Contaminación ambiental por microorganismos multirresistentes y el efecto de la limpieza y desinfección en una unidad de cuidados intensivos / Environmental contamination by multi-resistant microorganisms and the effect of cleaning and disinfection in an intensive care unit / Contaminação ambiental por micro-organismos multirresistentes e o efeito de limpeza e desinfecção em unidade de terapia intensiva

Conocer el rol del medio ambiente es fundamental para evitar las infecciones intra-hospitalarias. Con ese objetivo, se planteó evaluar la prevalencia de contaminación ambiental por microorganismos multirresistentes (MMR) antes y después de la limpieza terminal de habitaciones de pacientes colonizados y establecer si la aparatología de uso común actuaba como reservorio de estos en la unidad de cuidados intensivos (UTI). Se obtuvieron muestras ambientales de las habitaciones, 48 h posteriores a la detección de colonización y luego de las limpiezas. Los resultados mostraron que luego de ambos procedimientos de limpieza se logró reducir de 28,2% a 2,6% la contaminación por Acinetobacter spp. multirresistente (AMR). También, se tomaron muestras de aparatología de uso común encontrándose entre 1,8 y 5,4% de contaminación por MMR. La limpieza y desinfección reducen significativamente la contaminación ambiental. Sin embargo, la colonización de equipos por MMR y el incumplimiento de precauciones universales representan una posibilidad de transmisión cruzada.

It is essential to understand the role of the environment in order to avoid intrahospital infections. To achieve this objective, this research proposes to assess the prevalence of the environmental contamination caused by multi-resistant microorganisms (MRM) before and after terminal disinfection in rooms with colonized patients, but also to establish whether the commonly used device acts as a reservoir of those micro-organisms in an intensive care unit (ICU). Environmental samples were obtained from the rooms, 48 hours after detecting colonization and also after the first and second final cleaning. The results showed that after both procedures, there was a reduction from 28.2% to 2.6% of contamination caused by multi-resistant Acinetobacter spp. (AMR). Samples from appliances and supplies were taken as well, in which case, between 1.8 and 5.4% of contamination levels induced by MMR were found. Cleaning and disinfecting significantly reduce environmental contamination. However, both MMR bacterial colonization and the lack of universal precautions enforcement represent a possibility of cross-transmission.

É essencial conhecer o papel do meio ambiente para evitar as infecções intra-hospitalares. Com esse objetivo, planejou-se avaliar a prevalência de contaminação ambiental por microorganismos multirresistentes (MMR) antes e depois da limpeza final dos quartos de pacientes colonizados e estabelecer se os aparelhos de uso comum atuavam como um reservatório deles na unidade de terapia intensiva (UTI). Obtiveram-se amostras ambientais dos quartos 48 horas após a detecção da colonização e logo após as limpezas finais. Os resultados mostraram que depois dos dois procedimentos de limpeza se obteve uma redução de 28,2% para 2,6% da contaminação por Acinetobacter spp. multirresistente (AMR). Foram obtidas também amostras de aparelhos de uso comum onde se encontraram entre 1,8% e 5,4% de contaminação por MMR. A limpeza e a desinfecção reduzem significativamente a contaminação ambiental. Contudo, a colonização de equipamentos por MMR e o não cumprimento de providências universais representam uma possibilidade de transmissão cruzada.

Colonización rectal por bacilos gram negativos multirresistentes: importancia de la detección precoz durante la hospitalización / Rectal colonisation by multiresistant gram-negative bacilli: relevance of early detection in the course of hospitalization / Colonização retal por bacilos gram negativos multirresistentes: importância da identificação precoce durante a hospitalização

