The GPG perspective supports collective action in the area of infectious disease control when reduction in disease prevalence in Country A has a benefit for Country B as well. Areas in which this is particularly true are diseases for which eradication is feasible (polio) and diseases that are highly transmissible around the world, whether by human carriers (SARS), by trade in products (BSE), or by animal vectors (West Nile Virus, avian influenza). The control of antibiotic resistance is a closely related GPG problem.