Current characteristics of patients with hepatitis C virus: results from an automated alert system.

Alert systems are proving to be useful to increase hepatitis C virus (HCV) diagnoses and facilitating access to antiviral treatment. Since 2020, our health department has had a fully automated alert system set up at the Microbiology Department. In this study, we present the results of the 2022-2023 period to assess the current characteristics of HCV diagnosed patients. In addition, we analyzed, through a comparison, whether a limitation that we noticed during the 2020-2021 period (whose results were published) is still present. This limitation consists of that 24.2% (34/134) of those candidates for antiviral treatment were not treated because they could not be located or refused treatment. During the 2022-2023 period, 188 new cases were diagnosed, and 75% (141/188) were treated. The comparison of both periods showed that in 2022-2023, the rate of treatment rejection by the patient was significantly lower (1.4% vs 14.5%, p < 0.05) and, therefore, the rate of antiviral treatment increased (75% vs 58.9%, p < 0.05). These results suggest that our alert system is useful and efficient for the diagnosis and treatment of HCV.

Outcomes of an automated alert system from Microbiology to link diagnosis to treatment in patients with hepatitis C virus.

INTRODUCTION: simplification strategies for the care circuit of patients with hepatitis C virus (HCV) are key to achieve eradication. An electronic identification system was set up for HCV serology to link diagnosis to specialist management, aimed to reduce patient loss. MATERIAL AND METHODS: a retrospective, single-center study was performed in patients with HCV identified from 15/3/2020 to 15/12/2021, using an alert system from Microbiology that notified specialists of positive cases. The patient was contacted and appointed a Fibroscan® and viral load measurement, with antiviral therapy prescribed on the same day. Origin, public health data, patient location rate and antiviral therapy prescription were recorded. RESULTS: of 174 patients identified, 171 had positive viremia, with a mean age of 59.6 ± 15.9 years, 61.5 % were males and 81.2 % were Spanish nationals. Origin in the outpatient setting predominated (57.9 %, 99/171), particularly Primary Care (51/171), penitentiaries (21/171) and addiction units (14/171). Overall, 43.3 % (74/171) were aware of their diagnosis; 19.4 % (20/103) of patients had F3 fibrosis and 25.2 % (26/103) had F4 fibrosis. Also, 78.4 % (134/171) were deemed candidates for treatment. Of these, 74.6 % (100/134) were located and treatment was initiated, and all those who completed their treatment achieved a sustained viral response (96/96). This system managed 58.5 % (100/171) of the patients identified. The only association found between antiviral therapy and patient variables was comorbidities with being untreated (OR, 7.14; p ˂ 0.001). CONCLUSIONS: this alert system allows to minimize patient loss in the care circuit and provides high rates of treated patients.

Abnormal liver chemistry constitutes an independent prognostic factor of less favorable clinical course in patients with COVID-19.

INTRODUCTION: abnormal liver biochemistry (ALB) is correlated with increased clinical involvement or severity in COVID-19, but its prognostic implications have not been studied extensively. The aim of this study was to determine whether ALB is a risk factor for unfavorable clinical outcome and involvement. MATERIALS AND METHODS: a retrospective, single-center study in confirmed COVID-19 cases. Patients with pharmacological hepatotoxicity or liver diseases were excluded. ALB was defined as any elevation of total bilirubin, AST, ALT, alkaline phosphatase, and/or GGT above the upper limit of normal. First, an assessment was made of the correlation between ALB and need for hospitalization. This was followed by an assessment of the correlation of ALB in hospitalized patients with demographic variables, comorbidities, and treatment for COVID-19, and with clinical involvement and outcome. The statistical analysis was performed using an age-adjusted multiple logistic regression with a p-value < 0.05. RESULTS: of 1,277 confirmed cases, 346 required hospitalization and 302 were included. The prevalence of ALB was higher in hospitalized patients compared to non-hospitalized patients (60.9 % vs. 10.3 %, p ˂ 0.001). Among hospitalized patients, there was no correlation between ALB and demographic variables, comorbidities, or treatment for COVID-19, except for low molecular weight heparin. There was a significant correlation between ALB and moderate/severe COVID-19 involvement and between unfavorable clinical outcomes and elevated total bilirubin. The period of greatest clinical worsening and deterioration of liver biochemistry parameters occurred during the first seven days. There was a significant correlation of ALB with longer hospital stay and admission to the intensive care unit, but this did not imply increased mortality. CONCLUSIONS: ALB correlates with greater clinical involvement and worse clinical outcomes in hospitalized patients with COVID-19.

