Entanglement on an optical atomic-clock transition.

State-of-the-art atomic clocks are based on the precise detection of the energy difference between two atomic levels, which is measured in terms of the quantum phase accumulated over a given time interval1-4. The stability of optical-lattice clocks (OLCs) is limited both by the interrupted interrogation of the atomic system by the local-oscillator laser (Dick noise5) and by the standard quantum limit (SQL) that arises from the quantum noise associated with discrete measurement outcomes. Although schemes for removing the Dick noise have been recently proposed and implemented4,6-8, performance beyond the SQL by engineering quantum correlations (entanglement) between atoms9-20 has been demonstrated only in proof-of-principle experiments with microwave clocks of limited stability. The generation of entanglement on an optical-clock transition and operation of an OLC beyond the SQL represent important goals in quantum metrology, but have not yet been demonstrated experimentally16. Here we report the creation of a many-atom entangled state on an OLC transition, and use it to demonstrate a Ramsey sequence with an Allan deviation below the SQL after subtraction of the local-oscillator noise. We achieve a metrological gain of [Formula: see text] decibels over the SQL by using an ensemble consisting of a few hundred ytterbium-171 atoms, corresponding to a reduction of the averaging time by a factor of 2.8 ± 0.3. Our results are currently limited by the phase noise of the local oscillator and Dick noise, but demonstrate the possible performance improvement in state-of-the-art OLCs1-4 through the use of entanglement. This will enable further advances in timekeeping precision and accuracy, with many scientific and technological applications, including precision tests of the fundamental laws of physics21-23, geodesy24-26 and gravitational-wave detection27.

(Internet) Gaming Disorder in DSM-5 and ICD-11: A Case of the Glass Half Empty or Half Full: (Internet) Le trouble du jeu dans le DSM-5 et la CIM-11: Un cas de verre à moitié vide et à moitié plein.

BACKGROUND: Diagnostic and Statistical Manual of Mental Disorders (DSM-5) included in 2013 Internet gaming disorder (IGD) as a condition for further study, and in 2018, the World Health Organization included gaming disorder (GD) as a mental disorder in the International Classification of Disease (ICD-11). We aim to compare disorders of gaming in both diagnostic systems using a sample of young adults in Mexico. METHODS: Self-administered survey to estimate the prevalence of DSM-5 IGD and ICD-11 GD in 5 Mexican universities; 7,022 first-year students who participated in the University Project for Healthy Students, part of the World Health Organization World Mental Health International College Student Initiative. Cross-tabulation, logistic regression, and item response theory were used to inform on 12- month prevalence of DSM-5 IGD and ICD-11 GD, without and with impairment. RESULTS: The 12-month prevalence of DSM-5 IGD was 5.2% (95% CI, 4.7 to 5.8), almost twice as high as the prevalence using the ICD-11 GD criteria (2.7%; 95% CI, 2.4 to 3.1), and while adding an impairment requirement diminishes both estimates, prevalence remains larger in DSM-5. We found that DSM-5 cases detected and undetected by ICD-11 criteria were similar in demographics, comorbid mental disorders, service use, and impairment variables with the exception that cases detected by ICD-11 had a larger number of symptoms and were more likely to have probable drug dependence than undetected DSM-5 cases. CONCLUSION: DSM-5 cases detected by ICD-11 are mostly similar to cases undetected by ICD-11. By using ICD-11 instead of DSM-5, we may be leaving (similarly) affected people underserved. It is unlikely that purely epidemiological studies can solve this discrepancy and clinical validity studies maybe needed.

Prevalence of 12-month mental and substance use disorders in sexual minority college students in Mexico.

