Automated surveillance systems for healthcare-associated infections: results from a European survey and experiences from real-life utilization.

BACKGROUND: As most automated surveillance (AS) methods to detect healthcare-associated infections (HAIs) have been developed and implemented in research settings, information about the feasibility of large-scale implementation is scarce. AIM: To describe key aspects of the design of AS systems and implementation in European institutions and hospitals. METHODS: An online survey was distributed via e-mail in February/March 2019 among (i) PRAISE (Providing a Roadmap for Automated Infection Surveillance in Europe) network members; (ii) corresponding authors of peer-reviewed European publications on existing AS systems; and (iii) the mailing list of national infection prevention and control focal points of the European Centre for Disease Prevention and Control. Three AS systems from the survey were selected, based on quintessential features, for in-depth review focusing on implementation in practice. FINDINGS: Through the survey and the review of three selected AS systems, notable differences regarding the methods, algorithms, data sources, and targeted HAIs were identified. The majority of AS systems used a classification algorithm for semi-automated surveillance and targeted HAIs were mostly surgical site infections, urinary tract infections, sepsis, or other bloodstream infections. AS systems yielded a reduction of workload for hospital staff. Principal barriers of implementation were strict data security regulations as well as creating and maintaining an information technology infrastructure. CONCLUSION: AS in Europe is characterized by heterogeneity in methods and surveillance targets. To allow for comparisons and encourage homogenization, future publications on AS systems should provide detailed information on source data, methods, and the state of implementation.

The accuracy of fully automated algorithms for surveillance of healthcare-associated urinary tract infections in hospitalized patients.

BACKGROUND: Surveillance for healthcare-associated infections such as healthcare-associated urinary tract infections (HA-UTI) is important for directing resources and evaluating interventions. However, traditional surveillance methods are resource-intensive and subject to bias. AIM: To develop and validate a fully automated surveillance algorithm for HA-UTI using electronic health record (EHR) data. METHODS: Five algorithms were developed using EHR data from 2979 admissions at Karolinska University Hospital from 2010 to 2011: (1) positive urine culture (UCx); (2) positive UCx + UTI codes (International Statistical Classification of Diseases and Related Health Problems, 10th revision); (3) positive UCx + UTI-specific antibiotics; (4) positive UCx + fever and/or UTI symptoms; (5) algorithm 4 with negation for fever without UTI symptoms. Natural language processing (NLP) was used for processing free-text medical notes. The algorithms were validated in 1258 potential UTI episodes from January to March 2012 and results extrapolated to all UTI episodes within this period (N = 16,712). The reference standard for HA-UTIs was manual record review according to the European Centre for Disease Prevention and Control (and US Centers for Disease Control and Prevention) definitions by trained healthcare personnel. FINDINGS: Of the 1258 UTI episodes, 163 fulfilled the ECDC HA-UTI definition and the algorithms classified 391, 150, 189, 194, and 153 UTI episodes, respectively, as HA-UTI. Algorithms 1, 2, and 3 had insufficient performances. Algorithm 4 achieved better performance and algorithm 5 performed best for surveillance purposes with sensitivity 0.667 (95% confidence interval: 0.594-0.733), specificity 0.997 (0.996-0.998), positive predictive value 0.719 (0.624-0.807) and negative predictive value 0.997 (0.996-0.997). CONCLUSION: A fully automated surveillance algorithm based on NLP to find UTI symptoms in free-text had acceptable performance to detect HA-UTI compared to manual record review. Algorithms based on administrative and microbiology data only were not sufficient.

Impact of time to antibiotic therapy on clinical outcome in patients with bacterial infections in the emergency department: implications for antimicrobial stewardship.

