Infectious diseases are constantly in transition. New diseases develop, known dis-eases become widespread or reemerge, and occasionally a disease is eradicated.Infectious diseases such as HIV, tuberculosis, and cholera are significant causes ofillness and death in many parts of the world. Health care personnel are on thefront lines, helping to protect their clients from infectious diseases and treatingthem when infections occur. During the course of their work, health care person-nel perform clinical procedures or other activities that can expose both them andtheir clients to potentially infectious microorganisms. Many of their clients aresick and thus may be more susceptible to infections or may have infections thatcan be transmitted to others. Fortunately, all staff working at health care facilities can perform simple proce-dures to minimize risk—to themselves and clients—and reduce the spread ofinfections. These practices can be integrated at minimal cost into the routineworkday at clinics and hospitals around the world. This reference booklet isspecifically designed for use at all levels of the health care system, from thelargest hospitals to the smallest dispensaries or health posts, in settings whereresources are scarce. This booklet, which was first published in 1999, has now been updated. Whilemost practices remain the same, there have been a few important changes—forexample, in recommendations related to hand hygiene and standard precautions.Nonetheless, this booklet continues to present practical recommendations forsimple and relatively low-cost procedures that can be implemented anywhere,with basic supplies and little to no high-technology equipment.