Communicable disease threats report, 16-22 August 2025, week 34

The ECDC Communicable Disease Threats Report (CDTR) is a weekly bulletin for epidemiologists and health professionals on active public health threats. This issue of the CDTR covers the period 16-22 August 2025 and includes updates on Crimean-Congo haemorrhagic fever, dengue, West Nile virus infection, chikungunya virus disease, Oropouche virus disease, vaccine-derived poliovirus type 1 (cVDPV1) and the expert deployment to support the national response to the mpox clade IIb outbreak in Sierra Leone.