Clinical and Demographic Features of 49 Patients With Human Monkeypox Virus-Confirmed Infection in a Tertiary Care Center in Valencia, Spain: A Descriptive Study.

Monkeypox is a previously rare viral zoonosis affecting predominantly the African continent. Since May 2022, an increasing number of cases with no known epidemiologic link to Africa have been reported for the first time in the rest of the world. We described the epidemiologic and clinical characteristics of all patients attended at our center until August 9 with a confirmed diagnosis of monkeypox. Forty-nine patients were included. The mean age was 37.6 years. Ninety-eight percent of patients were male, 96% were men who have sex with men, and 4% were heterosexual. Thirty-one percent of patients had a history of human immunodeficiency virus infection. Ninety-six percent of patients declared a unprotected sexual relationship before the onset of symptoms, and 41% had a history of recent travel. Ninety-eight percent of patients presented with cutaneous involvement affecting the genital (59%), perianal (41%), and perioral (35%) regions. Systemic symptoms were present in 80% of the patients and included lymphadenopathies (71%), asthenia (65%), fever (65%), headache (37%), arthromyalgias (45%), pharyngitis (35%), proctitis (29%), and dysuria (6%). Coinfection by other sexually transmitted infections was detected in 20% of patients. The sensitivity values of polymerase chain reaction test for monkeypox in urethral, anal, and oropharyngeal exudates analyzed were 88%, 79%, and 68%, respectively. Complications included a myopericarditis that represented the only hospitalized patient, edema (8%) and bacterial superinfection (4%). No deaths were reported. The findings of this case series support the sexual contact as the main route of transmission of the disease and highlight some atypical clinical presentations not described in endemic cases.

[Validation and verfication of microbiology methods]. / Validación y verificación analítica de los métodos microbiológicos.

Clinical microbiologists should ensure, to the maximum level allowed by the scientific and technical development, the reliability of the results. This implies that, in addition to meeting the technical criteria to ensure their validity, they must be performed with a number of conditions that allows comparable results to be obtained, regardless of the laboratory that performs the test. In this sense, the use of recognized and accepted reference methodsis the most effective tool for these guarantees. The activities related to verification and validation of analytical methods has become very important, as there is continuous development, as well as updating techniques and increasingly complex analytical equipment, and an interest of professionals to ensure quality processes and results. The definitions of validation and verification are described, along with the different types of validation/verification, and the types of methods, and the level of validation necessary depending on the degree of standardization. The situations in which validation/verification is mandatory and/or recommended is discussed, including those particularly related to validation in Microbiology. It stresses the importance of promoting the use of reference strains as controls in Microbiology and the use of standard controls, as well as the importance of participation in External Quality Assessment programs to demonstrate technical competence. The emphasis is on how to calculate some of the parameters required for validation/verification, such as the accuracy and precision. The development of these concepts can be found in the microbiological process SEIMC number 48: «Validation and verification of microbiological methods¼ www.seimc.org/protocols/microbiology.

Comparison of culture media for the detection of Legionella spp. in sanitary water samples: Adaptation to ISO 11731:2017.

INTRODUCTION: Water sample culturing is the reference method to detect Legionella spp. in sanitary facilities. Until 2017, UNE-EN ISO 11731 only included the GVPC medium, which inhibits interfering microbiota but hinders the growth of Legionella spp. To improve its recovery, the new standard incorporates the BCYE medium into the working protocol. METHODS: We inoculated 1306 sanitary water samples onto BCYE and GVPC according to an accredited internal procedure. We compared the number of cfu/L of Legionella spp. detected in both media. RESULTS: The median in BCYE was 2000 cfu/L higher than in GVPC (P = .000). In the presence of high amounts of interfering microbiota, both media were similar; in the absence or low interfering microbiota BCYE was four times more sensitive than GVPC (P = .000). CONCLUSION: Including BCYE in the analysis of sanitary water significantly improves the recovery of Legionella spp. in low contaminated samples.

Opportunistic population screening as a hepatitis elimination strategy: the CRIVALVIR-FOCUS program.

