Diet therapy and metabolic control among Chilean adults with a neonatal diagnosis of Phenylketonuria

Abstract Phenylketonuria (PKU) is an autosomal recessive defect affecting the metabolic pathway of phenylalanine (Phe), causing hyperphenylalaninemia and neurotoxicity. Diagnosis must occur in the neonatal period and treatment should begin as early as possible. Evidence implies that treatment adherence declines as age advances. The aim was to describe the diet of a subgroup of Chilean adults with PKU currently in follow-up. Fifty-three subjects (49% women) followed up between January 2021 to April 2023 were considered. The concentration of Phe (PheC) in dried blood spots measured by fluorometry and 24-hour dietary recalls were analyzed. The median PheC of the sample was 438µmol/L (interquartile range(IQR):351-585µmol/L). A protein intake of 1.35±0.3 gr/Kg/d was observed of which 87% came from the protein substitute without Phe. Participants had a median Phe intake of 459mg/d (IQR:327-976) and 13.1g/d of fiber intake. Most participants, 51% and 92% reported consuming fruits and vegetables, respectively, and 32% consumed Low-Protein foods. Regarding micronutrients, all participants exceeded 90% adequacy according to recommendations. For vitamin-D and vitamin-B12, 100% is provided by the protein substitute. According to our results, it is mandatory to establish transition programs toward adulthood, to constantly maintain good metabolic control, and to adapt diet therapy to their new lifestyle.

Abordaje endoscópico extendido del seno frontal: Experiencia en Hospital Clínico Universidad de Chile / Extended endoscopic approach of the frontal sinus: Experience at Hospital Clínico Universidad de Chile

Introducción: El seno frontal es una estructura compleja y desafiante en términos quirúrgicos, siendo descritas numerosas técnicas para su abordaje. Dentro de ellas se destaca el abordaje endoscópico extendido de seno frontal: Draf IIB y Draf III, como una importante alternativa para resolución de patología refractaria de seno frontal. Objetivo: Describir las características de pacientes sometidos a abordaje endoscópico extendido de seno frontal en Hospital Clínico Universidad de Chile (HCUCH). Material y Método: Estudio retrospectivo, descriptivo. Se incluyeron a pacientes sometidos a abordaje endoscópico extendido de seno frontal entre los años 2013 y 2021. Se analizaron variables clínicas, intraoperatorias y de seguimiento. Resultados: Se registraron 118 pacientes, de los cuales 64 cumplieron criterios de inclusión al estudio, con una edad promedio de 48 años. La patología más frecuente fue la rinosinusitis crónica poliposa (42%) seguido del mucocele (20%). Del total de pacientes, el 68% fue sometido a cirugía Draf IIB y el resto a Draf III. Todos los pacientes fueron estudiados con endoscopía e imágenes, y seguidos con parámetros clínicos y endoscópicos. El porcentaje de estenosis postoperatoria se estimó en 10%. Conclusión: El abordaje endoscópico nasal extendido figura como una alternativa útil para manejo de patología de seno frontal refractario a tratamiento. En nuestra experiencia las indicaciones, tipos de cirugía y tasa de complicaciones son concordantes con la literatura internacional.

Introduction: The frontal sinus is a complex and challenging structure in surgical terms, numerous techniques have been described for its approach, among them the extended endoscopic approach: Draf IIB and Draf III, figures as an important alternative for the resolution of refractory pathology of frontal sinus. Aim: To describe the characteristics of patients who underwent an extended endoscopic approach to the frontal sinus at the Hospital Clínico Universidad de Chile (HCUCH). Material and Method: A retrospective, descriptive study included patients who underwent an extended endoscopic approach to the frontal sinus between 2013 and 2021. Clinical, intraoperative, and follow-up variables were analyzed. Results: 118 patients were registered, of which 64 met the inclusion criteria for the study, with an average age of 48 years. The most frequent pathology was chronic polypous rhinosinusitis (42%), followed by mucocele (20%). Of the patients, 68% underwent Draf IIB surgery, while the rest received a Draf III type procedure. All patients were studied with endoscopy and images and followed up with clinical and endoscopic parameters. The percentage of post operatory stenosis was 10%. Conclusion: The extended nasal endoscopic approach appears as a valuable alternative for managing frontal sinus pathology refractory to treatment. In our experience, the indications, types of surgery, and rate of complications are consistent with the international literature.

Interferon-alpha-2a as a salvage treatment for hemorrhagic enteritis associated with Epstein-Barr Virus reactivation: a case report.

