RESUMEN
Whole-genome sequencing (WGS) makes it possible to determine the relatedness of bacterial isolates at a high resolution, thereby helping to characterize outbreaks. However, for Staphylococcus aureus, the accumulation of within-host diversity during carriage might limit the interpretation of sequencing data. In this study, we hypothesized the converse, namely, that within-host diversity can in fact be exploited to reveal the involvement of long-term carriers (LTCs) in outbreaks. We analyzed WGS data from 20 historical outbreaks and applied phylogenetic methods to assess genetic relatedness and to estimate the time to most recent common ancestor (TMRCA). The findings were compared with the routine investigation results and epidemiological evidence. Outbreaks with epidemiological evidence for an LTC source had a mean estimated TMRCA (adjusted for outbreak duration) of 243 days (95% highest posterior density interval [HPD], 143 to 343 days) compared with 55 days (95% HPD, 28 to 81 days) for outbreaks lacking epidemiological evidence for an LTC (P = 0.004). A threshold of 156 days predicted LTC involvement with a sensitivity of 0.875 and a specificity of 1. We also found 6/20 outbreaks included isolates with differing antimicrobial susceptibility profiles; however, these had only modestly increased pairwise diversity (mean 17.5 single nucleotide variants [SNVs] [95% confidence interval {CI}, 17.3 to 17.8]) compared with isolates with identical antibiograms (12.7 SNVs [95% CI, 12.5 to 12.8]) (P < 0.0001). Additionally, for 2 outbreaks, WGS identified 1 or more isolates that were genetically distinct despite having the outbreak pulsed-field gel electrophoresis (PFGE) pulsotype. The duration-adjusted TMRCA allowed the involvement of LTCs in outbreaks to be identified and could be used to decide whether screening for long-term carriage (e.g., in health care workers) is warranted. Requiring identical antibiograms to trigger investigation could miss important contributors to outbreaks.
Asunto(s)
Portador Sano/epidemiología , Brotes de Enfermedades , Tipificación Molecular , Infecciones Estafilocócicas/epidemiología , Staphylococcus aureus/clasificación , Staphylococcus aureus/genética , Secuenciación Completa del Genoma , Adulto , Portador Sano/microbiología , Electroforesis en Gel de Campo Pulsado , Genotipo , Humanos , Pruebas de Sensibilidad Microbiana , Filogenia , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/aislamiento & purificaciónRESUMEN
BACKGROUND: Panton-Valentine leucocidin-positive meticillin-resistant Staphylococcus aureus (PVL-MRSA) has become a globally common cause of community-acquired infections. AIM: We report an outbreak of PVL-MRSA in a regional neonatal unit in the UK involving three babies and three staff members. METHODS: Quinolone susceptibility was helpful in identifying potential PVL-MRSA but toxin gene profiling and sequence-based typing were required to distinguish between two PVL-MRSA strains present in the unit. FINDINGS: All three symptomatic babies and two staff carriers, one of whom was symptomatic, were found to be carrying the South West Pacific (SWP) clone of PVL-MRSA (ST30). One of the staff carriers had recently visited the Philippines and was thought to be the source of the outbreak. Control was established using standard infection control procedures but one baby with relapsing MRSA colonization has required more than 100 days in isolation. CONCLUSION: This is the first reported neonatal outbreak associated with the SWP clone in the UK. Our study highlights the potential risk of further introductions of this organism by healthcare staff or patients epidemiologically linked with the Philippines.
Asunto(s)
Toxinas Bacterianas/genética , Brotes de Enfermedades , Exotoxinas/genética , Leucocidinas/genética , Staphylococcus aureus Resistente a Meticilina/clasificación , Staphylococcus aureus Resistente a Meticilina/patogenicidad , Tipificación Molecular , Infecciones Estafilocócicas/epidemiología , Adulto , Antibacterianos/farmacología , Portador Sano/epidemiología , Portador Sano/microbiología , Portador Sano/transmisión , Transmisión de Enfermedad Infecciosa/prevención & control , Femenino , Personal de Salud , Humanos , Lactante , Recién Nacido , Control de Infecciones/métodos , Unidades de Cuidado Intensivo Neonatal , Masculino , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Epidemiología Molecular , Filipinas , Quinolonas/farmacología , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/transmisión , Viaje , Reino Unido/epidemiología , Factores de Virulencia/genéticaRESUMEN
The aim of this study was to establish the relative importance of various risk factors for toxoplasmosis in a United Kingdom antenatal population. Toxoplasma immune status was determined by an immunoassay and linked to a questionnaire exploring dietary and environmental exposure to toxoplasmosis. The overall seroprevalence found was 9.1% (172/1897). A significantly higher seroprevalence was associated with rural location of the childhood home, childhood home in Europe excluding the United Kingdom, feeding a dog raw meat and increased age. A non-significant higher prevalence of toxoplasmosis was observed in women who had lived with a cat or kitten as a child. In contrast to recent European studies only weak associations between diet and toxoplasmosis were found. Gardening activity was not associated with seropositivity but a non-significant lower seroprevalence was seen in gardeners who always wore gloves. This study confirms that toxoplasma prevalence in the United Kingdom has continued to decline since the 1960s. The increasing seroprevalence with age found in this study, highlights the continuing need to educate women of childbearing age about the risk factors for toxoplasmosis.
