Exhaled Breath Analysis for Non-Invasive Diagnosis of Tropical Diseases

Les malalties tropicals desateses (MTD) pertanyen al grup de malalties infeccioses. Són endèmiques en la major part del món i afecten més de mil milions de persones a tot el món, especialment a les poblacions de baixos ingressos de les regions en desenvolupament. La infecció en humans es caracteritza per un període d'incubació asimptomàtica crònica i perllongada sense símptomes notables de la malaltia, el que retarda la prescripció d'un tractament mèdic adequat i oportú. La prevenció, el diagnòstic i el control d'aquestes malalties segueixen sent un desafiament metge no resolt encara. Aquesta tesi ha tingut com a objectiu desenvolupar una metodologia no invasiva, segura i amigable per al pacient per a un diagnòstic ràpid de les MTD. L'enfocament de la meva tesi es va basar en el diagnòstic de la malaltia a través de l'anàlisi de mostres d'alè exhalat, que són fàcils d'obtenir i no presenten molèsties ni riscos per a la salut dels pacients. El treball de la meva tesi es va centrar en tres tipus diferents de malalties tropicals desateses (dengue, equinococcosi i leishmaniosi) causades per tres patògens diferents (infeccions virals, helmínticas i protozoàries, respectivament). Les mostres d'alè es van recollir amb dispositius homologats Bio-VOC, que són fàcils d'usar i requereixen d'una preparació mínima. Per analitzar les mostres d'alè, primer es van emprar tècniques analítiques estàndard per a la identificació dels biomarcadors volàtils d'aquestes malalties. Un altre dels objectius de la meva tesi va ser dissenyar i fabricar una matriu de sensors químics de gasos amb sensibilitats creuades basats en nanopartícules de metall ultrapur funcionalitzades amb diversos compostos orgànics, per la qual cosa vaig emprar una tècnica innovadora basada en deposició física en fase vapor. Els nous sensors van ser caracteritzats i es van emprar per identificar els patrons de les malalties estudiades en les mostres d'alè. Les respostes dels sensors químics de gasos exposats a les mostres d'alè es van usar per a construir models de reconeixement de patrons per al diagnòstic d'aquestes malalties. Els resultats obtinguts han revelat que l'anàlisi de l'alè exhalat amb una matriu de sensors de gasos basats en nanoensamblajes de nanopartícules de metall ultrapur té un gran potencial com a prova diagnòstica fiable per a les MTD.Las enfermedades tropicales desatendidas (ETD) pertenecen al grupo de enfermedades infecciosas. Son endémicas en la mayor parte del mundo y afectan a más de mil millones de personas en todo el mundo, especialmente a las poblaciones de bajos ingresos de las regiones en desarrollo. La infección en humanos se caracteriza por un período de incubación asintomática crónica y prolongada sin síntomas notables de la enfermedad, lo que retrasa la prescripción de un tratamiento médico adecuado y oportuno. La prevención, el diagnóstico y el control de estas enfermedades siguen siendo un desafío médico no resuelto aún. Esta tesis ha tenido como objetivo desarrollar una metodología no invasiva, segura y amigable para el paciente para un diagnóstico rápido de las ETD. El enfoque de mi tesis se basó en el diagnóstico de la enfermedad a través del análisis de muestras de aliento exhalado, que son fáciles de obtener y no presentan molestias ni riesgos para la salud de los pacientes. El trabajo de mi tesis se centró en tres tipos diferentes de enfermedades tropicales desatendidas (dengue, equinococosis y leishmaniasis) causadas por tres patógenos diferentes (infecciones virales, helmínticas y protozoarias, respectivamente). Las muestras de aliento se recogieron con dispositivos homologados Bio-VOC, que son fáciles de usar y requieren de una preparación mínima. Para analizar las muestras de aliento, primero se emplearon técnicas analíticas estándar para la identificación de los biomarcadores volátiles de estas enfermedades. Otro de los objetivos de mi tesis fue diseñar y fabricar una matriz de sensores químicos de gases con sensibilidades cruzadas basados en nanopartículas de metal ultrapuro funcionalizadas con diversos compuestos orgánicos, para lo cual empleé una técnica innovadora basada en deposición física en fase vapor. Los nuevos sensores fueron caracterizados y se emplearon para identificar los patrones de las enfermedades estudiadas en las muestras de aliento. Las respuestas de los sensores químicos de gases expuestos a las muestras de aliento se usaron para construir modelos de reconocimiento de patrones para el diagnóstico de estas enfermedades. Los resultados obtenidos han revelado que el análisis del aliento exhalado con una matriz de sensores de gases basados en nanoensamblajes de nanopartículas de metal ultrapurNeglected Tropical Diseases (NTDs) belong to the group of infectious diseases. They are endemic in most parts of the world, affecting more than one billion people worldwide, especially low income populations from developing regions. The infection to humans is characterized by a chronic and prolonged asymptomatic incubation period without noticeable symptoms of the disease, which delays the prescription of a suitable and timely medical treatment. The prevention, diagnosis and control of these diseases still remain an unsolved medical challenge. This thesis aimed to develop a non-invasive, safe and patient-friendly methodology for rapid diagnosis of NTDs. The thesis approach was based on disease diagnosis via exhaled breath samples analyses, which are easy to obtain and present no discomfort or risk for patients’ health. The thesis work was focused on three different types of neglected tropical diseases (Dengue, Echinococcosis and Leishmaniasis) caused by three different pathogens (viral, helminthic and protozoan infections, respectively). Breath collection was realized with homologated Bio-VOCTM breath samplers, which are simple and user friendly and require minimal training. For analyzing the breath samples, at first standard analytical techniques were employed for the identification of the breath volatile biomarkers of these diseases. As another objective of my thesis, an array of cross reactive chemical gas sensors based on ultrapure metal nanoparticles – ligand nanoassemblies comprising diverse functional organic ligands was designed and fabricated employing an innovative physical deposition route. The new sensors were characterized and employed for the analysis of the breath print profiles of the diseases under study. The responses of the chemical gas sensors to the breath samples were used to build predictive pattern recognition models for the diagnoses of these diseases. The results obtained revealed that exhaled breath analysis with cross reactive gas sensors arrays based on ultrapure metal nanoparticles-ligand nanoassemblies holds significant potential as a cost-effective, simple and non-invasive diagnostic test for NTDs

