Antimicrobial susceptibility profile of clinically relevant Bacteroides, Phocaeicola, Parabacteroides and Prevotella species, isolated by eight laboratories in the Netherlands.

OBJECTIVES: Recently, reports on antimicrobial-resistant Bacteroides and Prevotella isolates have increased in the Netherlands. This urged the need for a surveillance study on the antimicrobial susceptibility profile of Bacteroides, Phocaeicola, Parabacteroides and Prevotella isolates consecutively isolated from human clinical specimens at eight different Dutch laboratories. METHODS: Each laboratory collected 20-25 Bacteroides (including Phocaeicola and Parabacteroides) and 10-15 Prevotella isolates for 3 months. At the national reference laboratory, the MICs of amoxicillin, amoxicillin/clavulanic acid, piperacillin/tazobactam, meropenem, imipenem, metronidazole, clindamycin, tetracycline and moxifloxacin were determined using agar dilution. Isolates with a high MIC of metronidazole or a carbapenem, or harbouring cfiA, were subjected to WGS. RESULTS: Bacteroides thetaiotaomicron/faecis isolates had the highest MIC90 values, whereas Bacteroides fragilis had the lowest MIC90 values for amoxicillin/clavulanic acid, piperacillin/tazobactam, meropenem, imipenem and moxifloxacin. The antimicrobial profiles of the different Prevotella species were similar, except for amoxicillin, for which the MIC50 ranged from 0.125 to 16 mg/L for Prevotella bivia and Prevotella buccae, respectively. Three isolates with high metronidazole MICs were sequenced, of which one Bacteroides thetaiotaomicron isolate harboured a plasmid-located nimE gene and a Prevotella melaninogenica isolate harboured a nimA gene chromosomally.Five Bacteroides isolates harboured a cfiA gene and three had an IS element upstream, resulting in high MICs of carbapenems. The other two isolates harboured no IS element upstream of the cfiA gene and had low MICs of carbapenems. CONCLUSIONS: Variations in resistance between species were observed. To combat emerging resistance in anaerobes, monitoring resistance and conducting surveillance are essential.

Seasonality in carriage of extended-spectrum ß-lactamase-producing Escherichia coli and Klebsiella pneumoniae in the general population: a pooled analysis of nationwide cross-sectional studies.

Infections due to extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-E) are often preceded by asymptomatic carriage. Higher incidences in enteric infectious diseases during summer have been reported. Here, we assessed whether the presence of seasonality in intestinal ESBL-Escherichia coli/Klebsiella pneumoniae (ESBL-E/K) carriage in the general Dutch population exists. From 2014 to 2017, the faecal carriage of ESBL-E/K in healthy individuals was determined in three cross-sectional studies in the Netherlands, including 5985 subjects. Results were pooled to identify seasonal trends in prevalence (by month of sampling). Multivariate logistic regression analysis was used to calculate pooled odds ratios and 95% confidence intervals. Results were adjusted for age, sex, antibiotic use and travel. Overall prevalence of ESBL-E/K carriage was 4.3% (n = 260 ESBL-E/K-positive), with differences between months ranging from 2.6% to 7.4%. Compared to January, the monthly prevalence of ESBL-E carriage was highest in August (OR 1.88, 95% CI 1.02-3.49) and September (OR 2.25, 95% CI 1.30-3.89). The observed monthly differences in ESBL-E/K carriage rates suggest that there is seasonal variation in exposure to ESBL-E/K other than due to travelling and antibiotic use. This should be taken into account in designing future ESBL-E prevalence studies in temperate regions.

Surveillance of infections in long-term care facilities (LTCFs): The impact of participation during multiple years on health care-associated infection incidence.

