Portuguese man-of-war (Physalia physalis) envenomation on the Aquitaine Coast of France: an emerging health risk.

CONTEXT: The Portuguese man-o-war is a cnidaria classically found in tropical waters. It can cause serious and even life-threatening envenomation in swimmers, surfers and seafarers. Presence of the Atlantic species Physalia physalis has long been reported in European coastal waters but was always an exceptional event.

OBJECTIVE: To describe the experience of the Bordeaux Poison centre about Physalia stings since the first collective episode reported in 2008.

METHODS: Clinical retrospective description of cases series of Physalia envenomations reported to the local poison centre from 2008 to 2011 inclusive.

RESULTS: In the summer of 2008, multiple-case incident involving 40 victims were recorded on the same day on one beach in the Southern French Atlantic coast. The following year in 2009, no envenomation cases were reported in the same area, but in the next 2 years, numerous man-of-war envenomations occurred along the Aquitaine coast, that is, 154 cases in 2010 and 885 in 2011. Portuguese man-o-war stings led to severe manifestations with 15-20% of patients suffering of general symptoms that were sometimes severe enough to be considered as potentially life-threatening (8% of patients in 2011, most frequent signs: muscle pain and cramps with fasciculations, confusion and drowsiness, fainting, respiratory distress). No deaths due to Portuguese man-o-war envenomation were reported over the 4-year study period.

CONCLUSION: The results suggest that national multidisciplinary summer surveillance program in the Aquitaine coast is required in order to provide alerts to the public, to better identify patients at risk for developing severe clinical symptoms, and hopefully to improve quality of health care.