Risk Factors for Surgical Site Infection in a Tanzanian District Hospital: A Challenge for the Traditional National Nosocomial Infections Surveillance System Index

The incidence of surgical site infections (SSIs) was 24% in a district hospital in Tanzania. Wound classification was not an independent risk factor for SSI, indicating that risk scores developed in industrialized countries may require adjustments for nonindustrialized countries. The National Nosocomial Infections Surveillance system score required adjustments to reliably predict SSI, probably to account for improper hygiene and the lack of adjustment for the duration of surgery (defined as the 75th percentile of the duration for each type of operative procedure) to reflect local circumstances. Multidrug-resistant pathogens, such as methicillin-resistant Staphylococcus aureus and gram-negative pathogens expressing broad-spectrum β-lactamases, have already emerged.

Key priorities in the prevention and control of healthcare-associated infection: a survey of European and other international infection prevention experts

PURPOSE

Prevention and control of healthcare-associated infection (HCAI) are important within and beyond Europe. However, it is unclear which areas are considered important by HCAI prevention and control professionals. This study assesses the priorities in the prevention and control of HCAI as judged by experts in the field.

METHODS

A survey was conducted by the European Society of Clinical Microbiology and Infectious Diseases focussing on seven topics using SurveyMonkey^®. Through a newsletter distributed by email, about 5000 individuals were targeted throughout the world in February and March 2013. Participants were asked to rate the importance of particular topics from one (low importance) to ten (extraordinary importance), and there was no restriction on giving equal importance to more than one topic.

RESULTS

A total of 589 experts from 86 countries participated including 462 from Europe (response rate: 11.8 %). Physicians accounted for 60 % of participants, and 57 % had ten or more years' experience in this area. Microbial epidemiology/resistance achieved the highest priority scoring with 8.9, followed by surveillance 8.2, and decolonisation/disinfection/antiseptics with 7.9. Under epidemiology/resistance, highly resistant Gram-negative bacilli scored highest (9.0-9.2). The provision of computerised healthcare information systems for the early detection of outbreaks was accorded the top priority under surveillance. The prevention of surgical site and central line infections ranked highest under the category of specific HCAI and HCAI in certain settings. Differences between regions are described.

CONCLUSION

These findings reflect the concerns of experts in HCAI prevention and control. The results from this survey should inform national and international agencies on future action and research priorities.

Preparedness of institutions around the world for managing patients with Ebola virus disease: an infection control readiness checklist

BACKGROUND

In response to global concerns about the largest Ebola virus disease (EVD), outbreak to-date in West Africa documented healthcare associated transmission and the risk of global spread, the International Society of Chemotherapy (ISC) Infection Control Working Group created an Ebola Infection Control Readiness Checklist to assess the preparedness of institutions around the globe. We report data from the electronic checklist that was disseminated to medical professionals from October to December 2014 and identify action needed towards better preparedness levels.

FINDINGS

Data from 192 medical professionals (one third from Africa) representing 125 hospitals in 45 countries around the globe were obtained through a specifically developed electronic survey. The survey contained 76 specific questions in 7 major sections: Administrative/operational support; Communications; Education and audit; Human resources, Supplies, Infection Prevention and Control practices and Clinical management of patients. The majority of respondents were infectious disease specialists/infection control consultants/clinical microbiologists (75; 39 %), followed by infection control professionals (59; 31 %) and medical doctors of other specialties (17; 9 %). Nearly all (149; 92 %) were directly involved in Ebola preparedness activities. Whilst, 54 % indicated that their hospital would need to handle suspected and proven Ebola cases, the others would subsequently transfer suspected cases to a specialized centre.

CONCLUSION

The results from our survey reveal that the general preparedness levels for management of potentially suspected cases of Ebola virus disease is only partially adequate in hospitals. Hospitals designated for admitting EVD suspected and proven patients had more frequently implemented Infection Control preparedness activities than hospitals that would subsequently transfer potential EVD cases to other centres. Results from this first international survey provide a framework for future efforts to improve hospital preparedness worldwide.

The roles of genetic drift and natural selection in quantitative trait divergence along an altitudinal gradient in Arabidopsis thaliana

