ patients. Material and method: descriptive observational study; between July-2016 and May-2019, serum samples from 169 asymptomatic HIV+ patients with CD4 ≤120 cells/μL were processed by lateral flow assay in Barranquilla, Colombia. Given a positive result, prophylaxis with fluconazole was indicated; all cases were followed up. Results: antigenemia was positive in five (2.96%) patients; one died; four received prophylaxis, and the test turned negative in two. The patients with an initial negative result, did not developed symptoms compatible with this mycosis during the study period. Discussion: lateral flow assay for Cryptococcus is recommended for the early diagnosis of cryptococcosis in the HIV/AIDS population. Conclusion: early detection of circulating Cryptococcus antigen by lateral flow assay in HIV+ patients allowed the establishment of timely prophylaxis, follow-up, and control to reduce mortality associated with meningeal cryptococcosis.

Hábitos alimentarios y de higiene asociados a la seroprevalencia de Helicobacter pylori en estudiantes universitarios peruanos / Dietary and hygiene habits associated with the Helicobacter pylori seroprevalence in Peruvian university students / Hábitos alimentares e de higiene associados à soroprevalência do Helicobacter pylori em estudantes universitários peruanos

RESUMEN Introducción: La infección por Helicobacter pylori es cada vez más frecuente en los jóvenes peruanos e incrementa su riesgo de padecer neoplasias gástricas. Objetivo: Determinar los hábitos alimentarios y de higiene asociados a la seroprevalencia de infección por Helicobacter pylori en estudiantes universitarios del departamento de Cajamarca, Perú, durante los meses de septiembre a octubre de 2019. Método: Estudio observacional, transversal, prospectivo con un diseño no experimental. La población estuvo conformada por 367 estudiantes de la carrera profesional de Tecnología Médica. El tamaño de la muestra fue de 188 estudiantes de ambos géneros. Se detectaron anticuerpos IgG frente a Helicobacter pylori en suero, mediante el método de inmunocromatografía. Los hábitos alimentarios y de higiene se recopilaron utilizando una encuesta estructurada. Resultados: El 51,1 % de estudiantes presentó anticuerpos IgG frente a Helicobacter pylori. El 31,38 % de los estudiantes que consumía "a veces" alimentos elaborados en la calle resultaron seropositivos a Helicobacter pylori. Aquellos estudiantes que manifestaron lavarse las manos "a veces" (29,79 %) y "siempre" (21,28 %) antes de ingerir los alimentos presentaron anticuerpos IgG contra la bacteria. Además, los estudiantes seropositivos frente a Helicobacter pylori lavaban sus frutas y verduras con el agua del grifo (43,62 %) y consumían agua de grifo no tratada (29,79 %). Conclusión: El consumo de alimentos preparados en la calle, lavado de manos antes de consumir alimentos, tipo de agua para consumo y lavado de frutas y verduras antes de ingerirlas son hábitos alimentarios y de higiene asociados a la seroprevalencia de Helicobacter pylori.

ABSTRACT Introduction: Helicobacter pylori infection is becoming more frequent in the young population of Peru and at the same time increases the risk of gastric neoplasms. Objective: To identify the dietary and higiene habits associated with the seroprevalence of Helicobacter pylori infection in university students at the Cajamarca Department. Assesed period from September throughout October 2019. Method: An observational, cross-sectional, prospective study with a non-experimental design was carried out. A population of 367 students on Medical technology career were involved and 188 of them, in both sex, were selected as trial. It was detected, using the immunochromatography method in serum assay, IgG antibodies against Helicobacter pylori. Dietary and hygiene habits were collected using a well-structed enquiry. Results: It was identified IgG antibodies against Helicobacter pylori infection in 51.1% of students. The 31.38% of those who, not frequently, had consumed food prepared outdoors were seropositive for Helicobacter pylori. Those students who revealed wash their hands, not frequently (29.79%) and frequently (21.28%) before eating, produced antibodies against this bacterial infection. In addition, Helicobacter pylori seropositive students washed their fruits and vegetables with obtained water from the tap (43.62%) and consumed untreated water fom the tap too (29.79%). Conclusions: Food intake outdoors, wash of hands, fruits and vegetables before eating, and the quality of water to be consumption are dietary and hygiene habits associated with the Helicobacter pylori seroprevalence.

