Vector-borne disease problems in rapid urbanization: new approaches to vector control

Abstract

Owing to population growth, poor levels of hygiene, and increasing urban poverty, the urban environment in many developing countries is rapidly deteriorating. Densely packed housing in shanty towns or slums and inadequate drinking-water supplies, garbage collection services, and surface-water drainage systems combine to create favourable habitats for the proliferation of vectors and reservoirs of communicable diseases. As a consequence, vector-borne diseases such as malaria, lymphatic filariasis and dengue are becoming major public health problems associated with rapid urbanization in many tropical countries. The problems in controlling these diseases and eliminating vectors and pests can be resolved by decision-makers and urban planners by moving away from the concept of "blanket" applications of pesticides towards integrated approaches. Sound environmental management practices and community education and participation form the mainstay of some of the most outstanding successes in this area. On the basis of these examples, it is argued that the municipal authorities need to apply a flexible methodology, which must be based on the possibilities of mobilizing community resources, with minimal reliance on routine pesticidal spraying. In this way, vector control becomes a by-product of human development in the city environment. This is now a true challenge.

PIP: Rural-urban migration and population growth are occurring more quickly now than ever before in history. These phenomena have resulted in overcrowded urbanization and increased densities of vectors which in turn have caused an increase in disease such as malaria and dengue and dengue hemorrhagic fever. Besides urban areas foster the breeding of mosquitoes, rats, and other pests. Further governmental services in both developed and developing countries have not been able to keep up with housing and sanitation needs. Moreover new migrants continue to move into temporary housing (slums) made of inferior materials with no services while the previous occupants improve their wages and move on to better housing. Thus little incentive exists to improve slums where sanitation is poor and disease common. In addition, many formerly rural people continue rural practices and traditions in urban areas such as patterns of water storage. Further people often try to control vectors by applying pesticides, but do so haphazardly and/or in an unsafe, uncontrolled manner. They even use empty pesticide containers for storing water or food. Besides insecticide resistance is spreading. WHO encourages governments to integrate disease control programs with primary health care, but most such integrated programs operate in developed countries. Integrated approaches include less dependence on pesticides; encouraging changes in human behavior; disseminating health messages; community participation, particularly the youth; mobilization of human and financial resources; and proper urban development, e.g., better quality housing and adequate sanitation and potable water.