scholarly journals Multiplex Recombinase Polymerase Amplification Assay for Simultaneous Detection of Treponema pallidum and Haemophilus ducreyi in yaws-like lesions

2020 ◽  
Author(s):  
Michael Frimpong ◽  
Shirley Victoria Simpson ◽  
Hubert Senanu Ahor ◽  
Abigail Agbanyo ◽  
Solomon Gyabaah ◽  
...  
Keyword(s):  
Simultaneous Detection ◽  
Treponema Pallidum ◽  
Recombinase Polymerase Amplification ◽  
Nucleic Acid Amplification ◽  
Haemophilus Ducreyi ◽  
World Health ◽  
Clinical Samples ◽  
Successful Implementation ◽  
Effective Diagnosis

Yaws is a skin debilitating disease caused by Treponema pallidum subspecies pertenue with most cases reported in children. World Health Organization (WHO) aims at total eradication of this disease through mass treatment of suspected cases followed by an intensive follow-up program. However, effective diagnosis is pivotal in the successful implementation of this control program. Recombinase polymerase amplification (RPA), an isothermal nucleic acid amplification technique offers a wider range of differentiation of pathogens including those isolated from chronic skin ulcers with similar characteristics such as Haemophilus ducreyi (H. ducreyi). We have developed a duplex RPA assay for the simultaneous detection of Treponema pallidum (T. pallidum) and H. ducreyi (TPHD-RPA). TPHD-RPA assay demonstrated no cross-reaction with other pathogens and enable detection of T. pallidum and H. ducreyi within 15 minutes at 42 oC. The duplex RPA assay was validated with 49 clinical samples from individuals confirmed to have yaws by serological tests. Compared with commercial multiplex real-time PCR, the TPHD-RPA assay demonstrated 94-95% sensitivity for T. pallidum and H. ducreyi confirmed samples, respectively and 100% specificity. This simple novel TPHD-RPA assay enables the rapid detection of both T. pallidum and H. ducreyi in yaws-like lesions. This test could support the yaws eradication programs by ensuring effective diagnosis as well as enable monitoring of eradication efforts success or failure and planning of follow-up interventions at the community level.

scholarly journals Multiplex Recombinase Polymerase Amplification Assay for Simultaneous Detection of Treponema pallidum and Haemophilus ducreyi in Yaws-Like Lesions

2020 ◽  
Vol 5 (4) ◽  
pp. 157
Author(s):  
Michael Frimpong ◽  
Shirley Victoria Simpson ◽  
Hubert Senanu Ahor ◽  
Abigail Agbanyo ◽  
Solomon Gyabaah ◽  
...  
Keyword(s):  
Simultaneous Detection ◽  
Treponema Pallidum ◽  
Recombinase Polymerase Amplification ◽  
Nucleic Acid Amplification ◽  
Haemophilus Ducreyi ◽  
World Health ◽  
Clinical Samples ◽  
Successful Implementation ◽  
Serological Tests

Yaws is a skin debilitating disease caused by Treponema pallidum subspecies pertenue with most cases reported in children. World Health Organization (WHO) aims at total eradication of this disease through mass treatment of suspected cases followed by an intensive follow-up program. However, effective diagnosis is pivotal in the successful implementation of this control program. Recombinase polymerase amplification (RPA), an isothermal nucleic acid amplification technique offers a wider range of differentiation of pathogens including those isolated from chronic skin ulcers with similar characteristics such as Haemophilus ducreyi (H. ducreyi). We have developed a RPA assay for the simultaneous detection of Treponema pallidum (T. pallidum) and H. ducreyi (TPHD-RPA). The assay demonstrated no cross-reaction with other pathogens and enable detection of T. pallidum and H. ducreyi within 15 min at 42 °C. The RPA assay was validated with 49 clinical samples from individuals confirmed to have yaws by serological tests. Comparing the developed assay with commercial multiplex real-time PCR, the assay demonstrated 94% and 95% sensitivity for T. pallidum and H. ducreyi, respectively and 100% specificity. This simple novel TPHD-RPA assay enables the rapid detection of both T. pallidum and H. ducreyi in yaws-like lesions. This test could support the yaws eradication efforts by ensuring reliable diagnosis, to enable monitoring of program success and planning of follow-up interventions at the community level.

