QuantiFERON-TB Gold In-Tube as a Confirmatory Test for Tuberculin Skin Test in Tuberculosis Contact Tracing: A Noninferiority Clinical Trial.

Background: Screening strategies based on interferon-γ release assays in tuberculosis contact tracing may reduce the need for preventive therapy without increasing subsequent active disease. Methods: We conducted an open-label, randomized trial to test the noninferiority of a 2-step strategy with the tuberculin skin test (TST) followed by QuantiFERON-TB Gold In-Tube (QFT-GIT) as a confirmatory test (the TST/QFT arm) to the standard TST-alone strategy (TST arm) for targeting preventive therapy in household contacts of patients with tuberculosis. Participants were followed for 24 months after randomization. The primary endpoint was the development of tuberculosis, with a noninferiority margin of 1.5 percentage points. Results: A total of 871 contacts were randomized. Four contacts in the TST arm and 2 in the TST/QFT arm developed tuberculosis. In the modified intention-to-treat analysis, this accounted for 0.99% in the TST arm and 0.51% in the TST/QFT arm (-0.48% difference; 97.5% confidence interval [CI], -1.86% to 0.90%); in the per-protocol analysis, the corresponding rates were 1.67% and 0.82% in the TST and TST/QFT arms, respectively (-0.85% difference; 97.5% CI, -3.14% to 1.43%). Of the 792 contacts analyzed, 65.3% in the TST arm and 42.2% in the TST/QFT arm were diagnosed with tuberculosis infection (23.1% difference; 95% CI, 16.4% to 30.0%). Conclusions: In low-incidence settings, screening household contacts with the TST and using QFT-GIT as a confirmatory test is not inferior to TST-alone for preventing active tuberculosis, allowing a safe reduction of preventive treatments. Clinical Trials Registration: NCT01223534.

Pulsed electric fields reduce bacterial attachment to stainless steel plates.

The purpose of this study was to evaluate the capacity of pulsed bilateral electric fields to control bacterial attachment on stainless steel plates. Previously sterilized circular metal plates of stainless steel were submerged in a liquid medium with a known concentration of Staphylococcus epidermidis and incubated for 1 hour at 36oC while a 200 Hz pulsed electric field of 18 V/cm was applied for 2.5 µseg and then sonicated for 5 minutes in 10 ml of saline. Three different models were cultured and compared: 1) negatively-charged plate, 2) positively-charged plate, and 3) control plate without electric current. A total of 39 metal plates were processed. The median adherence in the control group and the electric field group was 312 CFU/mm2 and 16,2 CFU/mm2 respectively (p < 0.001, reduction of 95% of bacterial attachment). Bilateral pulsed electric field is able to reduce bacterial attachment on stainless steel plates in in vitro conditions.

Quantification and Progress Over Time of Specific Antibodies Against Severe Acute Respiratory Syndrome Coronavirus 2 in Breast Milk of Lactating Women Vaccinated With BNT162b2 Pfizer-BioNTech Coronavirus Disease 2019 Vaccine (LacCOVID).

Background: Several observational studies demonstrated the passage of postvaccine antibodies through breast milk in women vaccinated against coronavirus disease 2019 (COVID-19), mostly with messenger RNA (mRNA)-based vaccines, but lacked long-term data. Methods: A 6-month prospective cohort study was performed to determine severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine-induced antibody levels in the breast milk of 33 lactating healthcare workers at different timepoints after mRNA BNT162b2 Pfizer-BioNTech COVID-19 vaccination. Moreover, we examined the correlation of SARS-CoV-2 antibody levels between serum and breast milk, adverse events related to vaccination, and rate of SARS-CoV-2 infections. Results: Mothers' median age was 38 (interquartile range [IQR], 36-39) years and 15 (IQR, 10-22) months for infants. Median (IQR) SARS-CoV-2 immunoglobulin G (IgG) spike protein subunit S1 (S1) vaccine-induced levels at different timepoints for serum-milk pairs were 519 (234-937) to 1 (0-2.9) arbitrary units (AU)/mL at 2 weeks after first dose and 18 644 (9923-29 264) to 78 (33.7-128), 12 478 (6870-20 801) to 50.4 (24.3-104), 4094 (2413-8480) to 19.9 (10.8-51.9), 1350 (831-2298) to 8.9 (7.8-31.5) AU/mL at 2, 4, 12 and 24 weeks after second dose, respectively. We observed a positive correlation of antibody levels between serum and breast milk, no serious adverse events related to vaccination, and 2 (6%) COVID-19 vaccine breakthrough infections. Conclusions: Women vaccinated with Pfizer-BioNTech transmit antibodies into breast milk with a positive correlation with serum levels. Both decreased over time in a 6-month follow-up.

