Clinical presentation of pediatric patients with symptomatic SARS-CoV-2 infection during the first months of the COVID-19 pandemic in a single center in Mexico City.

Background: The clinical spectrum of COVID-19 is broad, from asymptomatic to severe cases and death. The objective of this study is to analyze the clinical course of patients attended during the first months of the SARS-CoV-2 pandemic in a third-level pediatric hospital. Methods: Design: prospective cohort study. Patients with viral respiratory disease or suspected cases of COVID-19 were evaluated at the Pediatric Hospital, National Medical Center XXI Century, Mexico City, from 21 March 2020 to 13 January 2021. Statistical analysis: Chi-square test and Fisher's exact test were used for comparisons; a logistic regression model was constructed to identify clinical or laboratory characteristics associated with critical disease. A p-value < 0.05 was considered statistically significant. Results: A total of 697 patients met the operational definition of viral respiratory disease or suspected cases of COVID-19 and underwent real-time reverse transcription polymerase chain reaction (rRT-PCR) SARS-CoV-2 testing. Patients with a positive result were included. Of the 181 patients (26%), 121 (66.8%) had mild disease and were treated as outpatients and 60 (33.1%) were hospitalized. A total of six patients met the criteria for multisystem inflammatory syndrome in children (MIS-C). Of the 60 inpatients, 65% were males, and 82% had one or more comorbidities. The main comorbidities were cancer (42%) and overweight (15%). The median hospital stay was 9 days. The inpatients had a higher frequency of fever, general malaise, dyspnea, chills, polypnea, and cyanosis than the outpatients (p < 0.05). Only 21.4% of the outpatients had one or more comorbidities, which were lower than in the hospitalized patients (p < 0.001). Laboratory data at admission were similar between critically ill and those with moderate and severe disease. The patients who developed pneumonia were at higher risk of critical disease, while older age was associated with a better prognosis. A total of 13 of the 60 inpatients died (mortality 7.1%). All but one had one or more comorbidities: four had cancer, four congenital heart disease, one chronic kidney disease and epilepsy, one Epstein-Barr virus-induced hemophagocytic lymphohistiocytosis, one obesity, and one diabetes mellitus. Conclusion: Hospital mortality is high, especially in children with comorbidities. Despite 2 years having passed since the beginning of the COVID-19 pandemic, the epidemiological and clinical data on children are still helpful to improve their prognosis.

The Impact of a History of Pre-maturity on Viral Respiratory Infections in Children Under 2 Years of Age: A Propensity Score-Matching Analysis of in-hospital Complications and Mortality.

Introduction: A history of pre-maturity may be a risk factor for complications in patients under 24 months of age hospitalized for viral respiratory infections (VRIs). Objective: To identify the impact of a history of pre-maturity on in-hospital complications and mortality in patients under 24 months of age who were hospitalized for VRIs over a period of 5 years. Material and Methods: This was a propensity score-matched study. The database was compiled by physicians, electronically validated by engineers, and analyzed by statisticians. Patients diagnosed with VRIs (based on International Classification of Diseases [ICD-10]) codes B974, J12, J120-J129X, J168, J17, J171, J178, J20, J203-J209, J21, J210, J211, J218, J219, J22X, and J189) from 2013 to 2017 were enrolled in the study. The subjects were classified into two groups according to the absence or presence of a history of pre-maturity (P070, P072, P073). Patients with congenital heart disease (CHD) (Q20-Q26) were excluded. Length of hospital stay, in-hospital complications, surgical procedures, and mortality were analyzed. Statistical Analysis: Patients were matched according to age. For comparisons between groups, Student's t-tests and chi2 tests were applied. A logistic regression model was constructed to identify factors related to in-hospital complications and mortality. Results: In total, 5,880 patients were eligible for inclusion in the analysis. The average patient age was 14.25 weeks. The presence of pre-maturity (coefficient = 1.16), male sex, bronchopulmonary dysplasia (BPD), in-hospital infectious complications (coefficient = 11.31), and invasive medical procedures (coefficient = 18.4) increased the number of days of hospitalization. Invasive medical procedures (OR = 6.13), a history of pre-maturity (OR = 2.54), and male sex (OR = 1.78) increased the risk for in-hospital complications. In-hospital infectious complications (OR = 84.2) and invasive medical procedures (OR = 58.4) were risk factors for mortality. Conclusions: A history of pre-maturity increased the length of hospital stay and the rate of in-hospital complications but did not increase mortality in patients under 24 months of age hospitalized for VRIs.

