Availability and price of malaria rapid diagnostic tests in the public and private health sectors in 2011: results from 10 nationally representative cross-sectional retail surveys.

OBJECTIVES: To describe the state of the public and private malaria diagnostics market shortly after WHO updated its guidelines for testing all suspected malaria cases prior to treatment. METHODS: Ten nationally representative cross-sectional cluster surveys were conducted in 2011 among public and private health facilities, community health workers and retail outlets (pharmacies and drug shops) in nine countries (Tanzania mainland and Zanzibar surveyed separately). Eligible outlets had antimalarials in stock on the day of interview or had stocked antimalarials in the past 3 months. RESULTS: Three thousand four hundred and thirty-nine rapid diagnostic test (RDT) products from 39 manufacturers were audited among 12,197 outlets interviewed. Availability was typically highest in public health facilities, although availability in these facilities varied greatly across countries, from 15% in Nigeria to >90% in Madagascar and Cambodia. Private for-profit sector availability was 46% in Cambodia, 20% in Zambia, but low in other countries. Median retail prices for RDTs in the private for-profit sector ranged from $0.00 in Madagascar to $3.13 in Zambia. The reported number of RDTs used in the 7 days before the survey in public health facilities ranged from 3 (Benin) to 50 (Zambia). CONCLUSIONS: Eighteen months after WHO updated its case management guidelines, RDT availability remained poor in the private sector in sub-Saharan Africa. Given the ongoing importance of the private sector as a source of fever treatment, the goal of universal diagnosis will not be achievable under current circumstances. These results constitute national baselines against which progress in scaling-up diagnostic tests can be assessed.

[Role of plasma procalcitonin in the diagnosis of ventilator-associated pneumonia: systematic review and metaanalysis]. / Papel de la procalcitonina plasmática en el diagnóstico de la neumonía asociada a ventilación mecánica: revisión sistemática y metaanálisis.

OBJECTIVE: To determine the role of plasma procalcitonin (PCT) levels in diagnosing ventilator-associated pneumonia. DESIGN: A systematic review of publications prospectively assessing the diagnostic role of PCT in ventilator-associated pneumonia was carried out. The search was performed using Medline, Embase, the Cochrane Collaboration and MEDION, with reviewing of the references of retrieved articles. We extracted data that allowed the calculation of sensitivity, specificity, likelihood ratios and diagnostic odds ratio. Intervention Metaregression was performed to determine whether exposure to previous antibiotic treatment, the time to occurrence of ventilator-associated pneumonia and the type of patients had an impact upon the diagnostic performance of procalcitonin. RESULTS: Seven studies were considered (373 patients, 434 episodes). We found no publication bias or threshold effect. High plasma PCT levels were associated to an increased risk of suffering ventilator-associated pneumonia (OR: 8.39; 95% CI: 5.4-12.6). The pooled data on sensitivity, specificity, positive and negative likelihood ratio, and diagnostic odds ratio found were 76% (69-82), 79% (74-84), 4.35 (2.48-7.62), 0.26 (0.15-0.46) and 17.9 (10.1-31.7), respectively. Diagnostic yield was modified by prior exposure to antibiotics (rDOR 0.11, 0.02-0.069), but not by the type of critically ill patient or the time to occurrence of ventilator-associated pneumonia. CONCLUSIONS: Our results suggest that PCT provides additional information on the risk of VAP. Inclusion of PCT in diagnostic algorithms could improve their effectiveness.

[Evaluation of the diagnostic test for rapid detection of covid-19 antigen (Panbio Covid rapid test) in primary care]. / Evaluación de la prueba diagnóstica de detección rápida de antígeno de covid-19 (Panbio Covid rapid test) en atención primaria.

OBJECTIVE: COVID-19 infection requires early diagnosis, with PCR being the gold standard test. The protocols advocate the use of rapid antigenic tests that require evaluation in actual clinical practice. The objective was to evaluate the diagnostic test for rapid antigen detection, Panbio Covid rapid test, compared with PCR, in patients with symptoms of 5 or less days of evolution and with a high-suspicion of infection by COVID-19 in a health center. MATERIALS AND METHODS: 103 patients over 14 years of age who attended an urban health center located in the Usera District of Madrid, with high-suspicion of COVID-19 infection, in the first 5 days of evolution from the onset of symptoms during the month of November 2020. INTERVENTIONS: diagnostic tests for COVID-19 are performed: antigen and PCR. RESULTS: The prevalence of the disease was 24.3% according to the PCR test and 17.5% according to the rapid antigenic test. The sensitivity was 72% (95% CI: 54.3-89.6%). The specificity was 100%. The positive and negative predictive values were 100% and 91.8% respectively. In the bivariate analysis, there was no relationship between symptoms and the presence of disease, except for myalgias (p=0.030). The multivariate analysis found a relationship between cough, dyspnea, fever, myalgia, anosmia/ageusia, and ocular symptoms and the presence of disease. CONCLUSIONS: The sensitivity and specificity for the Panbio rapid antigen test are similar to other studies performed in primary care. In high-prevalence of disease and with highly suspected symptoms, positive test results can be considered definitive, but negative results will require confirmation. Myalgia, fever, dyspnea, anosmia/ageusia, and ocular symptoms may be more related to the presence of COVID-19.

Reasons for refusing diagnostic tests and therapeutic recommendations and associated complications in inherited heart diseases. The RELUCTANT study.

INTRODUCTION AND OBJECTIVES: Study of inherited heart diseases (IHD) involves performing diagnostic tests, which are sometimes inconvenient or stressful, in asymptomatic relatives. The aim of this study was to analyze refusal to undergo various diagnostic tests and follow therapeutic recommendations. METHODS: We assessed 1992 consecutive families with IHD to analyze refusal to undergo family screening. The study included 1539 individuals who were recommended to undergo cardiac magnetic resonance, and 837 who were recommended a drug challenge test. To study treatment refusal, we assessed 395 patients with an indication for an implantable cardioverter-defibrillator (ICD) and 402 patients with an indication for anticoagulation. RESULTS: A total of 28% of families who were recommended to undergo screening for suspected IHD did not attend, but refusal was lower if there was a family history of sudden cardiac death. In all, 23% did not undergo magnetic resonance, and the 2 main reasons were administrative problems (53%) and claustrophobia (18%). Refusal was more common in older people, women, symptomatic persons, individuals with arrhythmias, and relatives. Nearly one fifth (19%) did not take the drug challenge test, due to fear (46%) or administrative issues (25%). Refusal was more frequent in older individuals, asymptomatic persons, those with a history of arrhythmias, relatives, and those with a positive genetic study. Only a minority of patients rejected the treatments (5.1% ICD, 2.5% anticoagulation). The percentage of sudden cardiac death in persons rejecting ICD implantation was high (4.5% per year). CONCLUSIONS: One fifth of people attending screening for IHD refused to undergo more sophisticated and stressful tests. This study identified several independent predictors associated with refusal. Only a minority of high-risk patients refused treatments such as ICD implantation and anticoagulation.

