Jukka Ollgren

Antimicrobials Increase Travelers' Risk of Colonization by Extended-Spectrum Betalactamase-Producing Enterobacteriaceae

Colonized travelers contribute to the pandemic spread of resistant intestinal bacteria. This study is the first to show that antimicrobial use during travel predisposes to colonization by intestinal extended-spectrum beta-lactamase-producing Enterobacteriaceae. Travelers refrain from taking unnecessary antibiotics.

An Outbreak of Gastrointestinal Illness and Erythema Nodosum from Grated Carrots Contaminated with Yersinia pseudotuberculosis

BACKGROUND Outbreaks of Yersinia pseudotuberculosis infection have been epidemiologically linked to fresh produce, but the bacterium has not been recovered from the food items implicated. In May 2003, a cluster of gastrointestinal illness and erythema nodosum was detected among schoolchildren who had eaten lunches prepared by the same institutional kitchen. METHODS We conducted a case-control study and trace-back, environmental, and laboratory investigations. Case patients had culture-confirmed Y. pseudotuberculosis O:1 infection, erythema nodosum, or reactive arthritis. Bacterial isolates from clinical and environmental samples were compared using pulsed-field gel electrophoresis (PFGE). RESULTS Of 7392 persons at risk, 111 (1.5%) met the case definition; 76 case patients and 172 healthy control subjects were enrolled in the case-control study. Only raw grated carrots were significantly associated with illness in a logistic-regression model (multivariable odds ratio, 5.7 [95% confidence interval, 1.7-19.5]); a dose response was found for increasing amount of consumption. Y. pseudotuberculosis O:1 isolates from 39 stool specimens and from 5 (42%) of 12 soil samples that contained carrot residue and were obtained from peeling and washing equipment at the production farm were indistinguishable by PFGE. CONCLUSIONS Carrots contaminated early in the production process caused a large point-source outbreak. Our findings enable the development of evidence-based strategies to prevent outbreaks of this emerging foodborne pathogen.

Risk factors for poor tuberculosis treatment outcome in Finland: a cohort study

BackgroundWe investigated the patient- and treatment-system dependent factors affecting treatment outcome in a two-year cohort of all treated culture-verified pulmonary tuberculosis (TB) cases to establish a basis for improving outcomes.MethodsMedical records of all cases in 1995 – 1996 were abstracted to assess outcome of treatment. Outcome was divided into three groups: favourable, death and other unfavourable. Predictors of unfavourable outcome were assessed in univariate and multivariate analysis.ResultsAmong 629 cases a favourable outcome was achieved in 441 (70.1%), 17.2% (108) died and other unfavourable outcome took place in 12.7% (80). Significant independent risk factors for death were male sex, high age, non-HIV -related immunosuppression and any other than a pulmonary specialty being responsible for stopping treatment. History of previous tuberculosis was inversely associated with the risk of death. For other unfavourable treatment outcomes, significant risk factors were pause(s) in treatment, treatment with INH+RIF+EMB/SM, and internal medicine specialty being responsible at the end of the treatment.ConclusionWe observed a significant association with unfavourable outcome for the specialty responsible for treatment being other than pulmonary, but not for the volume of cases, which has implications for system arrangements. Poor outcomes associated with immunosuppression and advanced age, with frequent comorbidity, stress a low threshold of suspicion, availability of rapid diagnostics, and early empiric treatment as probable approaches in attempting to improve treatment outcomes in countries with very low incidence of TB.

Risk of invasive pneumococcal infections among working age adults with asthma

Background Information about the risk of invasive pneumococcal infection (IPI) among adults with asthma is limited and inconsistent. To evaluate this association, a population-based case–control study was conducted. Methods Cases of IPI (Streptococcus pneumoniae isolated from blood or cerebrospinal fluid) were identified through national, population-based laboratory surveillance during 1995–2002. To maximise exclusion of chronic obstructive pulmonary disease, the analysis was limited to patients aged 18–49 years and 10 selected age-, sex- and health district-matched controls for each case from the Population Information System. Information on underlying medical conditions was obtained through linking surveillance data to other national health registries. Asthma requiring ≥1 hospitalisation in the past 12 months was defined as high risk asthma (HRA); low risk asthma (LRA) was defined as entitlement to prescription drug benefits and no hospitalisation for asthma in the past 12 months. Results 1282 patients with IPI and 12 785 control subjects were identified. Overall, 7.1% of cases and 2.5% of controls had asthma (6.0% and 2.4% had LRA whereas 1.1% and 0.1% had HRA, respectively. After adjustment for other independent risk factors in a conditional logistic regression model, IPI was associated with both LRA (matched OR (mOR) 2.8; 95% CI 2.1 to 3.6) and HRA (mOR, 12.3; 95% CI 5.4 to 28.0). The adjusted population-attributable risk was 0.039 (95% CI 0.023 to 0.055) for LRA and 0.01 (95% CI 0.0035 to 0.017) for HRA. Conclusions Working age adults with asthma are at increased risk of IPI. In this population, ∼5% of disease burden could be attributed to asthma. These findings support adding medicated asthma in adults to the list of indications for pneumococcal vaccination.