PURPOSE: Mental health disparities have been documented among sexual minority college students, but there is a dearth of evidence from developing countries. The aim is to estimate the prevalence of 12-month mental and substance use disorders across a range of sexual identities among first-year college students in Mexican universities, and test whether there is an association between sexual identity and disorders and whether the association is moderated by gender. METHOD: The University Project for Healthy Students, a web-based survey conducted as part of the World Health Organization's World Mental Health International College Student initiative, recruited 7874 students from nine Mexican universities in 2016 and 2017. Logistic regressions estimated the association of sexual identity with 12-month major depressive episode, generalized anxiety disorder, panic disorder, alcohol abuse/dependence, and drug abuse/dependence, with interaction terms for gender. RESULTS: Compared to heterosexual students reporting no same-sex attraction (SSA), heterosexual students with SSA (AORs range 1.77-3.67) and lesbian/gay and bisexual students (AORs range 2.22-5.32) were at a higher risk for several disorders. Asexual students were at higher risk for drug abuse/dependence (AOR = 3.64). Students unsure of their sexual identity were at a higher risk for major depressive episode, panic disorder, and drug abuse/dependence (AORs range 2.25-3.82). Gender differences varied across sexual identity and disorder. CONCLUSION: These findings are the first empirical report of sexual minority psychiatric disparities among a college student population from a developing nation and underscore the importance of clinical interventions that address mental health needs among sexual minority college students.

Suicidal ideation and planning among Mexican adolescents are associated with depression polygenic risk scores.

Suicide is a major public health problem in Mexico and around the world. Genetic predisposition for major depressive disorder (MDD) has been associated with increased risk for suicidal behaviors (SB) in populations of European ancestry (EA). Here, we examine whether MDD polygenic risk scores (MDD PRS), derived from a genome-wide association study involving EA individuals, predict SB, including ideation, planning, and attempt, among Mexican youth using a longitudinal design. At baseline, participants (N = 1,128, 12-17 years, 55% women) were interviewed and genotyped as part of a general population survey on adolescent mental health. Eight years later, they were recontacted for a follow up visit (N = 437, 20-25 years, 63% women). At both assessments, individuals reported on their engagement in SB within the past year. MDD PRS were significantly positively associated with SB, particularly suicide ideation and planning during adolescence, accounting for ~4-5% of the variance in these outcomes. In contrast, associations between MDD PRS and SB during young adulthood did not reach statistical significance. Our results suggest that increased genetic liability for depression increased risk for SB, particularly during adolescence, expanding our knowledge of the genetic underpinnings of SB.

Near-Unitary Spin Squeezing in

Spin squeezing can improve atomic precision measurements beyond the standard quantum limit (SQL), and unitary spin squeezing is essential for improving atomic clocks. We report substantial and nearly unitary spin squeezing in ^{171}Yb, an optical lattice clock atom. The collective nuclear spin of ∼10^{3} atoms is squeezed by cavity feedback, using light detuned from the system's resonances to attain unitarity. The observed precision gain over the SQL is limited by state readout to 6.5(4) dB, while the generated states offer a gain of 12.9(6) dB, limited by the curvature of the Bloch sphere. Using a squeezed state within 30% of unitarity, we demonstrate an interferometer that improves the averaging time over the SQL by a factor of 3.7(2). In the future, the squeezing can be simply transferred onto the optical-clock transition of ^{171}Yb.

How Mental Health Interviews Conducted Alone, in the Presence of an Adult, a Child or Both Affects Adolescents' Reporting of Psychological Symptoms and Risky Behaviors.

The normative process of autonomy development in adolescence involves changes in adolescents' information management typically characterized by decreasing disclosure and increasing concealment. These changes may have an important impact on the early detection and timely treatment of mental health conditions and risky behavior. Therefore, the objective was to extend our understanding of how these developmental changes in adolescent disclosure might impact adolescent mental health interviews. Specifically, we estimated the effects of third party presence and type of third party presence (adult, child, or both) on adolescents' reports of psychiatric symptoms, substance use, suicidal behavior, and childhood adversity. In this representative sample of 3005 adolescents from Mexico City (52.1 % female), administered the World Mental Health Composite International Diagnostic Interview (WMH-CIDI-A), adult presence influenced reporting the most; in their presence, adolescents reported more ADHD, parental mental illness and economic adversity, but less panic disorder, PTSD, drug use and disorder, and suicidal behavior. The presence of children was associated with increased odds of reporting conduct disorder, opportunity for drug use, parental criminal behavior, neglect, and the death of a parent. While adolescent information management strategies are normative and even desirable as a means of gaining emotional autonomy, they may also interfere with timely detection and treatment or intervention for mental health conditions and risky behaviors. Research and practical implications of these findings are discussed.