A cost-effectiveness analysis of a novel algorithm to sequentially diagnose leprosy based on manufactured tests under the SUS perspective / Análise de custo-efetividade de um novo algoritmo para exame sequencial de hanseníase baseado em testes fabricados sob a perspectiva do SUS / Análisis de costo-efectividad de un nuevo algoritmo para el examen secuencial de lepra basado en pruebas fabricadas bajo la perspectiva del SUS

Abstract: Brazil has the second largest number of leprosy cases (a disease with a significant burden) in the world. Despite global and local efforts to eliminate this public health problem, inadequate or late diagnosis contribute to perpetuate its transmission, especially among household contacts. Tests such as the rapid IgM antibody detection (RT) and real-time polymerase chain reaction (RT-PCR) were developed to overcome the challenges of early diagnosis of leprosy. This study aimed to analyze the cost-effectiveness of a new diagnostic algorithm recommended by the Brazilian government to diagnose leprosy in household contacts of confirmed leprosy cases, which includes the RT and RT-PCR tests. A decision tree model was constructed and the perspective of the Brazilian Unified National Health System (SUS) and a 1-year time horizon were adopted. Only direct medical costs related to diagnostic tests were included. Effectiveness was measured as the number of avoided undiagnosed leprosy cases. Different scenarios were analyzed. The sequential use of RT, slit-skin smear (SSS) microscopy, and RT-PCR as recommended by the Brazilian Ministry of Health was compared to a base case (isolated SSS microscopy), yielding an incremental cost-effectiveness ratio of USD 616.46 per avoided undiagnosed leprosy case. Univariate sensitivity analysis showed that the prevalence of leprosy among household contacts was the variable that influenced the model the most. This is the first economic model to analyze a diagnostic algorithm of leprosy. Results may aid managers to define policies and strategies to eradicate leprosy in Brazil.

Resumo: O Brasil tem o segundo maior número de casos de hanseníase (doença com carga significativa) do mundo. Apesar dos esforços globais e locais para eliminar esse problema de saúde pública, o diagnóstico inadequado ou tardio contribui para perpetuar sua transmissão, especialmente entre contatos intradomiciliares. Exames como o teste rápido de anticorpos IgM (RT) e a reação em cadeia da polimerase em tempo real (RT-PCR) foram desenvolvidos para superar as barreiras do diagnóstico precoce da hanseníase. Este estudo teve como objetivo analisar a relação custo-efetividade de um novo algoritmo de diagnóstico recomendado pelo governo brasileiro para diagnosticar a hanseníase em contatos domiciliares de casos confirmados de hanseníase, que inclui os testes RT e RT-PCR. Foi construído um modelo de árvore de decisão e adotada a perspectiva do Sistema Único de Saúde (SUS) considerando o período de um ano. Foram incluídos apenas os custos médicos diretos relacionados aos exames diagnósticos. A efetividade foi medida considerando o número de casos evitados de hanseníase. Diferentes cenários foram analisados. O uso sequencial de RT, baciloscopia e RT-PCR, conforme recomendado pelo Ministério da Saúde, foi comparado a um caso base (baciloscopia isolada), obtendo-se uma razão de custo-efetividade incremental de USD 616,46 por caso evitado de hanseníase. A análise de sensibilidade univariada mostrou que a prevalência de hanseníase entre contatos intradomiciliares foi a variável que mais influenciou o modelo. Este é o primeiro modelo econômico a analisar um algoritmo diagnóstico da hanseníase. Os resultados poderão auxiliar os gestores na definição de políticas e estratégias para a erradicação da hanseníase no Brasil.

Resumen: Brasil tiene el segundo mayor número de casos de lepra (enfermedad con carga significativa) del mundo. A pesar de los esfuerzos globales y locales para eliminar ese problema de salud pública, el diagnóstico inadecuado o tardío contribuye a perpetuar su transmisión, sobre todo entre contactos intradomiciliarios. Los exámenes como la prueba rápida de anticuerpos IgM (RT) y la reacción en cadena de la polimerasa en tiempo real (RT-PCR) se desarrollaron para superar las barreras del diagnóstico precoz de la lepra. El objetivo de este estudio fue analizar la relación de costo-efectividad de un nuevo algoritmo de diagnóstico recomendado por el gobierno brasileño para diagnosticar la lepra en contactos domiciliarios de casos confirmados de lepra, que incluye las pruebas RT y RT-PCR. Se construyó un modelo de árbol de decisión y se adoptó la perspectiva del Sistema Único de Salud (SUS) teniendo en cuenta el periodo de un año. Solo se incluyeron los costos médicos directos relacionados con los exámenes diagnósticos. Se midió la efectividad teniendo en cuenta el número de casos de lepra evitados. Se analizaron distintos escenarios. Se comparó el uso secuencial de RT, baciloscopia y RT-PCR, conforme el Ministerio de Salud recomienda, con un caso base (baciloscopia aislada), y se obtuvo un cociente de costo-efectividad incremental de USD 616,46 por cada caso de lepra evitado. El análisis de sensibilidad univariante mostró que la prevalencia de lepra entre contactos intradomiciliarios fue la variable que más influyó el modelo. Este es el primer modelo económico que analiza un algoritmo diagnóstico de lepra. Los resultados podrán ayudar los gestores a definir políticas y estrategias para erradicar la lepra en Brasil.

[Evaluation of the usefulness of nail biopsy in the diagnosis of onychomycosis]. / Evaluación de la utilidad diagnóstica de la biopsia ungueal en las onicomicosis.

