Viable Legionella pneumophila bacteria in natural soil and rainwater puddles.

AIMS: For the majority of sporadic Legionnaires' disease cases the source of infection remains unknown. Infection may possible result from exposure to Legionella bacteria in sources that are not yet considered in outbreak investigations. Therefore, potential sources of pathogenic Legionella bacteria--natural soil and rainwater puddles on roads--were studied in 2012. METHODS AND RESULTS: Legionella bacteria were detected in 30% (6/20) of soils and 3·9% (3/77) of rainwater puddles by amoebal coculture. Legionella pneumophila was isolated from two out of six Legionella positive soil samples and two out of three Legionella positive rainwater samples. Several other species were found including the pathogenic Leg. gormanii and Leg. longbeachae. Sequence types (ST) could be assigned to two Leg. pneumophila strains isolated from soil, ST710 and ST477, and one strain isolated from rainwater, ST1064. These sequence types were previously associated with Legionnaires' disease patients. CONCLUSIONS: Rainwater and soil may be alternative sources for Legionella. SIGNIFICANCE AND IMPACT OF THE STUDY: The detection of clinically relevant strains indicates that rainwater and soil are potential sources of Legionella bacteria and future research should assess the public health implication of the presence of Leg. pneumophila in rainwater puddles and natural soil.

Isolation of Legionella pneumophila from pluvial floods by amoebal coculture.

Viable Legionella pneumophila bacteria were isolated by amoebal coculture from pluvial floods after intense rainfall and from water collected at sewage treatment plants. Several isolated L. pneumophila strains belonged to sequence types that have been previously identified in patients.

A single dose of doxycycline after an ixodes ricinus tick bite to prevent Lyme borreliosis: An open-label randomized controlled trial.

OBJECTIVES: A single dose of doxycycline after a tick bite can prevent the development of Lyme borreliosis in North America, but extrapolation to Europe is hampered by differences in Borrelia burgdorferi sensu lato genospecies and tick species. We assessed the efficacy of prophylaxis after a tick bite in Europe. METHODS: We conducted an open-label randomized controlled trial, administering a single dose of 200 mg doxycycline within 72 h after removing an attached tick from the skin, compared to no treatment. Potential participants ≥ 8 years of age who reported a recent tick bite online were invited for the study. After informed consent, they were randomly assigned to either the prophylaxis or the no-treatment group. Participants in the prophylaxis group were asked to visit their general practitioner to administer the antibiotics. All participants were followed up by online questionnaires. Our primary outcome was the development of physician-confirmed Lyme borreliosis in a modified-intention-to-treat analysis. This study is registered in the Netherlands Trial Register (NTR3953) and is closed. RESULTS: Between April 11, 2013, and June 10, 2015, 3538 potential participants were randomized, of whom 1689 were included in the modified-intention-to-treat analysis. 10 cases of Lyme borreliosis were reported out of 1041 participants (0.96%) in the prophylaxis group, and 19 cases out of 648 no-treatment participants (2.9%), resulting in a relative risk reduction of 67% (95% CI 31 - 84%), and a number-needed-to-treat of 51 (95% CI 29 - 180). No serious adverse events were reported. CONCLUSIONS: This primary care-based trial provides evidence that a single dose of doxycycline can prevent the development of Lyme borreliosis after an Ixodes ricinus tick bite.