Las infecciones asociadas con el cuidado de la salud son consideradas un problema epidémico, controlable pero difícilmente erradicable. La detección precoz de pacientes colonizados por microorganismos multirresistentes, a través de cultivos de vigilancia epidemiológica y la implementación de medidas preventivas pueden reducir su incidencia. El objetivo del trabajo fue establecer los momentos adecuados durante la hospitalización para realizar estudios de colonización y decidir los microorganismos a estudiar según el lugar de procedencia del paciente. Se analizaron hisopados rectales de pacientes internados en la Unidad de Terapia Intensiva, obtenidos al ingreso, a las 72 h y al sexto día de internación. Se investigó Acinetobacter spp multirresistente (AMR), enterobacterias productoras de BLEE (EB-BLEE) y de KPC (EB-KPC). Los resultados mostraron 15,2% de pacientes de la comunidad y 16,7% de geriátricos colonizados con EB-BLEE al ingreso. Dicho porcentaje fue mayor (28,6%) en pacientes previamente institucionalizados y, además, 2,6% colonizados con EB-KPC y 3,4% con AMR. Los controles posteriores mostraron porcentajes crecientes de portación con el transcurso de la internación. Por lo tanto, es importante la detección de estos microorganismos al ingreso hospitalario y continuar con vigilancia activa, para poder implementar medidas precoces tendientes a evitar las consecuencias de la rápida transmisión horizontal.

Healthcare associated infections are considered an epidemic problem; manageable but difficult to eradicate. The early detection of patients infected with antimicrobial multiresistant microorganisms by means of epidemiological surveillance cultures and the execution of prophylactic measures, are key to reduce their incidence. The aim of this work was to assess a suitable schedule in the course of hospitalisation to perform colonisation studies and to decide which microorganisms to analyse according to the provenance of the patient. Rectal swabs from patients admitted at the Intensive Care Unit obtained at the time of admission, 72 h and six days later were analysed. Multiresistant Acinetobacter spp.(MRA), ESBL- and KPC- producing Enterobacteriaceae (ESBL-EB and KPC-EB, respectively) were investigated. Results showed that 15.2% of patients without previous hospitalisation and 16.7% of patients coming from geriatric institutions were colonised by ESBL-EB at the moment of admission. This percentage was greater (28.6%) in previously hospitalised patients, of whom 2.6% were found to be colonized by KPC-EB and 3.4% by MRA. Subsequent monitoring showed increasing colonisation percentages with the course of hospitalisation. Therefore, detection of these microorganisms at the time of admission and constant active surveillance are crucial to implement early measures aiming to avoid the consequences of rapid horizontal dissemination.

As infecções relacionadas ao cuidado da saúde são consideradas um problema epidêmico controlável, mas dificilmente erradicável. A identificação precoce em pacientes colonizados por microorganismos multirresistentes, através de culturas de vigilância epidemiológica e a implementação de medidas preventivas, podem diminuir sua incidência. O objetivo do trabalho foi estabelecer os momentos adequados durante a hospitalização para realizar testes de colonização e decidir quais os microorganismos que serão estudados de acordo com o lugar de procedência do paciente. Foram testados Swabs retais de pacientes internados na Unidade de Terapia Intensiva (UTI), coletados ao serem admitidos, nas 72h e no sexto dia de internação. Foram analisados Acinetobacter spp. multirresistente (AMR), enterobactérias produtoras de BLEE (EB-BLEE) e de KPC (EB-KPC). Os resultados mostraram 15.2% de pacientes da comunidade e 16.7% de geriátricos colonizados com EB-BLEE ao serem admitidos. Ese percentual foi maior (28.6%) em pacientes previamente institucionalizados e, além disso, 2.6% colonizados com EB-KPC e 3.4% com AMR. Os controles posteriores mostraram percentuais crescentes de portação com o decorrer da internação. Portanto, é importante a identificação destes microorganismos no momento da admissão hospitalar e continuar com a vigilância ativa, para poder implementar medidas precoces tendentes a evitar as consequências da rápida transmissão horizontal.

Dengue virus genomic variation associated with mosquito adaptation defines the pattern of viral non-coding RNAs and fitness in human cells.