Understanding how natural selection and genetic drift shape biological variation is a central topic in biology, yet our understanding of the agents of natural selection and their target traits is limited. We investigated to what extent selection along an altitudinal gradient or genetic drift contributed to variation in ecologically relevant traits in Arabidopsis thaliana. We collected seeds from 8 to 14 individuals from each of 14 A. thaliana populations originating from sites between 800 and 2700 m above sea level in the Swiss Alps. Seed families were grown with and without vernalization, corresponding to winter-annual and summer-annual life histories, respectively. We analyzed putatively neutral genetic divergence between these populations using 24 simple sequence repeat markers. We measured seven traits related to growth, phenology and leaf morphology that are rarely reported in A. thaliana and performed analyses of altitudinal clines, as well as overall QST-FST comparisons and correlation analyses among pair-wise QST, FST and altitude of origin differences. Multivariate analyses suggested adaptive differentiation along altitude in the entire suite of traits, particularly when expressed in the summer-annual life history. Of the individual traits, a decrease in rosette leaf number in the vegetative state and an increase in leaf succulence with increasing altitude could be attributed to adaptive divergence. Interestingly, these patterns relate well to common within- and between-species trends of smaller plant size and thicker leaves at high altitude. Our results thus offer exciting possibilities to unravel the underlying mechanisms for these conspicuous trends using the model species A. thaliana.

Evaluation of treatment outcomes for Stenotrophomonas maltophilia bacteraemia

OBJECTIVE

The goal of this study was to retrospectively collect data about treatment outcomes in patients diagnosed with Stenotrophomonas maltophilia bacteraemia over a period of 20 years and evaluate these data with respect to the efficacy of treatment options.

METHODS

The setting was a 700-bed tertiary care hospital in a large urban area. Hospital databases and medical records provided information about episodes of S. maltophilia, patient characteristics and treatment outcomes. Patients with at least one positive blood culture for S. maltophilia were included in the study. Data were analysed with respect to clinical improvement and mortality ≤30 days after the onset of infection. We compared patient characteristics, laboratory values and treatments by using the Chi-square or Fisher's exact tests and the Mann-Whitney test.

RESULTS

We investigated 27 patients with S. maltophilia bacteraemia. The focus of infection was a central venous catheter in 18 (67 %) cases. The 30-day mortality rate was 11 %. All patients who were treated with an antibiotic that was effective in vitro against the pathogen recovered clinically and survived ≥30 days after the onset of infection. The most frequently used antibiotic was trimethoprim-sulfamethoxazole administered alone or in combination with a fluoroquinolone.

CONCLUSIONS

Despite the fact that S. maltophilia is resistant to multiple antibiotics, the prognosis for patients with S. maltophilia bacteraemia is good when they are treated with antibiotics that are effective against this pathogen in vitro.

Additive effect of Enterococcus faecium on Enterococcal bloodstream infections: a 14-year study in a Swiss tertiary hospital

We investigated whether an increase in enterococcal bloodstream infections (BSIs) depends on the emergence of Enterococcus faecium in an area with low vancomycin-resistant enterococci prevalence. From 1999 to 2012, a linear increase in E. faecium BSI rates (0.009 per 1,000 patient-days per year; P < .001) was noted. Enterococcus faecalis BSI rates remained stable.

High proportion of healthcare-associated urinary tract infection in the absence of prior exposure to urinary catheter: a cross-sectional study

Background

Exposure to urinary catheters is considered the most important risk factor for healthcare-associated urinary tract infection (UTI) and is associated with significant morbidity and substantial extra-costs. In this study, we assessed the impact of urinary catheterisation (UC) on symptomatic healthcare-associated UTI among hospitalized patients.

Methods

A nationwide period prevalence survey of healthcare-associated infections was conducted during 1 May to 30 June 2004 in 49 Swiss hospitals and included 8169 adult patients (4313 female; 52.8%) hospitalised in medical, surgical, intermediate, and intensive care wards. Additional data were collected on exposure to UC to investigate factors associated with UTI among hospitalised adult patients exposed and non-exposed to UC.

Results

1917 (23.5%) patients were exposed to UC within the week prior to survey day; 126 (126/8169; 1.5%) developed UTI. Exposure to UC preceded UTI only in 73 cases (58%). By multivariate logistic regression analysis, UTI was independently associated with exposure to UC (odds ratio [OR], 3.9 [95% CI, 2.6-5.9]), female gender (OR, 2.1 [95% CI, 1.4-3.1]), an American Society of Anesthesiologists’ score > 2 points (OR, 3.2 [95% CI, 1.1-9.4], and prolonged hospital stay >20 days (OR, 1.9 [95% CI, 1.4-3.2]. Further analysis showed that the only significant factor for UTI with exposure to UC use was prolonged hospital stay >40 days (OR, 2.9 [95% CI, 1.3-6.1], while female gender only showed a tendency (OR, 1.6 [95% CI, 1.0-2.7]. In the absence of exposure to UC, the only significant risk factor for UTI was female gender (OR, 3.3 [95% CI, 1.7-6.5]).

Conclusions

Exposure to UC was the most important risk factor for symptomatic healthcare-associated UTI, but only concerned about half of all patients with UTI. Further investigation is warranted to improve overall infection control strategies for UTI.