Epstein-Barr virus [EBV] is a virus that infects almost all humans worldwide. After the acute phase of the infection, it stays in a latent form in B lymphocytes. EBV reactivation tends to occur in immunosuppressed patients. EBV reactivation may involve the gastrointestinal tract ; it has been associated mainly with colitis, but hemorrhagic enteritis has been poorly reported. Treatment usually includes antivirals. However, our patient did not respond to conventional treatment, so interferon alpha-2a was given as a salvage treatment. To our knowledge, this is the first reported case of hemorrhagic enteritis associated to EBV reactivation treated successfully with interferon alpha-2a.

25 Hydroxy Vitamin D Level, Bone Health, Vitamin D and Calcium Intake in Chilean Patients with Phenylketonuria and Hyperphenylalaninemias

Abstract It has been shown that there is a decrease in the concentrations of 25 hydroxyvitamin D (25-OHD) and bone mineral density (BMD) in patients with phenylketonuria (PKU) in their follow-up. Our objective was to determine concentrations of 25-OHD in subjects with PKU and hyperphenylalaninemia (HPA). Transversal analytical study considered three groups: G1-PKU with neonatal diagnosis and formula intake without Phe; G2-HPA, without specific treatment and G3-C control group. Sixteen patients per group (aged 6-23) were included. Levels of 25-OHD, lumbar spine (L2-L4), femur and total BMD, intact parathormone (PTH) and vitamin D (VitD) and calcium intake were calculated. The Kruskal-Wallis statistical test was applied (p-value<0,05). Significant differences were detected in concentrations of 25-OHD between G1-PKU and G2-HPA (38.9 ng/mL; 28 ng/mL, respectively) (NV: >30 ng/mL). G1-PKU had a higher intake of VitD, with differences among groups. There were no significant differences among groups in relation to BMD and intact PTH. In conclusion, G1-PKU under treatment and with good adherence, does not present VitD deficiency and no BMD alterations are observed. In contrast, G2-HPA had a lower intake of VitD and decreased 25-OHD concentrations which could affect the bone architecture in the long term. Further studies on the G2-HPA are suggested.

Otalgia secundaria o referida, lo que el clínico debe saber

Resumen La otalgia es un motivo de consulta frecuente en otorrinolaringología que se puede clasificar en dos tipos: primaria y secundaria. La otalgia primaria es una consecuencia de una enfermedad otológica mientras que la secundaria o referida, surge de procesos patológicos que se originan en estructuras distintas del oído, pero que comparten vías neuronales comunes. Estas vías la componen los nervios craneales V, VII, IX y X y los nervios cervicales C2 y C3. Las causas más comunes de otalgia secundaria son la patología musculoesquelética como la disfunción de la articulación temporomandibular y el síndrome miofascial, la patología dental y las infecciones orofaríngeas. Para encontrar la etiología de la otalgia secundaria, en la mayoría de los casos, una historia clínica y examen físico acucioso resultarán suficientes, sin embargo, existe un grupo de pacientes con factores de riesgo que pudiesen requerir estudios adicionales. El objetivo de esta revisión es otorgar herramientas al lector para comprender los distintos procesos involucrados en la otalgia secundaria, conocer las patologías más relevantes relacionadas y de esta forma entregar al clínico una pauta para enfrentar este motivo de consulta.

Abstract Otalgia is a common reason for consultation in otolaryngology and can be classified into two types: primary or secondary otalgia. Primary otalgia is a consequence of an otological disease while secondary otalgia arises from pathological processes that originate in other structures different than the ears, but share common neuronal pathways. These pathways involve cranial nerves V, VII, IX and X and cervical nerves C2 and C3. The most common causes of secondary otalgia are musculoskeletal pathology such as temporomandibular joint dysfunction and myofascial syndrome, dental pathology and oropharyngeal infections. To find the etiology of secondary otalgia, in most cases a medical history and physical examination will be sufficient, however there is a group of patients with risk factors that may require additional studies. The objective of this review is to give the reader tools to understand the different processes involved in secondary otalgia, know the most relevant related pathologies and thus give the clinician a guide to deal with this problem.