Hospitalizations for viral respiratory infections in children under 2 years of age: epidemiology and in-hospital complications.

BACKGROUND: Viral respiratory infections (VRIs) are a frequent cause of hospitalization in children under 24 months of age. A history of prematurity or heart disease may be a risk factor for complications in patients hospitalized for VRI. The objective was to describe epidemiological data for children hospitalized for IRV and aged 1 to 24 months and to identify risk factors for the presence of in-hospital complications and mortality over a period of 5 years. METHODS: This was a cross-sectional study. Patients registered with VRI codes B974, J12, J120-J129X, J168, J17, J171, J178, J20, J203-J209, J21, J210, J211, J218, J219 (based on International Classification of Diseases [ICD-10]) from 2013 to 2017 were included. Three subanalyses were performed to compare [1] patients with pathological history (prematurity, bronchopulmonary dysplasia [BPD] and congenital heart disease [CHD]), [2] diagnoses (pneumonia, acute bronchitis, and acute bronchiolitis), and [3] admission to the pediatric intensive care unit. Days of hospital stay, in-hospital complications, invasive medical procedure and mortality were analyzed. STATISTICAL ANALYSIS: VRI hospitalization prevalence was described. For comparison between groups, Student's t-test, ANOVA and the Chi2 test were applied. To identify factors related to days of hospital stay, in-hospital complications and mortality, a linear and logistic regression model was performed. RESULTS: A total of 66,304 hospitalizations were reported. The average age was 14.7 weeks; hospitalization events were higher in winter (39%), followed by autumn (27.3%). A total of 371 (0.56%) patients died. A total of 7068 (10.6%) hospitalized patients with pathological histories were identified. The presence of BPD (coefficient = 1.6), CHD (coefficient = 1.2), diagnosis of pneumonia (coefficient = 1.2), in-hospital complications (coefficient = 2.1) and invasive medical procedures (coefficient = 15.7) were the most common factors that increased the length of hospital stay. Risk factors for in-hospital complications and mortality were invasive medical procedure (OR = 3.3 & 11.7), BPD (OR = 1.8 & 1.6), CHD (OR = 4.6 & 3.4) and diagnosis of pneumonia (OR = 1.8 & 4.2). CONCLUSIONS: Risk factors for morbidity and mortality in patients hospitalized for VRIs are BPD and CHD, diagnosis of pneumonia and invasive medical procedure.

Serum Dried Samples to Detect Dengue Antibodies: A Field Study.

BACKGROUND: Dried blood and serum samples are useful resources for detecting antiviral antibodies. The conditions for elution of the sample need to be optimized for each disease. Dengue is a widespread disease in Mexico which requires continuous surveillance. In this study, we standardized and validated a protocol for the specific detection of dengue antibodies from dried serum spots (DSSs). METHODS: Paired serum and DSS samples from 66 suspected cases of dengue were collected in a clinic in Veracruz, Mexico. Samples were sent to our laboratory, where the conditions for optimal elution of DSSs were established. The presence of anti-dengue antibodies was determined in the paired samples. RESULTS: DSS elution conditions were standardized as follows: 1 h at 4°C in 200 µl of DNase-, RNase-, and protease-free PBS (1x). The optimal volume of DSS eluate to be used in the IgG assay was 40 µl. Sensitivity of 94%, specificity of 93.3%, and kappa concordance of 0.87 were obtained when comparing the antidengue reactivity between DSSs and serum samples. CONCLUSION: DSS samples are useful for detecting anti-dengue IgG antibodies in the field.