Patterns of molecular evolution in dioecious and non-dioecious Silene

Dioecy (i.e. having separate sexes) is a rather rare breeding system in flowering plants. Such rareness may result from a high probability of extinction in dioecious species because of less efficient dispersal and the costs of sexual selection, which are expected to harm dioecious species' survival on the long term. These handicaps should decrease the effective population size (Ne) of dioecious species, which in turn should reduce the efficacy of selection. Moreover, sexual selection in dioecious species is expected to specifically affect some genes, which will evolve under positive selection. The relative contribution of these effects is currently unknown and we tried to disentangle them by comparing sequence evolution between dioecious and non-dioecious species in the Silene genus (Caryophyllaceae), where dioecy has evolved at least twice. For the dioecious species in the section Melandrium, where dioecy is the oldest, we found a global reduction of purifying selection, while on some, male-biased genes, positive selection was found. For section Otites, where dioecy evolved more recently, we found no significant differences between dioecious and non-dioecious species. Our results are consistent with the view that dioecy is an evolutionary dead end in flowering plants, although other scenarios for explaining reduced Ne cannot be ruled out. Our results also show that contrasting forces act on the genomes of dioecious plants, and suggest that some time is required before the genome of such plants bears the footprints of dioecy.

[Prevention of catheter-related infections]

Bloodstream infections due to intravascular catheterization, peritoneal catheters for dialysis, suprapubic or transurethral catheters, are one of the major sources of nosocomial infections. Therefore, the prevention of catheter-associated infections is an important issue for physicians and nursing staff working in hospitals or in outpatient settings. The risk can be minimized by diligent checking of the indications, hygienic measures, using the right materials, thorough follow-up and education of the medical and nursing staff. Thus it is possible to avoid individual suffering of patients and to reduce costs in the healthcare system.

Is floral divergence sufficient to maintain species boundaries upon secondary contact in Mediterranean food-deceptive orchids?

Analyzing the processes that determine whether species boundaries are maintained on secondary contact may shed light on the early phase of speciation. In Anacamptis morio and Anacamptis longicornu, two Mediterranean orchid sister-species, we used molecular and morphological analyses, together with estimates of pollination success and experimental crosses, to assess whether floral isolation can shelter the species' genomes from genetic admixture on secondary contact. We found substantial genetic and morphological homogenization in sympatric populations in combination with an apparent lack of postmating isolation. We further detected asymmetric introgression in the sympatric populations and an imbalance in cytotype representation, which may be due either to a difference in flowering phenology or else be a consequence of cytonuclear incompatibilities. Estimates of genetic clines for markers across sympatric zones revealed markers that significantly deviated from neutral expectations. We observed a significant correlation between spur length and reproductive success in sympatric populations, which may suggest that directional selection is the main cause of morphological differentiation in this species pair. Our results suggest that allopatric divergence has not led to the evolution of sufficient reproductive isolation to prevent genomic admixture on secondary contact in this orchid species pair.

Livestock-associated methicillin-resistant Staphylococcus aureus in humans, Europe

To estimate the proportion of methicillin-resistant Staphylococcus aureus (MRSA) isolates from humans that were sequence type (ST) 398, we surveyed 24 laboratories in 17 countries in Europe in 2007. Livestock-associated MRSA ST398 accounted for only a small proportion of MRSA isolates from humans; most were from the Netherlands, Belgium, Denmark, and Austria.

Genetic analysis of post-mating reproductive barriers in hybridizing European Populus species

Molecular genetic analyses of experimental crosses provide important information on the strength and nature of post-mating barriers to gene exchange between divergent populations, which are topics of great interest to evolutionary geneticists and breeders. Although not a trivial task in long-lived organisms such as trees, experimental interspecific recombinants can sometimes be created through controlled crosses involving natural F(1)'s. Here, we used this approach to understand the genetics of post-mating isolation and barriers to introgression in Populus alba and Populus tremula, two ecologically divergent, hybridizing forest trees. We studied 86 interspecific backcross (BC(1)) progeny and >350 individuals from natural populations of these species for up to 98 nuclear genetic markers, including microsatellites, indels and single nucleotide polymorphisms, and inferred the origin of the cytoplasm of the cross with plastid DNA. Genetic analysis of the BC(1) revealed extensive segregation distortions on six chromosomes, and >90% of these (12 out of 13) favored P. tremula donor alleles in the heterospecific genomic background. Since selection was documented during early diploid stages of the progeny, this surprising result was attributed to epistasis, cyto-nuclear coadaptation, heterozygote advantage at nuclear loci experiencing introgression or a combination of these. Our results indicate that gene flow across 'porous' species barriers affects these poplars and aspens beyond neutral, Mendelian expectations and suggests the mechanisms responsible. Contrary to expectations, the Populus sex determination region is not protected from introgression. Understanding the population dynamics of the Populus sex determination region will require tests based on natural interspecific hybrid zones.