Metástasis cervical con primario desconocido, cambios en los paradigmas: revisión sobre el enfrentamiento clínico, estudio y tratamiento / Cervical metastases from unknown primary tumor, paradigm changes: review on clinical confrontation, study and treatment

Resumen En adultos, una masa cervical detectada mediante examen físico o un estudio de imagen puede ser la única manifestación de un cáncer proveniente de cabeza y cuello. Un retraso en el diagnóstico repercute en el pronóstico de la enfermedad, por lo que debe haber un alto índice de sospecha. Las metástasis cervicales con primario desconocido (MCCPD) son tumores metastásicos en los que el estudio diagnóstico no logró identificar el sitio primario del cáncer, con una histología predominantemente de tipo escamosa. Según algunos estudios, el origen más frecuente resultó ser la orofaringe, incluyendo amígdala palatina y base de lengua. Factores de riesgo conocidos son edades avanzadas, consumo de tabaco y de alcohol. Actualmente, la infección por el virus del papiloma humano (VPH) está teniendo un rol cada vez más importante como factor de riesgo, formando parte de entre 20%-25% de los cánceres de cabeza y cuello. Al enfrentarse a un paciente con masa cervical es importante realizar una completa anamnesis y examen físico acucioso para detectar cualquier elemento sugerente de malignidad. Se debe complementar con nasofibroscopía para visualizar estructuras que no alcanzan a evaluarse en el examen habitual. También se puede orientar la búsqueda del primario desconocido en base a los patrones de drenaje linfático. Dentro del estudio complementario se puede comenzar con una tomografía computada (TC) y se puede considerar también el ultrasonido o un PET/TC. Si con esto aún no se logra definir el primario, continuar con una punción aspirativa con aguja fina (PAAF), luego biopsia core que consiste en tomar una muestra del centro de la lesión guiada por ecografía, si fuese necesario, incluyendo inmunohistoquímica para VPH; ambos estudios histológicos son preferibles en vez de una biopsia abierta debido al menor riesgo de diseminación y complicaciones. El siguiente paso incluye estudio endoscópico y biopsias bajo anestesia. El tratamiento de los pacientes con MCCPD, va a depender de factores relacionados con el estadio de la enfermedad: desde cirugía o radioterapia (RT) únicas, cirugía más RT, y en algunos casos quimioterapia. Se recomienda seguimiento clínico frecuente durante los primeros años y con imágenes dentro de los 6 primeros meses postratamiento.

Abstract In adults, a cervical mass detected by physical examination or an imaging study may be the only manifestation of cancer from the head and neck. A delay in the diagnosis affects the prognosis of the disease, so there must be a high index of suspicion. Cervical metastases from unknown primary tumor (CUP) are metastatic tumors in which the diagnostic study failed to identify the primary site of cancer, with predominantly squamous histology. According to some studies, the most frequent origin was the oropharynx, including palatine tonsil and tongue base. Known risk factors are advanced ages, tobacco and alcohol consumption. Currently, human papilloma virus (HPV) infection is playing an increasingly important role as a risk factor, being the cause of between 20-25% of cancers of the head and neck. When confronting a patient with cervical mass it is important to carry out a complete anamnesis and a thorough physical examination to detect any element suggestive of malignancy. Physical examination could be complemented with a flexible nasal endoscopic to evaluate structures that can not be evaluated in the habitual examination. The search for the unknown primary can also be oriented based on lymphatic drainage patterns. Within the complementary evaluations, one can start with a study of images such as computed tomography (CT) or magnetic resonance imaging (MRI) with contrast, and also could consider ultrasound or PET/CT. If the primary can not be defined yet, fine needle aspiration (FNAP) can be the next choice and then a core biopsy that consisting of taking a sample from the center of the ultrasound-guided lesion, if necessary, including immunohistochemistry for HPV; both histological studies are preferable to an open biopsy because of the lower risk of complications. The next step searching for the primary includes endoscopic study and biopsies under anesthesia. Regarding to the management of patients with CUP, it will depend on factors related to the stage of the disease: from surgery or radiotherapy (RT) only, surgery and RT, and in some cases chemotherapy. Frequent clinical follow-up is recommended during the first years and images within the first 6 months after treatment.

