Ecological competition and the incidence of Acinetobacter baumannii bloodstream infections in a teaching hospital in Southeastern Brazil

Abstract

Introduction: Recently, pathogen ecology has been recognized as an important epidemiological determinant of healthcareassociated infections (HAIs). Acinetobacter baumannii is one of the most important agents known to cause HAIs. It is widespread in healthcare settings and exhibits seasonal variations in incidence. Little is known about the impact of competition with other hospital pathogens on the incidence of A. baumannii infection. Methods: We conducted an ecological study, enrolling patients who presented with healthcare-associated bloodstream infections (HA-BSIs) from 2005 to 2010 at a 450-bed teaching hospital in Brazil. HA-BSIs were said to be present when bacteria or fungi were recovered from blood cultures collected at least three days after admission. Monthly incidence rates were calculated for all HA-BSIs (overall or caused by specifi c pathogens or groups of pathogens). Multivariate Poisson regression models were used to identify the impacts of the incidence of several pathogens on the incidence of A. baumannii. Results: The overall incidence rate of HA-BSI caused by A. baumannii was 2.5 per 10,000 patient-days. In the multivariate analysis, the incidence of HA-BSI caused by A. baumannii was negatively associated with the incidence rates of HA-BSI due to Staphylococcus aureus (rate ratio [RR]=0.88; 95% confi dence interval [CI]=0.80-0.97), Enterobacter spp. (RR=0.84; 95%CI=0.74-0.94) and a pool of less common gram-negative pathogens. Conclusions: Our results suggest that competition between pathogens infl uences the etiology of HA-BSIs. It would be benefi cial to take these fi ndings into account in infection control policies.

Seasonality and weather dependance of Acinetobacter baumannii complex bloodstream infections in different climates in Brazil

“…The same study found minor differences on overall HCAIs incidence among different regions in Brazil [ 19 ]. Other limitation was not assessing the incidence of pathogens (e.g., MRSA and GNB) that may compete ecologically for human and inanimate reservoirs inside hospitals [ 20 ]. It is therefore possible that the greater incidence of GNB such as Klebsiella spp in hospitals close to the Equator line [ 2 ] could have impacted on the lower incidence of A .…”

Eventos Gerenciais E Assistenciais Como Interferências Na Carga De Trabalho

“…Variações sazonais na ocorrência de infecções em UTI foram identificadas em estudos na mesma unidade. (26)(27)(28) As infecções de corrente sanguínea relacionadas ao uso de cateteres centrais aumentam em 57% nos meses de verão, entre outubro a março. As prováveis causas do aumento da incidência das infecções no verão seriam que algumas proteínas das bactérias sejam mais expressivas no verão, o aumento da umidade favorece a proliferação de bactérias e a sua capacidade de invadir tecidos e o subdimensionamento da equipe de enfermagem.…”

“…(26) Os estudos também indicaram que a cada 1ºC a mais na temperatura mensal, aumenta em 5% a incidência de bactérias gram-negativas, 13% para Acinetobacter e 10% para Enterobacter. (27,28) No período em que o hospital realizava transplantes hepáticos, com todos os pós-operatórios na UTI, o NAS foi maior no PII com NAS médio de 75 e no PEI foi menor (70), o que evidencia o aumento na carga de trabalho de enfermagem em UTI no atendimento de pacientes com intervenções específicas como no pós-operatório de pacientes com transplantes de fígado. O paciente em pós-operatório de transplante de fígado demanda recursos humanos treinados e disponibilidade de recursos materiais.…”

Roles of DJ41_1407 and DJ41_1408 in Acinetobacter baumannii ATCC19606 Virulence and Antibiotic Response

“…Acinetobacter baumannii is a Gram-negative bacterium that can act as an opportunistic pathogen in humans [1], and which is notorious for causing a wide range of severe nosocomial infections [2][3][4]. Among these, ventilator-associated pneumonia and bloodstream infections are regarded as the most significant, with high mortality rates [5].…”