We studied trends in the incidence of health care-associated infections (HAIs) in LTCFs between 2009 and 2015 and determined the effect of participation in our network. Elder-care physicians reported weekly the number of cases of influenza-like illness, gastroenteritis, (probable) pneumonia, urinary tract infections (UTIs) and all-cause mortality. Trends in the incidence of infection and mortality in relation to LTCF characteristics were calculated using multilevel univariate and multivariate logistic regression. Thirty LTCF participated for 3 years or more, 16 for 2 years and the remaining 12 LTCF for 1 year. During the study period, the median number of beds decreased from 158 to 139, whereas the percentage of residents with private bedrooms increased from 14% to 87%. UTIs were the most frequently reported infections, followed by (probable) pneumonia and gastroenteritis. Adjusted for calendar year and season, we observed a statistically significant decrease in the incidence of influenza-like illness (odds ratio (OR) = 0.8, P < 0.01) and (probable) pneumonia (OR = 0.8, P < 0.01) for each extra year an LTCF participated. Although there are other likely contributors, such as more private rooms and enhanced infection control measures, the decreasing trend of HAI in LTCFs participating in surveillance implies that surveillance is a valuable addition to current strategies to optimise infection control.

Intestinal carriage of ampicillin- and vancomycin-resistant Enterococcus faecium in humans, dogs and cats in the Netherlands.

Background: The prevalence of ampicillin- and/or vancomycin-resistant Enterococcus faecium (AREf and VREf) has increased in hospitalized patients in the Netherlands. Objectives: To quantify the prevalence, risk factors and co-carriage of AREf and VREf in humans, cats and dogs in the Dutch population. Methods: From 2014 to 2015, ∼2000 inhabitants of the Netherlands each month were randomly invited to complete a questionnaire and provide a faecal sample. Subjects owning pets were also asked to submit one dog or cat sample. Faecal samples were screened for AREf and VREf. The genetic relatedness of isolates was determined using core genome MLST. Logistic regression analysis was used to determine risk factors. Results: Of 25 365 subjects, 4721 (18.6%) completed the questionnaire and 1992 (42.2%) human, 277 dog and 118 cat samples were submitted. AREf was detected in 29 human (1.5%), 71 dog (25.6%) and 6 cat (5.1%) samples. VREf (vanA) was detected in one human and one dog. AREf/VREf co-carriage was not detected in 388 paired samples. The use of antibiotics (OR 4.2, 95% CI 1.7-11.2) and proton pump inhibitors (OR 2.7, 95% CI 1.1-6.3) were risk factors for AREf carriage in humans. In dogs, these were the use of antibiotics (OR 2.3, 95% CI 1.1-4.6) and eating raw meat (OR 3.2, 95% CI 1.4-6.6). Core genome MLST-based phylogenetic linkage indicated clonal relatedness for a minority of human (16.7%) and pet AREf isolates (23.8%) in three clusters. Conclusions: Intestinal carriage with AREf or VREf is rare in the Dutch general population. Although AREf carriage is high in dogs, phylogenetic linkage between human and pet AREf isolates was limited.

Incidence of surgical site infections cannot be derived reliably from point prevalence survey data in Dutch hospitals.

Thorough studies on whether point prevalence surveys of healthcare-associated infections (HAIs) can be used to reliably estimate incidence of surgical site infections (SSIs) are scarce. We examined this topic using surveillance data of 58 hospitals that participated in two Dutch national surveillances; HAI prevalence and SSI incidence surveillance, respectively. First, we simulated daily prevalences of SSIs from incidence data. Subsequently, Rhame & Sudderth's formula was used to estimate SSI incidence from prevalence. Finally, we developed random-effects models to predict SSI incidence from prevalence and other relevant variables. The prevalences simulated from incidence data indicated that daily prevalence varied greatly. Incidences calculated with Rhame & Sudderth's formula often had values below zero, due to the large number of SSIs occurring post-discharge. Excluding these SSIs, still resulted in poor correlation between calculated and observed incidence. The two models best predicting total incidence and incidence during initial hospital stay both performed poorly (proportion of explained variance of 0·25 and 0·10, respectively). In conclusion, incidence of SSIs cannot be reliably estimated from point prevalence data in Dutch hospitals by any of the applied methods. We therefore conclude that prevalence surveys are not a useful measure to give reliable insight into incidence of SSIs.