BACKGROUND: Rapid initiation of antibiotic treatment is considered crucial in patients with severe infections such as septic shock and bacterial meningitis, but may not be as important for other infectious syndromes. A better understanding of which patients can tolerate a delay in start of therapy is important for antibiotic stewardship purposes. OBJECTIVES: To explore the existing evidence on the impact of time to antibiotics on clinical outcomes in patients presenting to the emergency department (ED) with bacterial infections of different severity of illness and source of infection. SOURCES: A literature search was performed in the PubMed/MEDLINE database using combined search terms for various infectious syndromes (sepsis/septic shock, bacterial meningitis, lower respiratory tract infections, urinary tract infections, intra-abdominal infections and skin and soft tissue infections), time to antibiotic treatment, and clinical outcome. CONTENT: The literature search generated 8828 hits. After screening titles and abstracts and assessing potentially relevant full-text papers, 60 original articles (four randomized controlled trials, 43 observational studies) were included. Most articles addressed sepsis/septic shock, while few studies evaluated early initiation of therapy in mild to moderate disease. The lack of randomized trials and the risk of confounding factors and biases in observational studies warrant caution in the interpretation of results. We conclude that the literature supports prompt administration of effective antibiotics for septic shock and bacterial meningitis, but there is no clear evidence showing that a delayed start of therapy is associated with worse outcome for less severe infectious syndromes. IMPLICATIONS: For patients presenting with suspected bacterial infections, withholding antibiotic therapy until diagnostic results are available and a diagnosis has been established (e.g. by 4-8 h) seems acceptable in most cases unless septic shock or bacterial meningitis are suspected. This approach promotes the use of ecologically favourable antibiotics in the ED, reducing the risks of side effects and selection of resistance.

The changing epidemiology of community-acquired pneumonia: nationwide register-based study in Sweden.

BACKGROUND: There is limited evidence on the impact of pneumococcal conjugate vaccine childhood immunization programmes (PCV-CIP) on community-acquired pneumonia (CAP) in individuals with underlying diseases. METHODS: A nationwide cohort study using Swedish health registers to assess the incidence of hospitalization with all-cause (AC-CAP) and pneumococcal or lobar (PL-CAP) CAP between 2005 and 2015, in relation to PCV-CIP introduction in 2007-09. RESULTS: In total, 303 691 episodes of AC-CAP occurred, of which 14 225 were PL-CAP. Comparing before (2005-06) with after (2014-15) PCV-CIP, relative incidence reductions were 36% (95% Confidence Interval 32-40), 20% (14-25) and 16% (11-22) of AC-CAP for age groups < 2, 2-4 and 5-17 years, respectively, with similar reductions in young children with and without comorbidities. The reductions were more pronounced for PL-CAP. In the age groups 40-64, 65-74, 75-84 and ≥85 years there were relative increases of 11% (8-14), 18% (15-22), 15% (12-17) and 30% (27-34) of AC-CAP, respectively, but these increases were attenuated after adjustment for admittance practices using four control conditions. In adults with comorbidities, there was an increase in incidence of AC-CAP, and PL-CAP, in contrast to adults without reported underlying diseases where the incidence was stable or diminished for some age groups. Over the study period, there was an increased proportion of pneumonia patients with underlying diseases in all ages. CONCLUSION: This emphasizes that direct preventive interventions should be targeted towards individuals with underlying diseases. Future studies should investigate reasons for the observed increased risk in adults with comorbidities, for example due to pneumococcal nonvaccine serotypes, or other pathogens, preferentially affecting subjects with underlying diseases.

Risk factors for community-onset bloodstream infection with extended-spectrum ß-lactamase-producing Enterobacteriaceae: national population-based case-control study.

