<prompt> Modified plan of operation for Malaria is based onAPIABERSpleen rateInfant parasite rate  <response>: Modified Plan of Operation is based on Annual Parasite Incidence API. In 1977, the Modified Plan of Operation MPO was implemented with the immediate objectives of preventing deaths due to malaria and reducing morbidity due to malaria. The programme was also integrated with the primary health care delivery system. Under the MPO, the indoor residual spray was recommended in areas with Annual Parasite Incidence API 2 in addition to early diagnosis and prompt treatment. Ref : Park 23rd edition Pgno : 416 