Incidence of pneumonia in nursing home residents with dementia in the Netherlands: an estimation based on three differently designed studies.

Pneumonia leads to considerable morbidity and mortality in nursing home residents with dementia. We assessed pneumonia incidence based on data from three different studies: (1) real-time national surveillance of healthcare-associated infections in nursing home residents in 2009-2015; (2) a randomized controlled trial in 2012-2015 to assess effects of a practical guideline in nursing home residents with dementia and pneumonia; and (3) a study in 2007-2010 to assess quality of dying in newly admitted nursing home residents with dementia. In national surveillance data, pneumonia incidence was calculated separately for psychogeriatric and somatic beds, as a proxy for residents with and without dementia. Weekly pneumonia incidence was significantly lower per 1000 psychogeriatric beds (3·9; 95% confidence interval (CI) 3·2-4·6) compared with 1000 somatic beds (5·7; 95% CI 5·1-6·3). Annual incidence per 1000 psychogeriatric beds was similar in national surveillance (range 78·9-117·1) and the trial (range 71·0-94·3), and significantly higher in newly admitted dementia residents (range 267·3-363·2). The incidence was highest during the first months after admission when compared with residents with longer stay. In conclusion, follow-up of pneumonia in newly admitted dementia residents may result in higher incidence, possibly due to higher risk in this population.

Prevalence and risk factors for colonization of Clostridium difficile among adults living near livestock farms in the Netherlands.

A cross-sectional study was performed among 2494 adults not living or working on a farm to assess prevalence of Clostridium difficile (CD) colonization and risk factors in a livestock dense area. CD prevalence was 1·2%. Twenty-one persons were colonized with a toxigenic strain and nine with a non-toxigenic strain. CD-positive persons did not live closer to livestock farms than individuals negative for CD. Antibiotic exposure in the preceding 3 months was a risk factor for CD colonization (odds ratio 3·70; 95% confidence interval 1·25-10·95).

Risk factors for the acquisition of OXA-48-producing Enterobacteriaceae in a hospital outbreak setting: a matched case-control study.

OBJECTIVES: In the context of a large outbreak of OXA-48-producing Enterobacteriaceae (OXA-E) in a Dutch hospital we determined risk factors for acquisition of OXA-E. PATIENTS AND METHODS: A matched case-control study was performed in which cases (culture positive for OXA-E) were matched 1:3 to controls (culture negative for OXA-E) based on hospital ward, index date (±1 week) and time exposed in the hospital (best match). Stratified analyses were performed for patients with OXA-E producing and not producing ESBL. Potential risk factors included age, gender, surgery and ICU admission within 30 days preceding the index date, presence of comorbidities and in-hospital antibiotic treatment within 30 days preceding the index date. Data analysis was performed using multivariable conditional logistic regression with Firth correction. RESULTS: In total, 73 cases were matched to 211 controls. In the multivariable conditional logistic regression model, male gender (OR 2.63, 95% CI 1.25-5.53), age (per year increase, OR 1.03, 95% CI 1.00-1.05) and use of fluoroquinolones within 30 days preceding the index date (OR 2.98, 95% CI 1.06-8.41) were risk factors for acquisition of OXA-E. In the stratified multivariable conditional logistic regression model, quinolone use was a risk factor for the acquisition of ESBL-producing OXA-E and surgery was a risk factor for the acquisition of non-ESBL-producing OXA-E. CONCLUSIONS: During a large, hospital-wide OXA-E outbreak, male gender, age and previous use of fluoroquinolones were risk factors for acquisition of OXA-E. These findings may help in optimizing screening and isolation strategies in future OXA-E outbreaks.

Detection and epidemiology of carbapenemase producing Enterobacteriaceae in the Netherlands in 2013-2014.