scholarly journals Duplex On-Site Detection of Vibrio cholerae and Vibrio vulnificus by Recombinase Polymerase Amplification and Three-Segment Lateral Flow Strips

Biosensors ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 151
Author(s):  
Pei Wang ◽  
Lei Liao ◽  
Chao Ma ◽  
Xue Zhang ◽  
Junwei Yu ◽  
...  
Keyword(s):  
Food Safety ◽  
Vibrio Cholerae ◽  
Bacterial Infections ◽  
Vibrio Vulnificus ◽  
Simultaneous Detection ◽  
Lateral Flow ◽  
Recombinase Polymerase Amplification ◽  
Detection Methods ◽  
Global Ocean ◽  
Clinical Samples

Vibrio cholerae and Vibrio vulnificus are two most reported foodborne Vibrio pathogens related to seafood. Due to global ocean warming and an increase in seafood consumption worldwide, foodborne illnesses related to infection of these two bacteria are growing, leading to food safety issues and economic consequences. Molecular detection methods targeting species-specific genes are effective tools in the fight against bacterial infections for food safety. In this study, a duplex detection biosensor based on isothermal recombinase polymerase amplification (RPA) and a three-segment lateral flow strip (LFS) has been established. The biosensor used lolB gene of Vibrio cholerae and empV gene of Vibrio vulnificus as the detection markers based on previous reports. A duplex RPA reaction for both targets were constructed, and two chemical labels, FITC and DIG, of the amplification products were carefully tested for effective and accurate visualization on the strip. The biosensor demonstrated good specificity and achieved a sensitivity of 101 copies per reaction or one colony forming unit (CFU)/10 g of spiked food for both bacteria. Validation with clinical samples showed results consistent with that of real-time polymerase chain reaction. The detection process was simple and fast with a 30-min reaction at 37 °C and visualization on the strip within 5 min. With little dependence on laboratory settings, this biosensor was suitable for on-site detection, and the duplex system enabled simultaneous detection of the two important foodborne bacteria. Moreover, the principle can be extended to healthcare and food safety applications for other pathogens.

scholarly journals Identification of bacteria strains using the Recombinase Polymerase Amplification assay on a miniaturized solid-state pH sensor

2022 ◽  
Author(s):  
Anh H. Nguyen ◽  
Samir Malhotra ◽  
Michael P.H. Lau ◽  
Hung Cao
Keyword(s):  
Solid State ◽  
Nucleic Acid ◽  
Ph Sensor ◽  
Recombinase Polymerase Amplification ◽  
Nucleic Acid Amplification ◽  
Optical Systems ◽  
Molecular Diagnostic ◽  
Clinical Samples ◽  
E Coli ◽  
Identification Of Bacteria

Rapid identification of bacteria based on nucleic acid amplification allows dealing with the detection of pathogens in clinical, food, and environmental samples. Amplification products must be detected and analyzed by external devices or integrated complicated optical systems. Here, we developed a solid-state pH electrode based on iridium oxide (IrO2) films to measure released hydrogen ions (H+) from isothermal nucleic acid (NA) amplification of bacterial samples. By recombinase polymerase amplification (RPA), we achieved rapid (< 15 min) and sensitive (<30 copies) detection with an accuracy of about 0.03 pH. The RPA-based hydrogen ion sensing assay shows higher specificity, sensitivity, and efficiency as the same polymerase chain reaction (PCR) methods. We initially used the RPA-based sensor to detect E. coli species in laboratory samples. Among, 27 random laboratory samples of E. coli samples, 6 were found to be DH5alpha, 9 BL21, 3 HB101, 6 TOP10, and 3 JM109. The electrical detection of amplification provides generally applicable techniques for the detection of nucleic acid amplification, enabling molecular diagnostic tests in the field and integrating data transmission to the mobile device. These results can be future developed into an efficient tool for rapid on-site detection of bacterial pathogens in clinical samples.