BACKGROUND: Onychomycosis affects between 2% to 30% of the world population. Nail biopsy may help in making a diagnosis and can distinguish between invasion and colonisation. AIMS: To evaluate the diagnostic usefulness of nail biopsy with Periodic acid-Schiff (PAS) staining for onychomycosis, compared to direct KOH examination, culture and its combination in a reference laboratory in Colombia. METHODS: The study included 66 patients in whom a blind and independent reading of the three tests was performed. The usefulness was defined based on the validity (sensitivity, specificity, Youden's index, likelihood ratios), performance (predictive values) efficiency (proportion of correctly diagnosed patients), and reproducibility (kappa coefficient). RESULTS: The mean age of the patients was 55±16 years, and included 76% women. The direct tests with KOH were positive in 66.7% (n=44), 62.1% (n=41) were positive with culture, and 56.1% (n=37) with the biopsy. The main causal agents were non-dermatophytes moulds in 36.4% (n=24). The most frequent species were Neoscytalidium dimidiatum (n=11), Trichophyton rubrum (n=11), and Candida parapsilosis (n=13). The sensitivity of nail biopsy, when compared to the standard (KOH and/or culture), was 71%, specificity 83%, Youden's index 0.54, positive likelihood ratio 4.25, negative likelihood ratio 0.35, positive predictive value 92%, negative predictive value 52%, efficiency 74% and kappa coefficient 0.45. When biopsy was evaluated only in patients with onycholysis of the nail plate greater than 50%, all the parameters of diagnostic usefulness increased. CONCLUSIONS: The overall usefulness of the biopsy was moderate for patients with more severe symptomatology, which makes its use advisable in cases of extensive onycholysis, and when discriminating colonisation from invasion is required.

Use of the tetanus quick stick (TQS) test in the emergency services. / Uso del test rápido de tétanos (TQS) en los servicios de urgencias.

Standard procedure when treating tetanigenic risk wounds in an emergency room setting, usually includes administering a dose of gamma-globulin or/and a tetanus vaccine. The rapid detection test (Tetanus Quick Stick [TQS]) can better the current procedure of detecting people who are not immunized. Our objective was to review and analyse the validity of the TQS test, and determine the cost-benefit with the data available. We searched the following data bases for information: WoS, PubMed, EMBASE & SCOPUS. After reviewing articles and applying inclusion/exclusion criteria, we included 20 articles mostly European and written by Emergency room services. Sensitivity ranged from 55%-100%, specificity from 66.6%-100%, PPV: 81.1%-100%, NPV: 42.9%-100%. Most of the tests supported the cost-benefit analysis of the TQS test. We determined that in emergency room situations, it would be beneficial to use the TQS test, and an example of good clinical practice.

Frequency of Helicobacter pylori Infection in Patients Requiring GI Endoscopy in Seven Units in Three Antioquia Subregions

Aim: To determine the frequency of Helicobacter pylori and sociodemographic factors, life habits, and personal and family history of gastroduodenal diseases in patients who required and were taken to GI endoscopy (symptomatic or by screening) in seven endoscopy units in three Antioquia subregions. Materials and methods: A cross-sectional study conducted between 2016 and 2018 included 272 participants. Sociodemographic factors, life habits, and personal and family history were related to H. pylori infection. Descriptive statistics and bivariate analysis were performed to establish the association between the variables, and multivariate analysis (binomial regression) was used to adjust the prevalence ratios of the associated factors. A p-value ≤ 0.05 was considered statistically significant. Results: The frequency of H. pylori infection was 55.9%, with differences by subregion (Valle de Aburrá metropolitan area: 54.3%, Oriente: 64%, and Urabá: 79.2%). Factors associated with H. pylori infection were male sex (adjusted prevalence ratio [APR] = 1.26; 95% confidence interval [CI] = 1.04-1.52), age 18-55 years (APR = 1.62; CI 95% = 1.22-2.16), absence of drinking water (APR = 1.40; 95% CI: 1.15-1.72) and educational level below university (APR = 1.73; 95% CI% = 1.26-2.38). Conclusion: The frequency of H. pylori was higher than in other recent studies because different diagnostic tests were used for its detection, and differences were found in the frequency of infection by region, which is explained by the heterogeneity in the populations analyzed. This study suggests the need to improve the population's living conditions to reduce H. pylori and direct measures of primary prevention of the infection, especially in family groups, men, individuals between 18 and 55 years old without drinking water, and with an educational level lower than university.

Objetivo: determinar la frecuencia de Helicobacter pylori y la presencia de factores sociodemográficos, hábitos de vida y antecedentes personales y familiares de enfermedades gastroduodenales en pacientes que requirieron y fueron llevados a endoscopia digestiva (sintomáticos o por tamización) en siete unidades de endoscopia de tres subregiones de Antioquia. Materiales y métodos: estudio transversal realizado entre 2016 y 2018 que incluyó a 272 participantes. Los factores sociodemográficos, hábitos de vida, antecedentes personales y familiares se relacionaron con la infección por H. pylori. Se realizó estadística descriptiva y análisis bivariado para establecer la asociación entre las variables y el análisis multivariado (regresión binomial) para ajustar las razones de prevalencia de los factores asociados. Un valor p ≤ 0,05 se consideró estadísticamente significativo. Resultados: la frecuencia de infección por H. pylori fue de 55,9%, con diferencias por subregión (área metropolitana del Valle de Aburrá: 54,3%, oriente: 64% y Urabá: 79,2%). Los factores asociados a la infección por H. pylori fueron sexo masculino (razón de prevalencia ajustada [RPA] = 1,26; intervalo de confianza [IC] del 95% = 1,04-1,52), edad de 18-55 años (RPA = 1,62; IC 95% = 1,22-2,16), ausencia de agua potable (RPA = 1,40; IC 95%: 1,15-1,72) y nivel educativo inferior al universitario (RPA = 1,73; IC 95% = 1,26-2,38). Conclusión: la frecuencia de H. pylori fue mayor que en otros estudios recientes porque se emplearon diferentes pruebas diagnósticas para su detección y se demostraron diferencias en la frecuencia de la infección por región, lo cual se explica por la heterogeneidad en las poblaciones analizadas. Este estudio sugiere la necesidad de mejorar las condiciones de vida de la población para reducir la infección por H. pylori y dirigir medidas de prevención primaria de la infección especialmente en los grupos familiares, en hombres, individuos entre 18 y 55 años, sin agua potable y con un nivel educativo inferior al universitario.

