Quantitative skin cultures at potential catheter sites in neonates

Hand hygiene perception among health care workers in Hungarian hospitals: prior to a nationwide microbiological survey

Transmission of pathogens via healthcare workers' (HCWs) hands is one of the most frequent means of spreading multi-resistant organisms and occurring healthcare-associated infections (HAIs) in hospitals. The role of contaminated hands in pathogen transmission was recognized by Hungarian physician, Ignác Semmelweis. Hand hygiene prevents cross-infections in hospitals, but numerous epidemiological and microbiology-based studies have documented low compliance of HCWs with this simple procedure. Furthermore, hand hygiene perception of HCWs plays an important role in determining hand hygiene compliance. Our aim was to describe the opinion of HCWs about their perception regarding hand hygiene practice. Our further goal was to strengthen a laboratory basis for bacterial backup control of nosocomial pathogens. A cross-sectional descriptive study was conducted between December 2010 and February 2011 in 13 participating hospitals in Hungary. HCWs know that there is correlation between contaminated hands and HAIs (83%), but neither the frequency (62%) nor the implementation (73%) of their hand hygiene performance are satisfying.We recommend that multimodal interventions - highlighted active microbiological surveillance of HCWs' hands - are the most suitable strategies to reduce the occurrence of HAIs and to determine their impact on cross-transmission of microorganisms and to overcome barriers of HCWs.

Routine skin cultures in predicting sepsis pathogens among hospitalized preterm neonates in Bangladesh

BACKGROUND

Few studies from developing countries have examined sensitivity, specificity, positive and negative predictive values of routine surface cultures.

OBJECTIVES

The purpose of the study was to determine sensitivity, specificity, and positive predictive value (PPV) of skin cultures among preterm neonates admitted to Dhaka Shishu Hospital, Bangladesh.

METHODS

The study was nested within a prospective, randomized, controlled trial of emollient treatment in Dhaka Shishu Hospital, Bangladesh. A total of 497 preterm infants <33 weeks gestational age and <72 h of chronological age were enrolled, and the sensitivity, specificity, and PPV of skin cultures were analyzed among 3,765 blood-skin culture pairs, wherein the skin culture was obtained within 13 days before the blood culture.

RESULTS

Overall sensitivity, specificity, and PPV were 16, 38, and 5%, respectively. PPV during Klebsiella pneumoniae outbreaks was about 9%, and the inguinal site had the highest PPV (6%) among the three skin sites. Acinetobacter spp.- and K. pneumoniae-specific PPVs were 28 and 23%, respectively. PPV was <2% for Candida spp., Enterobacter spp., and Salmonella spp.

CONCLUSION

Routine skin culture is inefficient in predicting the pathogen responsible for sepsis among premature neonates, even in a developing country setting, where the burden of bacterial infection is relatively high. Skin cultures are also of limited utility during K. pneumoniae outbreaks, and are not recommended.

Infections associated with medical devices: pathogenesis, management and prophylaxis

The insertion or implantation of foreign bodies has become an indispensable part in almost all fields of medicine. However, medical devices are associated with a definitive risk of bacterial and fungal infections. Foreign body-related infections (FBRIs), particularly catheter-related infections, significantly contribute to the increasing problem of nosocomial infections. While a variety of micro-organisms may be involved as pathogens, staphylococci account for the majority of FBRIs. Their ability to adhere to materials and to promote formation of a biofilm is the most important feature of their pathogenicity. This biofilm on the surface of colonised foreign bodies is regarded as the biological correlative for the clinical experience with FBRI, that is, that the host defence mechanisms often seem to be unable to handle the infection and, in particular, to eliminate the micro-organisms from the infected device. Since antibacterial chemotherapy is also frequently not able to cure these infections despite the use of antibacterials with proven in vitro activity, removal of implanted devices is often inevitable and has been standard clinical practice. However, in specific circumstances, such as infections of implanted medical devices with coagulase-negative staphylococci, a trial of salvage of the device may be justified. All FBRIs should be treated with antibacterials to which the pathogens have been shown to be susceptible. In addition to systemic antibacterial therapy, an intraluminal application of antibacterial agents, referred to as the 'antibiotic-lock' technique, should be considered to circumvent the need for removal, especially in patients with implanted long-term catheters. To reduce the incidence of intravascular catheter-related bloodstream infections, specific guidelines comprising both technological and nontechnological strategies for prevention have been established. Quality assurance, continuing education, choice of the catheter insertion site, hand hygiene and aseptic techniques are aspects of particular interest. Furthermore, all steps in the pathogenesis of biofilm formation may represent targets against which prevention strategies may be directed. Alteration of the foreign body material surface may lead to a change in specific and nonspecific interactions with micro-organisms and, thus, to a reduced microbial adherence. Medical devices made out of a material that would be antiadhesive or at least colonisation resistant would be the most suitable candidates to avoid colonisation and subsequent infection. Another concept for the prevention of FBRIs involves the impregnation of devices with various substances such as antibacterials, antiseptics and/or metals. Finally, further studies are needed to translate the knowledge on the mechanisms of biofilm formation into applicable therapeutic and preventive strategies.

Protocols for the prevention of intravascular device-related infections

The frequency of nosocomial infections in intensive care unit (ICU) patients is estimated at 20%. Many of these infections are related to the frequent and prolonged use of intravascular devices. If ICU personnel are familiar with the established protocols for the selection, insertion, and maintenance of intravascular devices and are strict in their adherence to these protocols, it is expected that a significant number of these infections can be avoided.

Persistence of clones of coagulase-negative staphylococci among premature neonates in neonatal intensive care units: two-center study of bacterial genotyping and patient risk factors

From 1 January 1995 until 1 January 1996, we studied the molecular epidemiology of blood isolates of coagulase-negative staphylococci (CoNS) in the Neonatal Intensive Care Units (NICUs) of the Sophia Children's Hospital (SCH; Rotterdam, The Netherlands) and the Wilhelmina Children's Hospital (WCH; Utrecht, The Netherlands). The main goal of the present study was to detect putatively endemic clones of CoNS persisting in these NICUs. Pulsed-field gel electrophoresis was used to detect the possible presence of endemic clones of clinical significance. In addition, clinical data of patients in the SCH were analyzed retrospectively to identify risk factors for the acquisition of positive blood cultures. In both centers, endemic CoNS clones were persistently present. Thirty-three percent of the bacterial isolates derived from blood cultures in the SCH belonged to a single genotype. In the WCH, 45% of all bacterial strains belonged to a single clone. These clones were clearly different from each other, which implies that site specificity is involved. Interestingly, we observe that the clonal type in the SCH differed significantly from the incidentally occurring strains with respect to both the average pH and partial CO2 pressure of the patient's blood at the time of bacterial culture. We found that the use of intravascular catheters, low gestational age, and a long hospital stay were important risk factors for the development of a putative CoNS infection. When the antibiotic susceptibility of the bacterial isolates was assessed, a clear correlation between the nature of the antibiotics most frequently used as a first line of defense versus the resistance profile was observed. We conclude that the intensive use of antibiotics in an NICU setting with highly susceptible patients causes selection of multiresistant clones of CoNS which subsequently become endemic.