Eight-year incidence of psychiatric disorders and service use from adolescence to early adulthood: longitudinal follow-up of the Mexican Adolescent Mental Health Survey.

Half of mental disorders have their first onset before adulthood when the presence of a disorder may be particularly disruptive to developmental milestones. Retrospective prevalence estimates have been shown to underestimate the burden of mental illness and scarce data are available on the incidence of disorders throughout the adolescent period, especially in developing countries. Thus, the objective was to determine the incidence of mental disorders in an 8-year period from adolescence to young adulthood, onset of service use and their predictors in a Mexican cohort. 1071 respondents from a representative two-wave panel sample participated in the Mexican Adolescent Mental Health Survey in 2005 and in the follow-up survey in 2013. Disorders were evaluated with the World Mental Health Composite International Diagnostic Interview. 37.9% experienced the onset of a psychiatric disorder and 28.4% sought services for the first time. Substance use disorders had the greatest incidence, followed by mood and behavior disorders, anxiety disorders and lastly eating disorders. Sex, age, school dropout, childhood adversities and prior mental disorders predicted the onset of new disorders. Being female, having more educated parents and most classes of disorder predicted first time service use. These findings contribute to a paradigm shift in conceptions of mental disorder similar to how we think of common physical afflictions as near universal experiences across the life course, but less frequent at any given moment. Adolescents are particularly vulnerable. Therefore, public health policy should focus on early universal promotion of positive mental health and structural determinants of mental health.

Youth who neither study nor work: mental health, education and employment.

OBJECTIVE: Limited educational and job opportunities for youth has led to a phenomenon termed NEET (not in education, employment or training). The objective is to estimate the prevalence of psychiatric disorders, substance use and suicidal behavior in youth classified as NEET and to compare with those who study only, work only or do both. MATERIAL AND METHODS: 3 005 12-to-17 year-olds in Mexico City were evaluated in 2005 with the Composite International Diagnostic Interview. Descriptive and logistic regression analyses considered the multistage weighted sample design. RESULTS: NEET youth as well as those who work only or study and work simultaneously have greater odds of psychiatric disorder, substance use and suicidal behavior compared to those who study exclusively even after controlling for social disadvantage. CONCLUSION: Vulnerability is not circumscribed to NEET adolescents, but to all teens who are not exclusive students. Supporting youth to continue studying exclusively may buffer negative mental health outcomes.

The association of chronic adversity with psychiatric disorder and disorder severity in adolescents.

The purpose of this paper is to estimate the impact of chronic adversity on psychopathology in adolescents, taking into account the type of adversity, number of adversities experienced and type of psychiatric disorder, as well as to estimate the impact on severity of the disorder. A total of 3,005 male and female adolescents from the Mexican Adolescent Mental Health Survey aged 12-17 years were interviewed in a stratified multistage general population probability survey. Assessment of 20 DSM-IV disorders, disorder severity and 12 chronic childhood adversities were assessed with the adolescent version of the World Mental Health Composite International Diagnostic Interview (WMH-CIDI-A). Family dysfunction adversities including abuse presented the most consistent associations between chronic adversity and psychopathology and their impact was generally non-specific with regard to the type of disorder. Parental divorce, parental death and economic adversity were not individually associated with psychopathology. Among those with a psychiatric disorder, sexual abuse and family violence were associated with having a seriously impairing disorder. The odds of having a psychiatric disorder and a serious disorder increased with increasing numbers of adversities; however, each additional adversity increased the odds at a decreasing rate. While the study design does not allow for conclusions regarding causality, these findings suggest general pathways from family dysfunction to psychopathology rather than specific associations between particular adversities and particular disorders, and provide further evidence for the importance of family-focused intervention and prevention efforts.