RESUMO Introdução: A infecção por Helicobacter pylori é cada vez mais comum em jovens peruanos e aumenta o risco de neoplasias gástricas. Objetivo: Determinar os hábitos alimentares e de higiene associados à soroprevalência da infecção por Helicobacter pylori em universitários do departamento de Cajamarca, Peru, durante os meses de setembro a outubro de 2019. Método: Estudo observacional, transversal, prospectivo com um não experimental. A população foi composta por 367 alunos da carreira de Tecnologia Médica. O tamanho da amostra foi de 188 alunos de ambos os sexos. Os anticorpos IgG contra Helicobacter pylori foram detectados no soro pelo método de imunocromatografia. Os hábitos alimentares e de higiene foram coletados por meio de questionário estruturado. Resultados: 51,1% dos alunos apresentaram anticorpos IgG contra Helicobacter pylori. 31,38% dos alunos que comeram "às vezes" alimentos preparados na rua eram soropositivos para Helicobacter pylori. Os alunos que relataram lavar as mãos "às vezes" (29,79%) e "sempre" (21,28%) antes de comer apresentaram anticorpos IgG contra a bactéria. Além disso, os alunos soropositivos para Helicobacter pylori lavavam frutas e vegetais com água da torneira (43,62%) e consumiam água da torneira não tratada (29,79%). Conclusão: O consumo de alimentos preparados na rua, a lavagem das mãos antes de consumir os alimentos, o tipo de água para consumo e a lavagem de frutas e verduras antes de ingeri-los são hábitos alimentares e de higiene associados à soroprevalência do Helicobacter pylori.

Development of a lateral flow immunochromatography test for the rapid detection of bovine tuberculosis.

Detection of specific antibodies would be a useful test strategy for bovine tuberculosis (bTB) as a complement to the single skin test. We developed a lateral flow immunochromatography (LFIC) test for rapid bTB detection based on the use of a conjugate of gold nanoparticles with a recombinant G protein. After evaluating 3 Mycobacterium bovis (MB) antigens: ESAT-6, CFP-10 and MPB83 for the control line, we selected MPB83 given it was the most specific. The performance of the test was analyzed with 820 bovine sera, 40 sera corresponding to healthy animals, 5 sera from animals infected with Mycobacterium avium subsp. paratuberculosis (MAP) and 775 sera of animals from herds with bTB. All these sera were also submitted to a validated bTB-ELISA using whole-cell antigen from MB. From the 775 sera of animals from herds with bTB, 87 sera were positive by the bTB-ELISA, 45 were positive by LFIC and only 5 animals were positives by skin test (TST). To confirm bTB infection in the group of TST (-), bTB-ELISA (+) and LFIC (+) animals, we performed postmortem examination in 15 randomly selected animals. Macroscopically, these 15 animals had numerous small and large yellow-white granulomas, characteristic of bTB, and the infection was subsequently confirmed by PCR in these tissues with lesions (gold standard). No false positive test result was detected with the developed LFIC either with the sera from healthy animals or from animals infected with MAP demonstrating that it can be a useful technique for the rapid identification of animals infected with bTB.

Diagnostic comparison of stool exam and point-of-care circulating cathodic antigen (POC-CCA) test for schistosomiasis mansoni diagnosis in a high endemicity area in northeastern Brazil.

This study aimed to evaluate the performance of the point-of-care circulating cathodic antigen (POC-CCA) test in a highly endemic area in Brazil, comparing it to the Kato-Katz (KK) technique for sensitivity, specificity and the intensity of the reaction of the test in relation to the parasitic load. The community in Sergipe, Brazil, participated in the study, providing three stool samples, one of urine (POC-CCA) and fingers tick blood sample was tested by enzyme-linked immunosorbent assay (ELISA). Sensitivity, specificity, positive predictive value, negative predictive value, accuracy, kappa coefficient and Spearman's correlation were calculated for the POC-CCA test using the KK as the reference. The prevalence of schistosomiasis by KK testing was 48.82%; POC-CCA (t+) 66.14%; POC-CCA (t-) 45.24%. ELISA results showed 100% agreement in individuals with high and moderate eggs per gram (EPG). POC-CCA presented good diagnostic performance in individuals with medium and high EPG, but there were a high number of false negatives in individuals with low intensity infections. As observed, POC-CCA-filter test improves accuracy and sensitivity compared to a conventional test.