OBJECTIVES: Hepatitis B (HBV) and hepatitis C (HCV) viruses are significant causes of primary liver cancer, responsible for over a million deaths annually. We aimed to develop a screening strategy for viral hepatitis elimination in Spain, aligned with WHO's 2030 objectives. DESIGN: The CRIVALVIR-FOCUS program, conducted at the Consortium General University Hospital of Valencia, aimed to identify individuals with active blood-borne viral infections through opportunistic population screening. The hospital's Health Department serves more than 280,000 adults. RESULTS: Of the 31,995 adults screened (52% women; 15% immigrants), HBV prevalence was 0.44%, with higher rates in men (0.57%) than women (0.32%), and notably higher in migrants (1.27%) compared to Spanish nationals (0.30%). The 45-64 age group had the highest HBV prevalence (0.65%). HCV prevalence was 0.35%, again higher in men than women (0.51% vs 0.20%) and in migrants compared to Spanish nationals (0.58% vs 0.31%), with the 45-64 age group showing the highest HCV prevalence (0.76%). From the positive tests, 78.0% (110/141) of HBV cases and 71.4% (80/112) of HCV cases were patients previously unaware of their infections. CONCLUSION: Opportunistic screening effectively identifies early cases, potentially enhancing prevention of new infections. Our study highlights the need for targeted interventions for individuals aged 45-64 and migrants. Designing specific screening programs, in collaboration with social workers and cultural mediators, is critical to improve access to care. Training and involving primary care professionals are vital actions for the program's success.

Prospective observational study on scar sequelae after MPOX infection: an analysis of 40 patients.

BACKGROUND: Monkeypox (MPOX) caused a public health emergency of international concern (PHEIC) outbreak between 2022 and 2023, with a recent rise in cases that prompted the World Health Organization (WHO) to declare the disease a PHEIC once again. There is little information on its long-term scarring sequelae. OBJECTIVES: The objective of this study was to assess the risk and characteristics of scarring in patients with MPOX in a tertiary hospital. METHODS: This is a prospective cohort study including patients diagnosed using polymerase chain reaction (PCR) tests. Clinical data were collected and followed up at 12-15 months to assess scarring and its impact on quality of life. RESULTS: Of the 40 patients, 19 (47.5%) developed scars, which were more common in those with initial cutaneous manifestations. Scars significantly affected the quality of life, especially in the genital and mucosal areas. The limited sample and loss to follow-up may affect the validity of the results. CONCLUSION: Scarring is a frequent and disfiguring sequela of MPOX, particularly in patients with early skin symptoms. Prevention and close follow-up are crucial in mitigating these complications.

The first case of fungal endogenous endophthalmitis caused by Aspergillus nidulans: Diagnostic and therapeutic challenge.

SIGNIFICANCE: Fungal endogenous endophthalmitis is an uncommon and potentially blinding infection. Aspergillus is a causative organism in immunocompromized although is virulent enough to afflict immunocompetents. Their propensity to affect macula usually results in a dismal prognosis; thus, improving visual outcome has always been challenging to clinicians. A. nidulans has only rarely been implicated in exogenous endophthalmitis. PURPOSE: To report the first case of A. nidulans endogenous endophthalmitis. CASE REPORT: An asthmatic 42-year-old female presented with sudden unilateral vision loss due to a submacular abscess that progressively worsened in a matter of days. Vitreous PCR analysis after an urgent vitrectomy was positive for A. nidulans with no active systemic foci found. Oral and intravitreal Voriconazole was prescribed but multiple reactivations led to three vitrectomies in total alongside with subretinal Voriconazole, abscess aspiration, and endolaser. There was complete resolution of the infection and, although visual acuity was poor due to macular scar, enucleation was avoided. CONCLUSION: Although uncommon, we must consider Aspergillus as the causative organism in apparently immunocompetent patients with history of recent systemic corticosteroids treatment, especially if they suffer a broncopulmonary disorder. Aspergillus is an aggressive organism so a high index of suspicion along with early diagnosis and prompt treatment is the key for better outcomes. We highlight A. nidulans as the causative agent as there are no other reported cases.

[Epidemiological and clinical analysis of community-acquired Mycoplasma pneumonia in children from a Spanish population, 2010-2015]. / Características clínicas y epidemiológicas de las neumonías adquiridas en la comunidad por Mycoplasma pneumoniae en una población española, 2010-2015.