Laboratory detection of carbapenemase-producing Enterobacteriaceae (CPE) is complicated. Screening with MIC values below clinical breakpoints followed by genotypic confirmation is recommended. We evaluated the application of recommended CPE screening and confirmation methods and provide an overview of CPE epidemiology in E. coli and K. pneumoniae in the Netherlands. Data on E. coli and K. pneumoniae isolates with elevated meropenem (>0.25 mg/L) and/or imipenem (>1 mg/L) MIC values in 2013-2014 were selected from the Infectious Disease Surveillance Information System for Antibiotic Resistance. Laboratories were requested to provide additional results of any confirmatory testing performed. Confirmation of elevated carbapenem MIC values using gradient testing was performed in 59.8 % of eligible isolates. Confirmatory testing showed elevated MIC values in 8 % of E. coli and 32 % of K. pneumoniae isolates. The overall proportion of confirmed non-susceptible E. coli and K. pneumoniae was 0.01 % and 0.16 %, respectively. Genotypic confirmation was performed in 61.0 % of isolates with confirmed elevated carbapenem MIC values. A carbapenemase gene was identified in 47 % of E. coli and 65 % of K. pneumoniae isolates. OXA-48, NDM and KPC were the most frequently found carbapenemase genes. The majority (62 %) of CPE isolates was detected through targeted screening. CPE are a rare finding in the Netherlands. Adherence to the national guideline is suboptimal and differs between laboratories, implying a risk of inadequate CPE detection. Since accurate identification of CPE is the first step in prevention of CPE spread, successful implementation of guidelines for testing and reporting of CPE is essential.

Bacteraemic and non-bacteraemic/urinary antigen-positive pneumococcal community-acquired pneumonia compared.

The diagnosis of invasive pneumococcal pneumonia is based mainly on bacteraemia. Episodes without bacteraemia, but with a positive urinary antigen test (UAT), are considered non-invasive. We determined differences in outcome between patients with bacteraemic and non-bacteraemic/UAT-positive pneumococcal community-acquired pneumonia (CAP). Adult patients with clinical and radiological evidence of CAP with blood cultures and UAT tests performed at presentation in three Dutch laboratories between June 2008 and May 2010 were included. Clinical characteristics were retrospectively extracted from hospital records. Overall, 168 patients had non-bacteraemic/UAT-positive pneumococcal CAP and 123 had bacteraemic pneumococcal CAP. The day-30 mortality was 9% and 13% for non-bacteraemic/UAT-positive and bacteraemic pneumococcal CAP patients, respectively [risk difference -4%, 95% confidence interval (CI) -11% to +3%, p = 0.28]. In a multivariable logistic regression model, age ≥ 65 years, admission to the intensive care unit/coronary care unit (ICU/CCU) and presence of an immunocompromising condition were associated with day-30 mortality. A non-significant association with mortality was found for bacteraemia [odds ratio (OR) 2.21, 95% CI 0.94-5.21, p = 0.07). No such trend was found for UAT positivity. The median lengths of hospital stay were 8 [interquartile range (IQR) 5-14] and 10 (IQR 6-18) days for non-bacteraemic/UAT-positive and bacteraemic pneumococcal CAP patients, respectively (p = 0.05). As compared to non-bacteraemic/UAT-positive pneumococcal CAP, bacteraemic pneumococcal CAP has a stronger association with day-30 mortality.

Increased incidence of serotype-1 invasive pneumococcal disease in young female adults in The Netherlands.

Analysis of the Dutch national invasive pneumococcal disease (IPD) surveillance data by sex reveals an increase in the incidence of serotype-1 disease in young female adults in The Netherlands after the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in the national immunization schedule. This has led to an overall increase in IPD in women aged 20-45 years, which was not observed in men of the same age. No other differences in serotype shifts possibly induced by the introduction of PCV7 were observed between the sexes in this age group. Serotype 1 is a naturally fluctuating serotype in Europe and it has been associated with disease in young healthy adults before. It remains uncertain whether or not there is an association between the observed increase in serotype-1 disease in young female adults and the implementation of PCV7 in The Netherlands.

Successful control of a hospital-wide outbreak of OXA-48 producing Enterobacteriaceae in the Netherlands, 2009 to 2011.