Traumatic life-events and suicidality among Mexican adolescents as they grow up: A longitudinal community survey.

OBJECTIVE: Limited research exists on the impact of type and number of traumatic events on the incidence of suicide ideation and attempts (suicidality) among adolescents in low/middle income countries where violence is common. METHOD: We estimated prospective associations of 7 types of events on the new occurrence of suicidality from a follow-up conducted in 2013 (n = 1071; ages 19-26) of the original Mexican Adolescent Mental Health Survey conducted in 2005 (ages 12-17), by using Hazard Ratios (HR) estimates. RESULTS: For new onset of suicide ideation, those reporting "Ever raped or sexually assaulted" had the highest adjusted HR (3.8), followed by "Ever other traumatic event" (HR = 1.9), "Ever committed or witnessed violence" (HR = 1.7) and "Beaten as a child or witnessed physical fights at home" (HR = 1.5). For suicide attempt, those reporting "Ever beaten up by spouse, partner, someone else, mugged with a weapon, or stalked" (HR = 3.8) and "Ever other traumatic event" (HR = 2.0) had the higher hazards. Compared to those without a traumatic event, increased hazards of ideation and attempt were found for those reporting a greater number of types of events. CONCLUSIONS: Our sample is representative of the largest metropolitan area in Mexico but does not include other cities or age groups that may differ in risk factors. Traumatic events that happened in the eight years between waves are not considered. Traumatic events increased the risk of suicidality, independent of common mental disorders. Identifying and addressing these events in clinical settings may therefore be important for preventing suicide in this population.

Suicide thought and behaviors, non-suicidal self-injury, and perceived life stress among sexual minority Mexican college students.

BACKGROUND: Sexual minority college students are at a higher risk for suicidal thoughts and self-injurious behaviors compared to heterosexual students. Minority stress theory proposes sexual minority individuals experience higher stress due to stigma. Using a sample of Mexican college students, this study tested perceived life stress as a mediator of suicide and self-injury outcomes across various sexual orientation groups. METHODS: The sample of college students (N=7882) was recruited from nine Mexican universities as part of the WHO World Mental Health International College Student (WMH-ICS) initiative. Participants completed an online survey including demographic questions, measure of perceived life stress, suicide outcomes, and non-suicidal self-injury (NSSI) in the past 12 months. RESULTS: Logistic regression analyses revealed identifying as a sexual minority significantly predicted a higher likelihood of suicide ideation (ORs 2.05-3.00), suicide attempts (ORs 2.48-8.73), and NSSI (ORs 2.92-4.18) compared to heterosexual students reporting no same-gender attraction. Significant indirect effects from mediation path analyses showed perceived life stress mediated the relationship between a sexual minority identity and suicide ideation (range of proportion mediated 10.48-31.48%), attempts (10.48-31.48%), and NSSI (7.69-20.09%) across each group except among asexual students. LIMITATIONS: The cross-sectional nature of the survey design precludes drawing causal inferences. CONCLUSION: Findings from this study contribute to minority stress theory by elucidating the role of perceived life stress as a mediator of suicide ideation and attempts and NSSI among sexual minority college students. Clinical interventions may benefit in focusing on experiences of stress across various life areas when supporting sexual minority college students.

Laser smoothing of binary gratings and multilevel etched structures in fused silica.