Identification of Mycobacterium tuberculosis in the cerebrospinal fluid of patients with meningitis using nested PCR.

Tuberculous meningitis (TBM) is the most severe form of tuberculosis. It is caused by Mycobacterium tuberculosis (M. tuberculosis; MT) and it is very difficult to diagnose. The symptoms are similar to other infectious neurological diseases, such as neurocysticercosis, neuroborreliosis, or herpes viral infection. The aim of this study was to identify tuberculosis (TB) in cases of meningitis with clinical and laboratory evidence suggestive of TBM, and to confirm our findings with molecular tests for TB infection. We recruited patients with neurological symptoms who were examined at the neurology services of Hospitals of Instituto Mexicano del Seguro Social (IMSS) in Mexico City. A total of 144 consecutive patients with suggestive infectious meningitis were initially included; 94 cases of meningitis with clinical and laboratory evidence suggestive of TBM were included, but only 50 of these cases fulfilled the criteria for probable TBM. As the controls, we included 50 cases of meningitis with clinical and laboratory evidence suggestive of non-TBM. Cerebrospinal fluid (CSF) was collected from all 100 patients (cases and controls) and tested for TB by multiplex and nested PCR analyses. Nested PCR detected 0.1 fg of M. tuberculosis DNA. TB infection was confirmed with molecular tests in 49 patients from the 50 cases suggestive of TBM and in 1 of the 50 non-TBM cases. The analysis exhibited a sensitivity of 98.0%, a specificity of 92.0%, a positive predictive value of 88.0% and a negative predictive value of 98.0%. The use CSF for the analyses proved to be effective for the rapid diagnosis of TBM using a developed system of multiplex and nested PCR analyses in patients presenting neurological symptoms.

Intestinal Colonization by Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae in Infants.

BACKGROUND: Members of the Enterobacteriaceae family are common agents of nosocomial infections. Intestinal colonization by these microorganisms represents a major step in the development of systemic infection. Extended-spectrum b-lactamase-producing bacteria are usually associated with outbreaks, but endemic infections are common in intensive care units. OBJECTIVE: To determine the frequency of intestinal colonization with extended-spectrum b-lactamase-producing Enterobacteriaceae in newborns. PATIENTS AND METHODS: This was a descriptive cohort study. Newborns from two general hospitals (A and B) in Mexico City were included during a five-month period; those with a hospital stay > 7 days were selected. Fecal samples were obtained by rectal swab on day 7 and every week until discharge. Extended-spectrum b-lactamase production was confirmed in enterobacteria by the Etest. Clonal relatedness was established by pulsed-field gel electrophoresis. RESULTS: 102 newborns were included; 63/102 (61.7%) were colonized by extended-spectrum b-lactamase-producing Enterobacteriaceae on day 7, 17/21 (81%) on day 14, and 6/8 (75%) on day 21 of hospitalization. Klebsiella pneumoniae was recovered most frequently (75.4%). A predominant clone (95%) was found in hospital B, and a major clone (75%) in Hospital A. Other extended-spectrum b-lactamase-producing Enterobacteriaceae isolates were Enterobacter spp. (16%) and Escherichia coli (7.6%). CONCLUSIONS: High rates of colonization and horizontal transmission of extended-spectrum b-lactamase-producing Enterobacteriaceae were found in the newborn care units of two general hospitals. Clonal relatedness was identified. Lack of adherence to standard precautions and hand hygiene were determining factors.

Antibody responses to influenza viruses in paediatric patients and their contacts at the onset of the 2009 pandemic in Mexico.