scholarly journals Mapping of yaws endemicity in Ghana; Lessons to strengthen the planning and implementation of yaws eradication

2020 ◽  
Author(s):  
Laud Anthony Wihibeturo Basing ◽  
Moses Djan ◽  
Shirley Victoria Simpson ◽  
Yaw Adu-Sarkodie
Keyword(s):  
Treatment Plan ◽  
Demographic Data ◽  
Treponema Pallidum ◽  
World Health Organisation ◽  
Haemophilus Ducreyi ◽  
Community Treatment ◽  
World Health ◽  
Significant Difference ◽  
Ulcerative Lesions ◽  
Study Sites

AbstractIntroductionYaws caused by Treponema pallidum subsp pertenue is a disease of poverty and affects communities where basic socio-economic amenities are lacking. With results showing that single dose azithromycin is effective in the treatment of yaws, the World Health Organisation introduced the Morges strategy with the intent to eradicate yaws by 2020. Ghana is one of the countries with the most yaws cases globally, and the National Yaws Eradication Program in Ghana intends to conduct Mass Drug Administration (MDA) of endemic communities in line with the Total Community Treatment plan of the Morges strategy. It is therefore important to map out endemic communities to ensure that MDA is both effective and financially efficient.MethodsChildren with suspected yaws lesions were actively selected from the recruitment sites (schools and communities). A full medical history, study site information including GPS coordinates, demographic data including communities of residence and clinical assessment were taken. Each of the clinically diagnosed children were screened using the DPP® Syphilis Screen & Confirm Assay (DPP). Samples for PCR were collected by swabbing ulcerative lesions of participants and tested for Treponema pallidum subsp pertenue and Haemophilus ducreyi DNAResultsIn all, 625 children with a median age of 10 years were recruited into the study. While 401(64.2%) were DPP positive, only 141 of them had Treponema pallidum subsp pertenue DNA (TPE_DNA) accounting for 22.6% of those who were clinically diagnosed. Based on the DPP results, yaws was endemic in all the 4 study sites with participants from 88 communities in 13 districts in 4 regions in Ghana. There was no statistically significant difference between the various districts in terms of DPP results (x2=0.9364, p= 0.817) and 154 (24.6%) of those clinically diagnosed as yaws were positive for Haemophilus ducreyi i DNA.ConclusionOur study shows that communities endemic for yaws are also endemic for Haemophilus ducreyi i. Most yaws endemic communities were found at the border of other districts and regions. It is recommended that MDA should not only target endemic communities, it should target entire endemic districts as well as neighbouring districts in order to be effective.

Cathartic Effect of Suicide Attempts Not Limited to Depression

Crisis ◽  
2003 ◽  
Vol 24 (2) ◽  
pp. 73-78 ◽  
Author(s):  
Yves Sarfati ◽  
Blandine Bouchaud ◽  
Marie-Christine Hardy-Baylé
Keyword(s):  
Quality Of Life ◽  
Depressive Symptoms ◽  
Personality Traits ◽  
Rating Scales ◽  
Suicide Attempts ◽  
World Health ◽  
Life Questionnaire ◽  
Short Term

Summary: The cathartic effect of suicide is traditionally defined as the existence of a rapid, significant, and spontaneous decrease in the depressive symptoms of suicide attempters after the act. This study was designed to investigate short-term variations, following a suicide attempt by self-poisoning, of a number of other variables identified as suicidal risk factors: hopelessness, impulsivity, personality traits, and quality of life. Patients hospitalized less than 24 hours after a deliberate (moderate) overdose were presented with the Montgomery-Asberg Depression and Impulsivity Rating Scales, Hopelessness scale, MMPI and World Health Organization's Quality of Life questionnaire (abbreviated versions). They were also asked to complete the same scales and questionnaires 8 days after discharge. The study involved 39 patients, the average interval between initial and follow-up assessment being 13.5 days. All the scores improved significantly, with the exception of quality of life and three out of the eight personality traits. This finding emphasizes the fact that improvement is not limited to depressive symptoms and enables us to identify the relative importance of each studied variable as a risk factor for attempted suicide. The limitations of the study are discussed as well as in particular the nongeneralizability of the sample and setting.

