The emerging infectious diseases.

Emerging infectious diseases pose a significant but underappreciated threat to public health. In a world where international travellers, immigrants, and refugees can carry dangerous organisms almost anywhere, no region should be considered free from risk. Outbreaks of disease may be caused by newly recognized pathogens and drug-resistant organisms. These outbreaks demonstrate the need for improved worldwide surveillance and for improved compliance with guidelines for the use of antimicrobial agents.