OBJECTIVES: The aim was to investigate risk factors for community-onset bloodstream infections with extended-spectrum ß-lactamase-producing Enterobacteriaceae (EPE BSI). METHODS: It is mandatory to report EPE BSI to a national register at the Public Health Agency of Sweden. Using this register, we performed a population-based case-control study from 2007 to 2012 of 945 cases and 9390 controls. Exposure data on comorbidity, hospitalization, in- and outpatient antibiotic consumption and socio-economic status were collected from hospital and health registers. RESULTS: The overall incidence of EPE BSI was 1.7 per 100 000 person-years. The 30-day mortality was 11.3%. Urological disorders inferred the highest EPE BSI risk, adjusted odds ratio (aOR) 4.32 (95% Confidence Interval (CI) 3.41-5.47), followed by immunological disorders, aOR 3.54 (CI 2.01-6.23), haematological malignancy, aOR 2.77 (CI 1.57-4.87), solid tumours, aOR 2.28 (1.76-2.94) and diabetes, aOR 2.03 (1.58-2.61). Consumption of fluoroquinolones or mostly non-EPE-active antibiotics with selective Gram-negative spectrum of activity within the previous 3 months was associated with EPE BSI, aORs 5.52 (CI 2.8-11.0) and 3.8, CI 1.9-7.7) respectively. There was a dose-response relationship in EPE BSI risk with increasing number of consecutive regimens. Antibiotic consumption >3 months before EPE BSI was not associated with increased risk. Higher age, malignancies and education ≤12 years (aORs >2) were associated with increased 30-day mortality. CONCLUSIONS: Targeted interventions should be directed towards improving care for patients with immunosuppression, urological disorders and subjects with lower socio-economic status. Antibiotic stewardship should focus on reduction of fluoroquinolones.

Invasive infection caused by Klebsiella pneumoniae is a disease affecting patients with high comorbidity and associated with high long-term mortality.

Klebsiella pneumoniae (KP) is after Escherichia coli (EC) the most common gram-negative species causing invasive infections. Herein, we analyzed risk factors and prognosis in invasive infections caused by KP versus EC, in an area with low antimicrobial resistance. Moreover, we compared antimicrobial resistance and relative prevalence of KP and EC (KP/EC-ratio) in different European countries, using EARS-Net data. Adult patients admitted to Karolinska University Hospital 2006-2012 with invasive infection caused by KP (n = 599) were matched regarding sex and age with patients infected by EC. The medical records were retrospectively reviewed. Comorbidity was adjusted for with multivariable analysis. European data were retrieved from the EARS-Net database. No differences were observed in 7- and 30-day mortality between the groups. The 90-day mortality was significantly higher in the KP cohort (26% versus 17%, p<0.001), but not after adjusting for comorbidity. Malignancy was seen in 53% of the patients with KP versus 38% with EC, OR 1.86 (1.34-2.58). A significant increase in the rate of ESBL-production was observed in EC, but not in KP. The KP/EC-ratio remained stable. In contrast, European data showed increasing percentages of isolates non-susceptible to third-generation cephalosporins in EC and KP, and increasing KP/EC-ratio. Invasive infection caused by KP is a disease affecting patients with high comorbidity and associated with high 90-d mortality. The stable KP/EC-ratio and low occurrence of antimicrobial resistance in data from Karolinska University Hospital compared to aggregate data from 20 EARS-Net countries could be related to absence of clonal spread of multidrug-resistant KP.

Ceftriaxone versus ceftriaxone plus a macrolide for community-acquired pneumonia in hospitalized patients with HIV/AIDS: a randomized controlled trial

OBJECTIVES: To evaluate if treatment with ceftriaxone and a macrolide, improved patient outcome when compared with monotherapy with ceftriaxone, in hospitalized patients with human immunodeficiency virus/acquired immunodeficient syndrome (HIV/AIDS) with community-acquired pneumonia (CAP). METHODS: Adult patients with HIV hospitalized due to suspected CAP were randomized to receive one of two regimens, ceftriaxone plus macrolide or ceftriaxone plus placebo, at a 1:1 proportion (Brazilian Clinical Trials Registry: RBR-8wtq2b). The primary outcome was in-hospital mortality and the secondary outcomes were mortality within 14 days, need for vasoactive drugs, need for mechanical ventilation, time to clinical stability and length of hospitalization. RESULTS: A total of 227 patients were randomized, two were excluded after randomization; 225 patients were analysed (112 receiving ceftriaxone plus placebo and 113 receiving ceftriaxone plus macrolide). The frequency of the primary outcome, in-hospital mortality, was not statistically different between the regimens: 12/112 (11%) patients who received ceftriaxone plus placebo and 17/113 (15%) who received ceftriaxone plus macrolide died during hospitalization (hazard ratio 1.22, 95% CI 0.57-2.59). We did not find differences between the regimens for any of the secondary outcomes, including mortality within 14 days, which occurred in 5/112 (4%) patients with ceftriaxone plus placebo and in 12/113 (11%) patients with ceftriaxone plus macrolide (relative risk 2.38, 95% CI 0.87-6.53) CONCLUSIONS: Among hospitalized patients with HIV/AIDS with CAP, treatment with ceftriaxone and a macrolide did not improve patient outcomes, when compared with ceftriaxone monotherapy

