ciently verified and if it is likely to have international implications (likely spread to other countries, impact on international travel and trade, or requests for international assistance), it is shared through the weekly Outbreak Verification List (OVL) with WHO partners in international public health. The OVL reports the presented syndrome or disease, the location of the event, its source, the available figures and number of reported cases and deaths, and the contact details for WHO professionals who are monitoring this particular event. When an event is fully verified and when there is a need for public information, it is described on the WHO website and other websites and its description is published in the Weekly Epidemiological Record.
Verification can be difficult because of limited infrastructure and human resources in a country, poor communications systems, a lack of laboratory capacity, and civil conflict and war situations, which are increasingly common.
WHO responds to epidemics at the request of its member states. After WHO receives a request, its role is to mobilize the international response and to coordinate the response when there are different partners from different regions. Coordination is necessary for field activities, logistics, information vis-à-vis the media, contact with national authorities, and the raising of emergency funds. The response can be limited by a delay in the initial request, insufficient preparedness, time pressures, bilateral agreements that could impede coordination, and concerns for security in the field. In addition, the partners, either nongovernmental organizations or major laboratories, sometimes compete over visibility and access to clinical specimens and scientific data. When an outbreak is over, WHO should then ensure that there is a national follow-up plan, particularly in the area of epidemic preparedness and surveillance. Specific guidelines on how to handle certain types of outbreaks have also been developed, including videos, particularly targeting epidemic diseases specific to Africa, such as Ebola hemorrhagic fever.