INTRODUCTION AND OBJECTIVES: Mycoplasma pneumoniae (MP) is one of the most common etiological agents of community-acquired pneumonia (CAP) in children. We aimed to describe the clinical and epidemiological characteristics, treatment and outcome of children diagnosed with community-acquired MP pneumonia (CAMP) in a tertiary hospital in Valencia, Spain. MATERIAL AND METHODS: Medical records of children <14 years with CAMP were retrospectively reviewed from January 2010 to December 2015. Patients with radiological evidence of pneumonia and microbiological confirmation of MP (PCR from nasopharyngeal swab and/or serum specific IgM) were considered CAMP. RESULTS: One hundred and sixty two children were diagnosed with CAMP; median age 6 years (IQR: 4-9). The positive MP test rate among children with CAP progressively increased with age as did the empirical use of macrolides. There were two peaks of cases in 2011 and in 2015, being July, August, November and December the seasons with the higher number of cases. The most frequent radiological pattern was segmental infiltrate (62.3%) and 22 (13.6%) children had pleural effusion. It was noteworthy the mild symptomatology and low levels of inflammatory parameters that children with CAMP had. A macrolide was empirically initiated in 68.5% of cases. Hospital admission rate was inversely proportional to patient's age. CONCLUSIONS: According to this study, older, less symptomatic patients and with lower inflammatory parameters had the greatest rate of MP infection among children with CAP and thus they could benefit of empiric macrolide therapy. Therefore, knowing the epidemiology of a geographical area may be important for the management of CAP in children.

Epidemiological and clinical analysis of community-acquired Mycoplasma pneumonia in children from a Spanish population, 2010-2015.

INTRODUCTION AND OBJECTIVES: Mycoplasma pneumoniae (MP) is one of the most common etiological agents of community-acquired pneumonia (CAP) in children. We aimed to describe the clinical and epidemiological characteristics, treatment and outcome of children diagnosed with community-acquired MP pneumonia (CAMP) in a tertiary hospital in Valencia, Spain. MATERIAL AND METHODS: Medical records of children <14 years with CAMP were retrospectively reviewed from January 2010 to December 2015. Patients with radiological evidence of pneumonia and microbiological confirmation of MP (PCR from nasopharyngeal swab and/or serum specific IgM) were considered CAMP. RESULTS: One hundred and sixty two children were diagnosed with CAMP; median age 6 years (IQR: 4-9). The positive MP test rate among children with CAP progressively increased with age as did the empirical use of macrolides. There were two peaks of cases in 2011 and in 2015, being July, August, November and December the seasons with the higher number of cases. The most frequent radiological pattern was segmental infiltrate (62.3%) and 22 (13.6%) children had pleural effusion. It was noteworthy the mild symptomatology and low levels of inflammatory parameters that children with CAMP had. A macrolide was empirically initiated in 68.5% of cases. Hospital admission rate was inversely proportional to patient's age. CONCLUSIONS: According to this study, older, less symptomatic patients and with lower inflammatory parameters had the greatest rate of MP infection among children with CAP and thus they could benefit of empiric macrolide therapy. Therefore, knowing the epidemiology of a geographical area may be important for the management of CAP in children.

INTRODUCCIÓN Y OBJETIVOS: Mycoplasma pneumoniae (MP) es uno de los agentes etiológicos más comunes de las neumonías adquiridas en la comunidad (NAC) en niños. Objetivo: describir las características clínicas y epidemiológicas, tratamiento y evolución de los pacientes con NAC por MP (NACM) en un hospital terciario de Valencia, España. MATERIAL Y MÉTODOS: Se revisaron retrospectivamente las historias clínicas de los niños < 14 años con NACM entre enero de 2010 y diciembre de 2015. Los pacientes con evidencia radiológica de neumonía y confirmación microbiológica de MP (PCR de exudado nasofaríngeo y/o anticuerpos IgM específicos frente a MP) se consideraron NACM. RESULTADOS: Un total de 162 pacientes se diagnosticaron de NACM; mediana de edad de 6 años (rango intercuartílico: 4-9 años). La proporción de pruebas positivas para MP en pacientes con NAC, así como el uso empírico de macrólidos, aumentó progresivamente con la edad. Hubo un pico de casos en 2011 y en 2015, con un máximo de casos en julio, agosto, noviembre y diciembre. El patrón radiológico más frecuente fue el infiltrado segmentario (62,3%), mientras que 22 (13,6%) presentaron derrame pleural. Los niños con NACM desarrollaron una clínica leve, con poca elevación de parámetros inflamatorios. Se inició tratamiento empírico con un macrólido en el 68,5% de los casos. La necesidad de ingreso hospitalario fue inversamente proporcional a la edad del paciente. CONCLUSIONES: Según este estudio, los niños con NAC de mayor edad tuvieron la mayor proporción de infección por MP, siendo poco sintomáticos y con escasa elevación de parámetros inflamatorios, pudiéndose beneficiar del tratamiento empírico con macrólidos. Por consiguiente, conocer la epidemiología de un área geográfica podría ser importante para el abordaje de las NAC en niños.