Ceftriaxone versus ceftriaxone plus a macrolide for community-acquired pneumonia in hospitalized patients with HIV/AIDS: a randomized controlled trial.

OBJECTIVES: To evaluate if treatment with ceftriaxone and a macrolide, improved patient outcome when compared with monotherapy with ceftriaxone, in hospitalized patients with human immunodeficiency virus/acquired immunodeficient syndrome (HIV/AIDS) with community-acquired pneumonia (CAP). METHODS: Adult patients with HIV hospitalized due to suspected CAP were randomized to receive one of two regimens, ceftriaxone plus macrolide or ceftriaxone plus placebo, at a 1:1 proportion (Brazilian Clinical Trials Registry: RBR-8wtq2b). The primary outcome was in-hospital mortality and the secondary outcomes were mortality within 14 days, need for vasoactive drugs, need for mechanical ventilation, time to clinical stability and length of hospitalization. RESULTS: A total of 227 patients were randomized, two were excluded after randomization; 225 patients were analysed (112 receiving ceftriaxone plus placebo and 113 receiving ceftriaxone plus macrolide). The frequency of the primary outcome, in-hospital mortality, was not statistically different between the regimens: 12/112 (11%) patients who received ceftriaxone plus placebo and 17/113 (15%) who received ceftriaxone plus macrolide died during hospitalization (hazard ratio 1.22, 95% CI 0.57-2.59). We did not find differences between the regimens for any of the secondary outcomes, including mortality within 14 days, which occurred in 5/112 (4%) patients with ceftriaxone plus placebo and in 12/113 (11%) patients with ceftriaxone plus macrolide (relative risk 2.38, 95% CI 0.87-6.53). CONCLUSIONS: Among hospitalized patients with HIV/AIDS with CAP, treatment with ceftriaxone and a macrolide did not improve patient outcomes, when compared with ceftriaxone monotherapy.

Coeliac disease and invasive pneumococcal disease: a population-based cohort study.

Severe infections are recognized complications of coeliac disease (CD). In the present study we aimed to examine whether individuals with CD are at increased risk of invasive pneumococcal disease (IPD). To do so, we performed a population-based cohort study including 29 012 individuals with biopsy-proven CD identified through biopsy reports from all pathology departments in Sweden. Each individual with CD was matched with up to five controls (n = 144 257). IPD events were identified through regional and national microbiological databases, including the National Surveillance System for Infectious Diseases. We used Cox regression analyses to estimate hazard ratios (HRs) for diagnosed IPD. A total of 207 individuals had a record of IPD whereas 45/29 012 had CD (0·15%) and 162/144 257 were controls (0·11%). This corresponded to a 46% increased risk for IPD [HR 1·46, 95% confidence interval (CI) 1·05-2·03]. The risk estimate was similar after adjustment for socioeconomic status, educational level and comorbidities, but then failed to attain statistical significance (adjusted HR 1·40, 95% CI 0·99-1·97). Nonetheless, our study shows a trend towards an increased risk for IPD in CD patients. The findings support results seen in earlier research and taking that into consideration individuals with CD may be considered for pneumococcal vaccination.

Narrow-spectrum ß-lactam monotherapy in hospital treatment of community-acquired pneumonia: a register-based cohort study.