Increase in bloodstream infections in Finland, 1995-2002

A national, population-based laboratory surveillance of bloodstream infections (BSI) in Finland was performed. Blood-culturing rates were determined from data from clinical microbiology laboratories and trends in rates were evaluated using Poisson regression. During 1995-2002, 51,510 cases of BSI were notified; the annual incidence increased from 104 to 145 cases/100,000 (40%). Rates increased in all age groups but persons aged >or= 75 years accounted for 28% of cases and showed the largest rate increase. Escherichia coli, coagulase-negative staphylococci, Staphylococcus aureus and Streptococcus pneumoniae accounted for 58% of isolates and their relative proportions were unchanged over time. The annual blood-culturing rate increased by one-third during the study period but the number of BSI detected per blood cultures remained unchanged. Regional BSI incidence was significantly associated with blood-culturing rates. We conclude that the increase in BSI rates may have been due to more frequent blood culturing but was not associated with changes in the reporting system or aetiology of BSI.

Telephone Consultation Cannot Replace Bedside Infectious Disease Consultation in the Management of Staphylococcus aureus Bacteremia

BACKGROUND Infectious disease specialist (IDS) consultation improves the outcome of Staphylococcus aureus bacteremia (SAB). Although telephone consultations constitute a substantial part of IDS consultations, their impact on treatment outcome lacks evaluation. METHODS We retrospectively followed 342 SAB episodes with 90-day follow-up, excluding 5 methicillin-resistant S. aureus SAB cases. Patients were grouped according to bedside, telephone, or no IDS consultation within the first week. Patients with fatal outcome within 3 days after onset of SAB were excluded to allow for the possibility of death occurring before IDS consultation. RESULTS Seventy-two percent of patients received bedside, 18% telephone, and 10% no IDS consultation. Patients with bedside consultation were less often treated in an intensive care unit during the first 3 days compared to those with telephone consultation (odds ratio [OR], 0.53; 95% confidence interval [CI], .29-.97; P = .037; 21% vs 34%), with no other initial differences between these groups. Patients with bedside consultation more often had deep infection foci localized as compared to patients with telephone consultation (OR, 3.11; 95% CI, 1.74-5.57; P < .0001; 78% vs 53%). Patients with bedside consultation had lower mortality than patients with telephone consultation at 7 days (OR, 0.09; 95% CI, .02-.49; P = .001; 1% vs 8%), at 28 days (OR, 0.27; 95% CI, .11-.65; P = .002; 5% vs 16%) and at 90 days (OR, 0.25; 95% CI, .13-.51; P < .0001; 9% vs 29%). Considering all prognostic markers, 90-day mortality for telephone-consultation patients was higher (OR, 2.31; CI, 95% 1.22-4.38; P = .01) as compared to bedside consultation. CONCLUSIONS Telephone IDS consultation is inferior to bedside IDS consultation.

Disease burden of Puumala virus infections, 1995-2008

Puumala virus (PUUV) causes mild haemorrhagic fever with renal syndrome, a rodent-borne zoonosis. To evaluate the disease burden of PUUV infections in Finland, we analysed data reported by laboratories to the National Infectious Disease Registry during 1995-2008 and compared these with data from other national registries (death, 1998-2007; hospital discharge, 1996-2007; occupational diseases, 1995-2006). A total of 22,681 cases were reported (average annual incidence 31/100,000 population); 85% were in persons aged 20-64 years and 62% were males. There was an increasing trend in incidence, and the rates varied widely by season and region. We observed 13 deaths attributable to PUUV infection (case-fatality proportion 0.08%). Of all cases, 9599 (52%) were hospitalized. Only 590 cases (3%) were registered as occupational disease, of which most were related to farming and forestry. The wide seasonal and geographical variation is probably related to rodent density and human behaviour.

Longitudinal study on pneumococcal carriage during the first year of life in Bangladesh.