INTRODUCTION: On April 2009, the Mexican Ministry of Health received notification of cases of severe pneumonia mostly affecting young healthy people; this was the beginning of the first influenza pandemic of the 21st century. The nature of the immune response to the influenza A(H1N1)2009 pandemic strain in Mexico at the beginning of the pandemic outbreak has not been completely defined. We describe the serological response to the 2009 pandemic influenza virus in paediatric patients with influenza-like illness, their household contacts (HHCs), and exposed health-care workers (HCWs) at the beginning of the pandemic outbreak in Mexico City. METHODOLOGY: thirty pre-epidemic and 129 epidemic samples were collected and serum antibodies were measured against A(H1N1)2009 pandemic virus and two non-pandemic swine influenza viruses by an haemagglutination inhibition assay . RESULTS: 91% (29/32) of the convalescence samples from confirmed patients had an antibody titre ≥ 10 (GMT 25), 63% (41/65) of the HHCs (GMT 12), 41% of HCWs (GMT 6) and 13% (4/30) of pre-epidemic samples (GMT 6) for the pandemic influenza virus. Of the 32 confirmed cases, 60% had an antibody titre ≥ 40 for the pandemic strain, 53% for the A/swine/Iowa(H1N1) virus (GMT 62) and 43% for the A/swine/Texas(H3N2) virus (GMT 66). CONCLUSION: The antibody response to 2009 pandemic influenza virus was widespread in convalescence samples from patients with confirmed pandemic influenza infection but the GMT was below the protective titre. There was no evidence that antibodies to the swine influenza viruses had cross-protective effect against the 2009 pandemic influenza virus.

Use of Dried Plasma Spots for HIV-1 Viral Load Determination and Drug Resistance Genotyping in Mexican Patients.

Monitoring antiretroviral therapy using measurements of viral load (VL) and the genotyping of resistance mutations is not routinely performed in low- to middle-income countries because of the high costs of the commercial assays that are used. The analysis of dried plasma spot (DPS) samples on filter paper may represent an alternative for resource-limited settings. Therefore, we evaluated the usefulness of analyzing DPS samples to determine VL and identify drug resistance mutations (DRM) in a group of HIV-1 patients. The VL was measured from 22 paired plasma and DPS samples. In these samples, the average VL was 4.7 log10 copies/mL in liquid plasma and 4.1 log10 copies/mL in DPS, with a correlation coefficient of R = 0.83. A 1.1 kb fragment of HIV pol could be amplified in 14/22 (63.6%) of the DPS samples and the same value was amplified in plasma samples. A collection of ten paired DPS and liquid plasma samples was evaluated for the presence of DRM; an excellent correlation was found in the identification of DRM between the paired samples. All HIV-1 pol sequences that were obtained corresponded to HIV subtype B. The analysis of DPS samples offers an attractive alternative for monitoring ARV therapy in resource-limited settings.

Occult hepatitis B virus infection among Mexican human immunodeficiency virus-1-infected patients.

AIM: To determine the frequency of occult hepatitis B infection (OHBI) in a group of human immunodeficiency virus (HIV)-1+/ hepatitis B surface antigen negative (HBsAg)- patients from Mexico. METHODS: We investigated the presence of OHBI in 49 HIV-1+/HBsAg- patients. Hepatitis B virus (HBV) DNA was analyzed using nested PCR to amplify the Core (C) region and by real-time PCR to amplify a region of the S and X genes. The possible associations between the variables and OHBI were investigated using Pearson's χ(2) and/or Fisher's exact test. RESULTS: We found that the frequency of OHBI was 49% among the group of 49 HIV-1+/HBsAg- patients studied. The presence of OHBI was significantly associated with the HIV-1 RNA viral load [odds ratio (OR) = 8.75; P = 0.001; 95%CI: 2.26-33.79] and with HIV-antiretroviral treatment with drugs that interfere with HBV replication (lamivudine, tenofovir or emtricitabine) (OR = 0.25; P = 0.05; 95%CI: 0.08-1.05). CONCLUSION: The OHBI frequency is high among 49 Mexican HIV-1+/HBsAg- patients and it was more frequent in patients with detectable HIV RNA, and less frequent in patients who are undergoing HIV-ARV treatment with drugs active against HBV.