Características clínicas y epidemiológicas de las neumonías adquiridas en la comunidad por Mycoplasma pneumoniae en una población española, 2010-2015 / Epidemiological and clinical analysis of community-acquired Mycoplasma pneumonia in children from a Spanish population, 2010-2015

Introducción y objetivos: aMycoplasma pneumoniae (MP) es uno de los agentes etiológicos más comunes de las neumonías adquiridas en la comunidad (NAC) en niños. Objetivo: describir las características clínicas y epidemiológicas, tratamiento y evolución de los pacientes con NAC por MP (NACM) en un hospital terciario de Valencia, España. Material y métodos: Se revisaron retrospectivamente las historias clínicas de los niños<14 años con NACM entre enero de 2010 y diciembre de 2015. Los pacientes con evidencia radiológica de neumonía y confirmación microbiológica de MP (PCR de exudado nasofaríngeo y/o anticuerpos IgM específicos frente a MP) se consideraron NACM. Resultados: Un total de 162 pacientes se diagnosticaron de NACM; mediana de edad de 6 años (rango intercuartílico: 4-9 años). La proporción de pruebas positivas para MP en pacientes con NAC, así como el uso empírico de macrólidos, aumentó progresivamente con la edad. Hubo un pico de casos en 2011 y en 2015, con un máximo de casos en julio, agosto, noviembre y diciembre. El patrón radiológico más frecuente fue el infiltrado segmentario (62,3%), mientras que 22 (13,6%) presentaron derrame pleural. Los niños con NACM desarrollaron una clínica leve, con poca elevación de parámetros inflamatorios. Se inició tratamiento empírico con un macrólido en el 68,5% de los casos. La necesidad de ingreso hospitalario fue inversamente proporcional a la edad del paciente. Conclusiones: Según este estudio, los niños con NAC de mayor edad tuvieron la mayor proporción de infección por MP, siendo poco sintomáticos y con escasa elevación de parámetros inflamatorios, pudiéndose beneficiar del tratamiento empírico con macrólidos. Por consiguiente, conocer la epidemiología de un área geográfica podría ser importante para el abordaje de las NAC en niños

Introduction and objectives: Mycoplasma pneumoniae (MP) is one of the most common etiological agents of community-acquired pneumonia (CAP) in children. We aimed to describe the clinical and epidemiological characteristics, treatment and outcome of children diagnosed with community-acquired MP pneumonia (CAMP) in a tertiary hospital in Valencia, Spain. Material and methods: Medical records of children <14 years with CAMP were retrospectively reviewed from January 2010 to December 2015. Patients with radiological evidence of pneumonia and microbiological confirmation of MP (PCR from nasopharyngeal swab and/or serum specific IgM) were considered CAMP. Results: One hundred and sixty two children were diagnosed with CAMP; median age 6 years (IQR: 4-9). The positive MP test rate among children with CAP progressively increased with age as did the empirical use of macrolides. There were two peaks of cases in 2011 and in 2015, being July, August, November and December the seasons with the higher number of cases. The most frequent radiological pattern was segmental infiltrate (62.3%) and 22 (13.6%) children had pleural effusion. It was noteworthy the mild symptomatology and low levels of inflammatory parameters that children with CAMP had. A macrolide was empirically initiated in 68.5% of cases. Hospital admission rate was inversely proportional to patient's age. Conclusions: According to this study, older, less symptomatic patients and with lower inflammatory parameters had the greatest rate of MP infection among children with CAP and thus they could benefit of empiric macrolide therapy. Therefore, knowing the epidemiology of a geographical area may be important for the management of CAP in children

Resultados de un sistema de alertas automático desde Microbiología para ligar diagnóstico y tratamiento en pacientes con virus de la hepatitis C / Outcomes of an automated alert system from Microbiology to link diagnosis to treatment in patients with hepatitis C virus