Fístulas coronario-pulmonares asintomáticas. Reporte caso / Asymptomatic coronary-pulmonary fistulas. Case report / Fístulas coronário-pulmonares assintomáticaso. Relato de caso

Resumen: La fístula coronaria es una anomalía caracterizada por una comunicación anormal entre una arteria coronaria y una cámara cardíaca o un gran vaso. El 50% de las fístulas se originan de la arteria coronaria derecha, 45% de la arteria coronaria izquierda y menos del 5% en ambas. Se presenta una paciente femenina de 81 años de edad con historia de ataque cerebrovascular isquémico de forma previa, quien ingresa con nuevo evento isquémico cerebral. En estudios complementarios se documentó una fracción de eyección del ventrículo izquierdo reducida por lo que se realizó arteriografía con hallazgo de arterias coronarias epicárdicas sin enfermedad obstructiva significativa, pero con fístula coronario-pulmonar en segmento medio de arteria descendente anterior y una fístula coronario-pulmonar en segmento proximal de la arteria coronaria derecha. Las fístulas coronarias son una entidad rara, con síntomas inespecíficos. La mayoría de las veces se diagnostica de forma incidental al realizar una arteriografía coronaria por otro motivo. El manejo varía de acuerdo a las manifestaciones y anatomía encontrada junto con la experiencia del equipo de cardiología.

Abstract: Coronary fistula is an abnormality characterized by abnormal communication between a coronary artery and a cardiac chamber or large vessel. Half of fistulas originate from the right coronary artery, 45% from the left coronary artery, and less than 5% originate from both. We present an 81-year-old female patient with a history of previous ischemic stroke, who was admitted with a new cerebral ischemic event. In complementary studies, a reduced ejection fraction of the left ventricle was documented, then arteriography was performed showing epicardial coronary arteries without significant obstructive disease, but with coronary-pulmonary fistula in the middle segment of the anterior descending artery and a coronary-pulmonary fistula in the proximal segment of the right coronary artery. Coronary fistulas are a rare entity, with nonspecific symptoms. Most of the time this entity is diagnosed incidentally when performing a coronary arteriography for another reason. Management varies according to the manifestations and anatomy found along with the experience of the cardiology team.

Resumo: A fístula coronária é uma anormalidade caracterizada pela comunicação anormal entre uma artéria coronária e uma câmara cardíaca ou um vaso grande. Metade das fístulas são originárias da artéria coronária direita, 45% da artéria coronária esquerda e menos de 5% são originárias de ambas. Se você apresentar um paciente feminino de 81 anos de idade com história de ataque cerebrovascular isquêmico de forma prévia, que ingressou com o novo evento isquêmico cerebral. Em estudos complementares, documentou-se uma fração de ejeção reduzida do ventrículo esquerdo e, em seguida, foi realizada arteriografia mostrando artérias coronárias epicárdicas sem doença obstrutiva, mas com uma fístula coronário-pulmonar no segmento médio da artéria descendente anterior e uma fístula coronário-pulmonar no segmento proximal da artéria artéria coronária direita. As fístulas coronárias são uma entidade rara, com sintomas inespecíficos. Na maioria das vezes, essa entidade é diagnosticada incidentalmente ao realizar uma arteriografia coronariana por outro motivo. O manejo varia de acordo com as manifestações e anatomia encontradas, juntamente com a experiência da equipe de cardiologia.

Halitosis en otorrinolaringología: una revisión de la literatura / Halitosis in otolaryngology: a review of the literature

RESUMEN La halitosis es un motivo de consulta frecuente y que puede repercutir de gran manera en la calidad de vida de quien la presenta. Puede dividirse en halitosis genuina, pseudohalitosis y halitofobia. De las halitosis genuinas, cerca del 90% son secundarias a patología de la cavidad oral. En otorrinolaringología, las principales causas responden a tonsilolitiasis, patología rinosinusal y cuerpos extraños nasales. Existen distintos métodos diagnósticos que permiten medir e identificar la halitosis, con sus beneficios y desventajas. Las medidas generales de higiene oral, así como intervenciones específicas deben estar basadas en la evidencia a cargo de un equipo multidisciplinario que permita garantizar mejores resultados.

ABSTRACT Halitosis is a frequent health problem, that can have a huge impact in the quality of life of those affected. It can be classified as genuine halitosis, pseudohalitosis and halitophobia. Of genuine halitosis, approximately 90% is originated from the oral cavity. In otorhinolaryngology, most frequent causes are tonsiloliths, rhinosinusitis and nasal foreign bodies. There are different diagnostic methods, each one with its benefits and disadvantages. General measures of oral hygiene, as specific interventions must be evidence-based in charge of a multidisciplinary team that guarantees better results.

Interstitial sodium and lithium doping effects on the electronic and mechanical properties of silicon nanowires: a DFT study.