The Flavivirus genus includes a large number of medically relevant pathogens that cycle between humans and arthropods. This host alternation imposes a selective pressure on the viral population. Here, we found that dengue virus, the most important viral human pathogen transmitted by insects, evolved a mechanism to differentially regulate the production of viral non-coding RNAs in mosquitos and humans, with a significant impact on viral fitness in each host. Flavivirus infections accumulate non-coding RNAs derived from the viral 3'UTRs (known as sfRNAs), relevant in viral pathogenesis and immune evasion. We found that dengue virus host adaptation leads to the accumulation of different species of sfRNAs in vertebrate and invertebrate cells. This process does not depend on differences in the host machinery; but it was found to be dependent on the selection of specific mutations in the viral 3'UTR. Dissecting the viral population and studying phenotypes of cloned variants, the molecular determinants for the switch in the sfRNA pattern during host change were mapped to a single RNA structure. Point mutations selected in mosquito cells were sufficient to change the pattern of sfRNAs, induce higher type I interferon responses and reduce viral fitness in human cells, explaining the rapid clearance of certain viral variants after host change. In addition, using epidemic and pre-epidemic Zika viruses, similar patterns of sfRNAs were observed in mosquito and human infected cells, but they were different from those observed during dengue virus infections, indicating that distinct selective pressures act on the 3'UTR of these closely related viruses. In summary, we present a novel mechanism by which dengue virus evolved an RNA structure that is under strong selective pressure in the two hosts, as regulator of non-coding RNA accumulation and viral fitness. This work provides new ideas about the impact of host adaptation on the variability and evolution of flavivirus 3'UTRs with possible implications in virulence and viral transmission.

Serological detection of West Nile virus in horses and chicken from Pantanal, Brazil

In an effort to detect West Nile virus (WNV) in Brazil, we sampled serum from horses and chickens from the Pantanal region of the state of Mato Grosso and tested for flavivirus-reactive antibodies by blocking ELISA. The positive samples were further confirmed for serological evidence of WNV infection in three (8%) of the 38 horses and one (3.2%) of the 31 chickens using an 80% plaque-reduction neutralisation test (PRNT80). These results provide evidence of the circulation of WNV in chickens and horses in Pantanal.

Serological detection of West Nile virus in horses and chicken from Pantanal, Brazil.

In an effort to detect West Nile virus (WNV) in Brazil, we sampled serum from horses and chickens from the Pantanal region of the state of Mato Grosso and tested for flavivirus-reactive antibodies by blocking ELISA. The positive samples were further confirmed for serological evidence of WNV infection in three (8%) of the 38 horses and one (3.2%) of the 31 chickens using an 80% plaque-reduction neutralisation test (PRNT80). These results provide evidence of the circulation of WNV in chickens and horses in Pantanal.

Humoral and cell-mediated immune responses to monovalent 2009 influenza A/H1N1 and seasonal trivalent influenza vaccines in high-risk children.

OBJECTIVE: Humoral and cell-mediated immune responses to monovalent 2009 pandemic influenza A (H1N1/2009) and seasonal trivalent influenza (TIV) vaccines were evaluated in healthy children and children with asthma, sickle cell disease (SCD), systemic lupus erythematosus (SLE), and solid organ transplantation (SOT). STUDY DESIGN: Blood was collected from 112 subjects at the time of H1N1/2009 vaccination and 46 ± 15 days later for hemagglutination inhibition titers and γ-interferon ELISPOT responses to H1N1/2009 vaccine and TIV; unvaccinated children also received TIV at enrollment. RESULTS: A significant increase in the percentage of subjects with seroprotective hemagglutination inhibition titers to both vaccines was observed in all high-risk groups. Children with asthma and SCD were most likely to achieve seroprotective titers to H1N1/2009, whereas <50% of subjects with SOT and SLE had a seroprotective response. Subjects with SOT and SLE also had lower rates of seroprotection after TIV, and subjects with SLE had the lowest ELISPOT responses to both vaccines. Overall, 73% of healthy children exhibited protective responses to TIV; only 35% achieved seroprotection for H1N1/2009. CONCLUSIONS: This evaluation of immune responses to H1N1/2009 in high-risk children suggests suboptimal responses for SOT and SLE subjects, but not for subjects with SCD or asthma. Higher antigen dose, additional dose regimens, or both for immunocompromised children warrant further investigation.