Utilidad de la proteína C-reactiva para determinar la gravedad de infección por SARS-CoV-2 en Perú / Usefulness of C-reactive protein to determine the severity of SARS-CoV-2 infection in Peru

INTRODUCCIÓN: En los últimos años se han estudiado diversos biomarcadores para determinar los casos graves de COVID-19. La proteína C-reactiva (PCR) ha mostrado alta sensibilidad en la identificación de pacientes con enfermedad grave y utilidad comparable a la tomografía. OBJETIVO: Determinar la utilidad de la PCR para predecir gravedad de la infección por SARS-CoV-2 en pacientes hospitalizados en el Centro Médico Naval del Perú durante el periodo enero-septiembre del año 2021. MÉTODOS: Se empleó un diseño de tipo cuantitativo, observacional, analítico, retrospectivo, y de tipo prueba diagnóstica. Se calculó un tamaño muestral de 503 pacientes, quienes fueron divididos en dos grupos de acuerdo a su gravedad. RESULTADOS: Se determinó un punto de corte óptimo de 10,92 mg/L de los valores de PCR para el diagnóstico de enfermedad grave por COVID-19. Se calculó un área bajo la curva (AUC) de 0,762 y se obtuvieron valores de sensibilidad, especificidad, valores predictores positivo, negativo y precisión diagnóstica de 78,88%, 66,4%; 41,42%; 87,01%; y 67,27%, respectivamente. El normograma de Fagan mostró una probabilidad posprueba de 41%. En el modelo ajustado fueron significativas la PCR (ORa = 4,853; IC95% 2,987-7,886; p = 0,001), además de la ferritina (ORa = 1,001; IC 95%: 1,001-1,002; p = 0,001) e hipotiroidismo (OR ajustado = 4,899; IC 95%: 1,272-18,872; p = 0,021). CONCLUSIONES: El presente estudio mostró la asociación entre la PCR y la gravedad de infección por SARS-CoV-2 en un modelo ajustado, mostrando su potencial utilidad y contribuyendo a determinar el punto de corte de la PCR en población peruana y su comparación a nivel internacional.

BACKGROUND: Recently, many biomarkers have been studied to determine severe cases of COVID-19. C-reactive protein (CRP) has shown high sensitivity in identifying patients with severe disease and utility comparable to computed tomography. AIM: To determine the usefulness of CRP to predict the severity of SARS-CoV-2 infection in patients hospitalized at the Naval Medical Center of Peru during the period January-September in the year 2021. METHODS: A quantitative, observational, analytical, retrospective, and diagnostic test type design was used. A sample size of 503 patients was calculated, which were divided into two groups according to their severity. RESULTS: An optimal cut-off point of 10.92 mg/L for CRP levels was determined for the diagnosis of severe COVID-19. An area under the curve (AUC) of 0.762 was calculated and sensitivity, specificity, positive and negative predictive values and diagnostic accuracy values of 78.88%, 66.4%; 41.42%; 87.01%; and 67.27%; respectively. Fagan's normogram showed a post-test probability of 41%. In the adjusted model, CRP (aOR = 4.853; 95% CI 2.987-7.886; p = 0.001), ferritin (aOR = 1.001; 95% CI: 1.001-1.002; p = 0.001) and hypothyroidism (adjusted OR = 4899; 95% CI: 1272-18872; p = 0.021) showed significance. CONCLUSIONS: The present study showed an association between CRP and the severity of SARS-CoV-2 infection in an adjusted model, showing its potential utility and contributing to determine the cut-off point of CRP in the Peruvian population and its international comparison.

Customary practices in the monitoring of dry eye disease in Sjogren's syndrome.

PURPOSE: Diagnostic testing for dry eye disease (DED) in Sjogren's syndrome (SS) is well described. Little is published about monitoring this systemic autoimmune DED. We analyzed the SS related DED tests used in North American optometric practices and compared academic settings to private practice settings. METHODS: A retrospective chart review of 123 SS charts from 6 optometric practices in North America was conducted. Testing done during the first examination following a SS diagnosis was recorded on Research Electronic Data Capture (REDCap) database. The complete data file was reviewed and testing type and methodology were compared. RESULTS: Symptoms of DED (98.4% of charts),meibomian gland dysfunction (76.4% of charts), corneal staining with fluorescein (75.6% of charts) and anterior blepharitis (73.2% of charts) were the most frequently recorded variables. Clinicians used different methodologies to measure and grade these variables. Private practitioners were more likely to use symptom questionnaires and grading scales and to describe anterior blepharitis. Academic settings were more likely to record TBUT and tear meniscus height. CONCLUSIONS: The monitoring of DED in SS is not uniform in optometric offices across North America. Creating accepted standards of testing will improve the ability of clinicians and researchers to communicate and understand the course of DED in SS.

Situación epidemiológica de la tuberculosis en Chile 2020-2021: repercusiones de la pandemia de COVID-19 / Epidemiological situation of tuberculosis in Chile 2020-2021: repercussions of the COVID-19 pandemic

La situación epidemiológica y operacional de la tuberculosis en el mundo se vio afectada por la pandemia de COVID-19 durante los años 2020 y 2021. A nivel global, el número de casos de tuberculosis notificados disminuyó en un 18% el año 2020 con respecto al año anterior, y el número de muertes por esta causa mostró un aumento en el mismo año. En Chile, se observó una caída similar en el número de casos diagnosticados el año 2020, en directa relación con una disminución del 70% en el número de muestras procesadas para diagnóstico de tuberculosis pulmonar. El presente trabajo detalla indicadores epidemiológicos y operacionales del control de la tuberculosis en Chile para los años 2020 y 2021, y analiza su relación con el impacto de la pandemia COVID-19 sobre las actividades del Programa Nacional de Tuberculosis.

The COVID-19 pandemic during 2020 and 2021 affected the epidemiological and operational situation of tuberculosis control worldwide. Globally, there was a reduction of 18% in the number of notified cases of tuberculosis in 2020 in comparison to the previous year, and the number of deaths increased in the same year. In Chile, there was a similar fall in the number of notified cases, in direct relation to a decrease of 70% in the number of diagnostic tests performed for pulmonary tuberculosis at a national level. This article details the epidemiological and operational indicators of tuberculosis control in Chile during 2020-2021, and analyzes their relation with the impact of COVID-19 pandemic on the activities of the National Tuberculosis Program.

Aspectos novedosos del diagnóstico del SARS-CoV-2 en la era poscovid / Novel aspects of SARS-CoV-2 diagnosis of the post COVID era

RESUMEN Los coronavirus, en sentido amplio, son un grupo de virus de ARN de cadena simple con envoltura. A pesar del intenso escrutinio al que han sido sometidos, todavía no está definido por qué solo tres coronavirus -SARS-CoV-1, MERS-CoV y SARS-CoV-2- han provocado síntomas graves y elevada mortalidad. El objetivo de la presente revisión es incrementar los conocimientos acerca del uso de los exámenes diagnósticos de la COVID-19, por lo que se realizó una búsqueda actualizada sobre los métodos diagnósticos de la infección por SARS-CoV-2, en los principales buscadores, además de la información proveniente de las diferentes directrices publicadas en el país sobre el enfrentamiento a esta pandemia. Los resultados sugieren que ambas pruebas se complementan por su capacidad diagnóstica en función del tiempo de infección. Si se tiene un resultado positivo mediante cualquiera de las dos metodologías, el diagnóstico está definido. Ante la entrada a Cuba de la COVID-19, comenzó el despliegue de la gestión gubernamental, movilizando las más importantes capacidades científicas, tecnológicas y profesionales para enfrentar la pandemia. Así, diferentes institutos y centros de investigación, junto al sistema de salud, han trabajado en la creación de métodos de diagnóstico y manejo de la COVID. La nueva etapa, conocida como poscovid, necesita una valoración y uso adecuados de las pruebas que confirmen la presencia del virus.