European Recommendations for the Management of Healthcare Workers Occupationally Exposed to Hepatitis

2018 ◽  
Vol 2 (1) ◽  
pp. 49
Author(s):  
Enis Uruci
Keyword(s):  
Occupational Exposure ◽  
Hepatitis B ◽  
Healthcare Workers ◽  
Antiviral Treatment ◽  
World Health ◽  
Antibody Concentration ◽  
Post Exposure Prophylaxis ◽  
Transferase Activity ◽  
Mediterranean Countries

Exposure prevention is the primary strategy to reduce the risk of occupational bloodborne pathogen infections in healthcare workers (HCW). HCWs should be made aware of the medicolegal and clinical relevance of reporting an exposure, and have ready access to expert consultants to receive appropriate counselling, treatment and follow-up. Vaccination against hepatitis B virus (HBV), and demonstration of immunisation before employment are strongly recommended. HCWs with postvaccinal anti-HBs levels, 1-2 months after vaccine completion, .or=10 mIU/mL are considered as responders. Responders are protected against HBV infection: booster doses of vaccine or periodic antibody concentration testing are not recommended. Alternative strategies to overcome non-response should be adopted. Isolated anti-HBc positive HCWs should be tested for anti-HBcIgM and HBV-DNA: if negative, anti-HBs response to vaccination can distinguish between infection (anti-HBs .or=50 mIU/ml 30 days after 1st vaccination: anamnestic response) and false positive results(anti-HBs .or=10 mUI/ml 30 days after 3rd vaccination: primary response); true positive subjects have resistance to re-infection. and do not need vaccination The management of an occupational exposure to HBV differs according to the susceptibility of the exposed HCW and the serostatus of the source. When indicated, post-exposure prophylaxis with HBV vaccine, hepatitis B immunoglobulin or both must be started as soon as possible (within 1-7 days). In the absence of prophylaxis against hepatitis C virus (HCV) infection, follow-up management of HCV exposures depends on whether antiviral treatment during the acute phase is chosen. Test the HCW for HCV-Ab at baseline and after 6 months; up to 12 for HIV-HCV co-infected sources. If treatment is recommended, perform ALT (amino alanine transferase) activity at baseline and monthly for 4 months after exposure, and qualitative HCV-RNA when an increase is detected. Introduction Bloodborne pathogens such as hepatitis B (HBV) and C virus (HCV) represent an important hazard for healthcare workers (HCWs) (1). In the general population, HCV prevalence varies geographically from about 0.5% in northern countries to 2% in Mediterranean countries, with some 5 million chronic carriers estimated in Europe; while HBV prevalence ranges from 0.3% to 3%. The World Health Organization (WHO) estimates that each year in Europe 304 000 HCWs are exposed to at least one percutaneous injury with a sharp object contaminated with HBV, 149 000 are exposed to HCV and 22 000 to HIV. The probability of acquiring a bloodborne infection following an occupational exposure has been estimated to be on average.

scholarly journals Circulation and Molecular Epidemiology of Enteroviruses in Paralyzed, Immunodeficient and Healthy Individuals in Tunisia, a Country with a Polio-Free Status for Decades

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 380
Author(s):  
Anissa Chouikha ◽  
Dorra Rezig ◽  
Nadia Driss ◽  
Ichrak Abdelkhalek ◽  
Ahlem Ben Yahia ◽  
...  
Keyword(s):  
Detection Rate ◽  
Warning System ◽  
World Health ◽  
Clinical Samples ◽  
Nucleotide Sequencing ◽  
Comprehensive Picture ◽  
Set Up ◽  
Health Organization ◽  
Type 3

