other control measures, will be needed to regain long-term control over the mosquitoes that spread malaria. Some experts, however, argue that DDT has unfairly been declared an unacceptable hazard, and that it can play an important—and significantly larger—role in controlling not only malaria but also such other widespread diseases as dengue.
Research on resistance among vectors now takes two basic approaches. One approach is to study the molecular mechanisms involved. Scientists already have a relatively good understanding of the basic mechanisms underlying resistance to commonly used insecticides, and they are now using recently developed molecular techniques to begin to dissect these mechanisms at the DNA level. The next challenge will be to use this molecular understanding to develop novel vector-control methods that avoid or minimize resistance problems.
The second approach to research involves resistance management— that is, developing and implementing control methods that minimize the likelihood that vectors will evolve strong resistance to important insecticides. Two such promising control strategies are alternating the use of different insecticides and applying them in mosaic patterns over a given geographic area. Scientists are now conducting, in Mexico, a large-scale trial of these two strategies, compared to the use of DDT or a pyrethroid insecticide used in the conventional manner. Information from such trials may enable scientists and policy makers to establish rational strategies for long-term insecticide use.
Expanding the use of integrated pest management, or IPM, also holds promise for improving vector-control programs. Tackling a pest problem in numerous ways at once—including the use of pesticides in a timely manner at select locations—will likely yield more thorough and longer-lasting control than would result from any single method applied individually.
Developing and applying mathematical models can provide a solid basis for identifying new ways to effectively control the emergence of resistance among vector populations—and also to identify methods that are not effective. Among their benefits, models enable researchers to examine trends in data, explore questions of population dynamics, compare various management options, and generate new hypotheses for study. A major roadblock to progress in this area is the lack of interdisciplinary work among modelers studying insect resistance and those studying antimicrobial resistance in pathogens. Indeed, increased scientific collaboration across disciplines could foster scientific progress in numerous areas related to antimicrobial resistance. Likewise, policy makers developing programs to control the spread of antimicrobial resistance among pathogens could benefit by examining the successes and failures of current vector-control programs.