Is it safe to swim in the lakes?

Risk To Bathers From H5N1 Bird Flu Is Close To Zero
Main Category: Bird Flu / Avian Flu News
Article Date: 22 Jun 2006 - 1:00am (PDT)


An assessment issued today by the European Centre for Disease Prevention and Control (ECDC) concludes that the risk of catching H5N1 avian influenza from bathing in Europe's lakes, rivers and seas this summer is close to zero. After reviewing what is known about H5N1, including evidence from east Asia where H5N1 has been widespread in the bird population since 2003, and after reviewing current knowledge about other zoonoses (animal diseases capable of infecting humans) ECDC scientists concluded that the possible presence of birds infected with H5N1 near bodies of water where people bathe presents little or no risk to human health. H5N1 avian influenza is a bird virus, poorly adapted to humans. Once it is diluted in large volumes of water the risk of a person catching the virus becomes close to zero. Nonetheless, the risk assessment states the general health risks from zoonoses and human microbes in bathing water should not be underestimated, and highlights the need for the safety standards in the EU's Bathing Water Directive to be met.

Zsuzsanna Jakab, Director of ECDC said:

“H5N1 avian influenza is an animal virus that does not pass easily to humans. You have to be exposed to a large amount of this virus in order to be at risk of catching it. If an infected bird leaves droppings in a lake or river, the virus in those droppings will be too diluted to pose a health risk to humans. The only time I would be concerned is if a large number of infected birds are found near a small pond, though even here we have no evidence of risk.”

The ECDC risk assessment on bathing water has been issued on an interim basis and will be kept under review, particularly if any evidence emerges of the H5N1 virus changing and becoming more easily transmissible to humans. This is especially important for an influenza virus since these viruses are liable to change. The new risk assessment supplements opinions and advice already issued concerning the risk to human health from avian influenza. ECDC's advice that people should not touch dead or sick birds continues to be valid, as does advice to wash your hands after any contact with birds or their droppings. (see ecdc.eu.int/avian_influenza/Health_Advice.php)

Bathing in lakes, rivers, the sea and other untreated water continues to carry a small risk of becoming infected with microbes usually from other bathers, human sewage or some of the zoonoses that are more infectious to humans, such as campylobacter or salmonella. This is why there are Europe-wide standards on the purity of bathing water set out in the EU's Bathing Water Directive. In places where the EU standards are complied with, bathing can be considered as safe.

The ECDC guidance has been considered by experts from national public health institutes across Europe who sit on ECDC's Advisory Forum and draws on work done by a panel of independent scientists (the ECDC Panel on Influenza) created earlier this year.

Full text of risk assessment (PDF)

http://www.ecdc.eu.int