Introduction to Medical Entomology

Abstract

At the end of the 20th Century about 6 billion people lived in the world. Over 40% inhabited areas, mostly in the tropics, where they were at risk to malaria, a mosquitoborne disease. About 120 million new clinical cases of malaria occur each year, with over 1 million deaths among young children in Africa alone. About 300 million people probably are infected with the malarial parasite at any given time (World Health Organization 1990). In each year of the past 2 decades of the 20th Century, there was an epidemic of dengue, another mosquitoborne disease, in some part of the world, with each epidemic resulting in thousands of cases, many of them fatal in children (Fig. 1.1). Arthropods continually attack cattle, a primary source of food for many people of the world. These attacks can involve transmission of disease pathogens, which in turn can result in death, lower body weight, reduced milk production and slower development (Sellers 1981). Even when pathogen transmission does not take place, there can be direct injury and reduced economic return because of severe annoyance and blood loss (Steelman 1976). These examples emphasize that arthropod-mediated diseases are not phenomena associated only with the past. There have been spectacular advances in our under- standing of these diseases, and significant advances in technology aimed at disease detection, control and prevention. In spite of this progress, debilitating and often fatal diseases associated with insects and other terrestrial arthropods continue to plague people, their domestic animals and pets, and wildlife. Rapid transportation of people, domestic animals and commodities, and new or reemerging pathogens and their vectors put nearly everyone at risk for contracting arthropodborne diseases.