In a follow-up to the large Legionnaires’ disease outbreak in Vila Franca de Xira in suburban Lisbon, the Directorate-General for Health of Portugal now puts the number of cases at 302, including 5 fatalities.

Portugal map/CIA
Portugal map/CIA

In addition, four more deaths are currently being investigated. All cases have epidemiological links to the outbreak taking place in Vila Franca de Xira.

This is the biggest Legionella disease outbreak detected in Portugal, and the third largest outbreak since discovered in 1976, and public health officials say  it is evolving rapidly; therefore, the outbreak is considered to be a major public health emergency.

The investigation into the outbreak is ongoing and is supported by a large national team of experts in epidemiology, clinical, microbiology and environmental health.

As precautionary measures, ornamental fountains in the outbreak area have been closed, and the chlorine concentration of tap water has been increased. Cooling towers of the main industrial facilities in the affected area have been closed down.

The Directorate-General for Health of Portugal has issued the following precautionary recommendations to the population, until the source of the outbreak has been identified and eliminated:

  • to avoid showers, Jacuzzis and whirlpools;
  • to disinfect shower heads by immersion in bleach solutions for about 30 minutes once a week,
  • to set the temperature on water heaters above 75ºC, if possible.

Legionnaires’ disease is caused by a type of bacteria called Legionella. The Legionella bacteria are found naturally in the environment, usually in water. The bacteria grow best in warm water, like the kind found in hot tubs, cooling towers, hot water tanks, large plumbing systems and decorative fountains.

People get Legionnaires’ disease when they breathe in a mist or vapor (small droplets of water in the air) containing the bacteria.

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