ABSTRACT Coronaviruses, in a broad sense, are a group of enveloped single-stranded RNA viruses. Despite the intense scrutiny they have been subjected to, it is not still defined why only three coronaviruses-SARS-CoV-1, MERS-CoV y SARS-CoV-2-have caused serious symptoms and high mortality. The aim of this review is to increase the knowledge on the use of COVID-19 diagnostic tests, so an updated search was carried out on the diagnostic methods of SARS-CoV-2 infection, in the main searchers, besides the information gathered from the different guidelines published in the country on the confrontation of this pandemic. The results suggest that both tests complement themselves by their diagnostic capacity according to the infection time. If a positive result is obtained using either method, the diagnostic is defined. At the entrance of COVID-19 to Cuba, the organization of government management began, mobilizing the most important scientific, technological and professional capacities to confront the pandemic. Therefore, different research institutes and centers, together with the health system, have worked on the creation of COVID diagnostic methods and management. The new stage, known as post COVID era, needs a proper evaluation and use of the tests that confirm the virus presence.

Utilidad de las pruebas analíticas en el diagnóstico de alergia a las proteínas de la leche de vaca / Usefulness of analytic tests for the diagnosis of cow's milk protein allergy

Introducción. La alergia a las proteínas de la leche de vaca es la alergia alimentaria más frecuente en los niños y para su diagnóstico se emplean historia clínica dirigida y prueba de provocación oral (PPO), el dosaje sérico de inmunoglobulina E específica (sIgE) y pruebas cutáneas de puntura (SPT, por su sigla en inglés). Sin embargo, su utilidad diagnóstica es difícil de establecer en la población local. El objetivo fue evaluar la utilidad de las pruebas para el diagnóstico de alergia a las proteínas de la leche de vaca (PLV) en la población estudiada. Población y métodos. Análisis retrospectivo de datos de pacientes atendidos en la Unidad de Alergia del Hospital Elizalde entre 2015 y 2018. Se evaluaron SPT y sIgE para leche, alfa-lactoalbúmina, beta-lactoglobulina y caseína, seguidos de PPO y se determinó la utilidad diagnóstica para cada prueba, y sus combinaciones. Resultados. Se evaluaron las pruebas de 239 pacientes. La PPO fue hospitalaria en el 54,8 % de los casos, por reexposición domiciliara en el 35,5 % y en el 9,6 % por incorporación de PLV a la madre. La mayor especificidad fue la de SPT con caseína (96,7 %; intervalo de confianza [IC95%]: 90,8-99,3) y la mayor sensibilidad, la de la combinación de SPT y sIgE con los 4 alérgenos (55,3 %; IC95%: 45,7-64,6). Conclusiones. El trabajo estableció la utilidad diagnóstica de las SPT y el sIgE en la población estudiada.

Introduction. Cow's milk protein allergy is the most common food allergy among children. It can be diagnosed based on a guided history taking and using an oral food challenge (OFC), serum specific immunoglobulin E levels (sIgE), and skin prick tests (SPT). However, it is difficult to establish their diagnostic performance in the local population. Our objective was to assess the usefulness of tests used to diagnose cow's milk protein (CMP) allergy in the studied population. Population and methods. Retrospective analysis of data from patients seen at the Unit of Allergy of a tertiary care pediatric hospital between 2015 and 2018. SPT and sIgE tests were done for milk, alpha-lactalbumin, beta-lactoglobulin, and casein, followed by an OFC, and the diagnostic usefulness of each test, as well as their combination, was established. Results. The tests of 239 patients were assessed. OFC was performed at the hospital in 54.8 % of cases, via a rechallenge test at home in 35.5 %, and through CMP intake by the mother in 9.6 %. The highest specificity was observed with the casein SPT (96.7 %; 95 % confidence interval [CI]: 90.8-99.3) and the highest sensitivity, with the 4-allergen SPT and sIgE combination (55.3 %; 95 % CI: 45.7-64.6). Conclusions. The study established the diagnostic usefulness of SPT and sIgE in the studied population.

COVID-19: Some unresolved issues / COVID-19: Algunos asuntos no resueltos

Two years after the COVID-19 pandemic, many uncertainties persist about the causal agent, the disease and its future. This document contains the reflection of the COVID-19 working group of the Official College of Physicians of Madrid (ICOMEM) in relation to some questions that remain unresolved. The document includes considerations on the origin of the virus, the current indication for diagnostic tests, the value of severity scores in the onset of the disease and the added risk posed by hypertension or dementia. We also discuss the possibility of deducing viral behavior from the examination of the structure of the complete viral genome, the future of some drug associations and the current role of therapeutic resources such as corticosteroids or extracorporeal oxygenation (ECMO). We review the scarce existing information on the reality of COVID 19 in Africa, the uncertainties about the future of the pandemic and the status of vaccines, and the data and uncertainties about the long-term pulmonary sequelae of those who suffered severe pneumonia. (AU)

Cuando han transcurrido ya dos años de la pandemia de COVID-19 persisten muchas incertidumbres sobre el agente causal, la enfermedad y su futuro. El presente documento contiene la reflexión del grupo de trabajo sobre COVID-19 del Ilustre Colegio Oficial de Médicos de Madrid (ICOMEM) en relación a algunas preguntas que nos parecen sin resolver. El documento incluye reflexiones sobre el origen del virus, la indicación actual de pruebas diagnósticas, el valor de los “scores” de gravedad en el comienzo de la enfermedad y el riesgo añadido que supone la hipertensión o la demencia. Se discute también, la posibilidad de deducir del examen de la estructura del genoma viral completo el comportamiento viral, el futuro de algunas asociaciones de fármacos y el papel actual de recursos terapéuticos como los corticoides o la oxigenación extracorpórea (ECMO). Revisamos la escasa información existente sobre la realidad de la COVID-19 en África, las incertidumbres sobre el futuro de la pandemia y la situación de las vacunas y los datos e incertidumbres sobre las secuelas pulmonares a largo plazo de los que padecieron neumonía grave. (AU)