Background: The strong herd immunity effect and the serotype replacement associated with the use of the pneumococcal conjugate vaccine have highlighted the importance of asymptomatic pneumococcal carriage. To describe the development of pneumoccoccal carriage in a developing country setting we carried out a longitudinal pneumococcal carriage study in Bangladesh. Methods: Ninety-nine children, born in Savar, Bangladesh between May 2000 and April 2001, were enrolled in the study with their families. Nasopharyngeal samples were collected at prescheduled 2–4 week intervals from the index children and from their family members. The nasopharyngeal swabs were cultured for pneumococcal growth and pneumococci were identified and serotyped by standard methods. Results: We collected 1459 samples (92% of those planned) from the 99 index children and 2865 samples from other family members. The data showed high point prevalences of pneumococcal carriage among newborns (40–50% from 8 weeks of age on), a rapid pneumococcal acquisition with age (50% of the children had been colonized by pneumococci at least once by the age of 8 weeks) and a wide range of different serogroups/types (SGT). SGT 6 and 19 accounted for 35% of the pneumococci isolated from children <1-year-old, followed by SGT 15, 23, and 10 for a total of 56%. The SGT distribution in children up to 9-year-old was similar to that among the <1 year olds, with SGT 6 and 19 predominating. Older children and adults differed from the younger children by not having clearly predominating SGTs. Conclusions: The features found in our study are typical of pneumococcal carriage in developing countries. We believe that results from longitudinal modeling of carriage based on these extensive data can have wide geographic application.

Invasive pneumococcal infections among persons with and without underlying medical conditions: Implications for prevention strategies

BackgroundThe 23-valent pneumococcal polysaccharide vaccine (PPV23) is recommended for persons aged < 65 years with chronic medical conditions. We evaluated the risk and mortality from invasive pneumococcal disease (IPD) among persons with and without the underlying medical conditions which are considered PPV23 indications.MethodsPopulation-based data on all episodes of IPD (positive blood or cerebrospinal fluid culture) reported by Finnish clinical microbiology laboratories during 1995–2002 were linked to data in national health care registries and vital statistics to obtain information on the patients preceding hospitalisations, co-morbidities, and outcome of illness.ResultsOverall, 4357 first episodes of IPD were identified in all age groups (average annual incidence, 10.6/100,000). Patients aged 18–49 and 50–64 years accounted for 1282 (29%) and 934 (21%) of IPD cases, of which 372 (29%) and 427 (46%) had a current PPV23 indication, respectively. Overall, 536 (12%) IPD patients died within one month of first positive culture. Persons aged 18–64 years accounted for 254 (47%) of all deaths (case-fatality proportion, 12%). Of those who died 117 (46%) did not have a vaccine indication. In a survival model, patients with alcohol-related diseases, non-haematological malignancies, and those aged 50–64 years were most likely to die.ConclusionIn the general population of non-elderly adults, almost two-thirds of IPD and half of fatal cases occurred in persons without a recognised PPV23 indication. Policymakers should consider additional prevention strategies such as lowering the age of universal PPV23 vaccination and introducing routine childhood pneumococcal conjugate immunisation which could provide substantial health benefits to this population through indirect vaccine effects.

Population‐based burden of bloodstream infections in Finland

Bloodstream infections (BSI) are a major cause of mortality, morbidity and medical cost, but few population-based studies have concomitantly evaluated BSI incidence and mortality. Data on BSI episodes reported to national, population-based surveillance by all clinical microbiology laboratories in Finland during 2004-07 were linked to vital statistics. Age-, sex and microbe-specific incidence and mortality rates were calculated. During 2004-07, 33 473 BSI episodes were identified; BSI incidence increased from 147 to 168 per 100 000 population (average annual increase, 4.4%; p <0.001). Rates were highest among persons ≥65 years and <1 year, and higher among male patients than female patients (166 versus 152 per 100 000). The most common aetiologies were Escherichia coli (27%) and Staphylococcus aureus (13%). Among male patients, 52% of BSI were caused by gram-positive bacteria compared with 42% among female patients (p <0.001). The overall 30-day case-fatality was 13%. Of the deaths, 32% occurred within 2 days, 70% were among people aged 65 years or more and 33% were caused by E. coli or S. aureus infections. The BSI mortality rate increased from 19 to 22 per 100 000 (average annual increase: 4.0%, p 0.01). Among people aged 25 years or more, the mortality rate was 1.4-fold higher in men than women (34 versus 25 per 100 000 population). Overall excess annual mortality from BSI in the population was 18 per 100 000. The substantial BSI burden among the elderly and among adult men highlights the need for developing and implementing effective interventions, particularly for BSI caused by E. coli and S. aureus. One-third of BSI deaths occurred early, emphasizing the importance of early identification and treatment.