A cluster of Legionnaires' disease in Belgium linked to a cooling tower, August-September 2016: practical approach and challenges.

A cluster of Legionnaires' disease (LD) with 10 confirmed, three probable and four possible cases occurred in August and September 2016 in Dendermonde, Belgium. The incidence in the district was 7 cases/100 000 population, exceeding the maximum annual incidence in the previous 5 years of 1.5/100 000. Epidemiological, environmental and geographical investigations identified a cooling tower (CT) as the most likely source. The case risk around the tower decreased with increasing distance and was highest within 5 km. Legionella pneumophila serogroup 1, ST48, was identified in a human respiratory sample but could not be matched with the environmental results. Public health authorities imposed measures to control the contamination of the CT and organised follow-up sampling. We identified obstacles encountered during the cluster investigation and formulated recommendations for improved LD cluster management, including faster coordination of teams through the outbreak control team, improved communication about clinical and environmental sample analysis, more detailed documentation of potential exposures obtained through the case questionnaire and earlier use of a geographical information tool to compare potential sources and for hypothesis generation.

Outbreak with a novel avian influenza A(H7N9) virus in China--scenarios and triggers for assessing risks and planning responses in the European Union, May 2013.

As part of the risk assessment and strategic planning related to the emergence of avian influenza A(H7N9) in China the European Centre for Disease Prevention and Control (ECDC) has considered two major scenarios. The current situation is the one of a zoonotic epidemic (Scenario A) in which the virus might be transmitted sporadically to humans in close contact with an animal reservoir. The second scenario is the movement towards efficient human to human transmission (a pandemic Scenario B). We identified epidemiological events within the different scenarios that would trigger a new risk assessment and a review of the response activities to implement in the European Union (EU). Further, we identified the surveillance activities needed to detect these events. The EU should prepare for importation of isolated human cases infected in the affected area, though this event would not change the level of public health risk. Awareness among clinicians and local public health authorities, combined with nationally available testing, will be crucial. A 'one health' surveillance strategy is needed to detect extension of the infection towards Europe. The emergence of a novel reassortant influenza A(H7N9) underlines that pandemic preparedness remains important for Europe.

Travel-associated Legionnaires' disease in Europe, 2010.

In 2010, the European surveillance network for travel-associated Legionnaires' disease (ELDSNet, previously EWGLINET) received reports of 864 cases of travel-associated Legionnaires' disease, of whom 24 were reported to have had a fatal outcome. As in previous years, a very low proportion of clinical isolates were obtained (45 cases, 5.6%). In the 2010 dataset, male cases outnumbered female cases by 2.6:1 and had a median age of 61 years (range: 21-96), while the median age for women was 63 years (range: 12-95). The network identified 100 new clusters in 2010, of which 44 involved only one case from each reporting country and would probably not have been detected by national surveillance schemes alone. The largest cluster (having 14 cases) was associated with a cruise ship. Legionella species were detected at 61 of the 100 accommodation site clusters investigated. The names of five accommodation sites were published on the ECDC website.

The application of geographic information systems and spatial data during Legionnaires disease outbreak responses.

A literature review was conducted to highlight the application and potential benefit of using geographic information systems (GIS) during Legionnaires' disease outbreak investigations. Relatively few published sources were identified, however, certain types of data were found to be important in facilitating the use of GIS, namely: patient data, locations of potential sources (e.g. cooling towers), demographic data relating to the local population and meteorological data. These data were then analysed to gain a better understanding of the spatial relationships between cases and their environment, the cases' proximity to potential outbreak sources, and the modelled dispersion of contaminated aerosols. The use of GIS in an outbreak is not a replacement for traditional outbreak investigation techniques, but it can be a valuable supplement to a response.

Shigellosis outbreak linked to canteen-food consumption in a public institution: a matched case-control study.

On 13 November 2009, the authorities of Flemish Brabant, Belgium, received an alert concerning a potential outbreak of Shigella sonnei at a public institution. A study was conducted to assess the extent, discover the source and to implement further measures. We performed a matched case-control study to test an association between shigellosis and canteen-food consumption. Water samples and food handlers' faecal samples were tested. The reference laboratory characterized the retrospectively collected Shigella specimens. We found 52 cases distributed over space (25/35 departments) and time (2 months). We found a matched odds ratio of 3·84 (95% confidence interval 1·02-14·44) for canteen-food consumption. A food handler had travelled to Morocco shortly before detection of the first laboratory-confirmed case. Water samples and food handlers' faecal samples tested negative for Shigella. Confirmed cases presented PFGE profiles, highly similar to archived isolates from Morocco. Foodborne transmission associated with the canteen was strongly suspected.

Community transmission of influenza A (H1N1)v virus at a rock festival in Belgium, 2-5 July 2009.

On 6 July 2009 the Belgian enhanced surveillance system for influenza-like illness among travellers returning from influenza A(H1N1)v affected areas detected a case linked to a rock festival which took place on 2-5 July. The health authorities implemented communication and control measures leading to the detection of additional cases. This paper describes the outbreak and its impact on the management of the influenza pandemic in Belgium.

Cluster of hepatitis A cases among travellers returning from Egypt, Belgium, September through November 2008.

Following a European alert by France, we detected a hepatitis A cluster in Belgian travellers returning from Egypt. Our investigation supports the hypothesis of a common source outbreak, linked to Nile river cruises. The outbreak also suggests the need to consider an intensification of the vaccination policy for travellers to hepatitis A endemic countries.