[Rapid immune response against hepatitis B using an accelerated intradermal vaccination schedule]. / Respuesta inmune rápida contra la hepatitis B mediante esquema acelerado de vacunación intradérmica.

OBJECTIVE: To analyze the prescription of antiviral and antibiotic agents in children with upper airway infection (UAI) during Influenza H1N1 epidemic. METHODS: A cross-section study (01/04/2009 to 31/03/2010) was performed. We analyzed the antiviral and antibiotic agents' prescription and its relation with the presence of the triad of symptom of suspicion (migraine, fever and cough) and the cost for attention (medicines and screening test). RESULTS: 838 children were attendance for UAI, 40.3% with the suspicion triad. In 733 patients, the screening test were done with 155 positive results (120 had the triad). All patient with a positive result received oseltamivir. During the first five months of the epidemic, the medical prescriptions were: antibiotics 60-85%, 0-7% anti-viral and 20-30% symptomatic drugs. At the 6th at 8th months (peak of outbreak) antibiotics 35-70%, anti-virals 20-25% and 10-30% symptomatic drugs. At final months (9th to 11th) antimicrobials 65-80%, anti-virals 20-30% and symptomatic 0-10%. The cost for URI attention increased a 27%. CONCLUSIONS: Medical prescription changed during the epidemic, with an increased in the anti-virals, especially for patients with high suspicion for influenza and positive screening test.

Genotypic testing for HIV-1 drug resistance using dried blood samples.

In third-world countries, dried blood samples (DBS) are a convenient alternative to plasma for monitoring viral load during HIV-1 therapy. In this study, we evaluated the feasibility of using DBS to perform HIV-1 drug resistance genotyping in a ViroSeq assay in which the protease and reverse transcriptase regions of the pol gene are analyzed. Fifty-seven antiretroviral genotypes from plasma samples were tested, and drug resistance genotypes were determined. Only 38.6% paired DBS samples were sequenced. Failure to amplify DNA from DBS samples generally correlated with plasma viral loads below log(10) 5.1. The majority of the mutations identified in plasma pol sequences were also found in their DBS counterpart, with a concordance in genotype interpretation of 96.4%. Several factors were identified that could potentially improve both the sensitivity and the quality of genotype data, such as sample storage conditions and sequence analysis. Therefore, DBS sampling is useful to determine viral load and drug resistance genotypes in HIV patients.

Critical analysis of deaths due to atypical pneumonia during the onset of the influenza A (H1N1) virus epidemic.

BACKGROUND: The ongoing influenza A (H1N1) pandemic stroked Mexico and posed a huge challenge to the medical care and public health systems. This report analyzes the clinical course and process of care of patients who died due to atypical pneumonia and fulfilled the clinical criteria of suspected case of novel influenza A (H1N1) virus infection. METHODS: We conducted a retrospective analysis of a series of 38 patients who died between April 7 and April 28, 2009 at Instituto Mexicano del Seguro Social (IMSS) hospitals due to severe pneumonia and respiratory distress. These cases coincided with the beginning of the outbreak, so patients did not undergo laboratory testing to diagnose influenza. According to IMSS and CDC criteria, post-hoc analysis allowed considering the presumptive diagnosis of S-OIV infection. A multidisciplinary group analyzed the information from the clinical charts, laboratory tests, radiographic studies and death certificates, using descriptive statistics. RESULTS: Most cases were middle-aged (mean 33 years, range: 4-62 years) and previously healthy; 18.4% had an underlying chronic disease, 23.7% were obese and 7.9% were current smokers. None had received the seasonal influenza vaccine; they had cough (92%), fever (86.8%), and malaise (73.7%). The median time from disease onset to hospital admission was 6 days (range 0-8 days). All were admitted to the intensive care unit with pneumonia and/or respiratory distress. Average time from disease onset to death was 8 days (range 4-18 days). CONCLUSIONS: An increased number of severe cases of atypical pneumonia in previously healthy adults highlight the importance of the availability of a timely surveillance system able to identify sudden increases in the number of cases or presentation of apparently known diseases.