Differences in Drug-Susceptibility Patterns between Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium chimaera Clinical Isolates: Prospective 8.5-Year Analysis by Three Laboratories.

Background: It has been suggested that Mycobacterium avium, Mycobacterium intracellulare, and M. chimaera have differential drug susceptibility patterns. We prospectively analyzed and compared the drug susceptibility patterns among these species over an 8.5-year period. Methods: A microdilution method (Slomyco®) was performed for drug susceptibility testing of 402 M. avium, 273 M. intracellulare, and 139 M. chimaera clinical isolates. Results: M. avium showed significantly higher resistance to moxifloxacin, ciprofloxacin, rifampicin, ethambutol, streptomycin, linezolid, cotrimoxazole, and clarithromycin. M. avium also showed higher minimum inhibitory concentrations (MIC) than M. intracellulare and M. chimaera against all drugs except ethionamide, to which M. intracellulare and M. chimaera showed greater resistance. Conclusions: Our series demonstrated differential drug resistance patterns among the most frequent M. avium complex species. M. avium was more resistant than M. intracellulare and M. chimaera versus eight antibiotics and showed greater MIC values to most of the antibiotics studied. These data suggest that knowledge of the local distribution and susceptibility profiles of these pathogens is essential for adequate clinical management.

The prevalence of GB virus C/hepatitis G virus RNA among healthy and HCV-infected Catalan children.

GB virus C (GBV-C) is a blood-borne flavivirus. The prevalence of GBV-C viremia among healthy adults is 0.5% to 4% and, to date, no disease has been definitely associated with GBV-C infection. We conducted a cross-sectional study to evaluate GBV-C viremia prevalence in a group of 327 healthy children with normal alanine amino transferase (ALT) levels (Group A) and elevated ALT levels (Group B) of unknown origin, and among 38 pediatric patients with mother-to-child-transmitted hepatitis C virus (HCV) infection (Group C). No statistically significant differences were observed between prevalences in Groups A and B (2.2% vs 6.7%, p = 0.06). None of the children in Groups A or B who tested positive for GBV-C RNA showed any clinical symptoms. The prevalence of GBV-C viremia in Group A was lower than for patients in Group C (2.2% vs 13.2%, p = 0.007); no differences were observed in HCV infection characteristics between those patients who were co-infected with GBV-C and those who were not. In conclusion, while GBV-C viremia is more frequent among HCV-infected pediatric patients, it is neither associated with liver disease nor has any influence on HCV-related chronic hepatitis.

Usefulness of Urinoculture to Patients With Dementia and Femoral Neck Fracture at Admission to Hospital: Preliminary Results.