In this work, we present a theoretical study of the electronic band structure and the Young's modulus of hydrogen-passivated silicon nanowires (H-SiNWs), grown along the [110] crystallographic direction, as a function of the concentration of interstitial sodium (Na) and lithium (Li) atoms. The study is performed using the supercell scheme and the density functional theory (DFT), within the local density approximation (LDA). The results show that the presence of Na or Li atoms closes the former semiconducting band gap of the H-SiNWs and shifts the Fermi energy into the conduction band. The transition from semiconductor to metal occurs as soon as a single Na or Li atom is added to the nanowire and the number of occupied states near the Fermi level is larger for the H-SiNWs with Li atoms in comparison with those nanowires with the same concentration of Na atoms. The calculated formation energies reveal that the system becomes less stable when the concentration of Na and Li atoms augments. Moreover, the obtained binding energies indicate that Si-Li and Si-Na bonds are formed. It is worth mentioning that the binding energies of H-SiNWs with interstitial Li atoms are larger than those corresponding to the H-SiNWs with interstitial Na atoms. On the other hand, the Young's moduli of H-SiNWs with Na atoms are lower than those of pure H-SiNWs and their values diminish when the concentration of Na atoms increases. In contrast, Young's moduli of H-SiNWs present a non-monotonic behavior as a function of the concentration of interstitial Li atoms and for the largest studied concentration the nanowire fractures. These results give insight into the changes that electronic and mechanical properties of H-SiNWs suffer during the charge-discharge process, which should be taken into account in the design of electrodes of Na or Li-ion batteries.

Estudios de cohortes: 1a parte: descripción, metodología y aplicaciones / Cohort studies: 1st part: description, methodology and applications

Resumen Los estudio de cohortes (EC), son estudios de carácter longitudinal, observacional y analíticos. Corresponden a uno de los diseños más utilizados en investigación clínica, aportando altos niveles de evidencia, según el tipo de escenario en los que se aplique. Los EC tienen como objetivos, determinar asociación entre un factor de exposición y el desarrollo de alguna enfermedad o evento de interés, a partir de la estimación de riesgos; conocer la historia natural o el curso clínico de una enfermedad o de un evento de interés; determinar supervivencia; estudiar factores protectores y pronósticos. Los EC tienen diversas aplicaciones, por ejemplo: investigación de brotes epidemiológicos, estudios de causalidad, evaluación de intervenciones educacionales, etc. Teóricamente, la mejor aproximación es mediante un estudio de cohortes prospectivas; sin embargo, suelen exigir largos períodos de tiempo de seguimiento para obtener resultados útiles; por lo tanto, se puede recurrir a otras estrategias, como a los estudios retrospectivos y otros, que pueden resultar más factibles respecto de recursos y tiempos de seguimiento. El objetivo de este manuscrito fue generar un documento de estudio referente a descripción, metodología y aplicaciones de los EC en ciencias de la salud.

Cohort studies (CS) are longitudinal, observational and analytical studies. As one of the most utilized designs in clinical research, CS provides high levels of evidence, depending on the type of scenario in which they are applied. The objectives of CS are to determine the association between an exposure factor and the development of a disease or event of interest, based on the estimation of risks. Additionally, CS aim to provide insight into the natural history or the clinical course of an event of interest as well as generate results with regard to determine survival; study protective studies and prognostic factors. CS have various applications, for example: epidemiological outbreak research, causality studies, evaluation of educational interventions, etc. Theoretically, the method to generate the best approximations is through the use of a prospective CS; however, these usually require long periods of time performing follow-up to obtain useful results; therefore, it is possible to use other strategies, such as retrospective CS among others, which may be more feasible with respect to resources and monitoring times. The aim of this manuscript was to generate a document with reference to the description, methodology and applications of the CS in health sciences

Confinement effect on the low temperature specific heat for ultrathin silicon nanowires: a first principles study.

This work studied the phonon confinement effects at the low temperature specific heat of Si nanowires from first principles using density functional perturbation theory. The nanowires were modeled in the [0 0 1] direction for three different diameters, with the largest cross section being approximately 10 Å. The results indicate the specific heat can be described at low temperatures using a third-grade polynomial of the form c v = λT + ßT 2 + γT3, where the coefficients of quadratic and cubic terms are almost nonexistent for small diameters. These terms begin to have relevance at larger diameters. Further analysis shows λ > ß > γ, which shows the phonon confinement (λ) and surface atoms (ß) become more important than the volumetric contribution (γ) for ultrathin nanowires at low temperatures.

Fate of Mycobacterium avium subsp. paratuberculosis and changes in bacterial diversity populations in dairy slurry after chemical treatments.