Evaluación de pruebas diagnósticas para especialistas en rehabilitación cardiopulmonar / Evaluation of Diagnostic Tests for Professionals who Perform Cardiopulmonary Rehabilitation / Avaliação de testes de diagnóstico para especialistas em reabilitação cardiopulmonar

Introducción: A diario, los profesionales de la salud se enfrentan a importantes retos diagnósticos cuando atienden a sus pacientes, por lo que se apoyan en exámenes paraclínicos que complementan su ejercicio semiológico, porque les permiten confirmar o descartar una enfermedad. Objetivo: Explicar a los especialistas en rehabilitación cardiopulmonar los conceptos requeridos para interpretar de forma crítica los resultados de las pruebas diagnósticas. Materiales y métodos: Revisión narrativa de la literatura, que expone conceptos actualizados, ejemplos y gráficas con enfoque académico y didáctico. Resultado: Se realizó la actualización y explicación de los conceptos de sensibilidad, especificidad, valores predictivos positivo y negativo y los likelihood ratio positivo y negativo y su interpretación en el normograma de Fagan, a través de ejemplos del día a día del especialista. Conclusión: Comprender los conceptos que acompañan la evaluación de pruebas diagnósticas ayuda a que los especialistas en rehabilitación cardiopulmonar analicen críticamente los resultados de las ayudas paraclínicas funcionales y estructurales que acompañan a sus pacientes y, de esta manera, puedan caracterizar bien el diagnóstico y seguimiento de las personas

Introduction: Health professionals face important diagnostic challenges daily when they care for their patients, which is why they rely on paraclinical tests that complement their semiological exercise by confirming or ruling out a disease. Objective: Explain to cardiopulmonary rehabilitation specialists, the concepts necessary to critically interpret the results of diagnostic tests. Materials and methods: narrative review of the literature was carried out, which exposes updated concepts, examples, and graphs with an academic and didactic approach.Result: The concepts of sensitivity, specificity, positive and negative predictive values and the positive and negative Likelihood Ratio and their interpretation in the Fagan normogram were updated and explained, through examples of the specialists day-to-day. Conclusion: understanding the concepts that accompany the evaluation of diagnostic tests help car-diopulmonary rehabilitation specialists to critically analyze the results of the functional and structural paraclinical aids that accompany their patients, and thus be able to properly characterize the diagno-sis and follow-up. of people

Introdução: Diariamente, os profissionais da saúde enfrentam desafios diagnósticos, recorrendo a exames que complementem a sua prática semiológica, permitindo-lhes confirmar ou excluir uma doença. Objetivo: Explicar aos especialistas em reabilitação cardiopulmonar os conceitos necessários para interpretar criticamente os resultados dos testes de diagnóstico. Materiais e métodos: Revisão narrativa da literatura, fornecendo conceitos atualizados, exemplos e gráficas com uma abordagem académica e didática. Resultado: Os conceitos de sensibilidade, especificidade, valores preditivos positivos e negativos e razões de verossimilhança positivas e negativas e a sua interpretação no normograma de Fagan foram atualizados e explicados com exemplos do trabalho diário do especialista. Conclusão: A compreensão dos conceitos que acompanham a avaliação dos testes de diagnóstico ajuda aos especialistas em reabilitação cardiopulmonar na analise critica dos resultados das ajudas clínicas funcionais e estruturais dos pacientes e, desta forma, caracterizar bem o diagnóstico e o acompanhamento dos indivíduos

Motivos y complicaciones relacionadas con el rechazo de pruebas diagnósticas y recomendaciones terapéuticas en cardiopatías familiares. Estudio RELUCTANT / Reasons for refusing diagnostic tests and therapeutic recommendations and associated complications in inherited heart diseases. The RELUCTANT study

Introducción y objetivos: El estudio de las cardiopatías familiares implica realizar pruebas diagnósticas, a veces molestas, a familiares asintomáticos. El objetivo de este proyecto es cuantificar el rechazo a dichas pruebas y recomendaciones terapéuticas. Métodos: Se evaluó a 1.992 familias consecutivas con cardiopatías familiares para analizar el rechazo al cribado familiar. Se evaluó a 1.539 (recomendación de cardiorresonancia) y 837 (recomendación de test de provocación farmacológica). Se evaluó a 395 pacientes con indicación de desfibrilador automático implantable (DAI) y 402 con indicación de anticoagulación, para estudiar el rechazo de los tratamientos. Resultados: El 28% de las familias a las que se recomienda estudio por sospecha de cardiopatía familiar no acuden; el rechazo es menor si hay antecedentes familiares de muerte súbita. El 23% no se sometió a la resonancia; los 2 motivos más alegados son citación imposible (53%) y claustrofobia (18%). Las personas de más edad, las mujeres, los sintomáticos, los individuos con arritmias y los familiares rechazaron más la prueba. El 19% no se hizo el test de provocación farmacológica por temor (46%) o citación imposible (25%). Los individuos de más edad, los asintomáticos, aquellos con antecedente de arritmias, los familiares y aquellos con estudio genético positivo lo rechazaron en mayor proporción. Solo una minoría de pacientes rechazaron los tratamientos (el 5,1% el DAI y el 2,5% la anticoagulación). La tasa de muerte súbita entre los que rechazaron el DAI fue alta (el 4,5% al año). Conclusiones: Una quinta parte de las personas que acuden al cribado de cardiopatías familiares rechazan la realización de pruebas más sofisticadas y molestas. Se identifican varios predictores independientes asociados con el rechazo. Solo una minoría de pacientes en alto riesgo rechazan los tratamientos como la anticoagulación o el implante de DAI. (AU)

Introduction and objectives: Study of inherited heart diseases (IHD) involves performing diagnostic tests, which are sometimes inconvenient or stressful, in asymptomatic relatives. The aim of this study was to analyze refusal to undergo various diagnostic tests and follow therapeutic recommendations. Methods: We assessed 1992 consecutive families with IHD to analyze refusal to undergo family screening. The study included 1539 individuals who were recommended to undergo cardiac magnetic resonance, and 837 who were recommended a drug challenge test. To study treatment refusal, we assessed 395 patients with an indication for an implantable cardioverter-defibrillator (ICD) and 402 patients with an indication for anticoagulation. Results: A total of 28% of families who were recommended to undergo screening for suspected IHD did not attend, but refusal was lower if there was a family history of sudden cardiac death. In all, 23% did not undergo magnetic resonance, and the 2 main reasons were administrative problems (53%) and claustrophobia (18%). Refusal was more common in older people, women, symptomatic persons, individuals with arrhythmias, and relatives. Nearly one fifth (19%) did not take the drug challenge test, due to fear (46%) or administrative issues (25%). Refusal was more frequent in older individuals, asymptomatic persons, those with a history of arrhythmias, relatives, and those with a positive genetic study. Only a minority of patients rejected the treatments (5.1% ICD, 2.5% anticoagulation). The percentage of sudden cardiac death in persons rejecting ICD implantation was high (4.5% per year). Conclusions: One fifth of people attending screening for IHD refused to undergo more sophisticated and stressful tests. This study identified several independent predictors associated with refusal. Only a minority of high-risk patients refused treatments such as ICD implantation and anticoagulation. (AU)