INTRODUCTION: While preoperative urinary tract infection (UTI) has the potential to cause bacteremia and postsurgical acute prosthetic joint infections (APJIs), the influence of asymptomatic bacteriuria (AB) in these infections remains unclear. So the majority of guidelines not recommend the treatment of AB prior to the surgery. However, as patients with dementia usually cannot explain the symptoms of dysuria, the differential diagnosis between AB and UTI may be very difficult in this group of patients. The principal aim of the study was to compare the rate of positive urine culture at admission in patients with femoral neck fracture with and without dementia and secondarily try to assess the connection of positive urinoculture and postoperative acute gram-negative PJI. METHODS: All patients with a femoral neck fracture underwent a urine culture on hospital admission and were prospectively recorded. Variables such as sex, age, institutionalization, dementia and other comorbidities, PJI rate, and in-hospital death were collected. The results of cultures were retrospectively revised. Patients who received postoperative antibiotics or had been diagnosed with UTI during hospital stay were excluded. Statistical comparisons between patients with and without dementia were performed using SPSS software version 17. RESULTS: A total of 148 patients were included (52 with dementia). The rate of positive urine culture was 32% (n = 16) in patients with dementia and 11.5% in patients without dementia (P = .003). Of these 16 patients with dementia and positive urine culture, 2 (12.5%) developed an acute gram-negative PJI, whereas there were no cases in the group without dementia (P = .011). DISCUSSION: The only difference between UTI and AB is the expression of symptoms by the patient. However, as patients with dementia have difficulties to explain UTI symptoms, some UTI may be underdiagnosed. CONCLUSION: Patients with dementia have a statistically higher rate of presurgical positive urine culture compared with patients without dementia.

[Prevalence of hepatitis C virus in pregnant women and vertical transmission]. / Prevalencia de la infección por el virus de la hepatitis C en mujeres embarazadas y transmisión vertical de este virus.

BACKGROUND: The objectives of this study were to know the seroprevalence of HCV in pregnant women and to determine its vertical transmission rate as well as the viremia evolution in infected children. PATIENTS AND METHOD: Two different populations were studied: a) all pregnant women (n = 2,615) controlled in our hospital during 1999, and b) newborns (n = 228) to mothers with HCV antibodies (Ab) who were referred to our hospital from January 1995 to September 2000. Eighty of these infants were born to mothers coinfected with HIV-1. HCV Ab were determined by ELISA and RIBA techniques and viral ARN was studied by PCR. Risk factors in infected pregnant women were reviewed. RESULTS: HCV Ab were detected in 37 women using RIBA or PCR, hence meaning a seroprevalence rate of 1.4%. Usual risk factors were not identified in 35% of cases. Median viral load was 3.5 * 105 IU/ml. ARN HCV was detected in 15 infants, 9 out of them being born to mothers coinfected with HIV-1 (vertical transmission rate: 11.25%) and the remaining 6 being born to mothers without HIV-1 coinfection (vertical transmission rate: 4%). The difference in the transmission rate had statistical significance (p < 0.05). CONCLUSIONS: Seroprevalence of HCV infection in our population of pregnant women was relatively high. HCV screening in pregnant women is useful in order to identify this infection not only in this population but also in newborns and, consequently, to follow-up the vertical transmission cases.

Adherence of S. epidermidis on different metals. A comparative in vitro study.

AIM: Staphylococcus epidermidis is the most common cause of orthopedic infections. Adhesion and biofilm formation on orthopedic implant surfaces play an important role in the physiopathology of these infections. The aim of our study was to evaluate the adhesion of S. epidermidis on the surface of metals usually used in orthopedics. METHODS: Previously sterilized circular metal plates of titanium (Ti), porous titanium (p-Ti), cobalt chromium (CoCr) and stainless steel (SS) were hung completely submerged in a liquid medium with a known concentration of S. epidermidis (RP62A). They were incubated for 1 h or 24 h at 36°C. After incubation, each plate was washed with PBS and sonicated during 5 minutes in 10 mL of saline. Different dilutions were performed and 100 µL from each sample was cultured on agar plates. RESULTS: 26 metal plates were incubated for 1 h and other 55 metal plates for 24 h. The lowest bacterial count (cfu/mm2) at 1 h was observed in CoCr plates while in p-Ti it was 6 times higher. At 24 h the highest bacterial count was observed in SS plates while the lowest in Ti. However, these differences were not statistically significant. CONCLUSIONS: After 1 h and 24 h of exposure, the lowest adherence was observed in CoCr and Ti plates, respectively. However, bacterial attachment occurred with all materials. It is necessary to further investigate new materials able to avoid bacterial attachment.

[Rapid diagnosis of herpetic meningoencephalitis by PCR]. / Diagnóstico rápido de la meningoencefalitis herpética mediante PCR.