On 31 May 2011, after notification of Klebsiella pneumoniae (KP)(OXA-48;CTX-M-15) in two patients, nosocomial transmission was suspected in a Dutch hospital. Hospital-wide infection control measures and an outbreak investigation were initiated. A total of 72,147 patients were categorised into groups based on risk of OXA-48 colonisation or infection, and 7,527 were screened for Enterobacteriaceae(OXA-48) by polymerase chain reaction (PCR). Stored KP isolates (n=408) were retrospectively tested for OXA-48 and CTX-M-1 group extended-spectrum beta-lactamases (ESBL). 285 KP isolates from retrospective and prospective patient screening were genotyped by amplified fragment length polymorphism (AFLP). 41 isolates harbouring different Enterobacteriaceae species were analysed by plasmid multilocus sequence typing (pMLST). No nosocomial transmission of Enterobacteriaceae(OXA-48) was detected after 18 July 2011. Enterobacteriaceae(OXA-48) were found in 118 patients (KP (n=99), Escherichia coli (n=56), ≥1 Enterobacteriaceae(OXA-48) species (n=52)), of whom 21 had clinical infections. 39/41 (95%) of OXA-48 containing plasmids were identical in pMLST. Minimum inhibitory concentrations (MICs) of KP(OXA-48) and E. coli(OXA-48) for imipenem and meropenem ranged from ≤1 to ≥16 mg/L, and 153/157 (97%) had MIC >0.25 mg/L for ertapenem. AFLP identified a cluster of 203 genetically linked isolates (62 KP(OXA-48;CTX-M15); 107 KP(CTX-M-15); 34 KP(OXA-48)). The 'oldest' KP(CTX-M-15) and KP(OXA-48) clonal types originated from February 2009 and September 2010, respectively. The last presumed outbreak-related KP(OXA-48) was detected in April 2012. Uncontrolled transmission of KP(CTX-M-15) evolved into a nosocomial outbreak of KP(OXA-48;CTX-M15) with large phenotypical heterogeneity. Although the outbreak was successfully controlled, the contribution of individual containment measures and of the hospital relocating into a new building just before outbreak notification was impossible to quantify.

Prevalence of healthcare-associated infections in Dutch long-term care facilities from 2009 to 2019.

OBJECTIVE: We assessed trends in the prevalence of healthcare-associated infections (HCAIs) and associated resident and facility characteristics in a national network of long-term care facilities (LTCFs) in the Netherlands from 2009 to 2019. METHODS: Participating LTCFs registered the prevalence of urinary tract infection (UTI), lower respiratory tract infection (LRTI), gastrointestinal infection (GI), bacterial conjunctivitis, sepsis and skin infection, using standardized definitions, in biannual point-prevalence surveys (PPSs). In addition, resident and LTCF characteristics were collected. Multi-level analyses were performed to study changes in the HCAI prevalence over time and to identify resident and LTCF-related risk factors. Analyses were performed for HCAIs overall and for UTI, LRTI and GI combined as these were recorded throughout the period. RESULTS: Overall, 1353 HCAIs were registered in 44,551 residents with a prevalence of 3.0% (95% confidence interval: 2.8-3.1; range between years 2.3-5.1%). When including only UTI, LRTI and GI the prevalence decreased from 5.0% in 2009 to 2.1% in 2019. Multi-variable regression analyses for UTI, LRTI and GI combined indicated that both prolonged participation and calendar time were independently associated with HCAI prevalence; in LTCFs that participated ≥4 years, the HCAI risk was decreased (OR 0.72 (0.57-0.92)) compared with the first year, and the OR per calendar year was 0.93 (0.88-0.97). CONCLUSIONS: Over 11 years of PPS in LTCFs the HCAI prevalence decreased over time. Prolonged participation further reduced the HCAI prevalence, in particular UTIs, despite the increasing age and associated frailty of the LTCF population, illustrating the potential value of surveillance.

Mind the gap: knowledge, attitudes and perceptions on antimicrobial resistance, antimicrobial stewardship and infection prevention and control in long-term care facilities for people with disabilities in the Netherlands.