This report is an overview of enterovirus (EV) detection in Tunisian polio-suspected paralytic cases (acute flaccid paralysis (AFP) cases), healthy contacts and patients with primary immunodeficiencies (PID) during an 11-year period. A total of 2735 clinical samples were analyzed for EV isolation and type identification, according to the recommended protocols of the World Health Organization. Three poliovirus (PV) serotypes and 28 different nonpolio enteroviruses (NPEVs) were detected. The NPEV detection rate was 4.3%, 2.8% and 12.4% in AFP cases, healthy contacts and PID patients, respectively. The predominant species was EV-B, and the circulation of viruses from species EV-A was noted since 2011. All PVs detected were of Sabin origin. The PV detection rate was higher in PID patients compared to AFP cases and contacts (6.8%, 1.5% and 1.3% respectively). PV2 was not detected since 2015. Using nucleotide sequencing of the entire VP1 region, 61 strains were characterized as Sabin-like. Among them, six strains of types 1 and 3 PV were identified as pre-vaccine-derived polioviruses (VDPVs). Five type 2 PV, four strains belonging to type 1 PV and two strains belonging to type 3 PV, were classified as iVDPVs. The data presented provide a comprehensive picture of EVs circulating in Tunisia over an 11-year period, reveal changes in their epidemiology as compared to previous studies and highlight the need to set up a warning system to avoid unnoticed PVs.

scholarly journals High-grade astrocytoma with piloid features (HGAP): the Charité experience with a new central nervous system tumor entity

2021 ◽  
Author(s):  
Katja Bender ◽  
Eilís Perez ◽  
Mihaela Chirica ◽  
Julia Onken ◽  
Johannes Kahn ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Central Nervous System ◽  
Nervous System ◽  
World Health ◽  
Central Nervous System Tumor ◽  
High Grade ◽  
Thoracic Spinal Cord ◽  
High Grade Astrocytoma ◽  
Tumor Entity

Abstract Purpose High-grade astrocytoma with piloid features (HGAP) is a recently described brain tumor entity defined by a specific DNA methylation profile. HGAP has been proposed to be integrated in the upcoming World Health Organization classification of central nervous system tumors expected in 2021. In this series, we present the first single-center experience with this new entity. Methods During 2017 and 2020, six HGAP were identified. Clinical course, surgical procedure, histopathology, genome-wide DNA methylation analysis, imaging, and adjuvant therapy were collected. Results Tumors were localized in the brain stem (n = 1), cerebellar peduncle (n = 1), diencephalon (n = 1), mesencephalon (n = 1), cerebrum (n = 1) and the thoracic spinal cord (n = 2). The lesions typically presented as T1w hypo- to isointense and T2w hyperintense with inhomogeneous contrast enhancement on MRI. All patients underwent initial surgical intervention. Three patients received adjuvant radiochemotherapy, and one patient adjuvant radiotherapy alone. Four patients died of disease, with an overall survival of 1.8, 9.1, 14.8 and 18.1 months. One patient was alive at the time of last follow-up, 14.6 months after surgery, and one patient was lost to follow-up. Apart from one tumor, the lesions did not present with high grade histology, however patients showed poor clinical outcomes. Conclusions Here, we provide detailed clinical, neuroradiological, histological, and molecular pathological information which might aid in clinical decision making until larger case series are published. With the exception of one case, the tumors did not present with high-grade histology but patients still showed short intervals between diagnosis and tumor progression or death even after extensive multimodal therapy.

scholarly journals Programme for Harmonization to the International Scale in Latin America for BCR-ABL1 quantification in CML patients: findings and recommendations

2020 ◽  
Vol 58 (12) ◽  
pp. 2025-2035
Author(s):  
María Sol Ruiz ◽  
María Belén Sánchez ◽  
Yuly Masiel Vera Contreras ◽  
Evangelina Agrielo ◽  
Marta Alonso ◽  
...  
Keyword(s):  
Latin America ◽  
Myeloid Leukemia ◽  
World Health ◽  
Molecular Response ◽  
Limit Of Quantification ◽  
International Scale ◽  
Deep Molecular Response ◽  
Health Organization ◽  
First Time