OBJECTIVE: To evaluate the usefulness of a rapid and simple PCR method in the diagnosis of herpetic meningoencephalitis in a pediatric population. PATIENTS AND METHODS: One hundred twenty-three cerebrospinal fluid samples from 114 pediatric patients attending the Hospital Sant Joan de Déu in Barcelona for clinical suspicion of viral meningoencephalitis or to rule out a possible herpetic etiology were evaluated. In addition to classical methods, the diagnostic technique used was PCR amplification of a highly preserved region of the DNA polymerase gene common to herpes virus 1 and 2. All patients were administered acyclovir on admission and until the results of PCR were known. If the result was negative, withdrawal of acyclovir was considered after clinical reexamination. If the result was positive, the therapy was continued for 20 days. RESULTS: Herpes simplex DNA was detected in four patients. In all patients, clinical outcome confirmed the results of PCR, whether positive or negative. PCR results were available within 6.30 and 72 hours (mean: 18 hours). CONCLUSION: This simple and rapid PCR technique can be applied in the daily routine of the microbiology laboratory. It allows early diagnosis of herpetic meningocephalitis or, when lacking, exclusion of Herpes simplex etiology.

Actualización de la sensibilidad antibiótica de Streptococcus pyogenes en pediatría / An updating of the antibiotic sensitivity of Streptococcus pyogenes in pediatrics

No disponible

Infecciones por Helicobacter pylori: detección de antígeno en muestras fecales / Helicobacter pylori infections: antigen detection in stool samples

Fundamento. El objetivo del estudio es evaluar la técnica de detección del antígeno de Helicobacter pylori en heces (HpSA), y comparar los resultados con los de las técnicas standard (prueba del aliento con 13C-urea, serología, cultivo y estudio histológico), en una población de pacientes pediátricos con sintomatología gastrointestinal sugestiva de infección por H.pylori. Pacientes y métodos. Se estudiaron 60 pacientes pediátricos atendidos en el Servicio de Gastroenterología por manifestar síntomas de dispepsia. Ninguno refería haber tomado antibióticos, inhibidores de la bomba de protones, ni compuestos con sales de bismuto. A todos ellos se les realizó la prueba del aliento con 13C-urea, una determinación de IgG anti-H.pylori, se les practicó una endoscopia gastrointestinal con la finalidad de obtener muestras para estudio histológico, prueba de la urea inmediata y cultivo microbiológico, y se les recogió una muestra fecal para estudiar la presencia de antígeno de H.pylori. Resultados. Cuarenta y siete de los 60 pacientes estudiados mostraron estar infectados por H.pylori. En todos se aisló el microorganismo del cultivo y la prueba del aliento fue positiva. En 45 de ellos se positivizó la prueba HpSA (95,7 por ciento). No hubo ningún falso positivo de esta técnica. Conclusiones. La prueba HpSA además de la buena sensibilidad (95 por ciento) y especificidad (100 por ciento) que ha manifestado en este estudio, aporta ventajas sobre las otras técnicas no invasoras, por su simplicidad en la obtención de la muestra, realización de la técnica, rapidez en la obtención de los resultados y bajo coste económico, al compararlo con el elevado coste de la prueba del aliento (AU)

Diagnóstico rápido de la meningoencefalitis herpética mediante PCR / Rapid diagnosis of herpetic meningoencephalitis by PCR

OBJETIVO. Evaluar la utilidad de un método de PCR rápido y sencillo aplicado al diagnóstico de la meningoencefalitis herpética en la población pediátrica. PACIENTES Y MÉTODO. Se procesaron 123 muestras de líquido cefalorraquídeo de 114 pacientes pediátricos atendidos en el Hospital Sant Joan de Déu de Barcelona con sospecha clínica de meningoencefalitis vírica o interés en descartar la etiología herpética. Se utilizó como técnica diagnóstica la amplificación por PCR de una región altamente conservada del gen ADN polimerasa común a herpes 1 y 2, además de los métodos clásicos. En todos los pacientes se instauró tratamiento en el momento del ingreso con aciclovir en espera de los resultados de la PCR. Si el resultado era negativo, tras una adecuada revaluación clínica se consideraba la retirada del tratamiento con aciclovir; si era positivo se continuaba el tratamiento durante 20 días. RESULTADOS. El ADN de herpes simple se detectó en 4 pacientes. La evolución clínica de los enfermos confirmó los resultados de la PCR en todos los casos, tanto en los negativos como en los positivos. La entrega de los resultados de PCR se realizó en un rango de tiempo de 6,30 a 72 h (media, 18 h).CONCLUSIÓN. La aplicación de esta técnica de PCR, con un formato sencillo y rápido, adecuado a la rutina diaria de un laboratorio de microbiología contribuye a realizar un diagnóstico precoz o, en su defecto, exclusión de la etiología por herpes simple de la meningoencefalitis (AU)