BACKGROUND: Antimicrobial resistance (AMR) has become one of the major public health threats worldwide, emphasizing the necessity of preventing the development and transmission of drug resistant microorganisms. This is particularly important for people with vulnerable health conditions, such as people with intellectual disabilities (ID) and long-term care residents. This study aimed to assess the current status of AMR, antimicrobial stewardship (AMS) and infection prevention and control (IPC) in Dutch long-term care facilities for people with intellectual disabilities (ID-LTCFs). METHODS: A web-based cross-sectional survey distributed between July and November 2023, targeting (both nonmedically and medically trained) healthcare professionals working in ID-LTCFs in The Netherlands, to study knowledge, attitudes and perceptions regarding AMR, AMS and IPC. RESULTS: In total, 109 participants working in 37 long-term care organizations for people with intellectual disabilities throughout the Netherlands completed the questionnaire. The knowledge levels of AMR and IPC among nonmedically trained professionals (e.g., social care professionals) were lower than those among medically trained professionals (p = 0.026). In particular regarding the perceived protective value of glove use, insufficient knowledge levels were found. Furthermore, there was a lack of easy-read resources and useful information regarding IPC and AMR, for both healthcare professionals as well as people with disabilities. The majority of the participants (> 90%) reported that AMR and IPC need more attention within the disability care sector, but paradoxically, only 38.5% mentioned that they would like to receive additional information and training about IPC, and 72.5% would like to receive additional information and training about AMR. CONCLUSION: Although the importance of AMR and IPC is acknowledged by professionals working in ID-LTCFs, there is room for improvement in regards to appropriate glove use and setting-specific IPC and hygiene policies. As nonmedically trained professionals comprise most of the workforce within ID-LTCFs, it is also important to evaluate their needs. This can have a substantial impact on developing and implementing AMR, AMS and/or IPC guidelines and policies in ID-LTCFs.

Human carriage of ESBL/pAmpC-producing Escherichia coli and Klebsiella pneumoniae in relation to the consumption of raw or undercooked vegetables, fruits, and fresh herbs.

We investigated to what extent the consumption of raw or undercooked vegetables, fruits, and fresh herbs influences carriage rates of ESBL/pAmpC-producing Escherichia coli and Klebsiella pneumoniae (ESBL-E/K) in the general population. We assessed long-term carriage and changes in ESBL-E/K prevalence over time, by comparing the results to findings in the same population 5 years earlier. Between July and December 2021, participants sent in two fecal samples and questionnaires, 3 months apart. Food frequency questionnaires were sent on a monthly basis. Fecal samples were cultured and screened for ESBL-E/K, and phenotypically positive isolates were sequenced. Multivariable logistic regression models were established to assess the association between the consumption of fresh produce and ESBL-E/K carriage. The ESBL-E/K prevalence was 7.6% [41/537; 95% confidence interval (CI): 5.7-10.2] in the first sampling round and 7.0% (34/489; 95% CI: 5.0-9.6) in the second. Multivariable models did not result in statistical significance for any of the selected fruit and vegetable types. Trends for increased carriage rates were observed for the consumption of raspberry and blueberry in the summer period. ESBL-E/K prevalence was comparable with the prevalence in the same cohort 5 years earlier (7.5%; 95% CI: 5.6-10.1%). In six persons (1.2%) a genetically highly homologous ESBL-E/K was found. In conclusion, the contribution of the consumption of raw fruits, vegetables, and herbs to ESBL-E/K carriage in humans in the Netherlands is probably low. Despite COVID-19 containment measures (e.g., travel restrictions, social distancing, and hygiene) the ESBL-E/K prevalence was similar to 5 years earlier. Furthermore, indications for long-term carriage were found.IMPORTANCEESBL-producing bacteria are resistant against important classes of antibiotics, including penicillins and cephalosporines, which complicates treatment of infections. Food is one of the main routes of transmission for carriage of these bacteria in the general population. Although fruits, vegetables, and herbs are generally less frequently contaminated with ESBL-producing bacteria compared to meat, exposure might be higher since these products are often eaten raw or undercooked. This research showed that the contribution of the consumption of raw or undercooked fresh produce to ESBL-E/K carriage in the general Dutch population was low. No specific types of fruit or vegetables could be identified that gave a higher risk of carriage. In addition, we demonstrated the presence of genetically highly homologous ESBL-E/K in six persons after a period of 5 years, indicative for long-term carriage.

