The principal activities are regular insecticidal spraying and entomological assessment. The supportive activities are active and passive surveillance, presumptive and radical treatment. Under the MPO guidelines these areas are given 2 rounds of DDT, 3 rounds of malathion or 2 rounds of pyrethroids, the choice of insecticide depends on resistance developed by vector. Insecticidal spraying is guided by the periodic assessment of entomological assessment who study the behavior of vector mosquitoes. Various approaches are under study . These include source reduction, biological control , environmental improvement, health education and community participation.