High correlation of human immunodeficiency virus type-1 viral load measured in dried-blood spot samples and in plasma under different storage conditions.

BACKGROUND: To measure HIV-1 RNA concentration requires venous extraction of blood, use of RNAase-free materials, and transport in a cold chain, which makes difficult the management of samples in developing countries. We evaluated the utility of the determination of HIV-1 RNA concentration in blood samples dried on filter paper (DBS) and subjected to different conditions, as contrasted with determination in plasma. METHODS: HIV-1 RNA concentration was determined in HIV-infected patients in DBS and in plasma samples. Samples were subjected to the following: DBS were stored at 4, 22, and 37 degrees C for 1, 3, and 7 days; samples from patients from four regions of Mexico were mailed to a reference laboratory; DBS were sent under environmental conditions; and plasma samples were sent frozen. HIV-1 RNA concentrations were determined by NucliSens in DBS and by Amplicor test in plasma. RESULTS: HIV-1 RNA concentration determined in DBS subjected to different temperatures and times had a significant correlation (r=0.99) with those obtained in plasma. When compared with values in plasma, Kappa agreement coefficients of values in DBS stored for 7 days at 4, 22, and 37 degrees C were 0.98, 0.83, and 0.94, respectively. Quantification of HIV-1 RNA in 108 DBS mailed from remote areas with different climates demonstrated significant correlation with those obtained in plasma (r=0.95; p <0.001). CONCLUSIONS: DBS is a simple and reliable method to measure HIV-1 RNA concentration, especially when samples are mailed from remote areas to a reference center. This collection method is an economic and suitable alternative for use in developing countries.

Síndrome de rubéola congénita en lactantes atendidos en un hospital pediátrico / Congenital rubella syndrome in infants at a pediatric hospital

Los casos de rubéola congénita en México se consideran un problema esporádico.Objetivo: Analizar y describir los hallazgos clínicos asociados a rubéola congénita (RC) en lactantes atendidos en un hospital pediátrico durante un período de ocho años (1991-1998). Material y métodos: Estudio retrospectivo. Se inclu-yeron pacientes menores de 18 meses con resultado positivo de anticuerpos IgG o lgM contra virus de rubéola, medidos por técnica de ensayo inmunoenzi-mático de micropartículas.Resultados: Se identificaron 56 casos, analizándose 42 expedientes completos; 23 fueron del sexo femenino (54.7 por ciento) y 19 del masculino (45.3 por ciento), con mediana para la edad de cinco meses (intervalo 1-14 meses). En 9/42 madres (21.4 por ciento) hubo el antecedente de exantema durante el primer trimestre del embarazo. En 15 lactantes la serología fue positiva para IgM (todos menores de cuatro meses de edad) y en 27 para IgG. Las principales alteraciones fueron oculares (74 por ciento), neurológicas (66 por ciento) y cardiopatías congénitas (67 por ciento). En 69 por ciento se detectó catarata congénita, hepatomegalia en 52 por ciento, ictericia en 43 por ciento, anemia en 40 por ciento, trombocitopenia en 48 por ciento e hipoacusia en 19 por ciento. Las alteraciones poco comunes fueron hernia umbilical, criptorquidia, hidrocele, sinostosis y neumonitis

Sensibilidad de enterobacterias y Pseudomonas spp. a una nueva cefalosporina de cuarta generación: estudio comparativo con antibióticos en uso actual / Sensitivity of enterobacteria and Pseudomonas spp. to a new fourth-generation cephalosporine: a comparative study with in-use antibiotics