Testing COVID-19 in Brazil: fragmented efforts and challenges to expand diagnostic capacity at the Brazilian Unified National Health System / A testagem para COVID-19 no Brasil: esforços fragmentados e desafios para ampliar a capacidade diagnóstica no Sistema Único de Saúde / Testar para COVID-19 en Brasil: esfuerzos fragmentados y desafíos para expandir la capacidad diagnóstica en el Sistema Único de Salud

Abstract: Since the first recorded case of COVID-19 on February 26, 2020, Brazil has seen an exponential growth in the number of cases and deaths. The national testing approach has been insufficient to correctly use this tool in the support of containing the epidemic in the country. In this communication, we discuss efforts and challenges to scale-up COVID-19 testing at the Brazilian Unified National Health System (SUS). This communication presents the initial results of the research project created to investigate the political, industrial, technological, and regulatory aspects that may affect the diagnostic and testing capacity for COVID-19 in Brazil. The paper draws on the review of academic literature, media publication, and collection of public data on tests purchase and regulation. It enlists initiatives to enhance PCR testing, national production and development of technologies, as well as regulatory measures to fast-track new tests. Our analysis indicates some points of reflection. Firstly, the lack of a consistent national strategy to fight COVID-19 exarcebated supply problems of diagnostic components. If the country was eventually able to circumvent this situation, it still faces a more structural dependency on the importation of diagnostic components. Secondly, the discontinued funding and distribution of tests may have implied health policy fragmentation and the growing importance of local governments and non-state actors to fighting the epidemics within SUS. Finally, initiatives established since the second semester of 2020 have expanded the testing capacity at SUS. However, it has not been sufficient to control the progress of the epidemic in the country.

Resumo: Desde que o primeiro caso de COVID-19 no Brasil foi notificado, em 26 de fevereiro de 2020, o país assiste a um crescimento exponencial no número de casos e mortes. A estratégia nacional de testagem tem sido insuficiente para usar essa ferramenta corretamente no apoio à contenção da epidemia no país. O artigo discute os esforços e desafios para escalonar a testagem para COVID-19 no Sistema Único de Saúde (SUS). O texto apresenta os resultados iniciais de um projeto de pesquisa sobre os aspectos políticos, industriais, tecnológicos e regulatórios que podem afetar a capacidade diagnóstica e de testagem para COVID-19 no Brasil. O estudo se apoia em revisão da literatura cientifica, artigos publicados na mídia e coleta de dados públicos sobre a compra e regulamentação de testes. O texto faz referência a iniciativas para ampliar a testagem de PCR, a produção nacional e o desenvolvimento de tecnologias, além de medidas regulatórias fast-track para novos testes. Nossa análise sugere alguns pontos para reflexão. Primeiro, a falta de uma estratégia nacional consistente para combater a COVID-19 agravou os problemas de fornecimento de reagentes de diagnostico num primeiro momento. Esta situação foi posteriormente resolvida, embora coloque novamente em pauta a dependência estrutural do país na importação de insumos de saúde estratégicos. Em segundo lugar, financiamento e a distribuição de testes, que ocorreram de forma descontinuada, podem indicar a fragmentação da política sanitária, assim como o papel de governos estaduais, municipais e atores não estatais no combate à epidemia no âmbito do SUS. Por último, iniciativas estabelecidas no segundo semestre de 2020 contribuíram para ampliar a capacidade de testagem molecular no SUS. Contudo, essa capacidade não foi suficiente para controlar a epidemia no Brasil.

Resumen: Desde que se registró el primer caso de COVID-19 el 26 de febrero de 2020, Brasil ha visto un crecimiento exponencial en el número de casos y muertes. La estrategia nacional para preconizar el test de diagnóstico ha sido insuficiente en el uso correcto de esta herramienta, con el fin de ayudar a contener la epidemia en el país. Se presentó los esfuerzos y los desafíos para ampliar la realización de pruebas de COVID-19 en el Sistema Único de Salud brasileño (SUS). Este artículo presenta los resultados iniciales del proyecto de investigación sobre los aspectos políticos, industriales, tecnológicos y regulatorios que pueden afectar la capacidad de diagnóstico para la COVID-19 en Brasil. El grupo de investigación realizó una revisión de la literatura académica, medios de comunicación y recogida de datos públicos respecto a la adquisición de tests y su regulación. Se haz referencia a iniciativas para promover la realización de pruebas de PCR, la producción nacional y el desarrollo de tecnologías, así como las medidas regulatorias fast-track para nuevas pruebas. Nuestro análisis indica algunos puntos de reflexión. Primero, la falta de una estrategia nacional consistente para luchar contra la COVID-19 que exacerbó los problemas de sumistro de los componentes de diagnóstico en un primer momento. Se solucionó posteriormente esta situación, aunque se coloque nuevamente en pauta la dependencia estructural del país en la importación de insumos de salud estratégicos. Segundo, la financiación y la distribución de tests de forma descontinuada pueden indicar la fragmentación de la política de salud, así como los gobiernos estaduales, municipales, y atores no estatales asumiendo un rol preponderante en acciones de combate a la epidemia en el SUS. En último, las iniciativas establecidas en el segundo semestre del 2020 contribuyeron para ampliar la capacidad de realización de tests moleculares en el SUS. Sin embargo, esa capacidad no fue suficiente para controlar la epidemia en Brasil.