Exhaled Breath Analysis for Non-Invasive Diagnosis of Tropical Diseases

Les malalties tropicals desateses (MTD) pertanyen al grup de malalties infeccioses. Són endèmiques en la major part del món i afecten més de mil milions de persones a tot el món, especialment a les poblacions de baixos ingressos de les regions en desenvolupament. La infecció en humans es caracteritza per un període d'incubació asimptomàtica crònica i perllongada sense símptomes notables de la malaltia, el que retarda la prescripció d'un tractament mèdic adequat i oportú. La prevenció, el diagnòstic i el control d'aquestes malalties segueixen sent un desafiament metge no resolt encara. Aquesta tesi ha tingut com a objectiu desenvolupar una metodologia no invasiva, segura i amigable per al pacient per a un diagnòstic ràpid de les MTD. L'enfocament de la meva tesi es va basar en el diagnòstic de la malaltia a través de l'anàlisi de mostres d'alè exhalat, que són fàcils d'obtenir i no presenten molèsties ni riscos per a la salut dels pacients. El treball de la meva tesi es va centrar en tres tipus diferents de malalties tropicals desateses (dengue, equinococcosi i leishmaniosi) causades per tres patògens diferents (infeccions virals, helmínticas i protozoàries, respectivament). Les mostres d'alè es van recollir amb dispositius homologats Bio-VOC, que són fàcils d'usar i requereixen d'una preparació mínima. Per analitzar les mostres d'alè, primer es van emprar tècniques analítiques estàndard per a la identificació dels biomarcadors volàtils d'aquestes malalties. Un altre dels objectius de la meva tesi va ser dissenyar i fabricar una matriu de sensors químics de gasos amb sensibilitats creuades basats en nanopartícules de metall ultrapur funcionalitzades amb diversos compostos orgànics, per la qual cosa vaig emprar una tècnica innovadora basada en deposició física en fase vapor. Els nous sensors van ser caracteritzats i es van emprar per identificar els patrons de les malalties estudiades en les mostres d'alè. Les respostes dels sensors químics de gasos exposats a les mostres d'alè es van usar per a construir models de reconeixement de patrons per al diagnòstic d'aquestes malalties. Els resultats obtinguts han revelat que l'anàlisi de l'alè exhalat amb una matriu de sensors de gasos basats en nanoensamblajes de nanopartícules de metall ultrapur té un gran potencial com a prova diagnòstica fiable per a les MTD.Las enfermedades tropicales desatendidas (ETD) pertenecen al grupo de enfermedades infecciosas. Son endémicas en la mayor parte del mundo y afectan a más de mil millones de personas en todo el mundo, especialmente a las poblaciones de bajos ingresos de las regiones en desarrollo. La infección en humanos se caracteriza por un período de incubación asintomática crónica y prolongada sin síntomas notables de la enfermedad, lo que retrasa la prescripción de un tratamiento médico adecuado y oportuno. La prevención, el diagnóstico y el control de estas enfermedades siguen siendo un desafío médico no resuelto aún. Esta tesis ha tenido como objetivo desarrollar una metodología no invasiva, segura y amigable para el paciente para un diagnóstico rápido de las ETD. El enfoque de mi tesis se basó en el diagnóstico de la enfermedad a través del análisis de muestras de aliento exhalado, que son fáciles de obtener y no presentan molestias ni riesgos para la salud de los pacientes. El trabajo de mi tesis se centró en tres tipos diferentes de enfermedades tropicales desatendidas (dengue, equinococosis y leishmaniasis) causadas por tres patógenos diferentes (infecciones virales, helmínticas y protozoarias, respectivamente). Las muestras de aliento se recogieron con dispositivos homologados Bio-VOC, que son fáciles de usar y requieren de una preparación mínima. Para analizar las muestras de aliento, primero se emplearon técnicas analíticas estándar para la identificación de los biomarcadores volátiles de estas enfermedades. Otro de los objetivos de mi tesis fue diseñar y fabricar una matriz de sensores químicos de gases con sensibilidades cruzadas basados en nanopartículas de metal ultrapuro funcionalizadas con diversos compuestos orgánicos, para lo cual empleé una técnica innovadora basada en deposición física en fase vapor. Los nuevos sensores fueron caracterizados y se emplearon para identificar los patrones de las enfermedades estudiadas en las muestras de aliento. Las respuestas de los sensores químicos de gases expuestos a las muestras