Introducción: las estrategias de simplificación del circuitoasistencial para pacientes con virus de la hepatitis C (VHC)son fundamentales para lograr su erradicación. Para ello,introdujimos un sistema electrónico de detección de serología VHC con el objetivo de ligar diagnóstico y asistenciaespecializada para disminuir la pérdida de pacientes.Material y métodos: estudio retrospectivo unicéntrico depacientes VHC detectados del 15/3/2020 al 15/12/2021 mediante un sistema de alertas desde Microbiología que notificaba los casos positivos a facultativos especialistas. Se contactaba con el paciente concertando una cita donderealizaban Fibroscan® y determinación de carga viral y sepautaba tratamiento antiviral el mismo día. Registramosprocedencia, datos sociosanitarios, tasa de localización delpaciente y prescripción de tratamiento antiviral.Resultados: de 174 pacientes detectados, 171 presentaronviremia positiva, con edad media de 59,6 ± 15,9 años, un61,5 % varones y el 81,2 % españoles. Predominó la procedencia del ámbito extrahospitalario (57,9 %, 99/171), destacando Atención Primaria (51/171), centro penitenciario(21/171) y unidades de adicción (14/171). El 43,3 % (74/171)conocía el diagnóstico. Registramos un 19,4 % (20/103) depacientes con fibrosis F3 y un 25,2 % (26/103) con F4. Consideramos candidatos a tratamiento al 78,4 % (134/171). Deestos, fueron localizados e iniciaron tratamiento el 74,6 %(100/134) y lograron respuesta viral sostenida todos los quelo completaron (96/96). Con este sistema hemos tratado al58,5 % (100/171) de los pacientes detectados. La única asociación detectada entre tratamiento antiviral y variablesdel paciente fue que presentar comorbilidades se asociócon no ser tratado (OR 7,14, p < 0,001).Conclusiones: este sistema de alerta permite minimizar lapérdida de pacientes en el circuito asistencial y presentatasas elevadas de pacientes tratados. (AU)

Validación y verificación analítica de los métodos microbiológicos / Validation and verfication of microbiology methods

Los microbiólogos clínicos deben asegurar, al máximo nivel permitido por el desarrollo científico y técnico, la fiabilidad de los resultados. Esto implica que, además de reunir los criterios técnicos que aseguren su validez, deben ser realizados con una serie de garantías, que permitan obtener resultados comparables, con independencia del laboratorio que los ejecute. En este sentido, el empleo de métodos de referencia, reconocidos y aceptados, es la herramienta más eficaz para obtener estas garantías. Las actividades relacionadas con la verificación y validación de métodos analíticos ha cobrado gran importancia, debido por un lado al continuo desarrollo y actualización de técnicas y equipos analíticos cada vez más complejos, y por otro lado, al interés de los profesionales en garantizar la calidad de sus procesos y resultados. Se describen las definiciones de validación y verificación, las diferentes modalidades de validación/verificación, así como los tipos de métodos y el nivel de validación necesario según sea el grado de normalización. Se comentan las situaciones en las que es obligatoria y/o recomendable la validación/verificación, así como las particularidades que la validación tiene en microbiología. Se incide en la importancia de potenciar el uso de las cepas de referencia como control en microbiología y del uso de controles normalizados, así como en la importancia de la participación en programas de evaluación externa de la calidad para poder demostrar competencia técnica. Se hace hincapié en la forma de calcular algunos de los parámetros imprescindibles para la validación/verificación, como son la exactitud y la precisión. El desarrollo completo de estos conceptos se puede consultar en el procedimiento microbiológico SEIMC número 48: «Validación y verificación de métodos microbiológicos» disponible en: www.seimc.org/protocolos/microbiologia

Clinical microbiologists should ensure, to the maximum level allowed by the scientific and technical development, the reliability of the results. This implies that, in addition to meeting the technical criteria to ensure their validity, they must be performed with a number of conditions that allows comparable results to be obtained, regardless of the laboratory that performs the test. In this sense, the use of recognized and accepted reference methodsis the most effective tool for these guarantees. The activities related to verification and validation of analytical methods has become very important, as there is continuous development, as well as updating techniques and increasingly complex analytical equipment, and an interest of professionals to ensure quality processes and results. The definitions of validation and verification are described, along with the different types of validation/verification, and the types of methods, and the level of validation necessary depending on the degree of standardization. The situations in which validation/verification is mandatory and/or recommended is discussed, including those particularly related to validation in Microbiology. It stresses the importance of promoting the use of reference strains as controls in Microbiology and the use of standard controls, as well as the importance of participation in External Quality Assessment programs to demonstrate technical competence. The emphasis is on how to calculate some of the parameters required for validation/verification, such as the accuracy and precision. The development of these concepts can be found in the microbiological process SEIMC number 48: «Validation and verification of microbiological methods» www.seimc.org/protocols/microbiology