We describe a promising approach to the processing of micro-optical components, where CO(2) laser irradiation in raster scan is used to generate localized surface melting of binary or multilevel structures on silica, fabricated by conventional reactive-ion etching. The technique is shown to provide well-controlled local smoothing of step features by viscous flow under surface tension forces, relaxing the scale length of etch steps controllably between 1 and 30 microm. Uniform treatment of extended areas is obtained by raster scanning with a power stabilized, Gaussian beam profile in the 0.5 to 1 mm diameter range. For step heights of 1 microm or less, the laser-induced relaxation is symmetric, giving softening of just the upper and lower corners at a threshold power of 4.7 W, extending to symmetric long scale relaxation at 7.9 W, with the upper limit set by the onset of significant vaporization. Some asymmetry of the relaxation is observed for 3 microm high steps. Also, undercut steps or troughs produced by photolithography and etching of a deep 64 level multistep surface are found to have a polarization-dependent distortion after laser smoothing. The laser reflow process may be useful for improving the diffraction efficiency by suppressing high orders in binary diffractive optical elements, or for converting multilevel etched structures in fused silica into smoothed refractive surfaces in, for example, custom microlens arrays.

Incidence and recurrence of depression from adolescence to early adulthood: A longitudinal follow-up of the Mexican Adolescent Mental Health Survey.

BACKGROUND: Depression is a leading cause of disease burden around the globe, often develops during adolescence and is recurrent. Thus, disentangling risk factors for incidence from those of recurrence during adolescence is relevant and might suggest different strategies for prevention of onset than for relapse. The aim was to evaluate the relative risk of socio-demographic and clinical factors and traumatic events associated to incidence and recurrence of depression in youth from Mexico City. METHODS: This is a prospective longitudinal general population survey in which 1071 respondents from the Mexican Adolescent Mental Health Survey were interviewed between the ages of 12 and 17 and again eight years later when they were between 19 and 26 years of age. The World Mental Health Composite International Diagnostic Interview evaluated incidence and persistence of major depression and risk factors. RESULTS: Eight-year incidence was 12.9% while recurrence was 46.1%. Risk factors for incidence (female sex, any incident trauma, and specifically sexual abuse and an other/private event) differed from the risk factors for recurrence (childhood onset and domestic violence) with the exception of having a parent with depression, which was associated to increased risk for both. LIMITATIONS: The follow-up response rate was limited by inability to locate participants at wave II. Statistical power was limited for persistence due to low rate of depression at wave I. CONCLUSIONS: Intervening with both depressed and non-depressed children of parents with depression may have beneficial effects on both the development of depression as well as recurrence.

Spin transport in a Mott insulator of ultracold fermions.

Strongly correlated materials are expected to feature unconventional transport properties, such that charge, spin, and heat conduction are potentially independent probes of the dynamics. In contrast to charge transport, the measurement of spin transport in such materials is highly challenging. We observed spin conduction and diffusion in a system of ultracold fermionic atoms that realizes the half-filled Fermi-Hubbard model. For strong interactions, spin diffusion is driven by super-exchange and doublon-hole-assisted tunneling, and strongly violates the quantum limit of charge diffusion. The technique developed in this work can be extended to finite doping, which can shed light on the complex interplay between spin and charge in the Hubbard model.

DSM-5 Internet gaming disorder among a sample of Mexican first-year college students.