OBJECTIVES: To assess the clinical effect of empirical treatment with narrow-spectrum ß-lactam monotherapy (NSBM) versus broad-spectrum ß-lactam monotherapy (BSBM) in non-severe community-acquired pneumonia (CAP). METHODS: Hospitalized patients ≥18 years with CAP who received initial NSBM or BSBM, with a severity score according to CRB-65≤2 (C=confusion, R=respiratory rate >30/min, B=systolic blood pressure <90 mmHg or diastolic blood pressure ≤60 mmHg, 65= ≥65 years), in the Swedish Pneumonia Register from 2008 to 2011 were included. Primary outcome was 30-day mortality. Secondary outcomes were 90-day mortality, treatment at intensive care unit (ICU), and length of stay (LOS). Propensity score matching was performed to account for differences in baseline characteristics. RESULTS: There were 5961 patients with CRB-65≤1 and 1344 patients with CRB-65=2. In the propensity score matched cohorts the 30-day mortality was 40/1827 (2.2%) with NSBM and 56/1827 (3.1%) with BSBM in CRB-65≤1, and 57/524 (10.9%) and 51/524 (9.7%), respectively, in CRB-65=2. No significant differences in 30-day mortality were observed between NSBM and BSBM in patients with CRB-65≤1 or CRB-65=2, OR 1.41 (95% CI 0.94-2.14) and 0.88 (95% CI 0.59-1.32), respectively. There was no significant difference in 90-day mortality. Patients who received BSBM were more often treated at ICU and had longer LOS. CONCLUSIONS: Empirical NSBM appears to be effective in the majority of hospitalized immunocompetent adults with non-severe CAP and should be further evaluated in randomized trials.

Frequent acquisition of low-virulence strains of ESBL-producing Escherichia coli in travellers.

OBJECTIVES: International travel is a risk factor for intestinal colonization with ESBL-producing Enterobacteriaceae (EPE). This prospective cohort study focuses on molecular features of and risk factors for travel-acquired EPE. METHODS: Rectal swabs and survey data were collected from 188 Swedes travelling to four regions of high EPE prevalence. Samples were plated onto selective agars. ESBL producers were determined using phenotypic methods. Molecular characterization regarding virulence factors and phylogenetic grouping of ESBL-producing Escherichia coli was done using PCR. Isolates were also screened for the plasmid-mediated colistin resistance gene mcr-1. RESULTS: Among 175 pre-travel EPE-negative participants, 32% were positive upon return. No carbapenemase-producing Enterobacteriaceae were found, but one CTX-M-producing E. coli harboured mcr-1 (travel to Thailand). Most E. coli strains (43.1%) belonged to phylogroup A and were rarely associated with extraintestinal infections and a few (9.2%) expressed uropathogenicity pap genes. During 10-26 months of follow-up, no clinical infections were observed. Colonization rates varied by visited region: the Indian subcontinent, 49.2%; northern Africa, 44.0%; South-East Asia, 19.1%; and Turkey, 9.5%. Travellers' diarrhoea (OR 2.5, P = 0.04) or antimicrobial treatment during the trip (OR 5.9, P = 0.02) were both independent risk factors for EPE colonization. CONCLUSIONS: EPE acquired during travel have seemingly low pathogenicity, possibly indicating a low risk of clinical infection. Pre-travel advice should emphasize avoiding unnecessary antibiotic treatment during travel.

Betamethasone and dexamethasone in adult community-acquired bacterial meningitis: a quality registry study from 1995 to 2014.