de aliento se usaron para construir modelos de reconocimiento de patrones para el diagnóstico de estas enfermedades. Los resultados obtenidos han revelado que el análisis del aliento exhalado con una matriz de sensores de gases basados en nanoensamblajes de nanopartículas de metal ultrapurNeglected Tropical Diseases (NTDs) belong to the group of infectious diseases. They are endemic in most parts of the world, affecting more than one billion people worldwide, especially low income populations from developing regions. The infection to humans is characterized by a chronic and prolonged asymptomatic incubation period without noticeable symptoms of the disease, which delays the prescription of a suitable and timely medical treatment. The prevention, diagnosis and control of these diseases still remain an unsolved medical challenge. This thesis aimed to develop a non-invasive, safe and patient-friendly methodology for rapid diagnosis of NTDs. The thesis approach was based on disease diagnosis via exhaled breath samples analyses, which are easy to obtain and present no discomfort or risk for patients’ health. The thesis work was focused on three different types of neglected tropical diseases (Dengue, Echinococcosis and Leishmaniasis) caused by three different pathogens (viral, helminthic and protozoan infections, respectively). Breath collection was realized with homologated Bio-VOCTM breath samplers, which are simple and user friendly and require minimal training. For analyzing the breath samples, at first standard analytical techniques were employed for the identification of the breath volatile biomarkers of these diseases. As another objective of my thesis, an array of cross reactive chemical gas sensors based on ultrapure metal nanoparticles – ligand nanoassemblies comprising diverse functional organic ligands was designed and fabricated employing an innovative physical deposition route. The new sensors were characterized and employed for the analysis of the breath print profiles of the diseases under study. The responses of the chemical gas sensors to the breath samples were used to build predictive pattern recognition models for the diagnoses of these diseases. The results obtained revealed that exhaled breath analysis with cross reactive gas sensors arrays based on ultrapure metal nanoparticles-ligand nanoassemblies holds significant potential as a cost-effective, simple and non-invasive diagnostic test for NTDs

Ligand-Capped Ultrapure Metal Nanoparticle Sensors for the Detection of Cutaneous Leishmaniasis Disease in Exhaled Breath

International audienceHuman cutaneous leishmaniasis, although designated as one of the most neglected tropical diseases, remains underestimated due to its misdiagnosis. The diagnosis is mainly based on the microscopic detection of amastigote forms, isolation of the parasite, or the detection of Leishmania DNA, in addition to its differential clinical characterization; these tools are not always available in routine daily practice, and they are expensive and time-consuming. Here, we present a simple-to-use, noninvasive approach for human cutaneous leishmaniasis diagnosis, which is based on the analysis of volatile organic compounds in exhaled breath with an array of specifically designed chemical gas sensors. The study was realized on a group of n = 28 volunteers diagnosed with human cutaneous leishmaniasis and a group of n = 32 healthy controls, recruited in various sites from Tunisia, an endemic country of the disease. The classification success rate of human cutaneous leishmaniasis patients achieved by our sensors test was 98.2% accuracy, 96.4% sensitivity, and 100% specificity. Remarkably, one of the sensors, based on CuNPs functionalized with 2-mercaptobenzoxazole, yielded 100% accuracy, 100% sensitivity, and 100% specificity for human cutaneous leishmaniasis discrimination. While AuNPs have been the most extensively used in metal nanoparticle-ligand sensing films for breath sensing, our results demonstrate that chemical sensors based on ligand-capped CuNPs also hold great potential for breath volatile organic compounds detection. Additionally, the chemical analysis of the breath samples with gas chromatography coupled to mass spectrometry identified nine putative breath biomarkers for human cutaneous leishmaniasis

Diagnosis of Human Echinococcosis via Exhaled Breath Analysis: A Promise for Rapid Diagnosis of Infectious Diseases Caused by Helminths.