Prevalencia de la infección por el virus de la hepatitis C en mujeres embarazadas y transmisión vertical de este virus / Prevalence of hepatitis C virus in pregnant women and vertical transmission

FUNDAMENTO: Los objetivos de este estudio fueron conocer la tasa de seroprevalencia del virus de la hepatitis C (VHC) en mujeres embarazadas y determinar la tasa de transmisión vertical, así como la evolución de la viremia en los niños tras la primoinfección. PACIENTES Y MÉTODO: Se estudiaron dos poblaciones diferentes: a) todas las gestantes (n = 2.615) controladas en el Hospital Sant Joan de Déu durante 1999, y b) los recién nacidos (n = 228) hijos de madres con anticuerpos para el VHC, nacidos entre enero de 1995 y septiembre de 2000 que fueron remitidos a este hospital para control. Ochenta de estos niños eran hijos de madres coinfectadas con virus de la inmunodeficiencia humana (VIH). Los métodos utilizados fueron: detección de anticuerpos del VHC por técnicas de ELISA y RIBA, estudio de la presencia de ARN viral por técnica de PCR y revisión de los factores de riesgo en las gestantes infectadas. RESULTADOS: En 37 gestantes se detectaron anticuerpos del VHC, confirmados por PCR o RIBA (tasa de seroprevalencia 1,4 por ciento). En el 35 por ciento de estas gestantes no se encontró factores de riesgo conocidos. La media de la carga viral fue de 335.524 copias/ml. Se detectó ARN VHC en 15 niños, 9 hijos de madres coinfectadas con VIH-1 (tasa de transmisión vertical: 11,25 por ciento) y 6 hijos de madres no coinfectadas (tasa de transmisión vertical: 4 por ciento). La diferencia en la tasa de transmisión fue estadísticamente significativa (p < 0,05).CONCLUSIONES: En este estudio la prevalencia de la infección VHC fue relativamente elevada (1,4 por ciento). El cribado del VHC en gestantes es útil para identificar la infección en esta población y poder realizar en sus recién nacidos el diagnóstico y control de la posible infección VHC por transmisión vertical (AU)

Aplicación de los métodos de amplificación molecular para el diagnóstico y seguimiento de la infección por el VIH-1 en niños infectados por transmisión vertical / Application of molecular amplification methods to the diagnosis and follow-up of HIV-1 infection in children infected by vertical transmission

Fundamento: Describir mediante métodos moleculares la transmisión vertical por el VIH-1. Pacientes y métodos: Seguimiento prospectivo realizado durante 1995-1998 en dos grupos de pacientes: grupo A, 107 recién nacidos hijos de madre que sabían que estaban infectadas por el VIH-1, y grupo B, 11 lactantes con sospecha clínica de infección por el VIH y desconocimiento de la infección en la madre. Se estudiaron ADN y ARN mediante PCR (reacción en cadena de la polimerasa). Estudio de mutaciones genotípicas del gen RT. Resultados: Se diagnosticaron 11 pacientes infectados, 4 del grupo A y 7 del B. Todos presentaban carga viral superior a 100.000 copias/ml. En 10 pacientes no se detectaron mutaciones. Conclusión: El diagnóstico de la transmisión vertical por el VIH-1 puede realizarse de forma precoz y urgente mediante métodos de amplificación molecular. (AU)