Outbreak of multiple strains of non-O157 Shiga toxin-producing and enteropathogenic Escherichia coli associated with rocket salad, Finland, autumn 2016.

In August 2016, an outbreak of Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) with 237 cases occurred in the Helsinki metropolitan area, Finland. Gastroenteritis cases were reported at 11 events served by one catering company. Microbiological and epidemiological investigations suggested rocket salad as the cause of the outbreak. STEC ONT: H11 and EPEC O111:H8 strains isolated from food samples containing rocket were identical to the patient isolates. In this outbreak, the reported symptoms were milder than considered before for STEC infection, and the guidelines for STEC control measures need to be updated based on the severity of the illness. Based on our experience in this outbreak, national surveillance criteria for STEC have been updated to meet the practice in reporting laboratories covering both PCR-positive and culture-confirmed findings. We suggest that EPEC could be added to the national surveillance since diagnostics for EPEC are routinely done in clinical laboratories.

[Recognize tuberculosis--prevent outbreak]. / Tunnista tuberkuloosi--ehkäise epidemia.

INTRODUCTION: The number of tuberculosis cases in Finland has decreased. Cases among immigrants have, however, increased, and the disease may not be recognized early enough. METHODS: We describe four group exposures to tuberculosis that occurred in Finland, the index patient coming from a country with a high incidence rate of tuberculosis. RESULTS: Over 900 persons were exposed to tuberculosis. Coordination of the surveys was hampered by the fact that several healthcare operators participated in the study. Three index patients had drug-resistant tuberculosis, one of which was multidrug resistant. CONCLUSIONS: Extensive operations of tracking and prevention could have been avoided, if the symptoms would have been recognized earlier.

[Factors affecting transmission of contagious diseases]. / Infektioiden tarttuvuustekijät.

Factors affecting transmission of contagious diseases There are differences in the transmission rate of infectious diseases. The mathematic estimates of the transmission rate of various contagious diseases are impossible to predict. The Basic reproduction number, the so-called Ro-value tends to extrapolate the number of persons who can get infected from one person. To prevent some contagious diseases, a high rate of herd immunity is required. This immunity is achieved by mass vaccination. Infections are transmitted by aerosol, drop, fecalo-oral, blood or contact routes. Nosocomial infections are transmitted usually by contact or fecalo-oral routes whereas the majority of healthcare related infections are transmitted by contact with infected blood or through aerosol transmission.

Complement C4 deficiency--a plausible risk factor for non-tuberculous mycobacteria (NTM) infection in apparently immunocompetent patients.

BACKGROUND: Non-tuberculous mycobacteria (NTM) are ubiquitous in the environment and they infect mainly persons with underlying pulmonary diseases but also previously healthy elderly women. Defects in host resistance that lead to pulmonary infections by NTM are relatively unknown. A few genetic defects have been associated with both pulmonary and disseminated mycobacterial infections. Rare disseminated NTM infections have been associated with genetic defects in T-cell mediated immunity and in cytokine signaling in families. We investigated whether there was an association between NTM infections and deficiencies of complement components C4A or C4B that are encoded by major histocompatibility complex (MHC). METHODS: 50 adult patients with a positive NTM culture with symptoms and findings of a NTM disease were recruited. Patients' clinical history was collected and symptoms and clinical findings were categorized according to 2007 diagnostic criteria of The American Thoracic Society (ATS). To investigate the deficiencies of complement, C4A and C4B gene copy numbers and phenotype frequencies of the C4 allotypes were analyzed. Unselected, healthy, 149 Finnish adults were used as controls. RESULTS: NTM patients had more often C4 deficiencies (C4A or C4B) than controls (36/50 [72%] vs 83/149 [56%], OR = 2.05, 95%CI = 1.019-4.105, p = 0.042). C4 deficiencies for female NTM patients were more common than for controls (29/36 [81%] vs 55/100 [55%], OR = 3.39, 95% CI = 1.358-8.460, p = 0.007). C4 deficiences seemed not to be related to any specific underlying disease or C4 phenotype. CONCLUSIONS: C4 deficiency may be a risk factor for NTM infection in especially elderly female patients.

Prognostic value of American Thoracic Society criteria for non-tuberculous mycobacterial disease: a retrospective analysis of 120 cases with four years of follow-up.