Acute bacterial meningitis (ABM) is a highly lethal disease. Available data support the use of corticosteroids in high-income countries, but the effect on mortality is still controversial. The effects of corticosteroids on mortality and sequelae were evaluated in the national Swedish quality registry. In total, during 1995-2014 1746 adults with ABM were included, of whom 989 were treated with corticosteroids (betamethasone, n = 766; dexamethasone, n = 248; methylprednisolone, n = 2), 498 were not given corticosteroids and in 259 patients data for corticosteroids were missing. Fatal outcome was observed in 8.9% of the patients in the corticosteroid-treated group vs. 17.9% in the non-corticosteroid-treated group (p <0.001), resulting in an odds ratio (OR) of 0.57 with a 95% confidence interval (CI) of 0.40-0.81 adjusted for age, sex, mental status, and door-to-antibiotic time. In patients with meningitis caused by S. pneumoniae, mortality was 10.2% in the corticosteroid-treated group and 21.3% in the non-corticosteroid-treated group (p <0.001) with an adjusted OR of 0.50 (95% CI 0.31-0.80). In ABM patients with non-pneumococcal aetiology the adjusted OR was 0.71 (95% CI 0.40-1.26). Lower mortality was observed in the corticosteroid-treated group with impaired mental status, whereas no significant difference was found in patients with unaffected mental status. The adjusted ORs for betamethasone and dexamethasone were 0.49 (95% CI 0.28-0.84) and 0.61 (95% CI 0.37-1.01), respectively. Corticosteroid treatment decreases mortality in ABM and should be administered initially with antibiotics in adult ABM patients with impaired mental status regardless of presumed aetiology. Betamethasone seems to be at least as effective as dexamethasone.

Adult bacterial meningitis-a quality registry study: earlier treatment and favourable outcome if initial management by infectious diseases physicians.

Acute bacterial meningitis (ABM) is challenging for the admitting physician because it is a rare but fulminant disease, usually presenting without typical symptoms, and rapid treatment is pivotal. The purpose of this study was to evaluate the effect of initial management by infectious diseases (ID) physicians vs. non-ID physicians. A total of 520 consecutive adults (>17 years old), 110 with initial ID management and 410 with non-ID management, registered in the Swedish quality registry for community-acquired ABM January 2008 to December 2013, were analysed retrospectively. Primary outcome was appropriate treatment with antibiotics and corticosteroids <1 hour from admission. Secondary analyses were mortality during hospital stay and persisting neurological and hearing deficits at follow-up after 2 to 6 months. Differences in diagnostic treatment sequences also were analysed. Appropriate treatment <1 hour from admission was achieved significantly more often (41%) by ID physicians vs. non-ID physicians (24%) with an odds ratio (OR) of 2.4 (95% confidence interval [CI]: 1.40 to 4.14; p < 0.01) adjusted for confounders. The door-to-antibiotic time was significantly shorter, and significantly more patients were administered corticosteroids together with the first doses of antibiotics in the ID group. A trend of decreased mortality (4.5% vs. 8.0%) and sequelae at follow-up (24% vs. 44%; adjusted OR 0.55: 95% CI 0.31 to 1.00; p 0.05) were observed in the ID group vs. the non-ID group. Antibiotics were started without prior neuroimaging more often in the ID group (86% vs. 57%; p < 0.001). Initial management at the emergency department by ID physicians is associated with earlier appropriate treatment, more appropriate diagnostic treatment sequences and favourable outcome.

Duration of residency in a non-endemic area and risk of severe malaria in African immigrants.

In malaria-endemic areas, adults very rarely succumb to severe malaria, suggesting that immunity to severe disease is life-long under conditions of repeated exposure. To what extent this protection persists in the absence of exposure remains to be established. The aim of this study was to assess whether duration of residency in a malaria-free country affects the risk for severe malaria in immigrants originating from sub-Saharan Africa. We conducted a retrospective chart review of 948 cases of malaria diagnosed in Stockholm, Sweden in 1995-2013. Among 501 adult patients with Plasmodium falciparum (315 of endemic origin and 186 of non-endemic origin, mainly Sweden), 41 (8.2%) had severe malaria according to WHO criteria (including 5% with parasitaemia), 22 (4.4%) had factors prognostic of poor outcome, and 35 (7.0%) were admitted to intensive care. Overall, patient origin did not affect the odds of severe malaria, according to any of these definitions. However, when the immigrants were stratified with regard to their duration of residency in Sweden, the risk of factors prognostic for poor outcome was associated with duration of prior residency in a malaria-free country among patients of endemic origin (p 0.02), and immigrants who had lived for ≥ 15 years in Sweden had a similar risk as non-immune travellers. The results of this explorative study suggest that, although immunity to severe malaria is maintained for several years in African adults, this protection might be lost with time without repeated re-exposure. A larger study, preferably including multiple centres, will be needed to confirm our findings.