AIMS: A major drawback of using dairy slurry as fertilizer is that it may contains pathogens such as Mycobacterium avium subsp. paratuberculosis (MAP), and it could represent a risk to animal and public health. Thus, the aim of this study was to evaluate the fate of MAP and bacterial communities in dairy slurry after chemical treatments. METHODS AND RESULTS: Cattle slurry, naturally contaminated with MAP, was collected from a dairy herd and divided into 32 glass bottles which were assigned to eight different treatments (control, 3·0% CaO, 0·5% NaOH; 0·087%, 0·11% and 0·14% H2 SO4 ; and 1·0 and 2·5% KMnO4 ). Treated dairy slurry samples were evaluated at 0, 1, 3, 7, 15, 30 and 60-days following treatment application for viable MAP and dairy slurry pH, and in addition temperature in this material was monitored continuously. Bacterial counts were estimated at each sampling time. A Bayesian zero-inflated Poisson mixed model was fitted to assess the effect of each treatment on the count of MAP cells. Model results indicated that only the 3·0% CaO treatment had a statistically important negative effect on MAP counts during the study period. For most treatments, MAP was undetectable immediately after chemical treatment but re-appeared over time, in some replicates at low concentrations. However, in those cases MAP counts were not statistically different than the control treatment. Regarding the fate of the other bacterial populations, the Firmicutes phylum was the dominant population in the un-treated slurry while Clostridia class members were among the most prevalent bacteria after the application of most chemical treatments. CONCLUSION: Only 3% CaO treatment had a statistically important negative effect on MAP viability in cattle slurry. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides evidence of MAP partial control in dairy slurry. This information should be considered as a best management practice to reduce MAP and other pathogens for slurry management on dairy farms.

"CLUPS": A New Culture Medium for the Axenic Growth of Entamoeba histolytica.

Amebiasis remains a major health problem in Mexico. Therefore, the search for better culture media and low-cost diagnostic and therapeutic tools is fundamental. We present a new culture medium for Entamoeba histolytica which allows the microbe to preserve its virulence factors and ability to induce hepatic abscesses in animal models. The novel CLUPS medium is an improved version of the PEHPS medium, previously designed in our laboratory. The main difference is the substitution of raw beef liver in PEHPS by raw beef lung in the CLUPS medium. To compare the performance of three-culture media (traditional TYI-S-33, PEHPS, and CLUPS), E. histolytica trophozoites were cultured in quintuplicate, followed by the evaluation of phospholipase activity and the induction of liver abscesses in golden hamsters. E. histolytica trophozoites grew significantly better in CLUPS medium than in TYI-S-33. Likewise, CLUPS-cultured trophozoites produced significantly more phospholipases than TYI-S-33-cultured trophozoites. Finally, trophozoites grown in any of the three tested media had similar potential to induce liver abscesses.

Detection of latent tuberculosis infection among migrant farmworkers along the US-Mexico border.

BACKGROUND: Migrant farmworkers are among the highest-risk populations for latent TB infection (LTBI) in the United States with numerous barriers to healthcare access and increased vulnerability to infectious diseases. LTBI is usually diagnosed on the border using the tuberculin skin test (TST). QuantiFERON-TB Gold In-Tube (QFT-GIT) also measures immune response against specific Mycobacterium tuberculosis antigens. The objective of this study is to assess the comparability of TST and QFT-GIT to detect LTBI among migrant farmworkers on the border, as well as to examine the effects of various demographic and clinical factors on test positivity. METHODS: Participants were recruited using mobile clinics on the San Luis US-Mexico border and tested with QFT-GIT and TST. Demographic profiles and clinical histories were collected. Kappa coefficients assessed agreement between TST and QFT-GIT using various assay cutoffs. Logistic regression examined factors associated with positive TST or QFT-GIT results. RESULTS: Of 109 participants, 59 of 108 (55 %) were either TST (24/71, 34 %) or QFT-GIT (52/106, 50 %) positive. Concordance between TST and QFT-GIT was fair (71 % agreement, ĸ = 0.38, 95 % CI: 0.15, 0.61). Factors associated with LTBI positivity included smoking (OR = 1.26, 95 % CI-1.01-1.58) and diabetes/high blood sugar (OR = 0.70, 95 % CI = 0.51-0.98). DISCUSSION: Test concordance between the two tests was fair, with numerous discordant results observed. Greater proportion of positives detected using QFT-GIT may help avoid LTBI under-diagnosis. Assessment of LTBI status on the border provides evidence whether QFT-GIT should replace the TST in routine practice, as well as identifies risk factors for LTBI among migrant populations.