Asunto(s)
Complicaciones Parasitarias del Embarazo/epidemiología , Complicaciones Parasitarias del Embarazo/prevención & control , Toxoplasmosis/epidemiología , Toxoplasmosis/prevención & control , Adulto , Animales , Animales Domésticos , Dieta , Femenino , Humanos , Embarazo , Complicaciones Parasitarias del Embarazo/sangre , Complicaciones Parasitarias del Embarazo/etiología , Atención Prenatal , Factores de Riesgo , Salud Rural , Estudios Seroepidemiológicos , Encuestas y Cuestionarios , Toxoplasmosis/sangre , Toxoplasmosis/etiología , Reino Unido/epidemiologíaRESUMEN
To investigate the feasibility of using a record linkage method for identifying vaccine attributable adverse events, computerized hospital admissions and vaccination records from South East Kent district were linked and checked for accuracy. Records for 90% of children under 2 years of age admitted to hospital over a 2-year period were matched with vaccination records using a computer algorithm based on name, date of birth, sex, and post-code supplemented by visual inspection. Relative to this gold standard, matching on date of birth, sex and postcode alone had a sensitivity of 60% and an incorrect match rate of 0.2% after matches to more than one vaccine recipient were excluded. Manual checking of a sample of admissions showed that only 4% had been assigned incorrect International Classification of Disease (ICD) codes. Routine record linkage of ICD admission codes to vaccination records therefore yields data of good quality which may be used for surveillance purposes.
Asunto(s)
Hospitalización , Registro Médico Coordinado , Vigilancia de la Población/métodos , Vacunación/efectos adversos , Sistemas de Registro de Reacción Adversa a Medicamentos , Algoritmos , Preescolar , Enfermedad/clasificación , Estudios de Factibilidad , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Sistemas de Registros Médicos Computarizados , Sensibilidad y EspecificidadRESUMEN
Of 65 serum samples submitted for diagnostic purposes which proved to be anti-complementary by complement fixation test, 49 were parvovirus B19 IgM positive. Forty four of the 49 serum samples were from patients with arthropathy. Acute parvovirus B19 infection should be suspected when a patient has symptoms of disease of the joints and the serum is anticomplementary.
Asunto(s)
Artritis Infecciosa/inmunología , Pruebas de Fijación del Complemento , Eritema Infeccioso/inmunología , Parvovirus B19 Humano , Enfermedad Aguda , Complejo Antígeno-Anticuerpo/sangre , Artritis Infecciosa/diagnóstico , Eritema Infeccioso/diagnóstico , Humanos , Estudios RetrospectivosAsunto(s)
Varicela/virología , Neumonía Viral/virología , Complicaciones Infecciosas del Embarazo/virología , Aciclovir/administración & dosificación , Aciclovir/uso terapéutico , Adulto , Varicela/terapia , Enfermedades en Gemelos , Femenino , Humanos , Neumonía Viral/terapia , Embarazo , Complicaciones Infecciosas del Embarazo/terapia , Respiración Artificial , Índice de Severidad de la Enfermedad , Gemelos MonocigóticosRESUMEN
This report describes a double outbreak of staphylococcal scalded skin syndrome (SSSS) in which two distinct tetracycline-resistant strains of Staphylococcus aureus producing different exfoliative toxins were involved. In the first phase the daytime staff of the delivery unit and eczematous skin conditions in midwives were implicated as the probable source. In the second phase a source within a post-natal ward was suggested with local cross-infection. In the final phase both sources were epidemiologically linked to cases of SSSS. Because early discharge was the policy of the unit many cases presented in the community rather than in the hospital. Confirmation of epidemiological findings was provided by additional laboratory studies. Two distinct strains of S. aureus could be defined, differing in phage-typing patterns, the exfoliative toxin produced, plasmid profile, cadmium resistance and bacteriocin production. Strict care in hand washing with a chlorhexidine-containing detergent was an important control measure.
