Table 4.1.

Factors in the emergence of infectious diseases

Modern demographic, environmental, and behavioral factors that favor the spread of infectious diseases include: •global travel •globalization of the food supply and centralized processing of food •population growth and increased urbanization and crowding •population movements due to civil wars, famines and other manmade or natural disasters •irrigation, deforestation and reforestation projects that alter the habitats of disease-carrying insects and animals •human behaviors, such as intravenous drug use and risky sexual behavior •increased use of antimicrobial agents and pesticides, hastening the development of resistance •increased human contact with tropical rainforests and other wilderness habitats that are reservoirs for insects and animals that harbor unknown infectious agents •deteriorating public health infrastructures in many parts of the world •changes in climate and weather patterns •lack of political will to institute disease control measures •intentional release of pathogenic agents by terrorists.

Adapted from references3., 4., 5..