Negligible risk of H5N1 infection from bathing and drinking water in Europe: ECDC risk assessment
submited by kickingbird at Jun, 9, 2006 8:21 AM from Eurosurveillance Vol 11 Issue 6
Some wild birds infected with H5N1 have been found in Europe, and these have mostly been waterfowl such as swans. Each year, especially in summer, thousands of people in Europe bathe in the sea, rivers and lakes. There has been concern about the safety of water which could be contaminated by faeces containing H5N1 from infected waterfowl.
However, the currently circulating H5N1 virus is poorly adapted to humans and exposure to large quantities of the current virus strain is thought to be necessary for transmission to a human. If infected birds have defecated into bathing or drinking water, the ECDC panel concluded that the dilution would be too great for there to be an infection risk.
For drinking water, normal water treatment processes would also destroy the virus. Even private untreated water supplies, such as wells, are not thought to be risky because of the great dilution and likely low infectivity of the H5N1 virus.
However, if convincing evidence should emerge that H5N1 has become better adapted to humans, this risk assessment would be reviewed and a more precautionary approach could be taken. Additionally, more caution might be required in a scenario where very high numbers of dead birds were found near a body of water.
Greater risk to humans from other waterborne pathogens
However, people everywhere are at risk of other infections, such as salmonellosis and campylobacteriosis, if they bathe in water which is contaminated. The scientific panel concluded that the safest areas to bathe in Europe were those where the water is regularly tested and meets the standards laid down in the recently updated European Bathing Water Safety Directive .
- ECDC. H5N1 “bird flu” should not stop people bathing in EU water this summer. June 2006. (http://www.ecdc.eu.int/) [due to be available 9 June 2006]
- ECDC. Avian Influenza A/H5N1 in Bathing and Potable (Drinking) Water and Risks to Human Health. May 2006. (http://www.ecdc.eu.int/) [due to be available 9 June 2006]
- Directive 2006/7/EC of the European Parliament and of the Council of 15 February 2006 concerning the management of bathing water quality and repealing Directive 76/160/EEC. Official Journal of the European Union 2006: L 64/49. 4 March 2006 (http://eur-lex.europa.eu/LexUriServ/site/en/oj/2006/l_064/l_06420060304en00370051.pdf)
- WOAH: Influenza A viruses of high pathogenicity (Infection with H5N1) (non-poultry including wild birds) (2017-), China Aug, 1, 2022
- China: Confirmed human case of avian influenza A(H9N2) reported in Sichuan province Jun, 29, 2022
- China: A human case of avian influenza A(H5N6) reported in Jiangxi province Jun, 27, 2022
- China: Confirmed human cases of avian influenza A(H9N2) reported in Hunan and Guizhou province Jun, 9, 2022
- China: Confirmed human case of avian influenza A(H3N8) reported in Hunan province Jun, 1, 2022