Urbanization, Arthropod and Rodent Pests and Human Health

By the year 2025 about 61% of the world’s population will be living in urban areas, especially in developing countries. The urban population will double from 2.4 billion in 1995 to 5 billion in 2025. The world’s urban population is growing 2.5 times faster than the rural population. The impact on health in the urban conglomerations is visible with a significant spread of communicable diseases or new syndromes such as drug resistant tuberculosis. Many of these infections and diseases are carried by arthropod pests and rodents. A number of diseases are also found in urban areas of the developed world, among them tick-borne diseases such as Lyme disease, Ehrlichiosis, spotted fevers and tick-borne encephalitis. Murine typhus and lymphocytic choriomeningitis virus with rodent reservoirs and cat scratch-disease with flea vectors are widespread and trench fever with body louse vectors is reappearing. Mosquito-borne arboviruses such as St. Louis encephalitis and eastern equine encephalitis can occur in urban residential areas. In the tropical, developing world, rapid, unplanned, urbanization has exceeded the ability of health services to cope with degraded environmental conditions and vector and rodent-borne diseases often occur in epidemic proportions particularly dengue, dengue haemorrhagic fever, malaria, leishmaniasis, sandfly fever, plague and even Chagas disease.