Las enterobacterias y Pseudomonas spp. son agentes etiológicos de septicemia en recién nacidos lactantes e inmunosuprimidos. La aparición de resistencia a los antibióticos de uso común es frecuentemente relacionada con la frecuencia con que se prescriben. Objetivo: Evaluar la sensibilidad de enterobacterias y Pseudomonas spp. a una cefalosporina de cuarta generación (cefepime) comparando su actividad con otros antibióticos. Material y métodos: Se probaron 804 cepas: 675 enterobacterias, Pseudomonas aeruginosa 64 y bacilos gramnegativos no fermentadores 65. Se realizó sensibilidad por el método de dilución seriada en agar, utilizando los valores de corte propuestos por la NCCLS para los siguientes antibióticos: imipenem/cilastatin pefloxacina, ceftizoxima, cefotaxima, ceftazidima, cefepime, amikacina, netilmicina y gentamicina. Resultados: La resistencia a los aminoglucósidos fue elevada para gentamicina, entre el 48 y el 75 por ciento para enterobacterias, 54.8 por ciento para Pseudomonas aeruginosa y del 64.64 por ciento para los BGNNF, la resistencia netilmicina es semejante a la encontrada en gentamicina y menor para amikacina. De las cefalosporinas de tercera generación, cefotaxima y ceftizoxima tuvieron los menores porcentajes de resistencia, la sensibilidad de algunas especies de enterobacterias (Proteus mirabilis, E. coli) fue mejor para cefotaxima; para ceftazidima se observaron los mayores porcentajes de resistencia. La resistencia a pefloxacina fue semejante a la encontrada para cefotazima. Imipenem/cilastatin y cefepime mantienen los niveles más bajos de resistencia. Para cefepime la CM150 fue < 0.125 mg/l y la CM190 de 2 mg/l para E. coli, S. marcescens, Proteus mirabilis y Enterobacter spp; para las especies de Klebsiella, Pseudomonas aeruginosa y BGNNF, la CM190 fue de 32 mg/l. Conclusiones: La resistencia a cefepime de las cepas evaluadas fue menor que para otros antibióticos, con sensibilidades semejantes a imipenem/cilastatin. Cefepime es una alternativa para el manejo de infecciones por Enterobacterias y Pseudomonas spp., ofrece las ventajas de una penetración más rápida en las bacterias gramnegativas, una mayor afinidad por múltiples proteínas fijadoras en penicilina y una mayor resistencia a la hidrólisis por betalactamasas.

Prevalencia de marcadores serolórogicos para el virus de la hepatitis B en el hospital pediátrico / Prevalence of serological markers for hepatitis B among health care workers in a children's hospital

Se estudiaron 505 trabajadores de la salud en un hospital de Pediatría con el objeto de conocer la prevalencia de los marcadores serológicos para el virus de la hepatitis B. A los sueros se les determinó anticuerpos contra el antígeno "core" (Anti-HBc) y antígeno de superficie (HBsAg) mediante el método inmunoenzimático (EIA). A los que resultaron Anti-HBc positivos se les determinó anticuerpos contra el antígeno e (Anti-HBe) y anticuerpos contra el antígeno de superficie (HBsAg). Participaron 157 hombres y 348 mujeres con una antigüedad promedio en su trabajo de 9.05 años. Ninguno resultó positivo a HBsAg. Mediante la determinación de Anti-HBc hubo evidencia de exposición al VHB en 27 casos (5.34 por ciento); fueron a Anti-HBs 19 de 27 (70.3 por ciento) y a Anti-HBe 12 de 27 (44.4 por ciento). Se observó mayor riesgo a la infección en aquellas personas con historia de hapatitis y mayor tiempo de servicio profecional, particularmente los que trabajan en el área del laboratorio. Estos resultados muestran que la frecuencia de hepatitis B en el personal de unidades pediátricas resulta menor en comparación con el personal que atiende población adulta. Hepatitis B; seroprevalencia; personal de salud