A Review on COVID-19 Diagnosis Tests Approved for Use in Brazil and the Impact on Pandemic Control

Abstract With the COVID-19 pandemic, many diagnostic tests (molecular or immunological) were rapidly standardised, given the urgency of the situation, many are still in the process of being validated. The main objective of this study was to review the aspects of the diagnostic kits approved in Brazil and their application in the different federative units to gather epidemiological information. In order to achieve these objectives, a survey was carried out on the data available at the regulatory agency (ANVISA) and in the literature. The main countries that have registered products in Brazil are China (51.4%), Brazil (16.6%), South Korea (9.2%), USA (8.8%) and Germany (3.6%). The methodologies of these products are based on the detection of nucleic-acid (15.8%), antigen (13%) and antibody (71.2%). In the immunological tests, it was verified that the sensitivity ranged from 55 to 100% and the specificity from 80 to 100%. The percentage of cases in the samples tested in Brazil is elevated in almost all federative units since eight states showed 40% of positive cases in tested samples, while 18 states displayed between 20 and 40%. In conclusion, this review showed that Brazil is dependent on external technology to respond to pandemics, epidemics and endemics disease and needs to improve its biotechnological scheme to solve further diseases outbreaks.

A lateral flow immunoassay based on colored latex particles for detection of canine visceral leishmaniasis.

Canine visceral leishmaniasis (CVL) is the major source of human visceral leishmaniasis. To control the spread of this disease, early and accurate detection of infected dogs is critical but challenging. The serological diagnosis of CVL remains problematic because there are no reliable commercially available tests. Most laboratories use enzyme-linked immunosorbent assay or the indirect immunofluorescent antibody test. These tests use Leishmania chagasi recombinant antigens K39 or K26 assembled with either gold-labelled Staphylococcus aureus protein A or protein G from Streptococcus pyogenes. In this work, we propose the development, optimization and standardization of a lateral flow immunoassay (LFIA) based on functionalized colored particles and a specific recombinant antigen, as a visual in situ method for the diagnosis of CVL. The following analysis variables were considered: (i) the concentration of the latex-protein complex; (ii) the dilution of the serum; (iii) the composition of the employed buffers; (iv) the nominal capillary flow time through the nitrocellulose membrane; (v) the concentration of reagents fixed in the test and control lines; (vi) the particle size of the colored latex; and (vii) the conjugation method. Then, the obtained strips were evaluated as a visual diagnostic tool based on a panel of positive and negative sera. It was observed that because of its simplicity and performance the LFIA test is a quick and reliable alternative for the diagnosis of CVL either in conventional laboratories or for remote areas where laboratories are not readily accessible for conventional assays.

The different tests for the diagnosis of COVID-19 - A review in Brazil so far.

SARS-CoV-2 is a novel virus from the coronavirus family that emerged in the end of December 2019 in Wuhan, China. The virus is now widespread and causing the current pandemic of COVID-19, a highly pathogenic viral pneumonia, commonly presented with fever and cough, which frequently lead to lower respiratory tract disease with poor clinical outcomes associated with older age and underlying health conditions. Supportive care for patients is typically the standard protocol because no specific effective antiviral therapies have been identified so far. The current outbreak is challenging governments and health authorities all over the world. In here we present a comparison among the current diagnostic tools and kits being used to test Brazilian population.

Occurrence of Babesia vogeli, Mycoplasma spp., Ehrlichia canis and Anaplasma spp. in a hospital dog population of western Paraná / Ocorrência de Babesia vogeli, Mycoplasma spp., Ehrlichia canis e Anaplasma spp. em uma população hospitalar de cães do Oeste do Paraná

Ehrlichia canis, Anaplasma platys, and Babesia vogeli are frequently detected in the veterinary routine with varied pathogenesis that can lead to death, mainly in co-infections. Although canine hemotropic mycoplasmas are considered of low clinical importance, they have recently gained prominence in molecular research. The present study aimed to analyze two hospital populations of dogs, randomly selected from the year 2013 and 2015, from the municipalities of Toledo (n=68) and Cascavel (n=107). Direct examination of blood smears, serology, and PCR were used to detect the presence of E. canis, A. platys, B. vogeli and Mycoplasma sp. Direct blood smear examination was negative for the investigated agents in all samples. Serum immunochromatography (SensPERT ™, VetAll Laboratories, Korea) in 175 animals showed that only 4% (n = 7) had anti-E. canis antibodies, while 60% (n = 105) were positive for Anaplasma sp. All PCR samples were negative for E. canis, while 18.28% (n = 32) were positive for A. platys, 3.42% (n = 6) positive for Babesia vogeli, and 7.41% (n = 13) positive for Mycoplasma sp. The study revealed the presence of A. platys in Toledo and Cascavel by PCR, which accentuates the need to monitor vector populations and usual hosts and to evaluate the potential risk of infection in humans.