AbstractObjectivesThe quantitation of BCR-ABL1 mRNA is mandatory for chronic myeloid leukemia (CML) patients, and RT-qPCR is the most extensively used method in testing laboratories worldwide. Nevertheless, substantial variation in RT-qPCR results makes inter-laboratory comparability hard. To facilitate inter-laboratory comparative assessment, an international scale (IS) for BCR-ABL1 was proposed.MethodsThe laboratory-specific conversion factor (CF) to the IS can be derived from the World Health Organization (WHO) genetic reference panel; however, this material is limited to the manufacturers to produce and calibrate secondary reference reagents. Therefore, we developed secondary reference calibrators, as lyophilized cellular material, aligned to the IS. Our purpose was both to re-evaluate the CF in 18 previously harmonized laboratories and to propagate the IS to new laboratories.ResultsOur field trial including 30 laboratories across Latin America showed that, after correction of raw BCR-ABL1/ABL1 ratios using CF, the relative mean bias was significantly reduced. We also performed a follow-up of participating laboratories by annually revalidating the process; our results support the need for continuous revalidation of CFs. All participating laboratories also received a calibrator to determine the limit of quantification (LOQ); 90% of them could reproducibly detect BCR-ABL1, indicating that these laboratories can report a consistent deep molecular response. In addition, aiming to investigate the variability of BCR-ABL1 measurements across different RNA inputs, we calculated PCR efficiency for each individual assay by using different amounts of RNA.ConclusionsIn conclusion, for the first time in Latin America, we have successfully organized a harmonization platform for BCR-ABL1 measurement that could be of immediate clinical benefit for monitoring the molecular response of patients in low-resource regions.

scholarly journals A health worker knowledge, attitudes and practices survey of SARS-CoV-2 infection prevention and control in South Africa

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Saiendhra Vasudevan Moodley ◽  
Muzimkhulu Zungu ◽  
Molebogeng Malotle ◽  
Kuku Voyi ◽  
Nico Claassen ◽  
...  
Keyword(s):  
South Africa ◽  
Health Worker ◽  
Prevention And Control ◽  
Infection Prevention ◽  
Health Workers ◽  
Health Facilities ◽  
World Health ◽  
Infection Prevention And Control ◽  
Successful Implementation ◽  
And Control

Abstract Background Health workers are crucial to the successful implementation of infection prevention and control strategies to limit the transmission of SARS-CoV-2 at healthcare facilities. The aim of our study was to determine SARS-CoV-2 infection prevention and control knowledge and attitudes of frontline health workers in four provinces of South Africa as well as explore some elements of health worker and health facility infection prevention and control practices. Methods A cross-sectional study design was utilised. The study population comprised both clinical and non-clinical staff working in casualty departments, outpatient departments, and entrance points of health facilities. A structured self-administered questionnaire was developed using the World Health Organization guidance as the basis for the knowledge questions. COVID-19 protocols were observed during data collection. Results A total of 286 health workers from 47 health facilities at different levels of care participated in the survey. The mean score on the 10 knowledge items was 6.3 (SD = 1.6). Approximately two-thirds of participants (67.4%) answered six or more questions correctly while less than a quarter of all participants (24.1%) managed to score eight or more. A knowledge score of 8 or more was significantly associated with occupational category (being either a medical doctor or nurse), age (< 40 years) and level of hospital (tertiary level). Only half of participants (50.7%) felt adequately prepared to deal with patients with COVD-19 at the time of the survey. The health workers displaying attitudes that would put themselves or others at risk were in the minority. Only 55.6% of participants had received infection prevention and control training. Some participants indicated they did not have access to medical masks (11.8%) and gloves (9.9%) in their departments. Conclusions The attitudes of participants reflected a willingness to engage in appropriate SARS-CoV-2 infection prevention and control practices as well as a commitment to be involved in COVID-19 patient care. Ensuring adequate infection prevention and control training for all staff and universal access to appropriate PPE were identified as key areas that needed to be addressed. Interim and final reports which identified key shortcomings that needed to be addressed were provided to the relevant provincial departments of health.

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