Condutas que podem interferir na fase pré- analítica do exame sumário de urina / Conductas que pueden interferir en la fase preanalítica de la prueba sumaria de orina / Conducts that may interfere in the pre-analytical phase of the urine summary test

RESUMO Objetivo: identificar as condutas pré-analíticas que podem influenciar nos resultados do exame sumário de urina. Método: trata-se de um estudo exploratório, descritivo, do tipo transversal, de natureza quantitativa, realizada com 246 pacientes de um laboratório público de referência do município de João Pessoa, Paraíba, durante os meses de junho e julho de 2019. A análise de dados foi realizada por estatística descritiva e inferencial, com Teste de Qui-Quadrado e Correlação de Spearman, elencado após o teste de Kolmogorov-Sminorv. Resultados: em relação ao conhecimento sobre o exame, 138 (56,1%) dos participantes afirmaram possuí-lo, porém 174 (70,7%) relataram não terem sido orientados antes da coleta do exame. A correlação evidenciou que, quanto maior o conhecimento, mais adequadas eram as condutas pré-analíticas. Conclusão: observou-se baixo nível de conhecimento sobre o procedimento, contribuindo para condutas pré-analíticas inadequadas. Destaca-se a importância de ofertar ao cliente orientações sobre a coleta do exame.

RESUMEN Objetivo: identificar las condiciones preanalíticas que pueden influir en los resultados de la prueba sumaria de orina. Método: se trata de un estudio exploratorio, descriptivo, transversal, de carácter cuantitativo, realizado con 246 pacientes de un laboratorio público de referencia del municipio de João Pessoa, Paraíba, durante los meses de junio y julio de 2019. El análisis de los datos se realizó mediante estadísticas descriptivas e inferenciales, con la prueba de Chi-cuadrado y la correlación de Spearman, que figuran después de la prueba de Kolmogorov-Smirnov. Resultados: en cuanto a los conocimientos sobre el examen, 138 (56,1%) de los participantes afirmaron tenerlos, pero 174 (70,7%) declararon no haber recibido orientación antes del examen. La correlación demostró que cuanto mayor era el conocimiento, más adecuados eran los procedimientos preanalíticos. Conclusión: se observó un bajo nivel de conocimiento sobre el procedimiento, lo que contribuyó a que las conclusiones preanalíticas fueran inadecuadas. Destaca la importancia de ofrecer al cliente orientaciones sobre la coleta de la prueba.

ABSTRACT Objective: to identify the pre-analytical conducts that can influence the results of the urine summary test. Method: this is an exploratory, descriptive, cross-sectional study, of quantitative nature, conducted with 246 patients from a public reference laboratory in the municipality of João Pessoa, Paraíba, during the months of June and July 2019. Data analysis was performed by descriptive and inferential statistics, with Chi-square Test and Spearman Correlation, cast after Kolmogorov-Smirnov test. Results: regarding knowledge about the exam, 138 (56.1%) of the participants said they had it, but 174 (70.7%) reported not having been instructed before the exam. The correlation showed that the greater the knowledge, the more appropriate were the pre-analytical procedures. Conclusion: a low level of knowledge about the procedure was observed, contributing to inadequate pre-analytical conducts. The importance of offering the client guidance on the collection of the exam is highlighted.

Salud pública y pruebas diagnósticas del COVID-19: caso Venezuela / Public health and diagnostics tests for SARS-COVID-2 infection: The venezuela case

La salud pública mundial presenta en la actualidad un reto de grandes dimensiones para realizar las funciones esenciales del Siglo XXI, "el diagnóstico temprano y el tratamiento preventivo de las enfermedades"; por lo tanto la OMS considera que para conocer la magnitud de la epidemia COVID-19 es básico contar con suficientes pruebas diagnósticas en cantidad y calidad. En Venezuela, el Ministerio de la Salud comunica que se han realizado más de 80.484 pruebas por millón de habitantes (marzo-diciembre 2020), las más altas de la región; sin embargo, las pruebas diagnósticas de PCR y Prueba de antígenos, no alcanzan a 1.488,8 (105) y 11,9 (105) respectivamente, muy bajas. Se revisan las pruebas más usadas para detección de genoma, antígenos y serología, mediante pruebas de tiempo y rápidas, ambulatorias o de estricto manejo en laboratorio(AU)

Global public health currently presents a major challenge in performing the essential functions of the 21st century, "early diagnosis and preventive treatment of diseases", so WHO believes that sufficient diagnostic evidence in quantity and quality is essential to understand the scale of the COVID-19 epidemic. In Venezuela, the Ministry of Health reports that more than 80,484 tests per million inhabitants (march-december 2020) have been carried out; however, diagnostic tests of PCR and Antigen Test, do not reach 14,888 (106) and 110 (106) respectively, which is very low compared to neighboring countries. The most commonly used tests for genome, antigen and serology are reviewed(AU)

Métodos de diagnóstico para la detección de la infección por Helicobacter pylori / Diagnostic methods for detection of Helicobacter pylori infection

Helicobacter pylori (H. pylori) is a Gram-negative bacterium that survives in gastric acidity. Approximately 50% of the world population is a carrier of this infection and the prevalence is higher in African and Latin American populations. The clinical manifestations associated with this infection are gastritis, peptic ulcers, MALT lymphoma, gastric cancer (GC), and other extra-digestive pathologies. Chronic H. pylori infection is the most important risk factor for GC development. There are several diagnostic methods to detect H. pylori infection. The most widely used invasive methods are the rapid urease test and Giemsa staining in gastric biopsies. Culture and molecular techniques are very useful for the study of H. pylori presence and antibiotic resistance, but they are not easily available in health centers. The most widely used non-invasive methods are the urea breath test and bacterial antigens in stools. Serological studies are used for population studies. The use and indication of the diagnostic method for detecting H. pylori infection will depend on the clinical manifestations, risk factors for GC, and the age of the patient.

Helicobacter pylori (H. pylori) es una bacteria Gram negativa que sobrevive a la acidez gástrica. Se estima que aproximadamente el 50% de la población mundial es portadora de esta infección, siendo mayor la prevalencia en poblaciones africanas y latinoamericanas. Entre las manifestaciones clínicas asociadas a esta infección se encuentra gastritis, úlceras pépticas, linfoma MALT, cáncer gástrico y otras patologías extradigestivas. La infección crónica por H. pylori es el factor de riesgo más importante para el desarrollo de CG. Existen diversos métodos diagnósticos para detectar la infección por H. pylori, los métodos invasivos más utilizados son la prueba rápida de ureasa y tinción de Giemsa en biopsias gástricas. El cultivo y las técnicas moleculares son de gran utilidad para el estudio de presencia de H. pylori y estudios de resistencia antibiótica, pero suelen estar poco disponibles en los centros de atención en salud. Los métodos no invasivos más utilizados son la prueba de aire espirado con urea marcada y antígeno bacteriano en deposiciones. Los estudios serológicos son utilizados para estudios poblacionales. El uso e indicación de cada uno de los métodos de diagnóstico para la detección de infección por H. pylori, dependerá de las manifestaciones clínicas, los factores de riesgo de CG y la edad del paciente.