BACKGROUND: Non-tuberculous mycobacteria (NTM) cause disease in healthy and immunocompromised patients. The American Thoracic Society (ATS) 2007 diagnostic criteria were devised to distinguish NTM disease from airway colonization. The aim of this study was to evaluate the prognostic value of the ATS criteria. METHODS: In a 4-y follow-up study that ended on 8 June 2006, we retrospectively analyzed the symptoms, underlying diseases, and mortality of 120 adult non-HIV patients with NTM culture findings obtained between 1990 and 1998. We categorized the patients according to the 2007 ATS NTM case definition into positive and negative groups. RESULTS: Only 61/120 patients (51%) fulfilled the ATS criteria for NTM disease. As compared to ATS-negative subjects, the ATS-positive group showed lower age, a higher proportion of females, and fewer fatal underlying diseases. Among ATS-negative subjects, 46/59 (78%) did not fulfil the microbiological criteria and 43/59 (73%) did not fulfil the radiological criteria. Mycobacterium avium complex (MAC) comprised 61% of isolations in the ATS-positive and 47% in the ATS-negative group (p = 0.15). No significant difference in median survival time was found between the groups: ATS-positive 7.4 y (95% confidence interval (CI) 0.2-14.6) and ATS-negative 5.3 y (95% CI 3.0-7.6). No significant difference was found in symptoms except fatigue, which was more common in the ATS-positive (56% vs 37%, p = 0.04). Symptoms lasted for less than a year in 48%, which suggests a more rapid disease progression than has previously been reported. CONCLUSIONS: The fulfillment of ATS criteria was poorly associated with any difference in prognosis, and based on our findings would be a poor prognostic marker.

Evaluation of the filter paper IP-10 tests in school children after exposure to tuberculosis: a prospective cohort study with a 4-year follow-up.

OBJECTIVES: The prevalence of active tuberculosis (TB) is low in Finland, but outbreaks do occur. Following exposure national guidelines recommend either tuberculosis skin test or interferon-γ-release assay-testing of asymptomatic children. The aim of this study was to compare QuantiFERON-TB Gold In-Tube test (QFT) and interferon-γ-inducible protein (IP-10) release assay for detection of Mycobacterium tuberculosis infection following exposure to TB in a primary school. DESIGN: A prospective cohort study. SETTING: School children in Helsinki, Finland. PARTICIPANTS: Two siblings of the index case and 58 classmates exposed to M tuberculosis. INTERVENTION: All the children were screened using the QFT, which was used to guide preventive treatment. All those exposed were followed up through the national TB registry. OUTCOME MEASURES: IP-10 was measured in plasma supernatants from the QFT test supernatants and in plasma dried and stored for 1 year on filter paper. IP-10 test results were calculated using preset algorithms for positive and indeterminate tests. The negative predictive values of the tests were assessed. RESULTS: At an initial screening 2 months after the debut of symptoms in the index case, QFT was positive in two children; 56 tests were negative; one was indeterminate and one was borderline. IP-10 showed a perfect concordance between the dried plasma spot and plasma method; two children were IP-10 positive and two were IP-10 indeterminate. There were two (3%) discordant results between the QFT and IP-10 tests. Four children converted to positive QFT at a 1-3 month follow-up. None of the QFT negative/borderline children developed TB in the 4-year period since exposure. CONCLUSIONS: We demonstrated that IP-10 and QFT perform comparably as screening tools for infection with M tuberculosis in a contact investigation. IP-10 determined in dried plasma spots was at par with IP-10 determined in plasma, which further supports the usefulness of this alternative approach.

Clinical symptoms and survival in non-smoking and smoking HIV-negative patients with non-tuberculous mycobacterial isolation.

BACKGROUND: Non-tuberculous mycobacteria (NTM) cause infections in patients with smoking-related chronic lung diseases and also in non-smoking healthy elderly women. We analyzed the clinical symptoms, underlying diseases and mortality in patients with NTM culture findings, with special emphasis on smoking status. METHODS: A total of 120 consecutive adult HIV-negative patients with NTM isolation were followed between 1990 and 1998 by retrieving data from their medical records for a period of at least 4 y, until 8 June 2006. Their clinical pictures and outcomes were analysed according to smoking status. RESULTS: In this study, 42% of the patients had never smoked. Females accounted for 72% of non-smokers, but only 30% of smokers (p < 0.001). Mycobacterium avium complex (MAC) accounted for 72% of all isolates in non-smokers and 41% in smokers (p = 0.001). Furthermore, 28% of non-smokers and 19% of smokers had no previous pulmonary diseases (p = 0.223). In nearly half of all patients (48%), symptoms of NTM infection started within a year prior to NTM isolation. Smokers had a higher risk of mortality compared to non-smokers (hazard ratio 1.64, p = 0.049), though this was not found after adjusting for underlying diseases. No fatal underlying diseases were found for 82% of non-smokers and 59% of smokers (p < 0.01). CONCLUSIONS: Non-smokers with NTM isolates had fewer previous lung diseases but had a higher incidence of MAC and bronchiectasis. Time from symptoms to NTM isolation was shorter than previously reported.