Petri Ruutu

Lactobacillus Bacteremia during a Rapid Increase in Probiotic Use of Lactobacillus rhamnosus GG in Finland

Lactobacilli supposedly have low pathogenicity; they are seldom detected in blood culture. Lactobacillus rhamnosus GG, which originates indigenously in the human intestine, became available for use as a probiotic in 1990 in Finland. We evaluated the possible effects of the increased probiotic use of L. rhamnosus GG on the occurrence of bacteremia due to lactobacilli. Lactobacilli were isolated in 0.02% of all blood cultures and 0.2% of all blood cultures with positive results in Helsinki University Central Hospital and in Finland as a whole, and no trends were seen that suggested an increase in Lactobacillus bacteremia. The average incidence was 0.3 cases/100,000 inhabitants/year in 1995-2000 in Finland. Identification to the species level was done for 66 cases of Lactobacillus bacteremia, and 48 isolates were confirmed to be Lactobacillus strains. Twenty-six of these strains were L. rhamnosus, and 11 isolates were identical to L. rhamnosus GG. The results indicate that increased probiotic use of L. rhamnosus GG has not led to an increase in Lactobacillus bacteremia.

An outbreak of Listeria monocytogenes serotype 3a infections from butter in Finland.

In February 1999, an outbreak of listeriosis caused by Listeria monocytogenes serotype 3a occurred in Finland. All isolates were identical. The outbreak strain was first isolated in 1997 in dairy butter. This dairy began delivery to a tertiary care hospital (TCH) in June 1998. From June 1998 to April 1999, 25 case patients were identified (20 with sepsis, 4 with meningitis, and 1 with abscess; 6 patients died). Patients with the outbreak strain were more likely to have been admitted to the TCH than were patients with other strains of L. monocytogenes (60% vs. 8%; odds ratio, 17.3; 95% confidence interval, 2.8-136.8). Case patients admitted to the TCH had been hospitalized longer before cultures tested positive than had matched controls (median, 31 vs. 10 days; P=.008). An investigation found the outbreak strain in packaged butter served at the TCH and at the source dairy. Recall of the product ended the outbreak.

Efficacy of an 11-valent pneumococcal conjugate vaccine against radiologically confirmed pneumonia among children less than 2 years of age in the Philippines: a randomized, double-blind, placebo-controlled trial.

Background: Pneumococcus is a leading cause of childhood pneumonia worldwide. Pneumococcal conjugate vaccines (PCV) have demonstrated efficacy against childhood invasive pneumococcal disease (IPD) and pneumonia in the United States and Africa. No information is available from Asia on the impact of PCV on childhood pneumonia. Methods: We conducted a randomized, placebo-controlled, double-blind trial in Bohol, the Philippines (ISRCTN 62323832). Children 6 weeks to <6 months of age were randomly allocated to receive 3 doses of either an 11-valent PCV (11PCV, sanofi pasteur, Lyon, France) or a saline placebo, with a minimum interval of 4 weeks between doses to determine vaccine efficacy (VE) against the primary outcome of a child experiencing first episode of community-acquired radiologically defined pneumonia in the first 2 years of life. Secondary end points were clinical pneumonia, IPD, safety, and immunogenicity. Results: Twelve thousand one hundred ninety-one children were enrolled. By per protocol (PP) analysis, 93 of 6013 fully vaccinated 11PCV recipient children had a first episode of radiologic pneumonia compared with 120 of 6018 placebo recipients. VE against radiologically defined pneumonia for the PP cohort of children 3 to 23 months old was 22.9% (95% CI: −1.1, 41.2; P = 0.06), for the prespecified subgroups of children 3 to 11 months of age, 34.0% (95% CI: 4.8, 54.3; P = 0.02), and of those 12 to 23 months old, 2.7% (95% CI: −43.5, 34.0; P = 0.88). By intent-to-treat (ITT) analysis, 119 of 6097 11PCV recipient children had an episode of radiologic pneumonia compared with 141 of 6094 placebo recipients. VE against radiologic pneumonia for the ITT cohort of children <2 years old was 16.0% (95% CI −7.3, 34.2; P = 0.16), for a subgroup of children <12 months of age, 19.8% (95% CI: −8.8, 40.8; P = 0.15). VE against clinical pneumonia by PP was not significant (VE 0.1%; 95% CI −9.4, 8.7; P = 0.99). IPD was rare: only 3 cases of IPD due to vaccine serotypes were observed during the study. 11PCV was immunogenic and well tolerated. Among 11PCV recipients, a small excess of serious adverse respiratory events was observed in the first 28 days after the first and second dose of vaccine, and of nonrespiratory events after the first dose. An excess of pneumonia episodes in 11PCV recipients in the month following the second dose of vaccination was the principal reason for lower VE by ITT analysis than by PP analysis. Conclusions: In PP analysis, a 22.9% reduction of community-acquired radiologically confirmed pneumonia in children younger than 2 years of age in the 11-valent tetanus-diphtheria toxoid-conjugated PCV vaccinated group was observed; a reduction similar as observed in other PCV trials. We could not demonstrate any VE against clinical pneumonia. Our finding confirms for the first time that in a low-income, low-mortality developing country in Asia, at least one-fifth of radiologically confirmed pneumonia is caused by pneumococcus, and thus preventable by PCV. Whether PCV should be included in national program in such settings, however, depends on careful country specific disease burden measurement and cost-effectiveness calculation.