The effect of an intervention bundle to prevent central venous catheter-related bloodstream infection in a national programme in the Netherlands.

INTRODUCTION: Central venous catheters (CVCs) can lead to central line-related bloodstream infections (CRBSIs). A six-item bundle was introduced in 2009 to prevent CRBSI in Dutch hospitals. AIM: This study aimed to determine the impact of an intervention bundle on CRBSI risk. METHODS: Data were obtained from hospitals participating in the national CRBSI surveillance between 2009 and 2019. Bundle compliance was evaluated as a total ('overall') bundle (all six items) and as an insertion bundle (four items) and a maintenance bundle (two daily checks). We estimated the impact of the overall and partial bundles, using multi-level Cox regression. FINDINGS: Of the 66 hospitals in the CRBSI surveillance 56 (84.8%) recorded annual bundle (non)compliance for >80% of the CVCs, for one to nine years. In these 56 hospitals CRBSI incidence decreased from 4.0 to 1.6/1000 CVC days. In the intensive care units (ICUs), compliance was not associated with CRBSI risk (hazard ratio (HR) for the overall, insertion and maintenance bundle were 1.14 (95% confidence interval 0.80-1.64), 1.05 (0.56-1.95) and 1.13 (0.79-1.62)), respectively. Outside the ICU the non-significant association of compliance with the overall bundle (HR 1.36 (0.96-1.93)) resulted from opposite effects of the insertion bundle, associated with decreased risk (HR 0.50 (0.30-0.85)) and the maintenance bundle, associated with increased risk (HR 1.68 (1.19-2.36)). CONCLUSION: Following a national programme to introduce an intervention bundle, CRBSI incidence decreased significantly. In the ICU, bundle compliance was not associated with CRBSI risk, but outside the ICU improved compliance with the insertion bundle resulted in a decreased CRBSI risk.

Pertussis disease burden in the household: how to protect young infants.

BACKGROUND: We conducted a population-based, nation-wide, prospective study to identify who introduced pertussis into the household of infants aged 6 months admitted to the hospital for pertussis in the Netherlands. METHODS: During the period 2006-2008, a total of 560 household contacts of 164 hospitalized infants were tested by polymerase chain reaction, culture, and serological examination to establish Bordetella pertussis infection. Clinical symptoms and vaccination history were obtained by a questionnaire submitted during sample collection and 4-6 weeks afterwards. RESULTS: Overall, 299 household contacts (53%) had laboratory-confired pertussis; 159 (53%) had symptoms compatible with typical pertussis infection, and 42 (14%) had no symptoms. Among children vaccinated with a whole-cell vaccine, 17 (46%) of 37 had typical pertussis 1-3 years after completion of the primary series, compared with 9 (29%) of 31 children who had been completely vaccinated with an acellular vaccine. For 96 households (60%), the most likely source of infection of the infant was established, being a sibling (41%), mother (38%), or father (17%). CONCLUSIONS: If immunity to pertussis in parents is maintained or boosted, 35%-55% of infant cases could be prevented. Furthermore, we found that, 1-3 years after vaccination with whole-cell or acellular vaccine, a significant percentage of children are again susceptible for typical pertussis. In the long term, pertussis vaccines and vaccination strategies should be improved to provide longer protection and prevent transmission.

Trends in prevalence of healthcare-associated infections and antimicrobial use in hospitals in the Netherlands: 10 years of national point-prevalence surveys.