Asunto(s)
Infección Hospitalaria/epidemiología , Brotes de Enfermedades , Salas Cuna en Hospital , Infecciones Cutáneas Estafilocócicas/epidemiología , Staphylococcus aureus/clasificación , Adulto , Portador Sano/epidemiología , Portador Sano/microbiología , Infección Hospitalaria/microbiología , Infección Hospitalaria/transmisión , Exfoliatinas/biosíntesis , Humanos , Recién Nacido , Transmisión de Enfermedad Infecciosa de Profesional a Paciente , Partería , Servicio de Ginecología y Obstetricia en Hospital , Infecciones Cutáneas Estafilocócicas/microbiología , Infecciones Cutáneas Estafilocócicas/transmisión , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/metabolismo , Resistencia a la Tetraciclina , Reino Unido/epidemiologíaRESUMEN
Stable mouse monoclonal hybridoma cell lines secreting antibodies against Listeria monocytogenes were produced. Antibodies from two of these cell lines (designated CL2 and CL17) have been partially characterised. The specificities of these antibodies were assessed using indirect immunofluorescence antibody tests and L monocytogenes (166 strains) grown in vitro, other species of Listeria (21 strains), and bacteria from 14 other genera (87 strains). The antibodies were found to be specific for Listeria, and when used in combination, reacted with almost all strains of L monocytogenes. A simple and rapid direct immunofluorescence technique was developed, and the presence of L monocytogenes was shown in necropsy tissue from three patients where listeriosis had been confirmed by isolation of the bacterium. Bacteria were also confirmed using one of these antibodies in necropsy tissue from one further patient in whom listeriosis was suspected, but not confirmed by the cultivation of L monocytogenes.
Asunto(s)
Anticuerpos Monoclonales/inmunología , Listeria monocytogenes/inmunología , Adulto , Anciano , Anciano de 80 o más Años , Especificidad de Anticuerpos , Autopsia , Femenino , Técnica del Anticuerpo Fluorescente , Humanos , Listeriosis/inmunología , Masculino , Persona de Mediana EdadRESUMEN
The relationship between vaginal carriage and subsequent neonatal acquisition of Clostridium difficile was investigated. Vaginal carriage of C. difficile was detected in 11% of women attending the Department of Genital Medicine Clinic. C. difficile was isolated from the vagina in 18% of 50 mothers before delivery, and 8% after delivery; 62% of their babies had positive faecal cultures. Eight of nine of the babies whose mothers had positive cultures before delivery became colonised with C. difficile, while 23 of 41 babies whose mothers had negative cultures became colonised. This suggests that both the vagina and the environment may act as sources of neonatal acquisition of C. difficile. Broth enrichment culture proved a more sensitive method for isolating C. difficile from the vagina than direct plate culture and should be used in such investigations.
Asunto(s)
Clostridium/aislamiento & purificación , Recién Nacido , Vagina/microbiología , Infecciones por Clostridium/congénito , Infecciones por Clostridium/transmisión , Medios de Cultivo , Parto Obstétrico/métodos , Heces/microbiología , Femenino , Humanos , EmbarazoRESUMEN
Rectal swabs from 122 patients and 497 environmental swabs from several wards were examined for the presence of Clostridium difficile in order to assess the role of the environment in the spread of this organism. Clostridium difficile was isolated from 6/27 (22.2%) oncology patients and from 8/163 (4.9%) environmental specimens obtained from the oncology unit. Items found positive for C difficile were those subjected to faecal contamination such as commode chairs, bed pans, dust pans, discard bins, the sluice and a disposable bed pan machine. Fourteen of 51 (27.4%) asymptomatic neonates yielded mostly toxigenic C difficile in their stools during their first week of life. Five of 156 (3.2%) specimens taken from inanimate objects in the environment of the neonatal units were positive for C difficile. The organism was also isolated from the hands of a nurse. Similar antibiogram patterns were demonstrated in the strains obtained from the patients and their environment indicating the possible occurrence of cross infection. These results indicate that environmental contamination is important in the spread of C difficile in hospitalised patients and the implementation of isolation procedures may limit that spread.
Asunto(s)
Infecciones por Clostridium/transmisión , Infección Hospitalaria/transmisión , Antibacterianos/farmacología , Clostridium/efectos de los fármacos , Clostridium/aislamiento & purificación , Clostridium/metabolismo , Citotoxinas/biosíntesis , Reservorios de Enfermedades , Ambiente , Heces/microbiología , Unidades Hospitalarias , Humanos , Recién Nacido , Pruebas de Sensibilidad Microbiana , Habitaciones de PacientesRESUMEN
Over a five-month period 1239 unselected, routine faecal specimens from 856 patients were examined for Clostridium difficile. One hundred specimens representing 69 patients were culture-positive. Toxin was detected in the stool of ten. During the study period, there were 41 Salmonella, 12 Campylobacter and 9 Shigella infections. C difficile was isolated together with Salmonella from 12 patients. No patient required specific treatment for C difficile infection. The significance of these findings is discussed.