A Widespread Outbreak of Yersinia pseudotuberculosis O:3 Infection from Iceberg Lettuce

BACKGROUND The vehicles and sources of Yersinia pseudotuberculosis infection are unknown. In Finland, clinical microbiology laboratories routinely report Y. pseudotuberculosis isolations and submit isolates for serotype analysis. In October 1998, the number of serotype O:3 infections increased markedly. METHODS Case patients with culture-confirmed Y. pseudotuberculosis O:3 infection were identified by use of laboratory-based surveillance. We conducted a population-based case-control study. Healthy community control subjects were matched by age, sex, and postal code. Isolates were subtyped by pulsed-field gel electrophoresis (PFGE). RESULTS Nationwide, 47 case patients were identified (age range, 2-77 years; median, 19 years). One patient with bacteremia died; 5 underwent appendectomies. We enrolled 38 case patients and 76 control subjects in the case-control study. Seventy-one percent of case patients and 42% of control subjects reported having eaten iceberg lettuce (matched odds ratio, 3.8; 95% confidence interval, 1.3-9.4); a dose-response relationship was found for increasing frequency of consumption. Of the 27 isolates obtained from case patients and tested in the analysis, all had indistinguishable PFGE patterns. Four lunch cafeterias that had served iceberg lettuce were associated with clusters of case patients. The lettuce was traced back to originating farms. CONCLUSIONS Iceberg lettuce was implicated as the vehicle of a widespread foodborne Y. pseudotuberculosis outbreak. Ongoing laboratory-based surveillance and serotype analysis were essential in the rapid detection of infection. Cases of yersiniosis, which appear to be sporadic, may be part of unrecognized outbreaks caused by contaminated fresh produce.

Candidemia in Finland, 1995-1999

We analyzed laboratory-based surveillance candidemia data from the National Infectious Disease Register in Finland and reviewed cases of candidemia from one tertiary-care hospital from 1995 to 1999. A total of 479 candidemia cases were reported to the Register. The annual incidence rose from 1.7 per 100,000 population in 1995 to 2.2 in 1999. Species other than Candida albicans accounted for 30% of cases without change in the proportion. A total of 79 cases of candidemia were identified at the hospital; the rate varied from 0.03 to 0.05 per 1,000 patient-days by year. Predisposing factors included indwelling catheters (81%), gastrointestinal surgery (27%), hematologic malignancy (25%), other types of surgery (21%), and solid malignancies (20%). Crude 7-day and 30-day case-fatality ratios were 15% and 35%, respectively. The rate of candidemia increased in Finland but is still substantially lower than in the United States. No shift to non–C. albicans species could be detected.

Nosocomial Bloodstream Infections in Finnish Hospitals during 1999–2000

Prospective laboratory-based surveillance in 4 Finnish hospitals during 1999-2000 identified 1477 cases of nosocomial bloodstream infection (BSI), with an overall rate of 0.8 BSIs per 1000 patient-days. Of BSI cases, 33% were in patients with a hematological malignancy and 15% were in patients with a solid malignancy; 26% were in patients who had undergone surgery preceding infection. Twenty-six percent of BSIs were related to intensive care, and 61% occurred in patients with a central venous catheter. Sixty-five percent of the 1621 causative organisms were gram positive, 31% were gram negative, and 4% were fungi. The most common pathogens were coagulase-negative staphylococci (31%), Escherichia coli (11%), Staphylococcus aureus (11%), and enterococci (6%). Methicillin resistance was detected in 1% of S. aureus isolates and vancomycin resistance in 1% of enterococci. The 7-day case-fatality ratio was 9% and was highest for infections caused by Candida (21%) and enterococci (18%). The overall rate of nosocomial BSIs was similar to rates in England and the United States, but S. aureus, enterococci, and fungi were less common in our study, and the prevalence of antibiotic resistance was lower.

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.

Secular trend in candidemia and the use of fluconazole in Finland, 2004-2007

BackgroundIn a previous study we observed an increasing trend in candidemia in Finland in the 1990s. Our aim was now to investigate further population-based secular trends, as well as outcome, and evaluate the association of fluconazole consumption and prophylaxis policy with the observed findings.MethodsWe analyzed laboratory-based surveillance data on candidemia from the National Infectious Diseases Register during 2004-2007 in Finland. Data on fluconazole consumption, expressed as defined daily doses, DDDs, was obtained from the National Agency for Medicines, and regional prophylaxis policies were assessed by a telephone survey.ResultsA total of 603 candidemia cases were identified. The average annual incidence rate was 2.86 cases per 100,000 population (range by year, 2.59-3.09; range by region, 2.37-3.85). The highest incidence was detected in males aged >65 years (12.23 per 100,000 population). Candida albicans accounted for 67% of cases, and C. glabrata ranked the second (19%), both without any significant change in proportions. C. parapsilosis accounted for 5% of cases and C. krusei 3% of cases. The one-month case-fatality varied between 28-32% during the study period. Fluconazole consumption increased from 19.57 DDDs per 100,000 population in 2000 to 25.09 in 2007. Systematic fluconazole prophylaxis was implemented for premature neonates, patients with acute leukemias and liver transplant patients.ConclusionThe dominant proportion of C. albicans remained stable, but C. glabrata was the most frequent non-albicans species. The proportion of C. glabrata had increased from our previous study period in the presence of increasing use of fluconazole. The rate of candidemia in Finland is still low but mortality high like in other countries.

Multiple Outbreaks of Yersinia pseudotuberculosis Infections in Finland

ABSTRACT During 2001, 89 culture-confirmed cases of Yersinia pseudotuberculosis were reported in Finland; 55 (62%) were serotype O:1, and 34 (38%) were serotype O:3. Four major pulsed-field gel electrophoresis profiles were identified. A case-control study of 25 case patients and 71 healthy controls identified eating outside the home as a risk factor for infection.