Ehrlichia canis, Anaplasma platys e Babesia vogeli são frequentemente detectados na rotina veterinária com patogênese variada que pode levar à morte, principalmente em coinfecções. Embora os micoplasmas hemotrópicos caninos sejam considerados de baixa importância clínica, recentemente ganharam destaque na pesquisa molecular. O presente estudo teve como objetivo analisar duas populações hospitalares de cães, selecionadas aleatoriamente no ano de 2013 e 2015, dos municípios de Toledo (n = 68) e Cascavel (n = 107). O exame direto de esfregaços de sangue, sorologia e PCR foram usados para detectar a presença de E. canis, A. platys, B. vogeli e Mycoplasma sp. O esfregaço sanguíneo direto foi negativo para os agentes investigados em todas as amostras. A imunocromatografia sérica (SensPERT ™, VetAll Laboratories, Coréia) em 175 animais mostrou que apenas 4% (n = 7) tinham anticorpos contra E.canis, enquanto 60% (n = 105) foram positivos para Anaplasma sp. Todas as amostras de PCR foram negativas para E. canis, enquanto 18,28% (n = 32) foram positivas para A. platys, 3,42% (n = 6) positivas para Babesia vogeli e 7,41% (n = 13) positivas para Mycoplasma sp. O estudo revelou a presença de A. platys em Toledo e Cascavel por PCR, o que acentua a necessidade de monitorar populações de vetores e hospedeiros usuais e avaliar o risco potencial de infecção em humanos.

Occurrence of Babesia vogeli, Mycoplasma spp., Ehrlichia canis and Anaplasma spp. in a hospital dog population of western Paraná / Ocorrência de Babesia vogeli, Mycoplasma spp., Ehrlichia canis e Anaplasma spp. em uma população hospitalar de cães do Oeste do Paraná

Ehrlichia canis, Anaplasma platys, and Babesia vogeli are frequently detected in the veterinary routine with varied pathogenesis that can lead to death, mainly in co-infections. Although canine hemotropic mycoplasmas are considered of low clinical importance, they have recently gained prominence in molecular research. The present study aimed to analyze two hospital populations of dogs, randomly selected from the year 2013 and 2015, from the municipalities of Toledo (n=68) and Cascavel (n=107). Direct examination of blood smears, serology, and PCR were used to detect the presence of E. canis, A. platys, B. vogeli and Mycoplasma sp. Direct blood smear examination was negative for the investigated agents in all samples. Serum immunochromatography (SensPERT ™, VetAll Laboratories, Korea) in 175 animals showed that only 4% (n = 7) had anti-E. canis antibodies, while 60% (n = 105) were positive for Anaplasma sp. All PCR samples were negative for E. canis, while 18.28% (n = 32) were positive for A. platys, 3.42% (n = 6) positive for Babesia vogeli, and 7.41% (n = 13) positive for Mycoplasma sp. The study revealed the presence of A. platys in Toledo and Cascavel by PCR, which accentuates the need to monitor vector populations and usual hosts and to evaluate the potential risk of infection in humans.(AU)

Ehrlichia canis, Anaplasma platys e Babesia vogeli são frequentemente detectados na rotina veterinária com patogênese variada que pode levar à morte, principalmente em coinfecções. Embora os micoplasmas hemotrópicos caninos sejam considerados de baixa importância clínica, recentemente ganharam destaque na pesquisa molecular. O presente estudo teve como objetivo analisar duas populações hospitalares de cães, selecionadas aleatoriamente no ano de 2013 e 2015, dos municípios de Toledo (n = 68) e Cascavel (n = 107). O exame direto de esfregaços de sangue, sorologia e PCR foram usados para detectar a presença de E. canis, A. platys, B. vogeli e Mycoplasma sp. O esfregaço sanguíneo direto foi negativo para os agentes investigados em todas as amostras. A imunocromatografia sérica (SensPERT ™, VetAll Laboratories, Coréia) em 175 animais mostrou que apenas 4% (n = 7) tinham anticorpos contra E.canis, enquanto 60% (n = 105) foram positivos para Anaplasma sp. Todas as amostras de PCR foram negativas para E. canis, enquanto 18,28% (n = 32) foram positivas para A. platys, 3,42% (n = 6) positivas para Babesia vogeli e 7,41% (n = 13) positivas para Mycoplasma sp. O estudo revelou a presença de A. platys em Toledo e Cascavel por PCR, o que acentua a necessidade de monitorar populações de vetores e hospedeiros usuais e avaliar o risco potencial de infecção em humanos.(AU)