Water Safety concerns over Legionnaires Outbreak

On the 11th November, Portuguese authorities stated that cooling towers at a fertiliser plant were the likely source of an outbreak of Legionnaires disease that has now killed 10 people and infected over 336.  This makes it one of the world’s largest ever outbreaks.  The World Health Organization has declared the outbreak “a major public health emergency”

Environment Minister Jorge Moreira da Silva told reporters

all cooling towers in the affected area near Lisbon had been shut since Sunday to bring the flare-up under control.

Health Minister Paulo Macedo said

the detection of new cases was decelerating, but there will be more in the coming days.

The health ministry released data late on Monday (10th November) that showed the number of those infected had increased from 160 to to 233 from the previous day.  One other person had also died. Three dozen were in intensive care in various hospitals.  Since then these numbers have risen with 38 people still in intensive care.  They have now stated that they believe the risk of contracting the illness to be practically zero.

The authorities were investigating the “possible environmental crime of releasing microorganisms” into the air by Adubos de Portugal, a unit of Spanish company Fertiberia, in the affected area of Vila Franca de Xira, according to Moreira da Silva.

Company officials were not available for comment.

Samples collected over a period of a few days allowed the authorities to

consider with a large degree of certainty that (the bacteria) are associated with cooling towers, not with the water network, and in particular with one installation.

Four parishes in the district of Vila Franca de Xira had the greatest concentration of the cases. One of the infected was a man in Porto, 200 miles to the north, who had worked on the fertiliser plant’s cooling tower.

The disease is contracted by breathing in a mist or vapour contaminated with the Legionella bacteria, which can grow in cooling towers, showers, hot tubs and other water sources.  It is not transmitted directly from person to person.

People already in poor health are the most vulnerable.

While the flare-up is far from being among the world’s deadliest, it is already the third-largest by confirmed cases after the 2001 outbreak in neighbouring Spain, with some 450 cases and six dead, and the 1999 outbreak in the Netherlands, when 32 people died and more than 300 were infected after visiting a flower exhibition in the town of Bovenkarspel.

The illness is named after a 1976 outbreak at an American Legion convention in Philadelphia, which killed 34.


Our Water Safety Expert comments:

There are 5 key requirements of the HSE ACOP L8, duty holders need to ensure:

  1. That they appoint a person to be managerially responsible
  2. Identify & assess sources of risk
  3. Prepare a scheme of control measures
  4. Implement, manage & monitor the scheme
  5. Keep records of the precautions taken.

In order to fully discharge their duties under health & safety law, Duty holders should supervise the work of their employees & contractors.

Where organisations are unsure of their duties or do not have the expertise in-house they should seek competent assistance from outside the organisation.