BACKGROUND AND AIMS: DSM-5 includes Internet gaming disorder (IGD) as a condition for further study. While online and offline gaming may produce undesired negative effects on players, we know little about the nosology of IGD and its prevalence, especially in countries with emerging economies. METHODS: A self-administered survey has been employed to estimate prevalence of DSM-5 IGD and study the structure and performance of an instrument in Spanish to measure DSM-5 IGD among 7,022 first-year students in 5 Mexican universities that participated in the University Project for Healthy Students (PUERTAS), part of the World Health Organization's World Mental Health International College Student Initiative. RESULTS: The scale for IGD showed unidimensionality with factor loadings between 0.694 and 0.838 and a Cronbach's α = .816. Items derived from gaming and from substance disorders symptoms mixed together. We found a 12-month prevalence of IGD of 5.2% in the total sample; prevalence was different for males (10.2%) and females (1.2%), but similar for ages 18-19 years (5.0%) and age 20+ (5.8%) years. Among gamers, the prevalence was 8.6%. Students with IGD were more likely to report lifetime psychological or medical treatment [OR = 1.8 (1.4-2.4)] and any severe role impairment [OR = 2.4 (1.7-3.3)]. Adding any severe role impairment to the diagnostic criteria decreased the 12-month prevalence of IGD to 0.7%. DISCUSSION AND CONCLUSIONS: Prevalence of DSM-5 IGD and the performance of diagnostic criteria in this Mexican sample were within the bounds of what is reported elsewhere. Importantly, about one in every seven students with IGD showed levels of impairment that would qualify them for treatment under DSM-5.

Elicitor-dependent expression of the ribosome-inactivating protein beetin is developmentally regulated.

BE27 and BE29 are two forms of beetin, a virus-inducible type 1 ribosome-inactivating protein isolated from leaves of Beta vulgaris L. Western blot analysis revealed the presence of beetin forms in adult plants but not in germ or young plants, indicating that the expression of these proteins is developmentally regulated. While beetins are expressed only in adult plants, their transcripts are present through all stages of development. In addition, the treatment of B. vulgaris leaves with mediators of plant-acquired resistance such as salicylic acid and hydrogen peroxide promoted the expression of beetin by induction of its transcript, but only in adult plants. The plant expresses three mRNAs which differ only in their 3' untranslated region. All these observations suggest a dual regulation of beetin expression, i.e. at the post-transcriptional and transcriptional levels. Additionally, total RNA isolated from leaves treated with hydrogen peroxide, which express high levels of active beetin, is not de-adenylated by endogenous beetin, nor in vitro by the addition of BE27, thus suggesting that sugar beet ribosomes are resistant to beetin.

Measurement of wheat gluten and barley hordeins in contaminated oats from Europe, the United States and Canada by Sandwich R5 ELISA.

OBJECTIVES: We have investigated the extent of contamination with wheat, barley, rye or a mixture of these cereals in a large number of grains and commercial oats. We have also attempted to identify the type of cereal contaminant. METHODS: Sandwich R5 ELISA (using either gliadins or hordeins as standards), western blot, matrix-assisted laser desorption/ionization time-of-flight mass spectrometric and quantitative real-time PCR (Q-PCR) techniques have been used to analyze a total of 134 oats, comprising grains and commercial oat products collected from Europe, the United States and Canada. RESULTS: Twenty-five of the 134 pure, uncontaminated oat varieties were found to have undetectable levels of gluten, whereas most of the 109 grains and commercial oat products were mainly contaminated with mixtures of wheat, barley and rye, barley being the predominant contaminant. The percentages of these cereals in the oat samples have been calculated by specific wheat, barley and rye Q-PCR systems. The oat samples were grouped according to the avenin spectra determined by the mass spectrometric technique. The data confirmed that contaminated oat foods, based on the same variety, could have different levels of wheat, barley and rye contamination. CONCLUSION: This study has verified that contamination with wheat gliadins or barley hordeins in oat samples can be measured by the Sandwich R5 ELISA, using either gliadins or hordeins as standards, and also the importance of using confirmatory techniques (such as western blot, Q-PCR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry) to confirm that most oats are contaminated with mixtures of wheat, barley and rye.

Commercial assays to assess gluten content of gluten-free foods: why they are not created equal.