BACKGROUND: Prevalence of healthcare-associated infections (HCAIs) and antimicrobial use in hospitals in the Netherlands has been measured using voluntary biannual national point-prevalence surveys (PPSs). AIM: To describe trends in the prevalence of patients with HCAI, risk factors, and antimicrobial use in 2007-2016. METHODS: In the PPS, patient characteristics, use of medical devices and antimicrobials, and presence of HCAI on the survey day are reported for all hospitalized patients, excluding patients in the day-care unit and psychiatric wards. Analyses were performed using linear and (multivariate) logistic regression, accounting for clustering of patients within hospitals. FINDINGS: PPS data were reported for 171,116 patients. Annual prevalence of patients with HCAI with onset during hospitalization decreased from 6.1% in 2007 to 3.6% in 2016. The adjusted odds ratio (OR) for trend was 0.97 (95% confidence interval: 0.96-0.98). Most prominent trends were seen for surgical site infections (1.6%-0.8%; OR: 0.91 (0.90-0.93)) and urinary tract infections (2.1%-0.6%; OR: 0.85 (0.83-0.87)). From 2014 on, HCAIs at admission were also registered with a stable prevalence of approximately 1.5%. The mean length of stay decreased from 10 to 7 days. The percentage of patients treated with antibiotics increased from 31% to 36% (OR: 1.03 (1.02-1.03)). CONCLUSION: Repeated PPS data from 2007 to 2016 show a decrease in the prevalence of patients with HCAI with onset during hospitalization, and a stable prevalence of patients with HCAI at admission. The adjusted OR of 0.97 for HCAI during hospitalization indicates a true reduction in prevalence of approximately 3% per year.

Seasonal patterns in time series of pertussis.

To gain insight into pertussis disease dynamics, we studied age-specific long-term periodicity and seasonality of pertussis in The Netherlands. Hierarchical time-series models were used to analyse the monthly reported pertussis incidence in January 1996-June 2006 by age group. The incidence of pertussis showed a slightly increasing long-term trend with highest incidence rates seen in 1996, 1999, 2001 and 2004. For all age groups the annual peak incidence was found in August, except for the 13-18 years age group where the peak occurred in November. Monthly trends in adults showed high correlation with trends in age groups 0-4 years (0.94) and 5-12 years (0.92). We found no evidence for a relationship between annual rises in pertussis and the opening of schools. Concurrent annual fluctuations of pertussis incidence in adults and infants suggest frequent transmission within and between these age groups. Studying trends offers insight into transmission dynamics and may facilitate decisions on future vaccination strategies.

Burden of surgical site infections in the Netherlands: cost analyses and disability-adjusted life years.

BACKGROUND: Surgical site infections (SSIs) are associated with morbidity, mortality and costs. AIM: To identify the burden of (deep) SSIs in costs and disability-adjusted life years (DALYs) following colectomy, mastectomy and total hip arthroplasty (THA) in the Netherlands. METHODS: A retrospective cost-analysis was performed using 2011 data from the national SSI surveillance network PREZIES. Sixty-two patients with an SSI (exposed) were matched to 122 patients without an SSI (unexposed, same type of surgery). Patient records were studied until 1 year after SSI diagnosis. Unexposed patients were followed for the same duration. Costs were calculated from the hospital perspective (2016 price level), and cost differences were tested using linear regression analyses. Disease burden was estimated using the Burden of Communicable Disease in Europe Toolkit of the European Centre for Disease Prevention and Control. The SSI model was specified by type of surgery, with country- and surgery-specific parameters where possible. FINDINGS: Attributable costs per SSI were €21,569 (THA), €14,084 (colectomy) and €1881 (mastectomy), mainly caused by prolonged length of hospital stay. National hospital costs were estimated at €10 million, €29 million and €0.6 million, respectively. National disease burden was greatest for SSIs following colectomy (3200 DALYs/year, 150 DALYs/100 SSIs), while individual disease burden was highest following THA (1200 DALYs/year, 250 DALYs/100 SSIs). For mastectomy, these DALYs were <1. The total cost of DALYs for the three types of surgery exceeded €88 million. CONCLUSION: Depending on the type of surgery, SSIs cause a significant burden, both economically and in loss of years in full health. This underlines the importance of appropriate infection prevention and control measures.