Communicable disease threats report, 11-17 November 2012, week 46

On 3 October 2012, the Public Health Authority of Portugal reported two cases of dengue infection in patients residing in the Autonomous Region of Madeira, constituting the first known occurrence of locally transmitted dengue infection. As of 11 November 2012, the Portuguese Ministry of Health reported 1 357 cases of dengue infection from the public health sector in Madeira. 669 of these cases were laboratory confirmed, 688 probable cases. Since the beginning of the outbreak, 89 patients were hospitalised and five currently remain in hospital. So far, 25 patients have been diagnosed with dengue after returning from the island: cases were reported from mainland Portugal (nine), the UK (six), Germany (seven), Sweden (one) and France (two). In light of this, ECDC updated its initial rapid risk assessment on the situation.

However, residents and travellers visiting the island of Madeira are strongly advised to take individual protective measures, like using repellents, to avoid mosquito bites. Since dengue is transmitted by a daytime mosquito (Aedes aegypti) protective measures should be applied throughout the whole day. During the transmission season for West Nile fever (WNF) from June to November, ECDC monitors the situation in EU Member States and in neighbouring countries in order to identify significant changes in the epidemiology of the disease. To date, 235 probable and confirmed cases have been reported in the EU, and 621 cases in neighbouring countries. ECDC produces weekly West Nile fever risk maps to inform blood safety authorities regarding affected areas. The ECDC communicable disease threats report is a weekly bulletin intended for epidemiologists and health professionals in the area of communicable disease prevention and control.