PAHO/WHO shares the growing concern of the scientific and medical community in regard to antimicrobial resistance resulting from the excessive use of antibiotics in both humans and animals. This book makes a valuable contribution to the surveillance of resistance to antibiotics. The text offers noteworthy articles grouped under two major categories: monitoring bacterial resistance to antimicrobial drugs, and factors determining the use of antimicrobials. Some of the articles were presented at a conference on antimicrobial resistance held in Caraballeda, Venezuela, in 1998, and other pieces were prepared specifically for this book. Within the wide range of materials in the publication are articles that address general subjects, such as choosing a method to monitor antimicrobial-resistant bacteria, and other pieces that deal with situations specific to various countries of the Americas. The goal of this work is to contribute to awareness of the problem, to promote surveillance activities, and to find the best way to apply preventive measures, so that antibiotics are used judiciously with both humans and animals. The book is required reading for official health entities in the Region of the Americas as well as for health professionals in both private and public practice.