The purpose and scope of the International Health Regulations (IHR) (2005) are to "prevent, protect against, control and provide a public health response to the international spread of disease and avoid unnecessary interference with international traffic and trade."
In recent decades, cross-border travel and trade have increased and communication technology has developed markedly. New challenges have arisen in the control of emerging and re-emerging infectious diseases.
The updated IHR require States to notify WHO of all events that may constitute a public health emergency of international concern and aim to enhance communications between WHO and the States.
The IHR (2005) also establish a single code of procedures and practices for routine public health measures at international airports and ports and some ground crossings.
The International Health Regulations are an international legal instrument which is legally binding on all WHO Member States who have not rejected them (or, subject to the procedure foreseen in the IHR, who have made reservations) and on all Non-Member States of WHO that have agreed to be bound by them.
Source: WHO FAQ International Health Regulations