A standardized method of analysis is needed to quantitatively determine the gluten content of food and provide the basis for enforcing regulations regarding use of the term gluten-free in food labeling. People with celiac disease should feel confident that foods labeled "gluten-free" have been assessed for gluten using the same "best available" methodology. The Association of Analytical Communities and the Codex Alimentarius Commission endorse different methods. Both are used by manufacturers in the United States to determine the gluten-free status of food. The sandwich omega-gliadin enzyme-linked immunosorbent assay (ELISA) is the official method of the Association of Analytical Communities. It is able to quantify native and heated gluten. It is unable to accurately detect and quantify barley prolamins, can over- or underestimate gluten content, and cannot accurately quantify hydrolyzed gluten. The sandwich R5 ELISA was endorsed by Codex for gluten determination. It is able to quantify native and heated gluten. One criticism is that it overestimates barley hordein. It also is unable to accurately quantify hydrolyzed gluten. Foods that can be reliably assessed for gluten using a validated commercially available ELISA are those contaminated with native and heated proteins from wheat, barley, and rye. The degree of confidence that can be placed in a manufacturer's assertion that a product is gluten-free is based on the assay used to determine the gluten content and the specific food analyzed.

Globalization, binational communities, and imported food risks: results of an outbreak investigation of lead poisoning in Monterey County, California.

OBJECTIVES: Although the burden of lead poisoning has decreased across developed countries, it remains the most prevalent environmental poison worldwide. Our objective was to investigate the sources of an outbreak of lead poisoning in Monterey County, California. METHODS: An investigation in 3 county health department clinics in Monterey County, California, was conducted between 2001 and 2003 to identify risk factors for elevated blood lead levels (> or = 10 microg/dL) among children and pregnant women. RESULTS: The prevalence of elevated blood lead levels was significantly higher in 1 of the 3 clinics (6% among screened children and 13% among prenatal patients). Risk factors included eating imported foods (relative risk [RR]=3.4; 95% confidence interval [CI]=1.2, 9.5) and having originated from the Zimatlan area of Oaxaca, Mexico, compared with other areas of Oaxaca (RR=4.0; 95% CI=1.7, 9.5). Home-prepared dried grasshoppers (chapulines) sent from Oaxaca were found to contain significant amounts of lead. CONCLUSIONS: Consumption of foods imported from Oaxaca was identified as a risk factor for elevated blood lead levels in Monterey County, California. Lead-contaminated imported chapulines were identified as 1 source of lead poisoning, although other sources may also contribute to the observed findings. Food transport between binational communities presents a unique risk for the importation of environmental hazards [corrected]

Celiac disease screening by immunochromatographic visual assays: results of a multicenter study.

OBJECTIVE: To assay the efficiency for celiac disease (CD) screening of 2 immunochromatographic visual stick assays based on human recombinant tissue transglutaminase (tTG). One was the antitissue transglutaminase antibodies (AtTGA) stick for IgA/G antibodies to tTG detection, the other was the AtTGA/antigliadin antibodies (AGA) stick for IgA antibodies for tTG and/or gliadins. PATIENTS AND METHODS: In a prospective multicenter study, 4 pediatric gastroenterology units from Spain and 2 from Latin America enrolled 72 control children with a normal small bowel mucosa and 113 untreated patients with CD with Marsh type 3 lesions. RESULTS: Evaluation of results by the gastroenterologists and by 2 independent observers at the coordination center showed a remarkably low interobserver variability. For the AtTGA stick, sensitivity was 96.5% and specificity was 98.6%. The AtTGA/AGA stick displayed a sensitivity of 94.5% and a specificity of 98.6% for AtTGA and a sensitivity of 63.1% and a specificity of 95.2% for AGA. The highest efficiency and positive likelihood ratio was obtained for the AtTGA stick, higher than for IgA AtTGA by enzyme-linked immunosorbent assay. One additional advantage was that previous investigation of total serum IgA levels could be eluded. The IgA AtTGA/AGA stick, with an efficiency of 95.1%, compared with 89.2% when the combined results of the 2 enzyme-linked immunosorbent assays were considered, turned out to be an excellent diagnostic tool for infants with no IgA deficiency. CONCLUSION: These 2 assays are extremely efficient for CD screening, by combining a high diagnostic accuracy with the simplicity and rapidity of visual methods.