International audienceBackground:Human echinococcosis is a neglected infectious disease affecting more than one million people globally. Its diagnosis is expensive and difficult because of lack of adequate resources in low-resource locations, where most cases occur.Methods:A group of volunteers diagnosed with the two main types of echinococcosis and corresponding control groups were recruited in hospitals from Tunisia (32 patients with cystic echinococcosis and 43 controls) and Poland (16 patients with alveolar echinococcosis and 8 controls). Breath samples were collected from all patients and analyzed by means of gas chromatography coupled to mass spectrometry and a specifically developed electronic nose system.Results:The chemical analysis revealed two statistically different compounds in the breath of patients with cystic echinococcosis as compared to controls, and seven statistically different compounds in the breath of patients with alveolar echinococcosis as compared to controls. The discrimination accuracy achieved by the electronic nose system was 100% for cystic echinococcosis and 92.9% for alveolar echinococcosis, while the discrimination accuracy between these patient groups was 92.1%.Conclusion:Here we advocate a non-invasive, fast, easy-to-operate and non-expensive diagnostic tool for the diagnosis of human echinococcosis disease through exhaled breath analysis, suitable for early diagnosis and population screening

Assessment of Electronic Sensing Techniques for the Rapid Identification of Alveolar Echinococcosis through Exhaled Breath Analysis

Here we present a proof-of-concept study showing the potential of a chemical gas sensors system to identify the patients with alveolar echinococcosis disease through exhaled breath analysis. The sensors system employed comprised an array of three commercial gas sensors and a custom gas sensor based on WO3 nanowires doped with gold nanoparticles, optimized for the measurement of common breath volatile organic compounds. The measurement setup was designed for the concomitant measurement of both sensors DC resistance and AC fluctuations during breath samples exposure. Discriminant Function Analysis classification models were built with features extracted from sensors responses, and the discrimination of alveolar echinococcosis was estimated through bootstrap validation. The commercial sensor that detects gases such as alkane derivatives and ethanol, associated with lipid peroxidation and intestinal gut flora, provided the best classification (63.4% success rate, 66.3% sensitivity and 54.6% specificity) when sensors’ responses were individually analyzed, while the model built with the AC features extracted from the responses of the cross-reactive sensors array yielded 90.2% classification success rate, 93.6% sensitivity and 79.4% specificity. This result paves the way for the development of a noninvasive, easy to use, fast and inexpensive diagnostic test for alveolar echinococcosis diagnosis at an early stage, when curative treatment can be applied to the patients

Evaluation of Volatile Organic Compounds Obtained from Breath and Feces to Detect Mycobacterium tuberculosis Complex in Wild Boar (Sus scrofa) in Donana National Park, Spain

The presence of Mycobacterium tuberculosis complex (MTBC) in wild swine, such as in wild boar (Sus scrofa) in Eurasia, is cause for serious concern. Development of accurate, efficient, and noninvasive methods to detect MTBC in wild swine would be highly beneficial to surveillance and disease management efforts in affected populations. Here, we describe the first report of identification of volatile organic compounds (VOC) obtained from the breath and feces of wild boar to distinguish between MTBC-positive and MTBC-negative boar. We analyzed breath and fecal VOC collected from 15 MTBC-positive and 18 MTBC-negative wild boar in Donana National Park in Southeast Spain. Analyses were divided into three age classes, namely, adults (>2 years), sub-adults (12-24 months), and juveniles (<12 months). We identified significant compounds by applying the two-tailed statistical t-test for two samples assuming unequal variance, with an alpha value of 0.05. One statistically significant VOC was identified in breath samples from adult wild boar and 14 were identified in breath samples from juvenile wild boar. One statistically significant VOC was identified in fecal samples collected from sub-adult wild boar and three were identified in fecal samples from juvenile wild boar. In addition, discriminant function analysis (DFA) was used to build classification models for MTBC prediction in juvenile animals. Using DFA, we were able to distinguish between MTBC-positive juvenile wild boar and MTBC-negative juvenile wild boar using breath VOC or fecal VOC. Based on our results, further research is warranted and should be performed using larger sample sizes, as well as wild boar from various geographic locations, to verify these compounds as biomarkers for MTBC infection in this species. This new approach to detect MTBC infection in free-ranging wild boar potentially comprises a reliable and efficient screening tool for surveillance in animal populations