Faecal carriage of extended-spectrum ß-lactamase-producing Enterobacteriaceae is common 12 months after infection and is related to strain factors.

We aimed to determine the duration of faecal carriage of extended-spectrum ß-lactamase (ESBL) -producing Enterobacteriaceae (EPE) in patients with clinical infection caused by an EPE, to study host strains during carriage, and to identify factors associated with prolonged carriage. Patients (n = 61) were followed with faecal samples and questionnaires about antimicrobial treatment and risk factors for EPE, 1, 3, 6 and 12 months after EPE infection. The EPE isolates were subjected to ESBL genotyping, epidemiological typing with pulsed-field gel electrophoresis and PCR-based replicon typing. Escherichia coli isolates were analysed with PCR for phylogrouping, detection of pabB (ST131) and virulence content. Patient-related and strain-related variables were compared for carriers and non-carriers at 12 months. Carriage of EPE was observed in 51 of 61 (84%) patients after 1 month, 36 of 61 (66%) after 3 months, 31 of 61 (55%) after 6 months and 26 of 61 (43%) after 12 months. Of the 26 carriers at 12 months, five had previous negative samples. In 17 of 61 patients, ESBL was found in a new bacterial species and/or strain during carriage. Among E. coli, 14 of 49 belonged to the international clone ST131. Phylogroup B2 and CTX-M-gr.-9 were associated with being carriers at 12 months (OR 4.3, 95% CI 1.1-16.3 and OR 6.4, 95% CI 1.3-30.9, respectively). In conclusion, EPE carriage is common 12 months after infection and persisting carriage may be associated with E. coli phylogroup B2 and CTX-M-gr.-9. The host strain frequently changes throughout carriage and negative samples do not imply eliminated carriage.

Seroepidemiology as basis for design of a human papillomavirus vaccination program.

We have performed a serological survey of HPV type 16-antibody prevalence by age and sex in Sweden and used it as a basis for modelling the optimal vaccination strategies in this population. Samples of 3,317 subjects were tested for HPV16-specific antibodies. The observed age-specific seroprevalences along with sexual behaviour data were used to infer parameter values for a mathematical model representing Sweden and the preventive effect of possible strategies estimated. By the year 2055, vaccination of females starting at age 12 in 2008 was most efficient, estimated to prevent 5.8 million cumulative HPV16 infections. Catch-up programs had a strong additional preventive effect. Vaccination also targeting males increased protective effect by about 4%, but had lower preventive effect per vaccination given. Addition of an HPV serosurvey to existing models and data has enabled us to estimate effect of different vaccination strategies, optimized to the HPV epidemiology in our population.

HPV type-specific risks of high-grade CIN during 4 years of follow-up: a population-based prospective study.

We followed a population-based cohort of 5696 women, 32-38 years of age, by registry linkage with cytology and pathology registries during a mean follow-up time of 4.1 years to assess the importance for CIN2+ development of type-specific HPV DNA positivity at baseline. HPV 16, 31 and 33 conveyed the highest risks and were responsible for 33.1, 18.3 and 7.7% of CIN2+ cases, respectively. Women infected with HPV 18, 35, 39, 45, 51, 52, 56, 58, 59 and 66 had significantly lower risks of CIN2+ than women infected with HPV 16. After adjustment for infection with other HPV types, HPV types 35, 45, 59 and 66 had no detectable association with CIN2+. In summary, the different HPV types found in cervical cancer show distinctly different CIN2+ risks, with high risks being restricted to HPV 16 and its close relatives HPV 31 and HPV 33.